Table 2 Performance of predefined algorithms to identify patients with OA of hip and/or knee (Step 1, total N = 490 with available claims data)

1. ≥ 2 medical (inpatient and/or outpatient [both physicians’ office visits and all other outpatient settings]) encounters resulting in diagnoses OA of the hip and/or knee12 within 6 months

350

7

40

93

2. ≥ 2 medical encounters resulting in diagnoses of OA of the hip and/or knee ≤ 90 days apart

335

6

41

108

3. 1 inpatient admission resulting in a diagnosis of OA of the hip and/or knee

239

2

45

204

4. A diagnosis of OA of the hip and/or knee from ≥ 1 outpatient visit

401

21

26

42

5. A diagnosis of OA of the hip and/or knee from ≥ 2 outpatient visits in the same CY

345

6

41

98

6. A diagnosis of OA of the hip and/or knee from ≥ 3 outpatient visits in the same CY

294

6

41

149

7. A diagnosis of OA of the hip and/or knee from ≥ 4 outpatient visits in the same CY

263

2

45

180

8. A diagnosis of OA of the hip and/or knee from ≥ 1 outpatient visit; and ≥ X-rays of the hip and/or knee in the same CY

351

10

37

92

9. A diagnosis of OA of the hip and/or knee from ≥ 2 outpatient visits; and ≥ X-rays of the hip and/or knee in the same CY

318

3

44

125

10. A diagnosis of OA of the hip and/or knee from ≥ 3 outpatient visits; and ≥ X-rays of the hip and/or knee in the same CY

270

3

44

173

11. A diagnosis of OA of the hip and/or knee from ≥ 4 outpatient visits; and ≥ X-rays of the hip and/or knee in the same CY

244

1

46

199

12. 1 outpatient visit and ≥ 2 diagnoses of OA of the hip and/or knee from outpatient visits within 5 years

274

5

42

169

13. ≥ 2 outpatient visits resulting in diagnoses of OA of the hip and/or knee within 5 years

351

6

41

92

14. ≥ 2 outpatient visits resulting in diagnoses of OA of the hip and/or knee within 2 years

351

6

41

92

15. ≥ 1 medical encounter resulting in a diagnosis of OA of the hip and/or knee

401

21

26

42

16. ≥ 1 medical encounter resulting in a diagnosis of OA of the hip or knee plus ≥ 1 medical encounter resulting in a diagnosis of joint pain ≥ 30 days apart

325

4

43

118

17. ≥ 1 medical encounter resulting in a diagnosis of OA of the hip or knee plus ≥ 1 administration of either HA or IA corticosteroids

316

8

39

127

18. ≥ 1 medical encounter resulting in a diagnosis of OA of the hip or knee plus ≥ 1 relevant scans (i.e., X-ray, MRI) of knee or hip ± 2 years of the OA diagnosis

358

7

40

85

19. ≥ 1 medical encounter resulting in a diagnosis of OA of the hip or knee plus ≥ 1 procedure codes for knee or hip arthroplasty (partial or full; initial or revision) within 30 days after OA diagnosis

231

0

47

212

20. ≥ 1 medical encounter resulting in a diagnosis of OA of the hip or knee plus ≥ 1 mobility aid (e.g., cane, walker, wheelchair) ± 30 days of OA diagnosis

79

2

45

364

Combined Algorithm (using OR function)

 Combinations of all algorithms with performance ≥ 0.98 PPV

382

11

36

61

 Combinations of all algorithms with performance ≥ 0.95 PPV

403

21

26

40

 Combinations of all algorithms with performance ≥ 0.90 PPV

403

21

26

40

 Combinations of all algorithms with performance ≥ 0.85 PPV

403

21

26

40

 Combinations of all algorithms with performance ≥ 0.80 PPV

403

21

26

40