Repeated Gastrointestinal Disease Reporting and Subsequent Multidomain Health Deterioration: Longitudinal Analyses in CHARLS and ELSA.

AIM: To examine whether repeated gastrointestinal disease reporting was associated with subsequent multidomain health deterioration and whether the direction of association was consistent across two national aging cohorts. METHODS: CHARLS was the primary longitudinal cohort. Participants with at least two gastrointestinal exposure assessments across waves 1-3 were classified as never, intermittent/low, or persistent/high reporting. The primary composite comprised cognitive, ADL, IADL, or depressive-symptom deterioration. Logistic and robust Poisson models were fitted. ELSA provided a cross-cohort consistency analysis using a pre-Wave-1 gastrointestinal disease/medication proxy. RESULTS: CHARLS included 12 144 participants/5607 events; fully adjusted models included 9555/4523. Adjusted relative risks were 1.10 (95% CI 1.03-1.18) for intermittent/low and 1.06 (1.01-1.11) for persistent/high reporting. In ELSA, the fully adjusted three-level education model included 3286/1752 and yielded an odds ratio of 1.24 (0.97-1.59); the longitudinal-weighted estimate was 1.21 (0.90-1.63). Gastrointestinal exposure produced negligible incremental discrimination in either cohort. CONCLUSIONS: Repeated gastrointestinal reporting was associated with a small increase in subsequent deterioration in CHARLS, while ELSA estimates were directionally similar but less precise. Gastrointestinal history may prompt broader geriatric assessment but is not a stand-alone predictor or evidence of causality.