The indirect effects of cognitive function in the association between stroke and quality of life among older adults in a rural community: A cross-sectional study

Abstract

We examined whether cognitive function statistically accounted for associations between stroke and quality of life (QOL). A cross-sectional survey included adults aged ≥ 60 years in Segamat, Malaysia. Cognition was assessed using the Identification and Intervention for Dementia in Elderly Africans instrument, and QOL was assessed using the WHOQOL-BREF. Stroke survivors were matched 1:3 with non-stroke participants by propensity scores based on age, sex, and education. Stroke status was the exposure, cognition the proposed statistical mediator, and four QOL domains, overall QOL, and overall health the outcomes. Models were adjusted for sociodemographic and vascular factors, accounted for matching and multiple testing, and p < 0.05 was considered statistically significant. Among 596 participants, 149 reported stroke; the mean age was 70.36 years (SD 6.81); 41.6% female; 58.4% male. An indirect association between stroke and physical QOL via cognition was observed (β = −0.67, 95% CI − 1.30 to − 0.18; BH-adjusted p = 0.018). A residual correlation of ρ = 0.16 between cognition and physical-QOL models would attenuate this association to the null. The indirect association did not differ by sex (index β = −0.49, 95% bootstrap CI − 1.48 to 0.18; p = 0.164). Item-level physical-QOL analysis identified an indirect association with greater pain interference through lower cognition (β = −0.051, 95% CI − 0.113 to − 0.009; BH-adjusted p = 0.028). Reduced cognition partly accounted for associations of stroke with reduced physical QOL and greater pain interference. Findings were sensitive to modest unmeasured confounding but require confirmation from longitudinal studies. This study examined whether difficulties with thinking, remembering, understanding, learning, and making decisions might explain why older adults with a history of stroke report a reduced satisfaction with their quality of life (QOL) compared to those without a stroke. We asked adults aged 60 years and above in Segamat, and each participant with a history of stroke was compared with three participants of a similar age, sex, and education who had not experienced a stroke. We used responses from 596 adults in this analysis, of whom 149 reported that they had previously been diagnosed with stroke by a doctor. Our results suggested that difficulties with thinking, remembering, understanding, learning, and decision-making partly explained the relationship between stroke and reduced physical QOL. However, modest unmeasured differences in both thinking and remembering challenges and in physical QOL could have reduced this finding to zero. There was no evidence that this indirect relationship differed between males and females. The findings also suggested that thinking and remembering challenges partly explained the relationship between stroke and greater interference of pain with daily life. These findings suggest that problems with thinking, remembering, understanding, learning, decision-making and pain are potential targets for community-based support services for stroke survivors. Studies that assess people before a stroke occurs and repeat assessments over time are needed to confirm exactly how these events influence one another.