Measuring multimorbidity series. An overlooked complexity - Comparison of self-report vs. administrative data in community-living adults: Paper 3. Agreement across data sources and implications for estimating associations with health service use

OBJECTIVE: The objective of this study is to describe agreement between administrative and self-report data on the number and type of chronic conditions (CCs) and determine whether associations between CC count and health service use differ by data source. STUDY DESIGN AND SETTING: We linked Canadian Community Health Survey and administrative data for a cohort of adults aged 45+ years in Ontario and identified 12 CCs from both data sources. …