Validity Of The Patient-rated Forearm Evaluation Questionnaire As An Outcome Tool For Lateral Epicondylitis

Abstract

PURPOSE To assess the sensitivity to change of the Patient-Rated Forearm Evaluation Questionnaire (PRFEQ) for individuals with lateral epicondylitis (LE). METHODS 52 subjects who participated in a double-blind randomized control trial on the effectiveness of extracorporeal shockwave therapy (ESWT) in the treatment of lateral epicondylitis (LE) were administered the PRFEQ at 0, 4 and 8 weeks after initiation of therapy. All subjects had previously not received therapy for their LE. The PRFEQ has a highest possible score of 10 and lowest possible score of 0, where 0 indicates no pain and no difficulty in performing activities. Overall elbow pain (10cm visual analogue scale), quality of life (EuroQoL questionnaire) and grip strength were also evaluated. Subjects were classified as treatment successes or treatment non-successes based on the elbow pain VAS at 8 weeks. RESULTS The mean PRFEQ scores for treatment non-successes and treatment successes at baseline were 3.49 (SD=1.60) and 3.12 (SD=1.37) respectively. The mean PRFEQ scores for treatment non-successes and treatment successes at 8 weeks were 3.54 (SD=1.87) and 1.90 (SD=1.16) respectively. The mean change in score of the treatment non-success group was 0.5 with a 95% confidence interval of [0.1–0.9]. The mean change in score of the treatment success group was 1.6 with a 95% confidence interval of [1.2–2]. Test-retest reliability over 4 weeks, however, was poor (ICC=0.51) and the PRFEQ did not demonstrate acceptable item-specific convergent validity with similar or identical items in other validated tools. CONCLUSIONS The PRFEQ appears to be sensitive to clinically significant change in individuals with previously untreated lateral epicondylitis, but may not be a reliable outcome tool. Discrepancies between specific items of the PRFEQ and other measures of similar constructs may be related to the use of the visual numeric scale on the PRFEQ. Supported by the Alberta Provincial CIHR Bone and Joint Training Program and the Sport Science Association of Alberta.