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Table 1 Scaling assumptions of the SF-36v2 (N = 1884)

From: Performance of the Dutch SF-36 version 2 as a measure of health-related quality of life in patients with rheumatoid arthritis

   Range of correlations Item scaling tests
Scales ka Item internal consistencyb Item discriminant validityc Item internal consistencyd Item discriminant validitye
PF 10 0.58 to 0.79 0.24 to 0.64 10/10 (100%) 69/70 (98.6%)
RP 4 0.84 to 0.90 0.43 to 0.68 4/4 (100%) 28/28 (100%)
BP 2 0.81 0.36 to 0.70 2/2 (100%) 14/14 (100%)
GH 5 0.48 to 0.68 0.26 to 0.60 5/5 (100%) 31/35 (88.6%)
VT 4 0.36 to 0.69 0.22 to 0.62 3/4 (75%) 27/28 (96.4%)
SF 2 0.70 0.50 to 0.66 2/2 (100%) 13/14 (92.9%)
RE 3 0.86 to 0.91 0.39 to 0.64 3/3 (100%) 21/21 (100%)
MH 5 0.64 to 0.76 0.25 to 0.62 5/5 (100%) 35/35 (100%)
  1. aNumber of items; bPearson correlations between items and hypothesized scales corrected for overlap (correlation with the sum of the other items in the same scale); cPearson correlations between items and other scales; dNumber (%) of items out of k with correlation ≥ 0.40; eNumber (%) of items out of 7xk where the difference between the corrected correlation of the item with its own scale and correlation with the other scales ≥ 2SE (= 0.046). PF = Physical Functioning; RP, Role-physical; BP, Bodily pain; GH, General health; VT, Vitality; SF, Social functioning; RE, Role-emotional; MH, Mental health; HT, Health transition.