The relationship between long-term adherence to recommended clinical procedures and health care utilization for adults with diagnosed type 2 diabetes

Background: Diabetes is a common and serious chronic condition. If not well-managed, significant multi-system complications often arise, resulting in increased health care utilization and poor health outcomes. There is considerable evidence that people with diagnosed diabetes are not receiving recommended care. A comprehensive program aimed at improving adherence to recommended care can improve patient outcomes and result in cost-savings. The key aim of this study was to determine whether the long-term receipt of appropriate clinical procedures by patients with type 2 diabetes was associated with higher medical care costs. Methodology: A cohort of 20,288 diagnosed type 2 diabetes patients was identified using physician and hospital records. An analytic file was created by linking information on patient characteristics with utilization of physician and acute care services during a five-year period (1996 to 2001). Adherence to recommended clinical procedures for the assessment of blood glucose, blood pressure and cholesterol levels, as well as retinopathy and nephropathy, were measured during this same five-year period. Subjects were assigned to both a categorical (low, medium and high) and a binary (low and high) adherence group. Physician and acute care resource use was converted to constant 2000 Canadian dollars. Multivariate logistic regression was used to assess the relationship between patient characteristics, including adherence as a categorical variable, and utilization of physician and acute care services. Results: Long-term adherence was suboptimal, with patients receiving just 53% of recommended procedures. Adherence to recommended procedures, however, improved during the five year period. Patient characteristics associated with poor adherence include being male, younger, low socio-economic status, having no diabetes-specific complicating conditions and living in certain geographic areas. Patients with high long-term adherence (receiving 73% of recommended clinical procedures) were 59% more likely to use a high level of physician resources but 22% less likely to use a high level of acute care resources. On the other hand, patients with low adherence (receiving 31% of procedures) were 28% less likely to use a high level of physician resources but 17% more likely to use a high level of acute care resources. The utilization difference related to adherence was particularly noticeable in older adults with higher levels of morbidity. Elderly patients in this low adherence group were more likely to be hospitalized (64.3% vs. 55.8% over the five-year period) and, when they were hospitalized, tended to stay in hospital for longer periods of time (11.9 vs. 6.7 days) than patients in the high adherence group. Conclusion: Improving long-term adherence may result in the avoidance of $4 in acute care costs for every additional $1 in physician costs. If all patients moved into the high adherence category, as much as $3.1 million in annual costs might be avoided across the study sample. If this analysis is applied to all adults with diagnosed diabetes in the province of British Columbia, the annual costs avoided could reach the level of $34.4 million. Systemic changes are required in the provision of primary care to promote long-term adherence to recommended diabetes care.Medicine, Faculty ofPopulation and Public Health (SPPH), School ofGraduat