To test the measurement properties of Turkish version of the Anterior Cruciate Ligament Quality of Life (ACL-QOL) questionnaire.
One hundred and nineteen patients with ACL reconstruction (ACL-R) completed internal consistency, agreement, construct validity, floor and ceiling effect analyses. Eighty out of 119 patients with ACL-R completed Turkish version of the ACL-QOL questionnaire twice for the test-retest reliability. A subgroup of thirty-nine patients undergoing physiotherapy were also asked to answer the ACL-QOL questionnaire, the Lysholm Knee Scale (LKS), Knee Outcome Survey-Activities of Daily Living Scale (KOS-ADLS) and the short form 36 (SF-36) at pre-operative, 16th week and 2 years post-operatively to assess responsiveness.
The questionnaire had high internal consistency (Cronbach's α = 0.95). The paired t test showed no significant difference between the test-retest means. The intraclass correlation was excellent for reliability and agreement in five domains and overall score (ICC 0.95, 0.95, 0.97, 0.95, 0.96 and 0.95; p < 0.001). The standard error of measurement and the minimum detectable change (MDC95) were found to be 3.1 points and 8.7 points, respectively. The questionnaire showed a fair correlation (r = 0.23) with LKS and a poor correlation (r = 0.14) with KOS-ADLS; good and very good construct validity (r = 0.51, r = 0.62) with SF-36 physical component score and mental component score, respectively. No ceiling and floor effects were observed except the subdomain of 'work-related concerns' (22.9 %). A dramatic effect size was demonstrated at the 16th week (2.1) and 2 years (1.1) of follow-up.
Turkish version of the ACL-QOL questionnaire is a reproducible and responsive instrument that can be used in clinical studies.
LEVEL OF EVIDENCE:
Diagnostic study, Level I.