Parneet Grewal, MD

Akyea RK, Vinogradova Y, Qureshi N, Patel RS, Kontopantelis E, Ntaios G, Asselbergs FW, Kai J, Weng SF. Sex, Age, and Socioeconomic Differences in Nonfatal Stroke Incidence and Subsequent Major Adverse Outcomes. Stroke. 2021;52:396–405.

Stroke is a leading cause of disability worldwide, and despite advances in management, mortality and disability rates remain high. This prospective population-based cohort study explores demographic variations in incidence of first ever non-fatal stroke and incidence of major adverse outcomes (composite major adverse cardiovascular events (MACE), recurrent stroke, cardiovascular (CVD)-related and all-cause mortality) after it. The data source of the study is UK Clinical Practice Research Datalink (CPRD), which collects de-identified patient data from data quality-assured GP practices across the UK. The cohort included patients aged 18 years and over who had first record of non-fatal stroke between January 1, 1998 and December 31, 2018. The patients were followed until they developed a major adverse outcome or left the original cohort for a mean follow up time of 1.81 years (SD: 2.78).

The authors identified 82,774 individuals who met the inclusion criteria for the study with mean age of incident stroke being 74.3 year (SD: 13.6) and overall incidence rate of stroke being 109.21 per 100,000 person-years (95% CI: 108.47-109.96). Interestingly, incident rate of stroke was relatively steady between 1998 and 2003, with a peak in 2004 attributed to better documentation due to introduction of the Quality and Outcome Framework (QOF) and subsequent decline due to better primary prevention. Overall stroke incidence was higher in women (IR: 115.84, 95% CI: 114.77-116.92 vs IR 102.36, 95% CI: 101.34-103.39), with hypertension being the most prevalent co-morbid condition (48.4%). After adjusting for effects of age and sex, it was also observed that stroke incidence increased for every increase in Index of Multiple Deprivation (IMD) quintile. In respect to major adverse outcomes, 47,500 (69.0%) had a MACE; 33,831 (49.1%) recurrent stroke [hemorrhagic stroke: 2,378 (4.1%), ischemic stroke: 8,842 (15.1%), stroke (not specified): 22,611 (38.6)]; 9,174 (13.3%) cardiovascular death; and 20,335 (29.5%) all-cause death, occurring after the incident stroke events. The findings again show greater burden of adverse outcomes in women as compared to men.

The results of this study are consistent with meta-analysis using global burden of disease analytical technique, which showed stroke incidence in the UK to be 120 strokes per 100,000 population. Also in consistence with other studies, women had a higher rate of major adverse outcomes in the acute phase and were less likely to survive following stroke as compared to males. Some of the possible reasons for the observed sex differences were hypothesized to be more severity of stroke and lower quality of care in women as compared to men. Limitations include potentially wrong coding in CPRD in some cases and inability to determine the role of ethnicity due to a small number of minority ethnic groups. The study provides evidence of disparities in stroke care based on sex and socio-economic status and stresses access to good quality health care.