Table 2

Comparison of scores from the 5-, 10-, and 15-item OA-FUNCTION-CATs and the full item bank

Total (n = 328)

Both hip and knee (n = 89)

Hip (n = 53)

Knee (n = 186)

Version

Mean (SD)

Range

Mean (SD)

Range

Mean (SD)

Range

Mean (SD)

Range

Difficulty

5-CAT

49.7 (10.7)

23.7–82.3

47.2 (9.4)

31.6–79

52.3 (11.2)

35.8–82.3

50.1 (11)

23.9–82.3

10-CAT

50.1 (10.9)

23.7–91.2

47.6 (9.5)

31–88.6

53.4 (11.5)

37.9–91.2

50.4 (11.2)

23.7–91.2

15-CAT

50.4 (11.2)

22.7–95.6

47.8 (9.8)

30.2–91.8

53.8 (11.8)

37.4–95.6

50.6 (11.4)

22.7–95.6

Full item bank

50.4 (10.8)

24.2–96.7

47.6 (9.6)

28.5–95.8

54.1 (9.7)

37.5–75.7

50.7 (11.3)

24.2–96.7

Pain

5-CAT

49.9 (10.7)

24.5–84.6

47.4 (8.9)

31.1–74.8

53.7 (11.9)

34.6–76.9

49.9 (10.8)

24.5–84.6

10-CAT

50.5 (11.5)

25.8–98.4

47.6 (8.6)

31.7–66.1

55.2 (13.1)

37.2–87.6

50.6 (11.8)

25.8–98.4

15-CAT

50.6 (11.8)

26.2–107.3

47.5 (8.6)

32.8–67.8

55.3 (13.3)

36.2–87.1

50.7 (12.3)

26.2–107.3

Full item bank

50.7 (11.9)

25–112.9

47.4 (8.2)

32.2–72.6

55.3 (12.5)

36.9–90.8

50.9 (12.7)

25–112.9

CAT, computer adaptive test; OA, osteoarthritis; SD, standard deviation.

Jette et al. Arthritis Research & Therapy 2009 11:R107   doi:10.1186/ar2760