Impact of Continuous Care on Health Outcomes and Cost for Type 2 Diabetes Mellitus: Analysis Using National Health Insurance Cohort Database

BACKGROUND: The objective of the study was to determine the impact of continuous care on health outcomes and cost of type 2 diabetes mellitus (T2DM) in Korea. METHODS: A nationwide retrospective, observational case-control study was conducted. Continuity of treatment was measured using Continuity of Care (COC) score. Information of all patients newly diagnosed with T2DM in 2004 was retrieved from the National Health Insurance database for the period of 2002 to 2013. The study examined 2,373 patients after applying exclusion criteria, such as for patients who died from conditions not related to T2DM. Statistical analyses were performed using frequency distribution, simple analysis (t-test and chi-squared test), and multi-method analysis (simple linear regression, logistic regression, and survival analysis). RESULTS: The overall COC score was 0.8±0.24. The average incidence of diabetic complications was 0.39 per patient with a higher COC score, whereas it was 0.49 per patient with a lower COC score. In both survival and logistic analyses, patients who had high COC score were significantly less likely to have diabetic complications (hazard ratio, 0.69; 95% confidence interval, 0.54 to 0.88). The average medical cost was approximately 3,496 United States dollar (USD) per patient for patients with a higher COC score, whereas it was 3,973 USD per patient for patients with a lower COC score during the 2006 to 2013 period, with a difference of around 477 USD, which is statistically significant after adjusting for other factors (β=−0.152). CONCLUSION: Continuity of care for diabetes significantly reduced health complications and medical costs from patients with T2DM.