Table 3

Study characteristics and test measures of studies for hospital discharge data

Country	Study Years	Author^(Reference)	Reference	Type of administrative data	Diabetes case definition	ICD codes used	Study, N	Sensitivity % (95% CI)	Specificity % (95% CI)	PPV % (95% CI)	NPV % (95% CI)	κ
Canada	1995–2000	So et al24	Medical chart	Hospital discharge data	Diabetes with complications	ICD-9 250.1-.9	93	80 (51.91 to 95.67)	98.3 95.15 to 99.65)	80 (51.91 to 95.67)	98.3 (95.15 to 99.65)
Canada	2001–2004	So et al24	Medical chart	Hospital discharge data	Diabetes with complications	ICD-10 E10.0-.8, E11.0-.8, E12.0-.8, E13.0-.8, E14.0-.8	93	66.7 (38.38 to 88.18)	98.9 (96.00 to 99.86)	83.3 (51.59 to 97.91)	97.2 (93.67 to 99.10)
Canada	2003	Quan et al26	Medical chart	Hospital discharge data	Diabetes with chronic complications	ICD 9 250.4-.7	4008	63.6	98.9	62.5	99	0.62
					Diabetes with chronic complications	ICD 10 E10.2-.5, E10.7, E11.2-.5, E11.7, E12.2-.5, E12.7, E13.2-.5, E13.7, E14.2-.5, E14.7		59.1	99	63.1	98.9	0.6
					Diabetes without chronic complications	ICD 9 250.0-.3, 250.8, .9		77.7	98.4	86.5	97	0.8
					Diabetes without chronic complications	E10.0, .1, .6, .8, .9, E110, .1, .6, E11.8, .9, E12.0, .1, .6, .8, .9, E13.0, .1, .6, .8, .9, E14.0, .1, .6, .8, .9		75.8	98.7	88.5	96.8	0.79
Western Australia	1998	Nedkoff et al28	Medical chart	Hospital discharge data	Look back period: Index admission	ICD 9/ICD-9 CM 250	1685	91.1	98.7	93.3	97.4	0.912
					1 year			91.6	98.1	92.8	97.6	0.902
					2 years			92.1	97.9	92.1	97.8	0.903
					5 years			92.4	97.7	91.9	97.8	0.9
					10 years			92.6	97.6	91.4	97.8	0.9
					15 years			92.6	97.5		97.8	0.897
	2002–2004				Look back period: Index admission	ICD 10-AM E10-E14	2258	81.5	98.2	96	90.8	0.825
					1 year			86.3	97.3	94.4	93	0.853
					2 years			87.3	96.7	93.5	93.4	0.854
					5 years			89.3	95.9	92.2	94.4	0.859
					10 years			89.6	95.6	91.6	94.5	0.856
					15 years			89.6	95.5	91.5	94.5	0.855
Canada	1989–1990	Robinson et al22	Self-reported survey	Hospital discharge data and physician claims	1, 2 or 3 physician claim or 1 hospitalisation over 3 years	ICD 9 CM	2651	72	98	76	98	0.72 (0.67–0.77)

Superior performance characteristics within studies have been highlighted in bold.
Sensitivity identifies the proportion of patients who truly do have the disease/condition;
specificity identifies the proportion of patients who truly do not have the disease/condition;
PPV is the probability that participants with a positive screening test truly have the disease/condition;
NPV is the probability that participants with a negative screening test truly do not have the disease/condition;
κ is an inter-rater agreement statistic to evaluate the agreement between two classifications on ordinal or nominal scales.
ICD 10-AM, International Classification of Diseases, Tenth Revision, Australian Modification; ICD, International Classification of Diseases; ICD-9-CM, International Classification of Diseases, Ninth Revision, Clinical Modification; NPV, negative predictive value; PPV, positive predictive value.