Quebec Integrated Chronic Disease Surveillance System (QICDSS), an innovative approach

Abstract

Introduction With the growing burden of chronic diseases, surveillance will play an essential role in improving their prevention and control. The Institut national de santé publique du Québec has developed an innovative chronic disease surveillance system, the Quebec Integrated Chronic Disease Surveillance System (QICDSS). We discuss the primary features, strengths and limitations of this system in this report. Methodology The QICDSS was created by linking five health administrative databases. Updated annually, it currently covers the period from January 1, 1996, to March 31, 2012. The operational model comprises three steps: (1) extraction and linkage of health administrative data according to specific selection criteria; (2) analysis (validation of case definitions essentially) and production of surveillance measures; and (3) data interpretation, submission and dissemination of information. The QICDSS allows the surveillance of the following chronic diseases: diabetes, cardiovascular diseases, respiratory diseases, osteoporosis, osteoarticular diseases, mental disorders, Alzheimer's disease and related disorders. The system also lends itself to the analysis of multimorbidity and polypharmacy. Results For 2011–2012, the QICDSS contained information on 7 995 963 Quebecers with an average age of 40.8 years. Of these, 95.3% met at least one selection criterion allowing the application of case definitions for chronic disease surveillance. The actual proportion varied with age, from 90.1% for those aged 19 years or less to 99.3% for those aged 65 years or over. Conclusion The QICDSS provides a way of producing population-based data on the chronic disease burden, health services and prescription drug uses. The system facilitates the integrated study of several diseases in combination, an approach rarely implemented until now in the context of population surveillance. The QICDSS possesses all the essential features of a surveillance system and supports the dissemination of information to public health decision-makers for future actions.

A Surveillance System to Monitor Excess Mortality of People with Mental Illness in Canada

“…30 However, given that the QICDSS covers 97% of all insured people, who in turn represent 99% of the Quebec population, and that our study extends over 10 years, this would minimize the likelihood of missing any person in the population who received a mental disorder diagnosis. 17 In addition, one-off surveys can underestimate the treated prevalence by one-half. For example, 1 study that used the equivalent of the QICDSS databases but also took into account procedure codes for talk therapies estimated that, each year, 75% of the expected 1-in-5 people with a mental disorder was identified by GPs.…”

“…Administrative data may also be subject to recording bias, especially for diagnosis. Although 95% of billing claims made by psychiatrists in Quebec include a diagnosis, 17 evidence from Ontario suggests that accuracy is lower for substance abuse and disorders other than psychoses. 33 Elsewhere, a study 34 from Saskatchewan comparing anxiety or mood disorder diagnoses and the prescription of antidepressants reported a sensitivity of 84% and a specificity of 90%.…”

“…In terms of mortality, concordance between the vital statistics death database and the physician billings database improved from 95% to 98% between 1996 and 2009. 17 The CCDSS psychiatric case definition differs from those for other disorders by stipulating that a person must attend for treatment in the current year to be considered a prevalent case in that year. In the case of diabetes and hypertension, a case is considered to be active until the end of the study period, death, or emigration.…”

“…14,15 In Quebec, the INSPQ has applied the diagnostic definitions from these feasibility studies for the surveillance of mental disorders, excess mortality, and service use. 16,17 An advantage of the CCDSS is the inclusion of primary care where most people with chronic diseases, such as diabetes and mental disorders, are treated. Studies that have used administrative data from elsewhere, such as Italy, Sweden, and the United States, have been restricted to patients attending psychiatric services and thus may not reflect the mortality experience of most people with psychiatric problems.…”

“…We used the resources of the public health agency of Quebec (INSPQ). 17 Estimates were produced using linked administrative databases from the physician billing agency (Régie de l'assurance maladie du Québec) and the Quebec Ministry of Health and Social Services, which together make up the QICDSS. About 99% of Quebec's 7.5 million residents were registered with health insurance in 2006.…”