Table 1 Predefined hypotheses for evaluating the construct validity of the Dutch OKS-APQ

A. Strong positive correlation (r > 0.50):

 1. A strong positive correlation between OKS-APQ and OKS (pooled, pre- and postoperative patients);

 2. A strong positive correlation between OKS-APQ and FJS (in postoperative patients);

 3. A strong positive correlation between OKS-APQ and PCS (SF-36) (pooled, pre- and postoperative patients);

B. Moderate to strong negative correlation (r > 0.31):

 4. A moderate to strong negative correlation between OKS-APQ and VAS pain (pooled, pre- and postoperative patients);

C. Weak to moderate positive correlation (r 0.10 – 0.50):

 5. A weak to moderate positive correlation between OKS-APQ and MCS (SF-36) (pooled, pre- and postoperative patients);