Medical Costs Associated with Severity of Chronic Kidney Disease in Type 2 Diabetes Mellitus in Singapore

Introduction: This was a retrospective cross-sectional study to assess the impact of chronic kidney disease (CKD) and its severity in Type 2 diabetes mellitus (T2DM) on direct medical costs, and the effects of economic burden on CKD related complications in T2DM in Singapore. Methods: A total of 1,275 T2DM patients were recruited by the diabetes centre at Khoo Teck Puat Hospital from 2011-2014. CKD stages were classified based on improving global outcome (KDIGO) categories, namely the estimated glomerular filtration rate (eGFR) and albuminuria kidney disease. Medical costs were extracted from the hospital administrative database. Results: CKD occurred in 57.3% of patients. The total mean cost ratio for CKD relative to non-CKD was 2.2 (P<0.001). Mean (median) baseline annual unadjusted costs were significantly higher with increasing CKD severity-S$1,523 (S$949), S$2,065 (S$1,198), S$3,502 (S$1,613), and S$5,328 (S$2,556) for low, moderate, high, and very high risk respectively (P<0.001). CKD (P<0.001), age at study entry (P=0.001), Malay ethnicity (P=0.035), duration of diabetes mellitus (DM; P<0.001), use of statins/fibrates (P=0.021), and modified Diabetes Complications Severity Index (DCSI) (P<0.001) were positively associated with mean annual direct medical costs in the univariate analysis. In the fully adjusted model, association with mean annual total costs persisted for CKD, CKD severity and modified DCSI. Conclusion: The presence and increased severity of CKD is significantly associated with higher direct medical costs in T2DM patients. Actively preventing the occurrence and progression in DM-induced CKD may significantly reduce healthcare resource consumption and healthcare costs.