Concordance between health administrative data and survey-derived diagnoses for mood and anxiety disorders

Objective: To assess whether estimates of survey structured interview diagnoses of mood and anxiety disorders were concordant with diagnoses of these disorders obtained from health administrative data. Methods: All Ontario respondents to the 2012 Canadian Community Health Survey-Mental Health (CCHS-MH) were linked to health administrative databases at ICES (formerly known as the Institute for Clinical Evaluative Sciences). Survey structured interview diagnoses were compared with health administrative data diagnoses obtained using a standardized algorithm. We used modified Poisson regression analyses to assess whether socio-demographic factors were associated with concordance between the two measures. Results: Of the 4157 Ontarians included in our sample, 20.4% had either a structured interview diagnosis (13.9%) or health administrative diagnosis (10.4%) of a mood or anxiety disorder. There was high discordance between measures, with only 19.4% agreement. Migrant status, age, employment, and income were associated with discordance between measures. Conclusions: Our findings indicate that previous estimates of the 12-month prevalence of mood and anxiety disorders in Ontario may be underestimating the true prevalence, and that population-based surveys and health administrative data may be capturing different groups of people. Understanding the limitations of data commonly used in epidemiologic studies is a key foundation for improving population-based estimates of mental disorders.