Effect of glomerular filtration rate and proteinuria on medical cost among screened subjects.

Background: Chronic kidney disease is a predictor of end-stage renal disease (ESRD) and cardiovascular disease (CVD). Therefore, the medical expenses are higher with the decrease in glomerular filtration rate (GFR). However, few studies have examined the medical expenses according to the baseline GFR.

Methods: We investigated the relationship between GFR at health checks and medical expenses, combining the registries of both the health checks and report of medical expenses (receipts). The health checks were done from April 2008 to March 2009, and the eligible subjects were covered by the Okinawa Branch of the Japan Health Insurance Association. All reports of medical expenses were reviewed from April 2008 to March 2010 (24 months).

Results: A total of 74,354 subjects, 38.2 % females with the mean age of 48.1 years, were examined according to whether they had visited medical facilities during the study period. The total number of receipts was 773,276. The average receipt point, 1 point = 10 Yen, was 686,410 (eGFR < 15), 56,408 (eGFR 15-29), 47,263 (eGFR 30-44), 24,372 (45-59), 16,018 (eGFR 60-74), 13,893 (eGFR 75-89), 13,990 (eGFR 90-104), 14,717 (eGFR 105-119), and 19,139 (eGFR 120 and over), respectively. The relationship between eGFR and medical expense was U-shaped, and the expense was lowest at eGFR 75-89.

Conclusion: We demonstrate that the medical expenses increase as eGFR decreases. Subjects with higher eGFR, 120 and over, seemed to have higher medical expenses.