Physical Therapists' Prognosis of Outcomes After a Hip or Quadriceps Exercise Intervention in Patients With Patellofemoral Pain: A Secondary Analysis of a Randomized Trial

Abstract

OBJECTIVE: Can physical therapists who are treating patients with patellofemoral pain (PFP) predict the outcome of a 12-week exercise intervention based on initial assessment, and what are the physical therapists' reasons for prediction? DESIGN: Secondary analysis of a randomized trial. METHODS: After the initial assessment, physical therapists were asked to predict the prognosis of 200 patients with PFP who were allocated to 12 weeks of quadriceps exercises (QEs) or hip exercises (HEs) on a 1-to-10 Likert scale, and to describe their reasoning for the prediction score. OUTCOMES: measures were changes from baseline to weeks 12 and 26 on the Anterior Knee Pain Scale (range 0-100) and a transition questionnaire (TransQ). Linear mixed-effects models were used to assess the prediction. Secondly, we used a qualitative approach to summarize the physical therapists' reasoning (written notes) when predicting the outcome. RESULTS: There was no association between physical therapists' prognosis and changes in Anterior Knee Pain Scale for QE or HE at weeks 12 and 26 (slopes: -0.14 to -0.51 with wide 95% confidence intervals). There was no association between physical therapists' assessment of prognosis using TransQ for QE or HE at weeks 12 and 26 (odds ratio: 0.99 to 1.17 with wide 95% confidence intervals). CONCLUSION: Physical therapists' prognosis based on initial assessment was not associated with outcomes after 12 weeks of either quadriceps or hip exercise therapy among patients with PFP. Physical therapists' prognoses were not useful as a source of information and to identify PFP patients with poor or good projected outcomes. J Orthop Sports Phys Ther 2024;54(8):541-550. Epub 6 June 2024. doi:10.2519/jospt.2024.12258.

Trial registration: ClinicalTrials.gov NCT03069547.

Keywords: musculoskeletal; patellofemoral pain; physiotherapy; prediction; prognosis.