The impact of social deprivation on mortality following acute myocardial infarction, stroke or subarachnoid haemorrhage: A record linkage study

BACKGROUND: The impact of social deprivation on mortality following acute myocardial infarction (AMI), stroke and subarachnoid haemorrhage (SAH) is unclear. Our objectives were, firstly, to determine, for each condition, whether there was higher mortality following admission according to social deprivation and secondly, to determine how any higher mortality for deprived groups may be correlated with factors including patient demographics, timing of admission and hospital size. METHODS: Routinely collected, linked hospital inpatient, mortality and primary care data were analysed for patients admitted as an emergency to hospitals in Wales between 2004 and 2011 with AMI (n = 30,663), stroke (37,888) and SAH (1753). Logistic regression with Bonferroni correction was used to examine, firstly, any significant increases in mortality with social deprivation quintile and, secondly, the influence of patient demographics, timing of admission and hospital characteristics on any higher mortality among the most socially deprived groups. RESULTS: Mortality was 14.3 % at 30 days for AMI, 21.4 % for stroke and 35.6 % for SAH. Social deprivation was significantly associated with higher mortality for AMI (25 %; 95 % CI = 12 %, 40 %) higher for quintile V compared with I), stroke (24 %; 14 %, 34 %), and non-significantly for SAH (32 %; -7 %, 87 %). The higher mortality at 30 days with increased social deprivation varied significantly according to patient age for AMI patients and time period for SAH. It was also highest for both AMI and stroke patients, although not significantly for female patients, for admissions on weekdays and during autumn months. CONCLUSIONS: We have demonstrated a positive association between social deprivation and higher mortality following emergency admissions for both AMI and stroke. The study findings also suggest that the influence of patient demographics, timing of admission and hospital size on social inequalities in mortality are quite similar for AMI and stroke.