Jordy van Sambeeck

Dutch translation and validation of the NPI score and the BPII 8 129 physical functioning ( ρ = 0.64) and bodily pain (0.60), all KOOS sub-scales and with the KKS ( ρ =0.83), but not for role limitations due to physical problems ( ρ =0.49). The criteria set for divergent validity was not met for SF 36 sub-scale social functioning ( ρ =0.45) but was met for sub-scale mental health ( ρ =0.25). For the BPII we found no floor nor ceiling effect. For two specific question of BPII answers were frequently missing: for question 6 the response rate was only 74%, for question 18 the response rate was 72%. The response rate for the other questions was 100%. BPII NPI Kujala Knee Score 0.83 -0.78 KOOS symptoms 0.60 -0.58 KOOS pain 0.73 -0.69 KOOS ADL 0.74 -0.72 KOOS Sports 0.73 -0.76 KOOS QoL 0.85 -0.72 SF 36 PF 0.64 -0.60 SF 36 RP 0.49 -0.25 SF 36 RE 0.19 -0.003 SF 36 SF 0.45 -0.23 SF 36 MH 0.25 -0.10 SF 36 VT 0.39 -0.20 SF 36 BP 0.61 -0.55 SF 36 GH 0.35 -0.28 Table 2. Spearman’s rho correlation coefficient between BPII or NPI respectively and the other outcome measurements. ADL Activities of daily living, QoL quality of life, PF physical functioning, SF social functioning, RP role limitation resulting from physical problems, RE role limitation resulting from emotional problems, MH mental health, VT energy vitality, BP bodily pain, GH general health perception. The criteria set for convergent validity for the NPI met with strong correlations for SF 36 subscales physical functioning ( ρ =-0.60), bodily pain ( ρ =-0.55), all KOOS subscales and with the KKS ( ρ =-0.78) , but not for role limitations due to physical problems ( ρ =-0.25). The criteria set for divergent validity were met with weak correlations for SF 36 subscales social functioning ( ρ =-0.23) and mental health ( ρ =-0.10). For the NPI we found a floor effect but no ceiling effect. For 6 questions of the NPI data was missing: for question 2 in 25% of the patients, for question 3 for 23% of the patients, for questions 5 for 26% of the patients, for question 6 for 19% of the patients, for questions 7 for 18% of the patients and for question 8 for 17% of the patients.