Gender Differences in Calls to 9-1-1 During an Acute Coronary Syndrome




Calling 911 during acute coronary syndromes (ACS) decreases time to treatment and may improve prognosis. Women may have more atypical ACS symptoms compared to men, but few data are available on differences in gender and ACS symptoms in calling 911. In this study, patient interviews and structured chart reviews were conducted to determine gender differences in calling 911. Calls to 911 were assessed by self-report and validated by medical chart review. Of the 476 patients studied, 292 (61%) were diagnosed with unstable angina and 184 (39%) with myocardial infarctions (MIs). Overall, only 23% of patients called 911. Similar percentages of women and men with unstable angina called 911 (15% and 13%, respectively, p = 0.59). In contrast, women with MIs were significantly more likely to call 911 than men (57% vs 28%, p <0.001). After adjustment for sociodemographic factors, health insurance status, history of MI, the left ventricular ejection fraction, Global Registry of Acute Coronary Events (GRACE) score, and ACS symptoms, women were 1.79 times more likely to call 911 during an MI than men (prevalence ratio 1.79, 95% confidence interval 1.22 to 2.64, p <0.01). In conclusion, the findings of the present study suggest that initiatives to increase calls to 911 are needed for women and men.


Previous studies on differences in the proportion of men and women having acute coronary syndromes (ACS) who call 911 have produced inconsistent results. Although some studies have found no difference in calls to 911 between women and men with ACS, other studies restricted to patients with myocardial infarctions (MIs) found that women call 911 more often than men. However, few data have described gender differences in calls to 911 by ACS type or by specific ACS symptom experienced. Differences in the presenting characteristics and pathobiology of patients with MIs versus unstable angina pectoris (UAP) may influence patterns of 911 calling. Therefore, we analyzed data from an ongoing, observational cohort of patients with ACS to determine gender differences in calls to 911 and investigated whether clinical characteristics, ACS type, or ACS symptoms modified these differences.


Methods


Patients from the Prescription Use, Lifestyle, Stress Evaluation (PULSE) study at Columbia University Medical Center constituted the study population. PULSE is an ongoing, observational, single-site, prospective cohort study of the prognostic risk conferred by depressive symptoms and clinical depressive disorders at the time of ACS. Patients with UAP, ST-segment elevation MIs, or non–ST-segment elevation MIs by published American College of Cardiology and American Heart Association definitions were included and were recruited from Columbia University Medical Center within 1 week of hospitalization for their ACS. From February 1, 2009, and June 30, 2010, 500 patients were recruited; 24 (5%) were excluded from these analyses because of missing data on calls to 911. The present analysis included 476 English- or Spanish-speaking patients aged ≥18 years who either presented to the emergency department at Columbia University Medical Center or were transferred from nearby hospitals. The institutional review board of Columbia University Medical Center approved this study, and all participants provided informed consent.


Calling 911 was self-reported during an in-hospital interview within 7 days of admission and was verified by review of 100 randomly selected medical records. During the interview, patients were asked whether they (1) called 911, (2) went to the emergency department, or (3) called or went to a physician’s office at ACS onset. No other information on calling 911 was collected. Demographic, psychosocial, and clinical factors were assessed within 7 days of enrollment. Age, gender, ethnicity (Hispanic or Latino vs other), English fluency, marital status, high school education, health insurance over the previous 2 years and insurance with Medicaid or Medicare were assessed during a study interview. ACS symptom assessment was restricted to 2 typical (chest pain, arm and/or jaw pain) and 3 atypical (dyspnea, nausea and/or vomiting, syncope) symptoms, because these 5 symptom clusters have been identified as independent predictors of hospital mortality ; time course of ACS symptoms was assessed and dichotomized as constant or intermittent for analysis. ACS severity was determined using the Global Registry of Acute Coronary Events (GRACE) risk score. The GRACE score includes age and clinical parameters at presentation (heart rate, systolic blood pressure, serum creatinine, congestive heart failure, and the presence of cardiac arrest, ST-segment elevation, and cardiac enzymes or markers) and provides an estimate of mortality within 6 months of ACS. The Beck Depression Inventory was used to assess depressive symptoms; a score ≥10 was used to identify clinically significant depression, as this score has been independently associated with poor cardiovascular prognosis. History of MI and the left ventricular ejection fraction (LVEF) during admission were abstracted from the medical chart.


Previous studies have documented potential differences in prognosis and presentation for patients with MIs versus UAP. Therefore, gender differences in calls to 911 were first examined by ACS type. Because rates of 911 calling in this study were markedly different for patients with MIs versus UAP, all analyses were stratified by ACS type. Patient characteristics were calculated separately for women and men. The percentage of study patients calling 911 was calculated by characteristics including age, race, ethnicity, native English status, marital status, completion of high school, the LVEF, GRACE risk score, history of MI, insurance over the past 2 years, Medicare or Medicaid insurance, depressive symptoms, nausea and/or vomiting, syncope, constant symptoms, chest pain, arm and/or jaw pain, and dyspnea, with the statistical significance of differences determined using Student’s t tests for continuous variables and chi-square tests for categorical variables. Binomial regression was used to calculate prevalence ratios of calling 911 for women compared to men. Prevalence ratios are recommended instead of odds ratios for cross-sectional studies with common outcomes. An initial model was unadjusted (model 1). Subsequent models included progressive adjustment for age, race and ethnicity, public health insurance status, health insurance status within the past 2 years, high school education, and marital status (model 2); model 2 variables and history of MI model 3); model 3 variables and ACS symptoms (nausea and/or vomiting, syncope, and constant vs inconstant; model 4); and model 4 variables and the LVEF and GRACE risk score (model 5). Variables were selected for adjustment if significant at the p <0.10 level on calls to 911 in the unadjusted model or if identified in previous studies as potential determinants of calls to 911 (GRACE score, marital status, insurance status). Among patients with MIs, subgroup analyses were performed to examine the consistency of the relation between gender and calls to 911. Multiplicative interaction was assessed using the full population and including main effects and interaction terms (e.g., race × gender). Data on covariates were missing for 100 participants (21%). We used multiple imputation with chained equations and 5 data sets to account for the missing data. The association between gender and 911 calling was similar using a complete case analysis (data not presented). All analyses were conducted using Stata version 11 (StataCorp LP, College Station, Texas).




Results


Statistically significant differences in baseline characteristics were present between women and men with UAP and between women and men with MIs ( Table 1 ). There were also significant differences in calls to 911 by baseline characteristics in patients with UAP versus MI ( Table 2 ).



Table 1

Patient characteristics by acute coronary syndrome type and gender







































































































































































Variable UAP MI
Women (n = 101) Men (n = 191) p Value Women (n = 60) Men (n = 124) p Value
Age (yrs) 65.9 ± 11.8 63.1 ± 10.9 0.184 64.3 ± 11.3 61.3 ± 11.6 0.101
Black 24% 12% 0.010 28% 18% 0.099
Hispanic 30% 25% 0.347 50% 32% 0.020
Native English speaker 73% 72% 0.888 53% 65% 0.127
Married 51% 73% <0.001 37% 64% <0.001
At least high school education 72% 84% 0.014 60% 81% 0.003
LVEF (%) 55 ± 9 51 ± 10 <0.001 47 ± 13 47 ± 12 0.789
GRACE score 87.6 ± 25.1 85.3 ± 24.4 0.463 100.3 ± 33.5 92.6 ± 30.3 0.117
STEMI NA NA NA 27% 32% 0.440
History of myocardial infarction 29% 31% 0.669 32% 23% 0.163
Insured over past 2 yrs 91% 90% 0.888 92% 89% 0.634
Medicaid/Medicare insurance 62% 56% 0.378 65% 52% 0.099
Current depression 28% 11% <0.001 26% 12% 0.016
Nausea/vomiting 23% 9% 0.001 31% 16% 0.025
Syncope 11% 9% 0.575 12% 11% 0.909
Constant symptoms 26% 25% 0.851 65% 51% 0.069
Chest pain 90% 85% 0.237 78% 81% 0.714
Arm/jaw pain 41% 27% 0.020 42% 42% 0.955
Dyspnea 60% 50% 0.099 43% 39% 0.549

Data are expressed as mean ± SD or as percentages.

NA = not applicable.

Comparing differences across gender for UAP and MI using chi-square analysis for categorical data and analysis of variance for continuous data.


Beck Depression Inventory score ≥10.



Table 2

Percentage calling 911 by patient characteristics and acute coronary syndrome type































































































































































































































































































































Variable UAP MI
(n = 292) p Value (n = 184) p Value
Age (yrs) 0.79 0.61
<65 13% 36%
≥65 14% 40%
Race 0.74 0.045
Not black 13% 34%
Black 15% 51%
Ethnicity 0.026 0.034
Not Hispanic 11% 32%
Hispanic 21% 47%
Native English speaker 0.014 0.147
No 21% 44%
Yes 10% 33%
Marital status 0.111 0.870
Not married 18% 38%
Married 11% 37%
Completed high school <0.001 0.052
No 28% 50%
Yes 10% 34%
LVEF 0.506 0.643
<50% 13% 40%
≥50% 16% 36%
GRACE risk score 0.955 0.643
<87 14% 40%
≥87 13% 36%
History of myocardial infarction <0.001 0.281
No 9% 35%
Yes 24% 45%
Insured over past 2 yrs 0.889 0.504
No 15% 44%
Yes 14% 36%
Medicare/Medicaid insurance 0.003 0.134
No 7% 30%
Yes 19% 41%
Depressive symptoms 0.586 0.352
No 13% 37%
Yes 16% 46%
Syncope 0.009 0.125
No 11% 35%
Yes 29% 52%
Constant symptoms <0.001 0.001
No 7% 24%
Yes 32% 48%
Chest pain 0.282 0.419
No 8% 43%
Yes 14% 36%
Arm/jaw pain 0.560 0.617
No 13% 39%
Yes 15% 35%
Dyspnea 0.722 0.313
No 13% 35%
Yes 14% 42%

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Dec 7, 2016 | Posted by in CARDIOLOGY | Comments Off on Gender Differences in Calls to 9-1-1 During an Acute Coronary Syndrome

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