Investigating the prevalence of anxiety and depression in people living with patellofemoral pain in the UK: the Dep-Pf Study.

Background and aims Patellofemoral pain (PFP) is a common knee condition causing pain around or behind the kneecap which is exacerbated by certain activities. Traditionally it has been viewed as a self-limiting condition. Recent research proves this is not the case and the evidence for poor long-term outcomes is growing. Whilst the evidence base for PFP treatment and the understanding of its aetiology is improving, it remains a complex and difficult to treat condition. In many physical conditions, it has been shown that anxiety and depression negatively affect both their management and duration. It is unclear how prevalent anxiety and depression are in PFP. This study aimed to identify the prevalence of anxiety and depression in people living with PFP in the UK. Methods In order to investigate this, a cross-sectional online survey was undertaken. Four hundred participants with self-reported symptoms of PFP were recruited through a tailored social media campaign, using modified snowball sampling. Eligibility criteria were (i) aged between 18 and 44, (ii) self-reported symptoms of PFP (using accepted criteria) (iii) resident in the UK. Exclusion criteria were previous history of patella dislocation or previous surgery to affected knee. The survey recorded demographic information, previous treatment for both PFP and anxiety and depression, the Hospital Anxiety and Depression Scale and the Anterior Knee Pain Scale. Ethical approval was gained from a University of Plymouth Ethics Committee. Results Half (49.5%; n=198) of respondents were classified as experiencing anxiety and 20.8% (n=83) as experiencing depression. The levels of anxiety and depression identified in this study are higher than those found in the general population (5.9-7.8% and 3.3-7.8%, respectively). This mirrors results which have been reported in other studies into PFP in different settings and with other musculoskeletal conditions, such as osteoarthritis and contracted shoulder. Conclusions Anxiety and depression are more common in people living with PFP than in the general population. These findings support the need for greater research into the effects of psychological factors, such as anxiety and depression, in PFP. A key area of future research will be to determine whether these psychological factors affect treatment outcomes in people living with PFP. Implications This is the first study to investigate the prevalence of anxiety and depression in people living with patellofemoral pain in the UK. This study shows that anxiety and depression are very common in people living with patellofemoral pain. The need for further work into the effects of psychological factors in patellofemoral pain is indicated.