Table II.

Screening by IDRS followed by OGTT

IRDS cut-off	Subjects positive on IDRS at each cut-point* (% of 961)		NDD subjects detected via IDRS (% of 72)
	N	%	N	%
≥10	961	100.0	72	100.0
≥20	951	99.0	71	98.6
≥30	897	93.3	70	97.2
≥40	730	76.0	66	91.7
≥50	604	62.9	62	86.1
≥60	413	43.0	54	75.0
≥70	201	20.9	34	47.2
≥80	58	6.0	12	16.7
≥90	9	0.9	2	2.8

NDD, Newly detected diabetes. An IDRS score of ≥ 60 provided optimal sensitivity and specificity.⁶

^*All subjects with IDRS above a given threshold (e.g., ≥60) (n=413) would be screened with a subsequent OGTT. Therefore, a number of subjects without diabetes (e.g., 359 subjects would be screened with OGTT, and in this sense, were false positives. However, because OGTT was performed for all IDRS-positive individuals, the overall specificity of the combination of tests remained 100 per cent.