How well does routine hospitalisation data capture information on comorbidity in New Zealand?

Abstract

Aims: This study aims to assess the quality of routinely collected comorbidity data in New Zealand which are increasingly used in health service planning and research. Methods: Detailed medical notes-based comorbidity data from a cohort study of New Zealanders diagnosed with colon cancer in 1996-2003, were compared with routine hospital discharge data collected from the same patients using 1-year and 8-year lookback periods. We compared agreement between data sources for individual conditions, Charlson comorbidity index scores and total comorbidity counts using McNemar's p-test and the kappa statistic. We also assessed the association of comorbidity with all-cause survival using Cox proporti..