Pre-event quality of life and its influence on the post-event quality of life among patients with ST elevation and non-ST elevation myocardial infarctions of a premier province of Sri Lanka

Abstract

Background: Pre-event Quality of Life (QOL) reflects the true social circumstances in which people live prior to the onset of myocardial infarctions. It is believed to be a predictor of the post-event QOL. The aim of this study was to describe the pre-event QOL and its influence on the post-event Quality of Life among patients with ST elevation (STEMI) and Non-ST elevation myocardial infarctions (NSTEMI) using Short Form-36 (SF-36), a generic QOL tool with 8 domains. Documented literature is rare in this regard in Sri Lanka, which is a lower-middle-income country. Methods: A cross-sectional study with a 28-day post-discharge follow-up was carried out in 13 hospitals. Three hundred and forty-four patients who were diagnosed with STEMI or NSTEMI were recruited during the hospital stay. The pre-event QOL was measured using an interviewer-administered questionnaire which included the SF-36 QOL tool and medical details. Follow-up QOL was gathered using a questionnaire that was filled and posted back by participants. Of the recruited sample, 235 responded for the follow-up component. Analysis was conducted for associations between pre- and post-discharge QOL. Furthermore, comparisons were made between the STEMI and NSTEMI groups. Mann Whiney U test, Wilcoxon signed rank test and chi square test were used in the analysis. Results: The post-event QOL was lower in seven out of eight domains than the pre-event QOL (p<0.05). The NSTEMI group had more risk factors and a significantly lower pre-event QOL for seven domains (p<0.05), when compared to the STEMI group. For seven domains, the post-discharge QOL was not significantly different (p>0.05) between the STEMI and NSTEMI groups. Post-discharge general-health QOL domain score was higher than the pre-MI score (p=0.028) and was higher in the STEMI group compared to the NSTEMI group (p=0.042). Regression analysis showed a significant beta coefficient between pre- and post-QOL for five domains in STEMI and for all domains in NSTEMI groups when adjusted for the disease severity. The R square values ranged from 12.3 to 62.3% for STEMI and 7.3 to 64.8% for NSTEMI. Conclusions: Pre-event QOL is lower in the NSTEMI group compared to the STEMI group. Patients do not regain the previous QOL within one month post-discharge. Post-discharge QOL can be predicted by the pre-event QOL for most domains.