Table 1

Physical function instruments, baseline, 12-month, and change scores

Change Scores (12 months - Baseline)

Items (n)

Response options (n)

Baseline mean ± SD¹

12-Months Mean ± SD

Mean

SD

(95% CL² for SD)

P-value³

Legacy PF-10

10

3

47.2 ± 29

49.0 ± 29

1.8

18.4 (16.5, 20.2)

0.04

Legacy HAQ

20

4

29.2 ± 23

30.7 ± 24

1.5

10.6 (9.4, 11.8)

0.002

Item-Improved PF-10

10

5

41.5 ± 26

43.0 ± 27

1.5

16.3 (13.9, 18.6)

0.05

Item-Improved HAQ

20

5

21.0 ± 21

22.1 ± 21

1.1

8.6 (7.7, 9.6)

0.01

PROMIS PF 10

10

5

33.9 ± 22

35.2 ± 23

1.3

11.1 (10.0, 12.2)

0.01

PROMIS PF 20

20

5

30.6 ± 21

31.8 ± 22

1.2

9.4 (8.4, 10.1)

0.01

¹ Standard Deviation, ² Confidence Limits, ³ Pair-wise t-test.

HAQ, health assessment questionnaire; Item-Improved, Changes to items intended to improve their performance by altering parameters such as time frame and response options while retaining the same item stem; PF, physical function; PROMIS, Patient-Reported Outcomes Measurement Information System.

Fries et al. Arthritis Research & Therapy 2011 13:R147   doi:10.1186/ar3461