Validation of Administrative Osteoarthritis Diagnosis Using a Clinical and Radiological Population-Based Cohort

Table 2

Validation results with the 95% confidence intervals of administrative definition of osteoarthritis using four reference standards that include knee, hand, and hip OA.

Reference standard	Administrative osteoarthritis	Sensitivity% (95% CI)	Specificity% (95% CI)	PPV%; (95% CI)	NPV%; (95% CI)	LR+; (95% CI)	LR−; (95% CI)
RS1	AOA1	55 (45–64)	75 (61–85)	82 (71–89)	45 (34–55)	2.2 (1.4–3.6)	0.6 (0.5–0.8)
	AOA2	25 (17–34)	91 (80–97)	85 (68–94)	37 (29–46)	2.8 (1.2–6.9)	0.8 (0.7–0.9)
RS2	AOA1	55 (46–64)	77 (63–87)	84 (74–91)	44 (34–54)	2.4 (1.4–4.1)	0.6 (0.5–0.7)
	AOA2	26 (18–35)	94 (83–99)	91 (75–98)	36 (29–45)	4.6 (1.5–14.5)	0.8 (0.7–0.9)
RS3	AOA1	47 (39–55)	75 (43–93)	96 (88–99)	10 (5–18)	1.9 (0.7–5.0)	0.7 (0.5–1.0)
	AOA2	21 (15–29)	100 (70–100)	100 (87–100)	9 (5–15)	>21 (21–∞)	0.8 (0.7–0.9)
RS4	AOA1	57 (48–66)	87 (73–95)	92 (83–97)	42 (33–53)	4.4 (2.0–9.3)	0.5 (0.4–0.6)
	AOA2	26 (18–34)	96 (84–99)	94 (79–99)	32 (24–41)	6.5 (1.5–23.6)	0.8 (0.7–0.9)

AOA1 includes at least one visit to a health professional or one hospital admission for osteoarthritis and AOA2 includes at least two visits to health professionals in two years or one hospital admission for osteoarthritis. RS1, RS2, RS3, and RS4 are four reference standards that include knee, hand, and hip OA which are described in Methods.
PPV: positive predictive value; NPV: negative predictive value; LR+: positive likelihood ratio = sensitivity/(1 − specificity); LR−: negative likelihood ratio = (1 − sensitivity)/specificity.