Estimating the Prevalence of Knee Pain and the Association between Illness Perception Profiles and Self-Management Strategies in the Frederiksberg Cohort of Elderly Individuals with Knee Pain: A Cross-Sectional Study.

Knee pain is an early sign of later incident radiographic knee osteoarthritis (OA). However, the prevalence of knee pain in the general population is unknown. Additionally, it is unknown how people with knee pain choose to self-manage the condition and if the perception of the illness affects these choices. In this study, 9086 citizens between 60-69 years old in the municipality of Frederiksberg, Copenhagen, Denmark, were surveyed, of which 4292 responded. The prevalence of knee pain was estimated, and associations between illness perceptions (brief illness perception questionnaire [B-IPQ]), self-management strategies, and knee symptoms were assessed. The prevalence of knee pain was 21.4% of which 40.5% reported to use no self-management strategies (non-users). These non-users perceived their knee pain as less threatening and reported less severe symptoms than users of self-management strategies. Further, we found that a more positive illness perception was associated with less severe knee symptoms. In conclusion, among Danes aged 60-69 years, the knee pain prevalence is 21.4%, of which 40.5% use no treatment and perceive the condition as non-threatening. These non-users with knee pain represent a subpopulation being at increased risk of developing knee OA later in life, and there is a potential preventive gain in identifying these persons.

Prevalence of self-reported knee symptoms and management strategies among elderly individuals from Frederiksberg municipality: protocol for a prospective and pragmatic Danish cohort study.

INTRODUCTION: The Global Burden of Disease 2010 study ranked osteoarthritis (OA) as a leading cause of years lived with disability. With an ageing population, increasing body weight and sedentary lifestyle, a substantial increase especially in knee OA (KOA) is expected. Management strategies for KOA include non-pharmacological, pharmacological and surgical interventions. Meanwhile, over-the-counter pain medications have been discredited as they are associated with several risks with long-term usage. By consequence, the use of exercise and all sorts of complementary and alternative medicine (CAM) for joint pain has increased. The available self-management strategies are plenty, but there is no overview of their use at a population level and whether they are used along with doctors' prescriptions or replace these. The aim of this study is to estimate the population incidence of developing knee symptoms and analyse the association between (and impact of) the use of self-reported preventive measures and knee symptoms. METHODS AND ANALYSIS: This prospective cohort study pragmatically recruits individuals from the municipality of Frederiksberg, Denmark. All citizens aged 60-69 years old will be contacted annually for 10 years and asked to participate in a web-based survey. The major outcomes are self-reported knee symptoms and their association with use of various management strategies, including use of non-pharmacological treatments and CAM. Secondary outcomes include the influence of treatments on use of healthcare system and surgical procedures. Descriptive and analytic statistics (eg, logistic regression) will be used to provide summaries about the sample and observations made and the associations between self-management and development of knee symptoms. ETHICS AND DISSEMINATION: This study can be implemented without permission from the Health Research Ethics Committee. Permission has been obtained from the Danish Data Protection Agency. Study findings will be disseminated in peer-reviewed journals and presented at relevant conferences. TRIAL REGISTRATION NUMBER: NCT03472300.