Objective: To determine the effect of a clinical diagnosis of diabetes mellitus (DM) on healthcare utilization and health outcomes.
Study design: Cohort study.
Methods: A total of 197 United Kingdom family practices with 4974 subjects (mean age, 62.8 years; 52.2% men) with type 2 DM and 9948 matched nondiabetic control subjects. Healthcare utilization and the occurrence of complications were estimated from 2 years before to 2 years after the first clinical diagnosis of DM.
Results: From 24 months before the DM diagnosis, primary care consultations were increased in prediagnosis cases compared with controls (relative rate [RR], 1.31; 95% confidence interval [CI], 1.27-1.35), as were emergency and hospital care consultations, hospital specialist referrals, and prescription drug items. At diagnosis of DM, utilization of all forms of healthcare was increased (RR, 4.27; 95% CI, 4.17-4.36 for primary care consultations; RR, 2.49; 95% CI, 2.46-2.52 for prescription drug items). In the quarter following diagnosis, healthcare utilization was increased for acute myocardial infarction (RR, 6.29; 95% CI, 2.69-14.73), cerebrovascular disease (RR, 5.14; 95% CI, 3.37-7.84), ischemic heart disease (RR, 3.65; 95% CI, 2.77-4.80), and peripheral nerve disorders (RR, 5.01; 95% CI, 2.81-8.95). First diagnoses of myocardial infarction, cerebrovascular disease, and peripheral nerve disorders were increased during the period from 6 months before to 6 months after diagnosis.
Conclusions: Clinical diagnosis of DM is often the end of a process leading to established complications and is associated with greatly increased utilization of care. This adds to the justification of strategies for earlier detection of hyperglycemic states.