Lack of an association between medicare supplemental insurance and delay in seeking emergency care for patients with myocardial infarction

Study objective: Previous studies have shown that Medicare patients without supplemental insurance are less likely to receive preventive services, such as mammography. The effect of supplemental insurance on the appropriate use of emergency services is unknown. We sought to determine whether the absence of supplemental Medicare coverage is associated with increased delay in seeking care for acute myocardial infarction. Methods: In this retrospective cohort study, we compared the time from symptom onset to hospital arrival (the time-delay interval) in Medicare patients with and without supplemental insurance coverage who presented with an acute myocardial infarction to 1 of 19 hospitals in King County, WA, from 1989 to 1993. There were 1,373 patients with Medicare-only coverage and 2,050 patients with Medicare plus supplemental insurance coverage. Results: The age-, sex-, and race-adjusted median time delay was 135 minutes for the Medicare-only group and 130 minutes for the Medicare plus supplemental insurance group (P=.34; 95% confidence interval for median time-delay difference in minutes -5 to 10). There was no significant association between the presence of Medicare supplemental insurance coverage and time delay in Cox regression models, which also adjusted for event year, income, education, past cardiac history, and clinical symptoms. Conclusion: For this cohort of Medicare patients, the absence of supplemental insurance coverage did not lead to significantly increased delays in seeking care for myocardial infarction. Lack of supplemental insurance for Medicare patients might not have as great an effect on the use of emergency services as it has on other health care services.