ORIGINAL INVESTIGATION

Knowledge of Heart Attack Symptoms in a Population Survey in the United States The REACT Trial David C. Goff, Jr, MD, PhD; Deborah E. Sellers, PhD; Paul G. McGovern, PhD; Hendrika Meischke, PhD; Robert J. Goldberg, PhD; Vera Bittner, MD, MSPH; Jerris R. Hedges, MD, MS; P. Scott Allender, MD; Milton Z. Nichaman, MD, ScD; for the REACT Study Group

Background: Greater use of thrombolysis for patients

with myocardial infarction has been limited by patient delay in seeking care for heart attack symptoms. Deficiencies in knowledge of symptoms may contribute to delay and could be a target for intervention. We sought to characterize symptom knowledge. Methods: Rapid Early Action for Coronary Treatment

is a community trial designed to reduce this delay. At baseline, a random-digit dialed survey was conducted among 1294 adult respondents in the 20 study communities. Two open-ended questions were asked about heart attack symptom knowledge. Results: Chest pain or discomfort was reported as a symp-

tom by 89.7% of respondents and was thought to be the most important symptom by 56.6%. Knowledge of arm pain or numbness (67.3%), shortness of breath (50.8%), sweating (21.3%), and other heart attack symptoms was less com-

mon. The median number of correct symptoms reported was 3 (of 11). In a multivariable-adjusted model, significantly higher mean numbers of correct symptoms were reported by non-Hispanic whites than by other racial or ethnic groups, by middle-aged persons than by older and younger persons, by persons with higher socioeconomic status than by those with lower, and by persons with previous experience with heart attack than by those without. Conclusions: Knowledge of chest pain as an important heart attack symptom is high and relatively uniform; however, knowledge of the complex constellation of heart attack symptoms is deficient in the US population, especially in low socioeconomic and racial or ethnic minority groups. Efforts to reduce delay in seeking medical care among persons with heart attack symptoms should address these deficiencies in knowledge.

Arch Intern Med. 1998;158:2329-2338

N

The affiliations of the authors appear in the acknowledgment section at the end of the article. The members of the REACT Study Group and contributors to this work are listed on page 2332.

UMEROUS STUDIES have documented the benefit of thrombolytic therapy for patients with acute myocardial infarction1; thus, attention has shifted toward efforts to increase the use of this therapy.2,3 The frequency of use and the benefits of thrombolytic therapy are greater in the first several hours following the onset of heart attack symptoms than in the later stages.3 Thrombolytic therapy is used much less frequently in patients who delay seeking care for at least 6 hours relative to patients who respond more rapidly.3-6 This pattern of health care delivery appears to be a rational response to results of clinical trials that show diminishing benefit of thrombolytic therapy given later than 6 hours following the onset of acute ischemic symptoms.3 Approximately 22% of patients with heart attack delay seeking care for at least 6 hours following the onset of symptoms4; hence, patient delay in recognition of and response to heart attack

symptoms has been identified as a major obstacle to more widespread use of thrombolytic therapy.2,3 The prehospital delay encompasses the time required for recognizing the presence of symptoms, attributing the symptoms to a condition requiring medical attention, deciding to seek care, arranging transportation, and going to the hospital. Several barriers to rapid action can arise in this process. At the earliest stages, delay in the recognition of symptoms as being caused by a heart attack may be due to inadequate knowledge of heart attack symptoms or misattribution of the symptoms to another, noncardiac, and potentially less serious cause.7-12 The belief that symptoms were cardiac in origin has been associated with shorter delay and more frequent and earlier use of emergency medical services.10-12 Inadequate knowledge of heart attack symptoms can lead to erroneous symptom attribution. Individual knowledge of heart attack symptoms may be based

ARCH INTERN MED/ VOL 158, NOV 23, 1998 2329

Downloaded from www.archinternmed.com at Penn State Milton S Hershey Med Ctr, on April 16, 2008 ©1998 American Medical Association. All rights reserved.

PARTICIPANTS, MATERIALS, AND METHODS The design and rationale of the REACT communityintervention randomized trial have been described in detail previously.17,18 In brief, 20 communities were included in a matched design yielding 10 pairs of communities in 5 regions throughout the United States. One community from each pair was randomized to receive an 18month educational program following a 4-month baseline data collection. Communities were chosen, in part, to provide geographic diversity and to reflect the racial and ethnic composition of the general population of the United States. The REACT communities are in Alabama, Louisiana, Massachusetts, Minnesota, North Dakota, Oregon, South Dakota, Texas, Washington, and Wisconsin. The project was approved by the institutional review boards of all participating universities and hospitals. A random-digit dialed telephone survey was conducted before the educational activities in all 20 communities to establish a baseline for the assessment of the exposure to the intervention or similar programs in the study communities and the impact of the educational program on the knowledge, attitudes, and beliefs of community members. The survey was designed to collect data from 60 adults, aged 18 years or older, in each of the 20 communities. Sampling for the survey was completed by random-digit dialing. Each community’s designated geographical target area was defined by a specified set of ZIP codes. A list of telephone exchanges and a count of the households with listed telephone numbers in each ZIP code area was obtained from a commercial vendor. Counts of listed households were supplemented with estimates of unlisted households. Eligible telephone exchanges were divided into 5 strata based

more on common media presentations of immediately incapacitated heart attack victims than on the aggregate experience of real patients with heart attack. Knowledge may differ by demographic attributes as a reflection of, or independent of, level of education.13-16 Persons with risk factors for heart disease could be considered as having a greater need to know, and may have been educated about heart attack symptoms by health professionals. Finally, persons who have had previous experience with heart disease, whether personally or in a family member or close friend, could also have greater knowledge of heart attack symptoms than other persons. Our purpose herein is to describe knowledge regarding heart attack symptoms as reported by participants in a random-digit dialed survey conducted as part of the Rapid Early Action for Coronary Treatment (REACT) Trial, a multicenter community trial designed to test an education program to reduce prehospital delay among persons experiencing heart attack symptoms. We also examined whether symptom knowledge was related to sociodemographic characteristics, coronary heart disease risk factors, and previous experience with heart disease.

on the proportion of households (listed and unlisted). Disproportionate stratified sampling was used to increase the overall household rate. To adjust for the complex sampling design, survey responses were weighted by the reciprocal of the probability of selection. The sampling of adults and the structured interviews were conducted by the Survey Research Center at the New England Research Institutes, Watertown, Mass, the coordinating center for REACT. Since the REACT communities were not selected at random from all communities in the United States, the resulting sample formally represents only the 20 REACT communities. The degree to which selected characteristics of the survey sample approximated characteristics of the general US population was assessed qualitatively by comparing observed distributions of sociodemographic characteristics and medical attributes to published data on US population samples.19-24 Information was collected regarding a variety of topics of importance to the goals of REACT, including knowledge of heart attack symptoms, coronary heart disease risk factor status, and sociodemographic characteristics. Sociodemographic characteristics included age, sex, race or ethnicity, educational attainment, and household income. Knowledge regarding heart attack symptoms was assessed by asking the following 2 open-ended questions: “What would you say are the signs or symptoms that someone may be having a heart attack?” and “Of the heart attack signs or symptoms you just mentioned, which one would you say is the most important?” Participants were encouraged to give multiple responses to the first question through the use of the repeated follow-up question, “Anything else?” Survey Research Center staff coded responses into predetermined categories or as other. Following completion of data collection, reported symptoms that were not coded into a predetermined category were reviewed and categorized by 2 of us (D.C.G. and D.E.S.).

RESULTS

A total of 5603 random telephone numbers was generated for this survey. The dispositions of these numbers were as follows: 1584 were nonworking numbers; 635 resulted in no contact after 5 calls (whether they were households was not determined); 150 were not screened for eligibility due to refusal or language other than Spanish or English; 944 were not households; 55 were households with no one contacted after at least 15 calls; 520 resulted in refusals; 285 were ineligible due to nonstudy ZIP code or illness; 136 resulted in incomplete interviews; and 1294 resulted in completed interviews. Overall, 36.9% of the numbers were for ZIP code-eligible households. The overall interview rate (completed interviews divided by potentially eligible households) was 64.5%. The range across the 20 study communities was 48.0% to 77.3%. Participation rates were generally higher in the northern communities, intermediate in Alabama, and lowest in Texas and Louisiana. According to the 1990 census, telephone availability exceeded 80% in all communities and exceeded 90% in 18 of the 20 study communities.19

ARCH INTERN MED/ VOL 158, NOV 23, 1998 2330

Downloaded from www.archinternmed.com at Penn State Milton S Hershey Med Ctr, on April 16, 2008 ©1998 American Medical Association. All rights reserved.

Correct symptoms were defined as those consistent with a published list of heart attack symptoms, ie, chest pain or discomfort, arm or shoulder pain or discomfort, jaw pain, intrascapular (back) pain, shortness of breath, nausea or vomiting, sweating, lightheadedness, weakness, palpitations, and a feeling of impending doom.1 All of these symptoms except the last 2 were included in the REACT intervention messages following a review of multiple sources of information regarding heart attack symptoms. Any other reported symptom not on the previous list was considered incorrect for the purposes of this analysis. Chest pain or discomfort was identified as the correct response to the second question posed, since chest pain or discomfort is the most common symptom reported by patients with heart attack. For our purposes, the symptom chest pain or discomfort is the combination of the 4 nonexclusive descriptive categories of chest pain or discomfort that were coded in the survey. Respondents could report none, 1, or more than 1 of the following categories: pain, pressure, tightness, and discomfort. Other synonyms were coded into these categories. Presence of coronary heart disease risk factors (ie, diabetes, high blood pressure, high levels of serum cholesterol, and current cigarette smoking) and previous experience with heart disease were assessed by self-reports, including reports of physician diagnoses. Personal history of heart disease was defined as a positive response to either of the following questions: “Have you ever had a heart attack?” and “Have you ever been told by a physician that you have a heart condition?” Two other indicators of previous experience with heart disease were assessed. History of a heart attack in a spouse, parent, or sibling was assessed as an indication of an experience with high saliency. History of a heart attack in any other relative or close friend was assessed as an indication of an experience with lesser, but still substantial, salience.

Sociodemographic characteristics of the survey respondents and the prevalence of self-reported risk factors for coronary heart disease are shown in Table 1. In aggregate, these findings support the contention that the lowest socioeconomic group is underrepresented in this sample relative to the total US population,19 as would be expected for a random-digit dialed telephone survey. The total and correct mean numbers of heart attack symptoms reported and the percentage of participants reporting chest pain as the most important symptom of a heart attack are shown in Table 2 for the overall population and for subgroups defined by sociodemographic characteristics, coronary heart disease risk factor status, and previous experience with heart disease. The median number of correct symptoms reported was 3. Only 40 (3.1%) of 1294 participants reported at least 6 correct symptoms. There was evidence of a greater level of knowledge, as indicated by number of correct symptoms reported, in nonHispanic whites than in other race or ethnic groups, in the 2 older age groups than in youngest group, and in the more educated and higher-income groups than in the less educated and lower-income groups. The presence of coronary heart disease risk factors was not consistently associated with knowledge; respondents with diabetes exhibited

Data were analyzed using commercially available software (SAS version 6.11; SAS Institute, Cary, NC). The total and correct numbers of heart attack symptoms reported per individual, the percentage responding that chest pain or discomfort was the most important symptom, and the prevalence of specific symptom expectations were examined for the overall group and in subgroups defined by sociodemographic characteristics, coronary heart disease risk factors, and previous experience with heart disease. Given the large number of comparisons, statistical tests of association were not performed at this stage; however, 95% confidence intervals were computed to provide information regarding the precision of the point estimates. Two multivariable regression analyses were performed to examine the independence of associations between knowledge of heart attack symptoms and sociodemographic characteristics, risk factor status, and previous experience with heart disease. The number of correct symptoms reported per individual was regressed on sociodemographic characteristics, risk factors, and previous experience with heart disease using mixed-model linear regression. In this analysis, persons reporting 7 or more correct symptoms (n = 8) were reclassified with the group that originally reported 6 into a new group to prevent those few cases with very high values from exerting excessive influence on the results. Mixed-model logistic regression was used to examine the independence of associations between a correct report of chest pain or discomfort as the most important heart attack symptom and sociodemographic characteristics, coronary heart disease risk factor status, and previous experience with heart disease. In both mixed models, community was a random effect nested within pair and region. Pair was a random effect nested within region. Sociodemographic characteristics, risk factors, and previous experience with heart disease were fixed effects. In all analyses, survey responses were weighted by the reciprocal of the probability of selection to adjust for the complex sampling design within each community.

less knowledge and those with high levels of serum cholesterol exhibited greater knowledge than respondents without these conditions. Minimal differences in knowledge were observed between groups classified according to cigarette smoking and blood pressure status. Respondents with previous experience with heart disease exhibited greater knowledge of heart attack symptoms than those without such an experience. Chest pain was reported to be the most important symptom by 56.6%. Subgroup differences in reporting chest pain as the most important symptom were observed. Older respondents and lower-income groups were more likely to report chest pain as the most important symptom. Persons with missing data for income responded similarly to low-income respondents. Persons with diabetes were more likely to report chest pain as the most important heart attack symptom than persons without this condition. The prevalence of reported expectations of specific symptoms is listed in Table 3, Table 4, and Table 5 for the overall population and in subgroups defined by demographic characteristics (Table 3), socioeconomic characteristics (Table 4), and coronary heart disease risk factor status and previous experience with heart disease (Table 5). Some form of chest pain or discomfort was reported by 89.7% of respondents. Respondents reported

ARCH INTERN MED/ VOL 158, NOV 23, 1998 2331

Downloaded from www.archinternmed.com at Penn State Milton S Hershey Med Ctr, on April 16, 2008 ©1998 American Medical Association. All rights reserved.

The REACT Study Group and Contributors to This Work University of Alabama at Birmingham, School of Medicine: James Raczynski, PhD (principal investigator), Vera Bittner, MD (coprincipal investigator and medical director), Carol Cornell, PhD (coprincipal investigator and project director), Diane Caddell, Eli Capilouto, DMD, MPH, ScD, Diane Gibb, Janice Gilliland, MA, MSPH, Linda Goodson,RN, Liz Hester, Laura Leviton, PhD, Janet Pribble, MD, Herman Taylor, MD, Judy Taylor, PhD, Sue Williams, Karen Nelson, Barbara Theobald, Earle Overton, and Shelly Jordan; University of Massachusetts Medical School, Worcester: Robert Goldberg, PhD (principal investigator), Jane Zapka, ScD (coprincipal investigator), Barbara Estabrook, MSPH (project director), Sharon Melville, Mark Robbins, Lucy Jenkins, Susan Demoga, Beth Ewy, MPH, Kathleen Lovell, MEd, and Lorraine Wallace, MPH; University of Minnesota School of Public Health, Minneapolis: Russell Luepker, MD (principal investigator), John Finnegan, PhD (coprincipal investigator and project officer), Deborah Alexander, Neil Bracht, MSW, MPH, Richard Fouschee, PhD, Bernadette Gloeb, Nancy Hall, Brian Laing, Paul McGovern, David Murray, PhD, Janelle Traut, Carol Grimm, and Michele Hartshorn; University of Texas Health Science Center, School of Public Health, Houston: David Goff, MD, PhD (former principal investigator), Milton Nichaman, MD, ScD (principal investigator), Alfred McAlister, PhD (coprincipal investigator), Angela Meshack, DrPH (project director), Ruby Benjamin-Garner, MA, Wenyaw Chan, PhD, Marcia Davis, Holly Harrison, Adriana Linares, MD, MPH, Dilip Pandey, MD, PhD, Paul Pepe, MD, MPH, Roy Reyna, MD, MPH, Richard Smalling, MD, PhD, Janet Williams, MPH, Guillermo Chapa, Rafael Cardenas, PhD, Marilyn Fielding, MS, RN, Alfonso Gutierrez, MS, and Suzanne Norwood, MA; King County Department of Emergency Medical Services and University of Washington Medical Center, Seattle, and Oregon Health Sciences University, Portland: Mickey Eisenberg, MD, PhD (principal investigator), Jerris Hedges, MD (coprincipal investigator), Hendrika Meischke, PhD (coprincipal investigator), Sheri Schaeffer (project coordinator), Mohamed Daya, MD, Eric Dulberg, PhD, Dan Henwood, MA, Jon Jui, MD, Denise Macko, N. Clay Mann, PhD, Colleen Gillespie, Gene Liddell, MA, Jean Lum, and Laura Philips, MSW; New England Research Institutes, Watertown, Mass: Voula Osganian, MD (principal investigator), Henry Feldman, PhD (coprincipal investigator), Sarah McGraw, PhD (coprincipal investigator), Deborah Sellers, PhD (project director), Kathy Schulman, MS (project director), Cheryl Caswell, MBA, Norina Coppinger, Maggie Cotter, Vanessa Hosein, Paul Mitchell, MS, Kevin Smith, MA, Foss Tighe, and Dinh Tran; and National Heart, Lung, and Blood Institute, Bethesda, Md: Denise Simons-Morton, MD, PhD (project officer), Lawton Cooper, MD (deputy project officer), Scott Allender, MD, John Bradley, Mary Hand, MSPH, RN, Sandy Kamisar, Terry Long, Michael Proschan, PhD, Elaine Stone, and Mario Stylianou, MS.

the specific nonexclusive subcategories as follows: pain, 81.9%; pressure, 6.4%; tightness, 6.2%; and discomfort, 6.2%. Approximately two thirds of respondents reported that arm pain and/or numbness was a heart attack symptom, and one half reported that shortness of breath was. The remaining 8 correct heart attack symptoms were reported by fewer than one quarter of respondents; 4 of the correct symptoms were reported by fewer than 10.0% of respondents. None of the incorrect symptoms was reported by as many as 10.0% of respondents. Subgroup differences in knowledge of symptoms were observed (Tables 3-5). Differences between women and men were modest in magnitude and somewhat inconsistent in direction. Differences between the racial and ethnic groups were more obvious and more consistent. Non-Hispanic whites showed consistently greater knowledge of correct symptoms. Furthermore, nonHispanic whites tended to report the incorrect symptoms at a similar or lower frequency relative to other racial or ethnic groups. The youngest group (aged 18-34 years) showed generally less knowledge than the older groups. The higher socioeconomic groups showed greater knowledge of correct symptoms than the lower socioeconomic groups. The group with missing data on income most closely resembled the lowest-income group. There were no large differences in the reporting of incorrect symptoms across socioeconomic groups. Differences in knowledge between individuals with and without risk factors for coronary heart disease were less consistent. Of the risk factors examined, only persons with high levels of serum cholesterol showed consistently greater knowledge than those without this condition. Individuals with previous experience with heart

disease were consistently more knowledgeable regarding correct heart attack symptoms, but also tended to report incorrect symptoms more often. A weighted multivariable linear regression analysis provided estimates of the adjusted subgroup differences in mean number of correct symptoms reported (Table 6). Statistically significant differences were observed between several subgroups. These differences largely confirmed the results of the unadjusted analyses described previously. No substantial difference was observed between women and men. Hispanic and Asian groups demonstrated substantially less knowledge than non-Hispanic whites. There was a trend toward greater knowledge in the middle-aged group relative to younger and older respondents. The lowerincome groups showed less knowledge than the higherincome groups. After adjustment for income, educational attainment was not associated with heart attack symptom knowledge. The presence of risk factors for heart disease did not identify subgroups with greater knowledge. In fact, persons with diabetes mellitus showed a trend toward less knowledge than those without this condition. Previous experience with heart disease in the respondents, their family, or their close friends was associated with greater knowledge of heart attack symptoms. In summary, this analysis provided evidence of subgroup differences in knowledge of the complex constellation of heart attack symptoms. The results of a weighted, multivariable-adjusted logistic regression analysis of factors associated with the reporting of chest pain as the most important heart attack symptom are shown in Table 7 . Only 1 adjusted odds ratio had a 95% confidence interval that excluded 1.0; persons with household income of less than $25 000 per year were approximately 50% more

ARCH INTERN MED/ VOL 158, NOV 23, 1998 2332

Downloaded from www.archinternmed.com at Penn State Milton S Hershey Med Ctr, on April 16, 2008 ©1998 American Medical Association. All rights reserved.

Table 1. Prevalence of Sociodemographic Characteristics and Self-Reported Coronary Heart Disease Risk Factors* No. of Respondents (N = 1294)

Characteristic Sex Women Men Refused or missing Race or ethnicity Hispanic† Non-Hispanic black Non-Hispanic white Native American Asian or Pacific Islander Other Age, y 18-34 35-54 $55 Refused or missing Education Up to high school Beyond high school Refused or missing Annual household income, $ ,25 000 25 000-54 999 $55 000 Refused, do not know, or missing Coronary heart disease risk factors Diabetes High blood pressure High serum cholesterol level Current cigarette smoking Previous experience with heart disease Personal Family or spouse Other relative or close friend

Prevalence, % REACT

US

735 547 12

56.8 42.3 0.9

52.2 47.8 ...

145 106 970 8 31 34

11.2 8.2 75.0 0.6 2.4 2.6

7.7 10.8 77.5 0.7 2.8 0.3

464 516 289 25

35.9 39.9 22.3 1.9

37.7 34.1 28.2 ...

473 805 16

36.6 62.2 1.2

54.6 45.4 ...

382 480 287

29.5 37.1 22.2

41.9 38.1 20.0

145

11.2

...

61 277 270 311

4.7 21.4 20.9 24.0

3.4 24.2 20.0 25.6

166 430 774

12.8 33.2 59.8

7.3 NA NA

*REACT indicates Rapid Early Action for Coronary Treatment trial; NA, not available. Prevalences have been rounded and may not sum 100. Ellipses indicate not applicable. †May be of any race.

likely than persons with household incomes of at least $55 000 per year to report chest pain as the most important heart attack symptom. This finding contrasts with the results of the first multivariable analysis that showed less knowledge of the complex constellation of heart attack symptoms in this same lower-income subgroup. In summary, this latter analysis provided little evidence of subgroup differences in knowledge of chest pain as an important heart attack symptom. These findings suggest that the subgroup differences described in Table 6 are related primarily to differences in knowledge of heart attack symptoms other than chest pain. COMMENT

The level of knowledge of heart attack symptoms exhibited in our survey compares favorably with that of the few published reports from other studies. In a 1992 report from a survey regarding heart attack recognition con-

ducted in 302 members of the general population in Dublin, Ireland, 67.5% of respondents reported that chest pain was an indicator of heart attack.25 In a 1995 report of a survey of 65 patients with heart attack in Chicago, Ill, 71% expected chest symptoms of an unspecified nature, and 75% expected pain of unspecified location. Only 43% expected any other symptom in association with pain.12 In a survey of 1315 Mexican Americans and nonHispanic whites in the general population in San Antonio, Tex, from 1979 to 1981, knowledge of heart attack symptoms differed by ethnicity and socioeconomic status, ranging from 39% to 82% for chest pain, from 26% to 51% for shortness of breath, and from 4% to 32% for the combination of sweating and nausea.13 Compared with these earlier surveys, the level of knowledge of heart attack symptoms represented in our survey is clearly better, with nearly complete recognition of chest pain and substantial recognition of arm pain and/or numbness and shortness of breath as heart attack symptoms. The greater knowledge shown in our survey compared with previous surveys may be related, in part, to the characteristics of the populations studied or to other methodological differences. In contrast to previous surveys, the REACT population is fairly representative of the general US population, with underrepresentation of the lowest socioeconomic group introduced by the choice of a random-digit dialed telephone survey design. The populations surveyed in Dublin and Chicago were of unspecified social class; the population surveyed in San Antonio included substantial socioeconomic diversity and was biased toward lower socioeconomic status. A temporal improvement in general knowledge of heart attack symptoms is an alternative explanation for the greater knowledge seen in REACT than in these earlier studies. Chest pain was identified as a heart attack symptom by 89.7% of respondents and as the most important heart attack symptom by more than half. Given this apparently high level of knowledge regarding chest pain as a heart attack symptom, why do individuals with chest pain or discomfort delay seeking care for a median of 2.5 to 3.5 hours?26 Our survey is limited by lack of detailed information regarding the expected quality of the chest pain; however, of the 4 categories coded, a nonspecific response of pain was much more common than more specific descriptions of pressure, tightness, or heaviness. It may be that the quality of the chest discomfort experienced by patients with heart attack fails to meet their expectations, expectations that may often be based on dramatic portrayals of such persons in popular media. In addition, fewer than one quarter of respondents demonstrated knowledge of several other important symptoms, including sweating, nausea, and vomiting, thereby indicating that knowledge of the often complex constellation of heart attack symptoms is deficient in the US population. Other possible explanations of prolonged delay include denial, self-treatment, other maladaptive coping strategies, fear, concerns about costs, and embarrassment about being wrong despite awareness that the symptoms might be cardiac in origin.7-10 Subgroup differences in knowledge of heart attack symptoms have been reported once previously.13 Knowl-

ARCH INTERN MED/ VOL 158, NOV 23, 1998 2333

Downloaded from www.archinternmed.com at Penn State Milton S Hershey Med Ctr, on April 16, 2008 ©1998 American Medical Association. All rights reserved.

Table 2. Total and Correct Symptoms Reported as Characteristic of a Heart Attack and Percentage Responding Chest Pain as the Most Important Heart Attack Symptom by Sociodemographic and Risk Factor Status* Mean (95% CI) Characteristic Total population Sex Women Men Race or ethnicity Hispanic† Non-Hispanic black Non-Hispanic white Asian or Pacific Islander Age, y 18-34 35-54 $55 Education Up to high school Beyond high school Annual household income, $ ,25 000 25 000-54 999 $55 000 Not reported Diabetes Yes No High blood pressure Yes No High serum cholesterol level Yes No Current cigarette smoking Yes No Personal history of heart disease Yes No Heart attack in family or spouse Yes No Heart attack in other relative or close friend Yes No

No. of Symptoms Reported

No. of Correct Symptoms Reported

Chest Pain as Most Important Symptom, % (95% CI)

3.25 (3.16-3.34)

2.90 (2.74-3.07)

56.6 (53.9-59.3)

3.30 (3.19-3.42) 3.25 (3.11-3.39)

2.95 (2.85-3.06) 2.89 (2.77-3.01)

57.6 (54.1-61.1) 55.9 (51.6-60.2)

2.90 (2.57-3.23) 2.64 (2.34-2.94) 3.41 (3.31-3.51) 2.99 (2.26-3.72)

2.46 (2.20-2.72) 2.30 (2.07-2.53) 3.08 (2.99-3.17) 2.36 (1.79-2.91)

60.2 (51.8-68.6) 56.6 (46.6-66.6) 56.3 (53.2-59.4) 55.1 (36.3-73.9)

2.95 (2.80-3.11) 3.55 (3.40-3.69) 3.30 (3.13-3.46)

2.62 (2.50-2.75) 3.17 (3.05-3.30) 2.95 (2.79-3.11)

55.8 (51.0-60.6) 53.7 (49.4-58.0) 62.7 (57.5-67.9)

3.00 (2.86-3.14) 3.45 (3.34-3.56)

2.72 (2.60-2.85) 3.05 (2.94-3.15)

58.4 (53.8-63.0) 55.5 (52.1-58.9)

2.95 (2.79-3.10) 3.31 (3.18-3.45) 3.67 (3.45-3.88) 3.06 (2.77-3.35)

2.55 (2.42-2.68) 3.01 (2.89-3.13) 3.28 (3.09-3.47) 2.75 (2.50-3.02)

61.8 (57.0-66.6) 56.1 (51.7-60.5) 49.0 (42.9-55.1) 59.8 (52.1-67.5)

2.84 (2.51-3.18) 3.30 (3.21-3.39)

2.52 (2.03-2.83) 2.94 (2.86-3.03)

69.2 (58.1-80.3) 56.0 (53.2-58.8)

3.30 (3.11-3.48) 3.27 (3.17-3.37)

2.97 (2.80-3.14) 2.91 (2.82-3.00)

60.9 (55.4-66.4) 55.4 (52.3-58.5)

3.61 (3.41-3.80) 3.18 (3.08-3.29)

3.21 (3.04-3.39) 2.84 (2.75-2.93)

54.2 (48.5-59.9) 57.2 (54.1-60.3)

3.10 (2.93-3.26) 3.33 (3.22-3.43)

2.83 (2.68-2.97) 2.95 (2.86-3.05)

54.8 (49.3-60.3) 56.7 (53.5-59.9)

3.73 (3.51-3.96) 3.21 (3.11-3.31)

3.24 (3.03-3.45) 2.88 (2.79-2.96)

61.8 (55.1-68.5) 55.8 (52.8-58.8)

3.68 (3.53-3.83) 3.07 (2.96-3.18)

3.25 (3.11-3.38) 2.75 (2.66-2.85)

55.6 (51.0-60.2) 57.4 (54.0-60.8)

3.52 (3.40-3.63) 2.93 (2.79-3.06)

3.12 (3.02-3.23) 2.62 (2.50-2.74)

57.4 (53.9-60.9) 55.0 (50.6-59.4)

*CI indicates confidence interval. †May be of any race.

edge of chest pain, nausea, and sweating as heart attack symptoms was greater in non-Hispanic whites than in Mexican Americans, independent of socioeconomic status. No gender-related differences in knowledge were seen; however, there was a strong, positive association between socioeconomic status and knowledge of heart attack symptoms.13 Our findings with respect to gender, race or ethnicity, and socioeconomic status are similar and extend those findings to other race or ethnic groups. Knowledge of heart attack symptoms was highest in non-Hispanic whites. Hispanics, non-Hispanic blacks, and Asian Americans and Pacific Islanders showed less knowledge, although the difference for non-Hispanic blacks disappeared following adjustment for socioeconomic status.

Socioeconomic status also predicted knowledge, with less knowledge seen in the lower-income and lower educational attainment groups. In our study, income was more strongly associated with heart attack symptom knowledge than was educational attainment. Educational attainment was associated with knowledge in models that did not include income (results not shown). The race and ethnic findings probably represent the result of cultural influences and other barriers to access to information about health in general and heart attack symptoms in particular that compound the effects of lower socioeconomic status or that are not reflected in our measures of socioeconomic status. Together, these findings underscore the primary importance of designing interventions that can reach the so-

ARCH INTERN MED/ VOL 158, NOV 23, 1998 2334

Downloaded from www.archinternmed.com at Penn State Milton S Hershey Med Ctr, on April 16, 2008 ©1998 American Medical Association. All rights reserved.

Table 3. Prevalence of Reported Signs or Symptoms of Heart Attack by Demographic Characteristics* Demographic Characteristics of Respondents, %

Total Women (N = 1294) (n = 735)

Symptom Correct Chest pain or discomfort Arm pain or numbness Shortness of breath Sweating Nausea or vomiting Dizziness or light headedness Weakness, fatigue, or malaise Jaw or neck pain Palpitations Back pain Sense of impending doom Other Heartburn Loss of consciousness Change in color Other

Asian or Non-Hispanic Non-Hispanic Pacific Men Hispanics† Blacks Whites Islander 18-34 (n = 547) (n = 145) (n = 970) (n = 106) (n = 31) (n = 464)

Age, y 35-54 (n = 516)

$55 (n = 289)

89.7

90.2

90.4

87.0

89.5

91.4

76.6

90.9

90.7

88.6

67.3 50.8 21.3 14.5 12.1

71.0 49.0 18.9 17.0 10.2

63.6 54.3 25.0 11.5 14.8

51.7 47.7 10.6 2.5 7.2

47.0 45.1 12.3 5.6 4.3

73.2 52.4 24.9 17.6 12.5

32.4 51.8 8.6 12.4 36.2

55.4 52.9 16.0 7.5 13.9

77.9 53.5 24.9 18.9 12.6

69.8 43.9 24.1 17.9 9.3

10.8

10.3

11.7

11.7

7.5

11.3

12.8

11.7

11.4

9.0

9.9 7.1 6.3 0.6

13.4 7.4 6.7 1.0

5.3 6.7 5.9 0.0

11.1 8.4 6.4 1.3

6.7 11.5 0.7 0.0

10.7 6.6 7.1 0.6

0.0 5.0 0.0 0.0

3.9 6.4 3.4 0.3

11.6 8.2 6.5 1.1

16.3 5.8 10.1 0.0

8.0 6.4 5.5 14.7

10.4 7.1 3.9 13.2

4.9 5.5 7.6 16.9

9.9 3.6 0.9 28.6

6.1 3.2 1.5 22.6

8.4 6.6 6.0 11.5

0.0 24.7 17.4 21.2

4.9 6.1 6.2 15.3

9.1 7.2 5.1 15.6

11.7 5.8 4.4 11.7

*Data are reported in percentages. For some subgroup comparisons, the sum of the groups dose not equal the total sample size because of missing data †May be of any race.

Table 4. Prevalence of Reported Signs or Symptoms of Heart Attack by Socioeconomic Status* Annual Household Income, $

Education Symptom Correct Chest pain or discomfort Arm pain or numbness Shortness of breath Sweating Nausea or vomiting Dizziness or light headedness Weakness, fatigue, or malaise Jaw or neck pain Palpitations Back pain Sense of impending doom Other Heartburn Loss of consciousness Change in color Other

Up to High School (n = 473)

Beyond High School (n = 805)

,25 000 (n = 382)

25 000-54 999 (n = 480)

$55 000 (n = 287)

Not Reported (n = 145)

89.6 65.2 52.3 15.0 10.8 8.1 9.2 9.0 6.6 6.1 0.4

90.8 69.5 50.8 25.1 17.0 14.5 12.0 10.4 7.4 6.5 0.6

88.3 51.0 48.4 12.8 9.3 11.3 8.7 10.1 9.8 4.1 1.2

92.9 76.4 52.6 20.5 15.4 12.7 9.2 9.1 4.7 7.1 0.4

88.7 76.3 55.6 32.2 20.9 13.5 16.0 10.4 7.6 6.5 0.2

84.6 62.8 41.6 24.6 12.4 8.9 11.7 11.0 6.5 8.9 0.0

7.0 5.7 3.2 10.8

8.8 6.9 6.9 17.2

7.3 7.9 5.9 17.5

8.3 6.4 5.3 10.1

7.4 6.3 5.3 18.7

10.2 2.4 5.1 14.3

*Data are reported in percentages.

cioeconomically disadvantaged and racial and ethnic minority groups with health and urgent care information in attempts to improve the public’s health and response to cardiac emergencies. The pattern of age-group differences in knowledge of heart attack symptoms that we observed was somewhat surprising. We had anticipated greater knowledge in older than younger individuals related to the greater importance of heart disease as a health problem in older

persons. The observation of greater knowledge in the middle-aged than the youngest group was consistent with our expectation. However, the observation of less knowledge in the oldest group relative to the middle-aged group was not. The basis for this finding is not obvious, but may include differences in education and access to information about health that are not reflected in our unrefined measures of socioeconomic status. These issues deserve further attention.

ARCH INTERN MED/ VOL 158, NOV 23, 1998 2335

Downloaded from www.archinternmed.com at Penn State Milton S Hershey Med Ctr, on April 16, 2008 ©1998 American Medical Association. All rights reserved.

Table 5. Prevalence of Reported Signs or Symptoms of Heart Attack by Coronary Heart Disease Risk Factor Status* History of Heart Disease Diabetes Symptom Correct Chest pain or discomfort Arm pain or numbness Shortness of breath Sweating Nausea or vomiting Dizziness or light headedness Weakness, fatigue, or malaise Jaw or neck pain Palpitations Back pain Sense of impending doom Other Heartburn Loss of consciousness Change in color Other

High Blood Pressure

High Serum Cholesterol Level

Current Cigarette Smoking

Personal

Family or Spouse

Close Friend or Relative

Yes

No

Yes

No

Yes

No

Yes

No

Yes

No

Yes

No

Yes

No

86.0 72.2 30.2 12.0 10.8 7.8 2.2

90.6 67.5 52.2 22.0 14.8 12.4 11.4

88.2 69.3 49.1 27.0 18.0 9.8 9.1

91.0 67.3 51.7 20.0 13.7 12.9 11.4

91.6 75.6 54.6 27.3 19.7 6.5 13.6

89.9 65.6 49.9 19.9 13.2 13.6 10.3

89.9 68.5 50.9 16.0 11.9 13.9 10.4

90.5 67.6 51.1 23.1 15.6 11.5 11.0

90.4 79.1 51.3 25.0 18.1 12.1 8.9

90.3 66.1 51.1 21.0 14.2 12.2 11.2

89.0 76.7 54.8 28.7 19.1 13.8 12.4

91.1 63.2 49.2 17.7 12.1 11.2 10.3

91.4 74.0 51.8 26.7 17.1 11.5 11.3

88.5 58.2 50.2 13.7 10.9 13.5 10.4

16.4 3.1 11.2 0.0

9.7 7.3 6.1 0.4

10.8 8.4 7.5 0.0

9.7 6.8 6.0 0.5

14.7 7.7 9.2 0.8

8.4 7.1 5.6 0.3

9.6 5.4 5.9 0.2

10.2 7.6 6.5 0.7

17.2 9.7 11.3 0.8

8.9 6.8 5.6 0.4

13.0 7.6 8.4 1.4

8.2 7.0 5.3 0.2

12.1 7.9 7.9 0.7

6.6 5.8 4.1 0.4

10.8 6.0 5.6 10.3

8.0 6.4 5.5 14.9

8.1 5.7 4.9 13.1

8.1 6.6 5.7 15.1

12.4 6.5 5.6 13.4

7.0 6.5 5.6 15.0

6.4 7.2 4.2 9.1

8.7 6.1 5.6 16.5

15.6 8.6 4.9 18.4

7.0 6.1 5.6 14.1

11.2 7.3 7.3 16.3

6.6 5.8 4.7 14.1

9.0 6.9 6.7 15.6

6.8 5.6 3.6 13.8

*Data are reported in percentages.

Table 6. Difference in Reported Number of Correct Heart Attack Symptoms Between Subgroups Defined by Sociodemographic Attributes and Risk Factors* Difference (95% Confidence Interval)

Characteristic Sex, women vs men Race or ethnicity vs non-Hispanic white Hispanic† Non-Hispanic black Asian or Pacific Islander Age, y, vs $55 18-34 35-54 Education, up to vs beyond high school Annual household income, $, vs $55 000 ,25 000 25 000-54 999 Not reported Coronary heart disease risk factors Diabetes High blood pressure High serum cholesterol level Current cigarette smoking Previous experience with heart disease Personal Family or spouse Other relative or close friend

0.08 (20.08 to 0.23) 20.60 (20.93 to 20.27) 20.10 (20.40 to 0.20) 20.55 (21.05 to 20.06) 20.06 (20.29 to 0.18) 0.21 (20.01 to 0.42) 20.12 (20.29 to 0.04) 20.45 (20.68 to 20.21) 20.19 (20.40 to 0.01) 20.18 (20.48 to 0.12) 20.33 (20.70 to 0.04) 0.03 (20.18 to 0.23) 0.12 (20.08 to 0.32) 20.01 (20.19 to 0.17) 0.29 (0.05 to 0.52) 0.33 (0.16 to 0.50) 0.34 (0.18 to 0.50)

*Data are reported in percentages. †May be of any race.

Table 7. Multivariable Adjusted Odds Ratios for Reporting Chest Pain as the Most Important Heart Attack Symptom Associated With Sociodemographics and Risk Factors

Characteristic Sex, women vs men Race or ethnicity vs non-Hispanic white Hispanic* Non-Hispanic black Asian or Pacific Islander Age, y, vs $55 18-34 35-54 Education, up to vs beyond high school Annual household income, $, vs $55 000 ,25 000 25 000-54 999 Not reported Coronary heart disease risk factors Diabetes High blood pressure High serum cholesterol level Current cigarette smoking Previous experience with heart disease Personal Family or spouse Other relative or close friend

Odds Ratio (95% Confidence Interval) 0.81 (0.64-1.04) 0.90 (0.54-1.50) 1.14 (0.70-1.86) 1.03 (0.46-2.31) 0.77 (0.52-1.12) 0.72 (0.51-1.02) 1.01 (0.77-1.32) 1.52 (1.05-2.22) 1.25 (0.91-1.73) 1.44 (0.88-2.33) 1.63 (0.87-3.07) 1.16 (0.84-1.61) 0.73 (0.54-1.01) 0.95 (0.71-1.27) 1.22 (0.83-1.80) 0.80 (0.61-1.06) 1.11 (0.86-1.44)

*May be of any race.

Our major new findings relate to the importance of a salient previous experience with heart disease and the relative lack of importance of risk factor status in predicting knowledge. Individuals with a personal history of heart disease and those with a history of a heart attack in a family member, other relative, or close friend

were all more knowledgeable about the complex constellation of heart attack symptoms than persons without such exposures. It is likely that persons with such exposures had heard the patient’s story firsthand or secondhand and were attentive to this information. These findings support the idea that dissemination of role model

ARCH INTERN MED/ VOL 158, NOV 23, 1998 2336

Downloaded from www.archinternmed.com at Penn State Milton S Hershey Med Ctr, on April 16, 2008 ©1998 American Medical Association. All rights reserved.

stories, based on the real experiences of patients with heart attack, may be effective in educating the public about the constellation of heart attack symptoms and the need for and benefits of rapid, early action for treatment. In contrast to our expectations, risk factor status was not associated with knowledge of heart attack symptoms. Since individuals with risk factors for coronary heart disease constitute a subgroup with greater need to know and greater opportunity for education by health care professionals, we had anticipated greater knowledge in these individuals. This disappointing finding supports the conclusion that health care professionals are not targeting these patients effectively for education about heart attack symptoms. These subgroup differences in knowledge correspond relatively well with reported subgroup differences in prehospital delay time among persons hospitalized for heart attacks. Older patients delay longer than middle-aged patients.27-31 Racial and ethnic minorities delay longer than non-Hispanic whites.14-16 Persons of lower socioeconomic status delay longer than persons of higher socioeconomic status.30,32 Persons with coronary heart disease risk factors delay longer than persons without such conditions.27,29,30 Contrary to this general pattern of agreement are several reports that women delay longer than men27,30,33; however, in other reports, no gender differences in prehospital delay have been seen.7,14,29,31,34-40 Finally, in contrast to our finding of greater symptom knowledge in persons with experience with heart disease, a personal history of coronary heart disease has been associated with increased delay in seeking care.7,14,16,27-29,31,34-36,38,41-47 From this body of evidence, it seems reasonable to surmise that knowledge of heart attack symptoms facilitates rapid action, but lack of symptom knowledge is not the only barrier to seeking care promptly. Denial, self-treatment and other maladaptive coping strategies, fear, concerns about costs, embarrassment about being wrong, and other barriers also contribute to prolonged delay.7-10 The necessity of using an arbitrary list of correct symptoms is a limitation of our study. The symptoms experienced by patients with heart attack may not always be limited to the chosen list. Ideally, patients would not misattribute symptoms to heart attack when the symptoms were related to a less severe condition. However, misattribution of symptoms to heart attack is a much less important mistake than is misattribution of heart attack symptoms to a less severe condition. Hence, we attempted no detailed analysis of incorrect symptom reporting or construction of a misinformation index. Nevertheless, it was necessary to make an arbitrary judgment concerning the correctness of reported symptoms to be able to comment on the level of knowledge represented herein. Total and item nonresponses for some variables (eg, income) could introduce bias in these findings. We attempted to limit this potential bias by using an indicator variable to denote missing data. Thus, we were able to examine the group defined as missing income in unadjusted and adjusted analyses. Imputation was not attempted. Other limitations include small numbers of some racial or ethnic minorities (especially Asian Americans and Pacific Islanders), reliance on self-report for risk factors, no information regarding some risk factors (eg, physi-

cal activity habits), and an inability to refine other important subgroups, such as those defined by socioeconomic status. Reliance on self-report for classification of risk factor status introduces a potential bias resulting from the restriction of the high-risk category (eg, high levels of serum cholesterol or diabetes) to those respondents who know their status and fall in the risk class. Knowledge of risk factor status might be associated with knowledge of symptoms. We did not examine this issue. Oversampling of minorities and use of more detailed measurement and validation procedures were beyond the fiscal constraints of this project. As mentioned previously, the use of a random-digit dialed telephone survey design probably resulted in underrepresentation of members of the lowest socioeconomic group. Our study has several strengths. First is the sociodemographic and geographic diversity of the surveyed population. Second is an acceptable response rate. Third is the use of standardized procedures and open-ended questions about heart attack symptoms. The use of openended questions reduces the tendency of individuals to respond positively to questions about specified symptoms. Fourth is the breadth of data collection with respect to variables that might be associated with knowledge of heart attack symptoms. Unlike previous studies, we were able to examine the independent influences of sociodemographic characteristics, risk factor status, and previous experience with heart disease. In summary, knowledge of chest pain as an important heart attack symptom is high and fairly uniform across subgroups; however, knowledge of the complex constellation of heart attack symptoms is deficient in the US population, especially in socioeconomically disadvantaged and racial and ethnic minority groups. Furthermore, persons with risk factors for coronary heart disease do not demonstrate greater knowledge of heart attack symptoms than those with lower risk factors. Whereas persons with a previous experience with heart disease are more knowledgeable than those without such experiences, the former have far from complete knowledge. Together, these findings underscore the importance of designing interventions that can reach the socioeconomically disadvantaged, racial and ethnic minorities, and highrisk groups with messages describing the complex constellation of heart attack symptoms, and they support the idea that role model stories may be effective in these educational efforts. The translation of enhanced knowledge about heart attack symptoms into the rapid seeking of medical care in the setting of an acute cardiac emergency needs further attention to increase the number and percentage of patients with heart attack symptoms who are eligible to receive effective interventions to reduce the morbidity and mortality associated with acute ischemic heart disease. Accepted for publication March 12, 1998. From the Wake Forest University School of Medicine, Winston-Salem, NC (Dr Goff); New England Research Institutes, Watertown, Mass (Dr Sellers); Department of Epidemiology, University of Minnesota School of Public Health, Minneapolis (Dr McGovern); Department of Emergency Medical Services, University of Washington, Seattle (Dr

ARCH INTERN MED/ VOL 158, NOV 23, 1998 2337

Downloaded from www.archinternmed.com at Penn State Milton S Hershey Med Ctr, on April 16, 2008 ©1998 American Medical Association. All rights reserved.

Meischke); Department of Cardiology, University of Massachusetts Medical School, Worcester (Dr Goldberg); Department of Internal Medicine, University of Alabama at Birmingham School of Medicine (Dr Bittner); Department of Emergency Medicine, Oregon Health Sciences University, Portland (Dr Hedges); Division of Epidemiology and Clinical Applications, National Heart, Lung, and Blood Institute, Bethesda, Md (Dr Allender); and Discipline of Epidemiology, University of Texas Health Sciences Center, School of Public Health, Houston (Dr Nichaman). Dr Goff is now with the Department of Public Health Sciences, Wake Forest University School of Medicine, where he participates in Rapid Early Action for Coronary Treatment (REACT) Study Group as a coinvestigator. This research was supported by grants HL-53149, HL53142, HL-53155, HL-53211, HL-53135, and HL-53141 from the National Heart, Lung, and Blood Institute, Bethesda, Md. Additional support for intervention materials was provided by Genentech, Inc, South San Francisco, Calif. Reprints: David C. Goff, Jr, MD, PhD, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1063 (e-mail: dgoff @rc.phs.wfubmc.edu). REFERENCES 1. Pasternak RC, Braunwald EB, Sobel BE. Acute myocardial infarction. In: Braunwald EB, ed. Heart Disease: A Textbook of Cardiovascular Medicine. Philadelphia, Pa: WB Saunders Co; 1988:1222-1313. 2. Gunnar RM, Bourdillon PD, Dixon DW, et al. ACC/AHA guidelines for the early management of patients with acute myocardial infarction: a report of the American College of Cardiology/American Heart Association Task Force on Assessment of Diagnostic and Therapeutic Cardiovascular Procedures (Subcommittee to Develop Guidelines for the Early Management of Patients With Acute Myocardial Infarction). Circulation. 1990;82:664-707. 3. National Heart Attack Alert Program Coordinating Committee, 60 Minutes to Treatment Working Group. Emergency department: rapid identification and treatment of patients with acute myocardial infarction. Ann Emerg Med. 1994;23: 311-329. 4. Goff DC, Nichaman MZ, Ramsey DJ, Meyer PS, Labarthe DR. A populationbased assessment of the use and effectiveness of thrombolytic therapy: The Corpus Christi Heart Project. Ann Epidemiol. 1995;5:171-178. 5. Goldberg RJ, Gurwitz J, Yarzebski J, et al. Patient delay and receipt of thrombolytic therapy among patients with acute myocardial infarction from a communitywide perspective. Am J Cardiol. 1992;70:421-425. 6. Lee TH, Weisberg MC, Brand DA, Rouan GW, Goldman L. Candidates for thrombolysis among emergency room patients with acute chest pain. Ann Intern Med. 1989;110:957-962. 7. Hackett TP, Cassem NH. Factors contributing to delay in responding to the signs and symptoms of acute myocardial infarction. Am J Cardiol. 1969;24:651658. 8. Sjogren A, Erhardt LR, Theorell T. Circumstances around the onset of a myocardial infarction: a study of factors relevant to the perception of symptoms and to the delay in arriving at a coronary care unit. Acta Med Scand. 1979;205:287-292. 9. Bleeker JK, Lamers LM, Leenders IM, et al. Psychological and knowledge factors related to delay of help-seeking by patients with acute myocardial infarction. Psychother Psychosom. 1995;63:151-158. 10. Meischke H, Ho MT, Eisenberg MS, Schaeffer SM, Larsen MP. Reasons patients with chest pain delay or do not call 911. Ann Emerg Med. 1995;25:193-197. 11. Meischke H, Eisenberg MS, Schaeffer SM, Damon SK, Larsen MP, Henwood DK. Utilization of emergency medical services for symptoms of acute myocardial infarction. Heart Lung. 1995;24:11-18. 12. Johnson JA, King KB. Influence of expectations about symptoms on delay in seeking treatment during a myocardial infarction. Am J Crit Care. 1995;4:29-35. 13. Hazuda HP, Stern MP, Gaskill SP, Haffner SM, Gardner LI. Ethnic differences in health knowledge and behaviors related to the prevention and treatment of coronary heart disease: The San Antonio Heart Study. Am J Epidemiol. 1983;117:717-728. 14. Clark LT, Bellam SV, Shah AH, Feldman JG. Analysis of prehospital delay among inner-city patients with symptoms of myocardial infarction: implications for therapeutic intervention. J Natl Med Assoc. 1992;84:931-937. 15. Cooper RS, Simmons B, Castaner A, Prasad R, Franklin C, Ferlinz J. Survival rates and pre-hospital delay during myocardial infarction among black persons. Am J Cardiol. 1986;57:208-211.

16. Simon AB, Feinlab M, Thompson HK. Components of delay in the pre-hospital phase of acute myocardial infarction. Am J Cardiol. 1972;30:476-482. 17. Simons-Morton DG, Goff DC, Osganian S, et al. Rapid Early Action for Coronary Treatment: rationale, design, and baseline characteristics. Acad Emerg Med. 1998; 5:726-738.. 18. Feldman HA, Proschan MA, Murray DM, et al. Statistical design of REACT (Rapid Early Action for Coronary Treatment), a multi-site community trial with continual data collection. Control Clin Trials. 1997;19:391-403. 19. 1990 Census summary tape file 3. 1990 Census Lookup (1.4). US Census Bureau: the Official Statistics. Available at: http://venus.census.gov/cdrom/lookup. Accessed December 17, 1996. 20. Harris MI, Hadden WC, Knowler WC, Bennett PH. Prevalence of diabetes and impaired glucose tolerance and plasma glucose level in the US population aged 20-74 years. Diabetes. 1987;36:523-534. 21. Burt VL, Cutler JA, Higgins M, et al. Trends in the prevalence, awareness, treatment, and control of hypertension in the adult US population. Hypertension. 1995; 26:60-69. 22. Johnson CL, Rifkind BM, Sempos CT, et al. Declining serum total cholesterol levels among US adults: The National Health and Nutrition Examination Surveys. JAMA. 1993;269:3002-3008. 23. Cigarette smoking among adults: United States, 1992, and changes in the definition of cigarette smoking. MMWR Morb Mortal Wkly Rep. 1994;43:342-346. 24. American Heart Association. Heart and Stroke Facts: 1996 Statistical Supplement. Dallas, Tex: American Heart Association; December 1995. Publication 55-0522. 25. Bury G, Murphy AW, Power R, Daly S, Mehigan C, Walsh JP. Awareness of heart attack signals and cardiac risk markers amongst the general public in Dublin. Ir Med J. 1992;85:96-97. 26. Yarzebski J, Goldberg RJ, Gore JM, Alpert JS. Temporal trends and factors associated with extent of delay to hospital arrival in patients with acute myocardial infarction: the Worcester Heart Attack Study. Am Heart J. 1994;128: 255-263. 27. Turi ZG, Stone PH, Muller JE, et al. Implications for acute intervention related to time of hospital arrival in acute myocardial infarction. Am J Cardiol. 1986;58: 203-209. 28. Rawles JM, Haites NE. Patient and general practitioner delays in acute myocardial infarction. BMJ. 1988;296:882-884. 29. Moss AJ, Wynar B, Goldstein S. Delay in hospitalization during the acute coronary period. Am J Cardiol. 1969;24:659-665. 30. Schmidt SB, Borsch MA. The prehospital phase of acute myocardial infarction in the era of thrombolysis. Am J Cardiol. 1990;65:1411-1415. 31. Maynard C, Althouse R, Olsufka M, Ritchie JL, Davis KB, Kennedy JW. Early versus late hospital arrival for acute myocardial infarction in the Western Washington thrombolytic therapy trials. Am J Cardiol. 1989;63:1296-1300. 32. Weissman JS, Stern R, Fielding SL, Epstein AM. Delayed access to health care: risk factors, reasons, and consequences. Ann Intern Med. 1991;114:325-331. 33. Alonzo AA. The impact of the family and lay others on care-seeking during lifethreatening episodes of suspected coronary artery disease. Soc Sci Med. 1986; 22:1297-1311. 34. Moss AJ, Goldstein S. The pre-hospital phase of acute myocardial infarction. Circulation. 1970;41:737-742. 35. Schroeder JS, Lamb IH, Hu M. The pre-hospital course of patients with chest pain: analysis of the prodromal, symptomatic, decision-making, transportation and emergency room periods. Am J Med. 1978;64:742-748. 36. Wielgosz ATJ, Nolan RP, Earp JA, Biro E, Wielgosz MB. Reasons for patients’ delay in response to symptoms of acute myocardial infarction. CMAJ. 1988;139: 853-857. 37. Doehrman SR. Psychosocial aspects of recovery from coronary heart disease: a review. Soc Sci Med. 1977;11:199-218. 38. Erhardt LR, Sjogren A, Sawe U, Theorell T. Prehospital phase of patients admitted to a coronary care unit. Acta Med Scand. 1974;196:41-46. 39. Gilchrist IC. Patient delay before treatment of myocardial infarction. BMJ. 1973; 1:535-537. 40. Matthews KA, Siegel JM, Kuller LH, Thompson M, Varat M. Determinants of decisions to seek medical treatment by patients with acute myocardial infarction symptoms. J Pers Soc Psychol. 1983;44:1144-1156. 41. Leitch JW, Birbara T, Freedman B, Wilcox I, Harris PJ. Factors influencing the time from onset of chest pain to arrival at the hospital. Med J Aust. 1989; 150:6-8. 42. Hofgren K, Bondestam D, Johansson FG, Jern S, Herlitz J, Holmberg S. Initial pain course and delay to hospital admission in relation to myocardial infarction size. Heart Lung. 1988;17:274-280. 43. Pole D. Delays between onset of acute myocardial infarction and definitive care. Heart Lung. 1974;3:263-267. 44. Heriot AG, Brecker SJ, Coltart DJ. Delay in presentation after myocardial infarction. J R Soc Med. 1993;86:642-644. 45. Kenyon LW, Ketterer MW, Gheorghiade M, Goldstein S. Psychological factors related to pre-hospital delay during acute myocardial infarction. Circulation. 1991; 84:1969-1976. 46. Goldstein S, Moss AJ, Green W. Sudden death in acute myocardial infarction. JAMA. 1972;190:977. 47. Olin HS, Hackett TP. Denial of pain in acute myocardial infarction. JAMA. 1964; 190:977.

ARCH INTERN MED/ VOL 158, NOV 23, 1998 2338

Downloaded from www.archinternmed.com at Penn State Milton S Hershey Med Ctr, on April 16, 2008 ©1998 American Medical Association. All rights reserved.