Subjective cognitive impairment and quality of life: a systematic review.

BACKGROUND: Older adults with subjective cognitive impairment (SCI) experience increased affective symptoms, reduced engagement in a range of activities, as well as more functional problems when compared to those without SCI. These associations suggest that SCI may be detrimental to older adults' quality of life (QoL). The purpose of this paper is to advance understanding of the SCI-QoL relationship through a comprehensive review of the empirical literature relating SCI and QoL.
METHODS: A systematic literature review was conducted in CINAHL, PsycINFO, and PubMed per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. Eligible articles were appraised using the weight of evidence (WoE) framework to evaluate methodological quality, methodological relevance, and topic relevance. A narrative synthesis of results was conducted, based on conceptual definitions of QoL.
RESULTS: Eleven articles were identified that met eligibility criteria. WoE ratings ranged from low to high scores. Studies reviewed reported that the presence, greater frequency, or greater severity of SCI is associated with lower QoL regardless of methodological quality rating, sample characteristics (e.g. geographic location, clinical vs. community settings), study design (e.g. cross-sectional vs. longitudinal), and operationalization of SCI or QoL.
CONCLUSION: Across studies, QoL was negatively associated with SCI. However, a frequent limitation of the reviewed literature was the mismatch between the conceptual and operational definitions of SCI and QoL. Similarly, SCI measures varied in quality across the reviewed literature. This suggests future empirical work should focus on the appropriate strategies for conceptually and operationally defining these constructs.