Table 3

Construct validity of the instruments in patients with an ankle fracture

(Sub)scaleAOFAS
PainFunctionAlignmentTotal
AOFAS
 Pain10.23 [65]0.01 [69]0.66 [65]
 Function0.23 [65]10.28 [65]0.85 [65]
 Alignment0.01 [69]0.28 [65]10.35 [65]
 Total0.66 [65]0.85 [65]0.35 [65]1
FFI
 Pain−0.81 [70]−0.41 [65]−0.14 [69]−0.70 [65]
 Disability−0.41 [70]−0.75 [65]−0.19 [69]−0.74 [65]
 Activity limiation−0.34 [70]−0.80 [65]−0.23 [69]−0.77 [65]
 Total−0.55 [70]−0.73 [65]−0.21 [69]−0.80 [65]
SF-36
 PF0.21 [70]0.64 [65]0.21 [69]0.60 [65]
 RP0.32 [70]0.50 [65]0.19 [69]0.58 [65]
 BP0.59 [70]0.53 [65]0.03 [69]0.67 [65]
 GH0.15 [70]−0.01 [65]−0.09 [69]0.04 [65]
 VT0.28 [70]0.19 [65]−0.02 [69]0.27 [65]
 SF0.14 [70]0.65 [65]0.18 [69]0.56 [65]
 RE0.10 [70]0.32 [65]0.22 [69]0.33 [65]
 MH0.24 [70]0.20 [65]0.02 [69]0.24 [65]
 PCS0.40 [70]0.62 [65]0.11 [69]0.65 [65]
 MCS0.11 [70]0.24 [65]0.13 [69]0.24 [65]

  • Data for t=1 were used. Spearman’s rank correlation coefficients are given for all possible combinations of (sub)scales, with the N between square brackets. The maximum possible number of patients was 70.

  • r>0.6 indicates high correlation, 0.3 < r>0.6 moderate correlation and r<0.3 low correlation. Bold and underlined correlations were not hypothesised correctly.

  • AOFAS, American Orthopaedic Foot and Ankle Society; BP, bodily pain; FFI, Foot Function Index; GH, general health perceptions; MCS, mental component summary; MH, general mental health; PCS, physical component summary; PF, physical functioning; RE, role limitations due to emotional problems; RP, role limitations due to physical health; SF, social functioning; SF-36, Short Form-36; VT, vitality, energy or fatigue.