Systematic reviews on multimorbidity: methodological challenges

Article type
Authors
Menear M1, Fournier L1
1University of Montreal, Canada
Abstract
Background: Health care systems are undergoing dramatic transformations in response to the rise of chronic diseases in populations. In most cases, such system transformations have been driven by single-disease approaches to chronic care management and improvement. A wave of evidence in the past decade has shown however that a significant proportion of the population lives with multiple chronic diseases, i.e. multimorbidity. Given this reality, it is important that high-quality evidence related to services or interventions for people with multimorbidity be available to decision-makers. Systematic reviews examining populations with multimorbidity have the potential to inform current quality improvement efforts, yet such reviews are challenging to conduct on a number of levels.

Objectives: To present several methodological challenges related to the conduct of systematic reviews on the topic of multimorbidity.

Approach: The challenges encountered at each stage of the review process will be presented. First, defining review questions and inclusion criteria can be difficult, as review authors must weigh the relevance of the concepts of multimorbidity versus comorbidity, identify a clear population of interest among many possibilities, and decide on an appropriate scope for the review. This is a highly iterative process that occurs while attempting to search for studies. Searches are time- and resource-intensive given the importance in this case of searching multiple databases and using multiple data sources. Designing effective search strategies is complicated by the relative novelty of the multimorbidity concept. Study selection and data analysis is challenged by a lack of consistency in multimorbidity definitions and measures, and heterogeneity between studies makes data comparisons and quality assessment difficult.

Conclusions: There is a rapidly growing literature related to services and interventions for people with multimorbidity. Reviews of this literature can be challenging, but are urgently needed to inform efforts to improve care and outcomes for this large, vulnerable population.