Mediation Analyses of the Mechanisms by Which Socioeconomic Status, Comorbidity, Stroke Severity, and Acute Care Influence Stroke Outcome

Socioeconomic Differences in Patient Reported Outcome Measures 3 Months After Stroke: A Nationwide Swedish Register-Based Study

BACKGROUND

There is a well-known association between low socioeconomic status (SES), poor survival, and clinician-reported outcomes after stroke. We aimed to assess socioeconomic differences in Patient Reported Outcome Measures 3 months after stroke.

METHODS

This nationwide cohort study included patients registered with acute stroke in the Swedish Stroke Register 2015-2017. Patient Reported Outcome Measures included activities of daily living (mobility, toileting, and dressing), and poststroke symptoms (low mood, fatigue, pain, and poor general health). Information on SES prestroke was retrieved from Statistics Sweden and defined by a composite measure based on education and income tertiles. Associations between SES and Patient Reported Outcome Measures were analyzed using logistic regression adjusting for confounders (sex and age) and additionally for potential mediators (stroke type, severity, cardiovascular disease risk factors, and living alone). Subgroup analyses were performed for stroke type, men and women, and younger and older patients.

RESULTS

The study included 44 511 patients. Of these, 31.1% required assistance with mobility, 18% with toileting, and 22.2% with dressing 3 months after stroke. For poststroke symptoms, 12.3% reported low mood, 39.1% fatigue, and 22.7% pain often/constantly, while 21.4% rated their general health as poor/very poor. Adjusted for confounders, the odds of needing assistance with activities of daily living were highest for patients with low income and primary school education, for example, for mobility, odds ratio was 2.06 (95% CI, 1.89-2.24) compared with patients with high income and university education. For poststroke symptoms, odds of poor outcome were highest for patients with low income and university education (eg, odds ratio, 1.79 [95% CI, 1.49-2.15] for low mood). Adjustments for potential mediators attenuated but did not remove associations. The associations were similar in ischemic and hemorrhagic strokes and more pronounced in men and patients <65 years old.

CONCLUSIONS

There are substantial SES-related differences in Patient Reported Outcome Measures poststroke. The more severe outcome associated with low SES is more pronounced in men and in patients of working age.

Does health literacy mediate the relationship between socioeconomic status and health related outcomes in the Belgian adult population?

BACKGROUND

Health literacy (HL) has been put forward as a potential mediator through which socioeconomic status (SES) affects health. This study explores whether HL mediates the relation between SES and a selection of health or health-related outcomes.

METHODS

Data from the participants of the Belgian health interview survey 2018 aged 18 years or older were individually linked with data from the Belgian compulsory health insurance (n = 8080). HL was assessed with the HLS-EU-Q6. Mediation analyses were performed with health behaviour (physical activity, diet, alcohol and tobacco consumption), health status (perceived health status, mental health status), use of medicine (purchase of antibiotics), and use of preventive care (preventive dental care, influenza vaccination, breast cancer screening) as dependent outcome variables, educational attainment and income as independent variables of interest, age and sex as potential confounders and HL as mediating variable.

RESULTS

The study showed that unhealthy behaviours (except alcohol consumption), poorer health status, higher use of medicine and lower use of preventive care (except flu vaccination) were associated with low SES (i.e., low education and low income) and with insufficient HL. HL partially mediated the relationship between education and health behaviour, perceived health status and mental health status, accounting for 3.8-16.0% of the total effect. HL also constituted a pathway by which income influences health behaviour, perceived health status, mental health status and preventive dental care, with the mediation effects accounting for 2.1-10.8% of the total effect.

CONCLUSIONS

Although the influence of HL in the pathway is limited, our findings suggest that strategies for improving various health-related outcomes among low SES groups should include initiatives to enhance HL in these population groups. Further research is needed to confirm our results and to better explore the mediating effects of HL.