Aims/hypothesis: The prognostic information about CKD progression, particularly for GFR categories 1 and 2, is still limited. This cohort was therefore conducted to determine the CKD progression using a competing risk approach.
Methods: We conducted an ambi-directional cohort study linking community health screening with hospitals and death registry data in a province of Thailand, from 1997-2011. A competing risk model was applied by treating death as a competing risk factor to estimate 2-, 5-, and 10-yearprobability of kidney failure and median time for CKD progression from lower to higher GFR category.
Results: There were 17,074 non-diabetic and 15,032 diabetic CKD subjects. Diabetic subjects progressed more rapidly through GFR categories with the median times for CKD progression from GFR categories G1 to G2, G2 to G3a, G3a to G3b, G3b to G4, and G4 to G5 of 4.4, 6.1, 4.9, 6.3, and 9.0 years, respectively. Non-diabetic subjects took longer to progress with the corresponding median time of 9.4, 14.0, 11.0, 13.8, and >14.3 years. After adjusting for confounders, diabetic subjects were 49% (cause-specific hazard ratio (csHR=1.49, 95% CI: 1.37, 1.62) more likely to develop kidney failure than non-diabetic subjects. Albuminuria categories A3 and A2 were respectively 3.40 (95% CI: 3.07, 3.76) and 1.71 (95% CI: 1.53, 1.92) higher risk of kidney failure when compared to A1. For each albumin category, death rate increased as albuminuria increased particularly in diabetic subjects, which was approximately two times higher in A3 compared to A1.
Before 2008 (when the “PD first” project was launched), an access rate to renal replacement therapy for kidney failure patients belonging to the universal coverage scheme, civil servant medical benefit scheme, and social security scheme were 1%, 14%, and 18% respectively. The corresponding access rates rose to 25%, 43%, and 56% after 2008. Subjects with kidney failure who were members of the universal coverage scheme had increased risk of death when compared to the other 2 schemes.
Conclusions: Diabetic subjects progress through GFR and albuminuria categories and reach kidney failure about twice as rapidly as non-diabetic subjects.Although an access rate to renal replacement therapy among 3 health insurance schemes has consistentlyincreased since 2008, members of the universal coverage scheme still had substantially lower access rate when compared to the other 2 schemes. Further study assessing factors contributing to such low access rate and comparing CAPD and hemodialysis should be conducted.