Evaluation of the value of diabetes risk scores in screening for undiagnosed diabetes and prediabetes: a community-based study in southwestern China

Objectives To evaluate the performance and cost-effectiveness of existing diabetes risk scores (DRSs) to screen for undiagnosed diabetes mellitus (UDM) and prediabetes (PD) in a community-based southwestern Chinese population. Methods Participants in TIDE-Chengdu survey with requisite data and without known diabetes were included. Five Chinese-derived DRSs and six non-Chinese-derived DRSs were included for evaluation. Their performance in detecting UDM and UMD or PD (UDM/PD) was assessed using the C-statistic. The cost-effectiveness of the optimal DRS was compared with that of capillary fasting blood glucose (CFBG). Results Of the 1,692 TIDE-Chengdu survey participants included, 177 (10.5%) had UDM and 339 (20.0%) had PD. The rural participants (N = 737) were more likely to have UDM (13.4%vs. 8.2%) and PD (24.8%vs. 16.3%) than their urban counterparts (N = 955) (P 0.0001). In the full population, the included DRSs all showed good discrimination in detecting UDM (C-statistic: 0.699 to 0.762) and UDM/PD (C-statistic: 0.717 to 0.769), but the New Chinese DRS (NCDRS) performed best for both UDM and UDM/PD. The DRSs evaluated all showed better performance in urban participants than rural participants for both UDM (C-statistic: 0.718 to 0.795vs. 0.642 to 0.720) and UDM/PD (C-statistic: 0.729 to 0.793vs. 0.682 to 0.726) (allP 0.05). The mean cost per UDM/PD case identified was lower with NCDRS at score 25 ( yen 503.3($71.9)) and 27 ( yen 490.5 ($70.1)) than CFBG at 5.0, 5.1, 5.2, or 5.3 mmol/L ( yen 631.7 ($90.2), yen 611.8 ($87.4), yen 579.2 ($82.7) and yen 551.9 ($78.8)), whereas the mean costs per UDM case identified was higher with NCDRS at score 25 ( yen 1379.3 ($197.0)) and 27 ( yen 1315.1 ($187.9)) than CFBG at 5.3, 5.4, or 5.5 mmol/L ( yen 1301.7 ($186.0), yen 1247.7 ($178.2) and yen 1173.3 ($167.6)). Conclusion The NCDRS represents a valid and cost-effective tool for use in southwestern China to identify high-risk patients with UDM or PD who need a diagnostic test.