Importance Sleep-wake disturbances in midlife are common and potentially modifiable contributors to long-term brain health, yet primary care lacks a brief, validated tool that reliably identifies adults with early cognitive vulnerability.

Objective To evaluate associations between commonly used sleep questionnaires and cognitive impairment among midlife primary care patients.

Design, Setting, and Participants Cross-sectional analysis of baseline data from the MidCog cohort, an observational study of English-speaking adults aged 35 to 64 years receiving primary care at academic practices or federally qualified health centers in the Chicagoland area.

Exposures Five validated sleep questionnaires were used to assess distinct sleep-wake disturbance phenotypes: (A) unsatisfactory sleep (PROMIS Sleep Disturbance T-score >55), (B) short sleep duration (<6 hours; Munich Chronotype Questionnaire), (C) obstructive sleep apnea (OSA) risk (STOP-Bang ≥3), (D) insomnia symptoms (Insomnia Severity Index ≥15), and (E) poor multidimensional sleep health (RU-SATED ≤6).

Main Outcomes and Measures The primary outcome was cognitive impairment defined as an age- and education-adjusted NIH Toolbox Cognition Battery (NIHTB-CB) Fluid Composite T-score <40 (>1 SD below the population mean). Cognitive impairment defined by the Montreal Cognitive Assessment (MoCA) score <23 served as the secondary outcome. Logistic regression estimated adjusted odds ratios (aOR), controlling for age, sex, education, body mass index, hypertension, hypercholesterolemia, diabetes, smoking, depressive symptoms, and recruitment site.

Results Among 646 participants (mean [SD] age, 52.3 [8.1] years; 62.4% female; 38.0% non-Hispanic Black, 38.4% non-Hispanic White, 16.0% Hispanic), cognitive impairment was present in 18.7% by NIHTB-CB and 22.3% by MoCA. Among five sleep-wake disturbance phenotypes evaluated, only poor multidimensional sleep health was consistently associated with cognitive impairment after multivariable adjustment (NIHTB-CB: adjusted OR [95% CI] = 2.03 [1.25-3.26]; MoCA: 1.98 [1.20-3.26]).

Conclusions and Relevance Poor multidimensional sleep health was associated with cognitive impairment in midlife primary care patients. Brief multidimensional sleep health screening may identify individuals with early cognitive vulnerability and represent a potential strategy for targeting sleep-focused interventions to promote long-term brain health.

Question Among commonly used brief sleep questionnaires, which measure, if any, best identifies midlife primary care patients at risk of early cognitive vulnerability?

Findings In this cross-sectional study of 646 primary care patients aged 35-64 years, poor multidimensional sleep health assessed using the RU-SATED questionnaire was the only sleep-wake disturbance phenotype consistently associated with cognitive impairment across two cognitive measures (NIH Toolbox Cognitive Battery and Montreal Cognitive Assessment).

Meaning Brief multidimensional sleep health screening may help identify midlife adults with sleep-related early cognitive vulnerability in primary care and may represent a potential target for sleep-focused interventions to promote long-term brain health.

M.K. received research funding from Genentech, Inc. and NIH. All other authors report no competing interests.

This study was supported by grant funding from the National Institute on Aging K23AG088497 and R01AG070212, with institutional support from UL1TR001422 and the Claude D. Pepper Older Americans Independence Center at Northwestern University Feinberg School of Medicine (P30AG059988). The funding agency played no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

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The Northwestern University Feinberg School of Medicine Institutional Review Board (STU00214736, STU00221343) approved the study, and all participants provided written informed consent.

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