By Elizabeth Muggah
Our paper, The impact of Multiple Chronic Diseases on ambulatory care use; a population based study in Ontario, Canada, was recently published in BMC Health Services Research. This study is an important addition to what we know about the burden of multimorbidity on the primary care system as we focused specifically on ambulatory health care use and looked at the burden of disease on both the patient and on the health system more broadly.
This research was completed using health administrative data housed at the Institute of Clinical Evaluative Sciences (ICES) in Toronto, Canada. We used well validated methods to search administrative data in one large province of Canada to identify persons who had at least one of nine common chronic diseases (diabetes, congestive heart failure, acute myocardial infarction, stroke, hypertension, asthma, chronic obstructive lung disease, peripheral vascular disease and end stage renal failure). We then identified the number of outpatient primary care and specialist visits over a 2 year period.
We found that multiple chronic diseases were common among the Ontario population, (in 2009, 26.3% of Ontarians had one chronic disease, 10.3% had two diseases, and 5.6% had three or more diseases). The annual number of primary health care visits per patient increased significantly with each additional chronic disease and patients with two or more diseases made more than twice as many visits each year to primary health care providers compared to specialists. At the extremes of age we saw an increase in the number of primary care visits across all groups while specialist care dropped off. Looking from a health system perspective we found the largest total number of visits were made by those with no or one chronic disease compared to those with multiple diseases.
This study reinforces what we know about the considerable burden of illness felt by persons with multiple chronic diseases and confirms that these patients seek care disproportionately from their primary care providers. However from a health system perspective those with no or one chronic disease are responsible for the largest number of ambulatory health care visits. In our view continued investment in primary health care is needed both to care for those with multiple diseases as well as to maintain a focus on preventing the accumulation of chronic diseases with advancing age. It would be important to explore these trends over time to see if the pattern of health care use we found is changing given the predicted rise in the prevalence of multiple chronic diseases with the aging of our population.