By Martin Fortin
Multimorbidity is associated with negative outcomes and increased resource use. Both create a burden on the health-care system.
Concerned healthcare professionals and decision-makers aware of this information may wonder:
- What is the magnitude of this problem in our region?
- What is the prevalence of multimorbidity in our population?
Some researchers have attempted to answer these questions with studies involving either nation-wide populations or smaller groups. However, studies in different populations have yielded results with differences in prevalence estimates as important as 95% for a given age. Is this information reliable? Can it be used to determine the allocation of resources to deal with the problem of multimorbidity? Differences of this magnitude are unlikely to reflect real differences between populations and more likely due to methods biases.
In a systematic review recently published in the Annals of Family Medicine we identified and compared studies reporting the prevalence of multimorbidity in primary care settings and in the general population. Apart from differences in location, we identified differences in recruitment method and sample size, data collection, and in the operational definition of multimorbidity including the number of conditions and the conditions selected. All of these factors may affect prevalence estimates.
In this review we discussed differences among studies and possible explanations for variations in the results of prevalence estimates. We also promoted the adoption of a more uniform methodology in this type of research by suggesting methodological aspects to be considered in the conduct of such studies.
Availability of strong epidemiological data for multimorbidity would benefit both the research and care of this problem.