[Translation, Adaptation, Reliability and Validity of the German Version of the Prosthesis Mobility Questionnaire 2.0 (PMQ) on Patients with Major Lower Limb Amputation].

Abstract

PURPOSE\nThe aim of this prospective validation study was to translate the Prosthesis Mobility Questionnaire 2.0 (PMQ) into German based on a guideline, following by psychometric testing for its validity and reliability using classical test theory.\n\n\nMETHODS\nThe PMQ was translated into German according to ISPOR guidelines using double forward and double backward translations, finalized by pilot testing (N=10). Subsequently, assessment of the validity and reliability was performed from March 2020 to August 2020 on N=61 patients with unilateral lower limb amputation. Construct validity was determined by using the German version of the Locomotor Capabilities Index-5 (LCI-5-D), the Rivermead Mobility Index (RMI), the Timed up and go Test (TUG), and K-levels. Cronbach s alpha was calculated to check internal consistency and discriminatory power was determined by item correlations. Test-retest reliability was calculated using ICC (2,1). Based on the ICC, the minimum detectable difference (MDC) was calculated.\n\n\nRESULTS\nThe translation process required small changes after the pilot test. The validation study was performed on N=61 patients (56.59±13.16 years, m/f=38/23). A mean PMQ of 26.23±8.89 points was achieved. Ceilings or floor effects for total score did not appear. Construct validity showed strong positive correlations to LCI-5-D (r=0.74, p<0.001), RMI (r=0.63 p<0.001) as well as k-levels (r=0.61 p<0.001) and moderate negative correlation to TUG (r=-\u20090.49, p<0.001). Internal consistency was excellent with Cronbach s alpha=0.95). All items showed a value greater than r=0.40 for item-to-total score correlation. Test-retest reliability was excellent with an ICC (2,1)=0.98 with a timespan between T0 and T1 of 3.2±2.83 days. Based on this results, the MDC was 3.40 points.\n\n\nCONCLUSION\nThe German version of the Prosthesis Mobility Questionnaire 2.0 is a valid, reliable patient reported outcome measure (PROM) for measuring mobility and functional ability of patients with exoprosthesis due to unilateral lower limb amputation. It can be used for a German-speaking population.