Effects of diagnostic labels on management intentions for patellofemoral pain: An online randomised experimental study

Abstract

OBJECTIVES: To investigate whether different labels for patellofemoral pain influence peoples' perceived need for imaging (primary outcome), surgery, an injection, a second opinion, and relative rest and activity modification, perceived seriousness of the conditions, concern about exercise and physical activity engagement, and recovery expectations; and whether being engaged in recreational sport influenced the effect of labels on outcomes. DESIGN: Online randomised experiment. METHODS: 1080 adults with self-reported non-traumatic anterior knee pain read a vignette describing a patient with patellofemoral pain and were randomised to one of four terms describing patellofemoral pain: patellofemoral pain, anterior knee pain, runner's knee, and chondromalacia patella. Outcomes included perceived need for imaging (primary), surgery, an injection, a second opinion, and relative rest and activity modification, perceived seriousness of the conditions, concern about exercise and physical activity engagement, and recovery expectations. Participants were categorised as being engaged in recreational sports (Tegner Activity Scale ?6) or not (Tegner Activity Scale <6) for sub-group analyses. Linear regression models were used for analyses of outcomes and interaction analyses. RESULTS: Labelling did not influence any outcomes for the total sample. Labelling as anterior knee pain decreased perceived need for relative rest and activity modification compared to labelling as runner's knee and chondromalacia patella among those not engaged in recreational sports, but had no effect for those engaged in recreational sports. No other analyses were statistically significant. CONCLUSIONS: The labels patellofemoral pain, anterior knee pain, runner's knee, and chondromalacia patella have similar effects on patient management preferences for patellofemoral pain.