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 standardAdministrative osteoarthritisSensitivity% (95% CI)Specificity% (95% CI)PPV%
(95% CI)
NPV%
(95% CI)
LR+
(95% CI)
LR−
(95% CI)

RS1AOA155 (45–64)75 (61–85)82 (71–89)45 (34–55)2.2 (1.4–3.6)0.6 (0.5–0.8)
AOA225 (17–34)91 (80–97)85 (68–94)37 (29–46)2.8 (1.2–6.9)0.8 (0.7–0.9)

RS2AOA155 (46–64)77 (63–87)84 (74–91)44 (34–54)2.4 (1.4–4.1)0.6 (0.5–0.7)
AOA226 (18–35)94 (83–99)91 (75–98)36 (29–45)4.6 (1.5–14.5)0.8 (0.7–0.9)

RS3AOA147 (39–55)75 (43–93)96 (88–99)10 (5–18)1.9 (0.7–5.0)0.7 (0.5–1.0)
AOA221 (15–29)100 (70–100)100 (87–100)9 (5–15)>21 (21–∞)0.8 (0.7–0.9)

RS4AOA157 (48–66)87 (73–95)92 (83–97)42 (33–53)4.4 (2.0–9.3)0.5 (0.4–0.6)
AOA226 (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.