The Trans-femoral Fitting Predictor: a functional measure to predict prosthetic fitting in transfemoral amputees-validity and reliability

Objective: To assess the psychometric properties of the Trans-femoral Fitting Predictor (TFP).

Design: Prospective observational study.

Setting: Hospital sites (N=9).

Participants: Transfemoral amputees (N=93).

Intervention: The TFP, a 9-item instrument describing graded tasks, aims to assess the prosthetic potential of transfemoral amputees. The instrument was used in its paper form (N=93) and for a video assessment of a subset of these amputees (n=75).

Main Outcome Measure(s): Reliability and validity of the TFP, both paper and video assessments.

Results: The TFP yielded Cronbach alpha of .92, and all intraclass correlation coefficients between values were greater than 0.8, with narrow 95% confidence intervals. Factor analysis suggested the TFP had 2 constructs representing more advanced and less advanced tasks. Both discriminant analysis and logistic regression suggested that tasks 7 (stand with early walking aid [EWA] for 30s) and 8 (walk to the end of the parallel bars with the EWA and turn around) were more predictive of whether an amputee will go on to receive a prosthesis.

Conclusion: The TFP is a simple, valid, and reliable measure of prosthetic potential for transfemoral amputees. Video assessment with the TFP was very successful and in the future could be used for both training purposes and to provide expert assessment through telehealth.