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Objectives The primary aim of this study was to investigate whether different labels for patellofemoral pain influence people’s perceived need for imaging. Secondary aims were to investigate i) the effect of labels on perceived need for surgery, an injection, a second opinion, relative rest and activity modification, perceived seriousness of the conditions, concern about exercise and physical activity engagement, and recovery expectations; and ii) whether being engaged in recreational sport influenced the effect of labels on outcomes.Methods We recruited participants aged 18 to 65 years old with non-traumatic knee pain who read a vignette describing a patient with knee pain and were then randomised to 1 of 4 labels describing the condition in the vignette: patellofemoral pain, anterior knee pain, runner’s knee, and chondromalacia patella. The primary outcome was perceived need for imaging. Perceived need for surgery, an injection, a second opinion, relative rest and activity modification, perceived seriousness of the conditions, concern about exercise and physical activity engagement, and recovery expectations were secondary outcomes. Participants were categorised as being engaged in recreational sport (Tegner Activity Scale, TAS ≥6) or not (TAS <6) for sub-group analyses. Multivariate linear regression models using a Bonferroni correction (p<0.017) were used for analyses of outcomes. An interaction term (label x TAS score) was included in the analyses investigating whether being engaged in recreational sport influenced the effect of labels on outcomes.Results A total of 1080 responses (99% of those randomised) were analysed. Labelling did not influence perceived need for imaging and any secondary outcomes. Labelling as anterior knee pain decreased perceived need for relative rest and activity modification (on a 0–10 scale) compared to labelling as runner’s knee (mean difference: -0.9, 98.3% CI: -1.7 to -0.2) and chondromalacia patella (mean difference: -0.9, 98.3% CI: -1.6 to -0.2) among those not engaged in recreational sport, but had no effect for those engaged in recreational sport. There was a significant label x TAS score interaction for the effect of labelling as patellofemoral pain vs. runner’s knee on perceived need for relative rest and activity modification (mean difference: -1.1, 98.3%CI: -2.2 to 0.0, p=0.015). No other analyses or interaction was statistically significant.Conclusion The labels patellofemoral pain, anterior knee pain, runner’s knee, and chondromalacia patella have similar effects on patient management preferences for PFP. Future trials could investigate the effect of other labels for PFP on patient engagement with recommended treatment and use of unnecessary healthcare for PFP.