Details of the European Project on OSteoArthritis (EPOSA)
Introduction
The European Project on OSteoArthritis (EPOSA) addresses the personal and societal burden of osteoarthritis (OA) and its determinants in the ageing European population.
The EPOSA project is a collaborative study including pre-harmonized data from six ongoing cohort studies on older community-dwelling persons aged 65 to 85 years. The cohort studies are from six European countries and include: the Activity and Function in the Elderly in Ulm study (Germany), the Longitudinal Aging Study Amsterdam (the Netherlands), the Peñagrande study (Spain), the Swedish Twin Register (Sweden) and the Hertfordshire Cohort Study (United Kingdom). In Italy, a new sample was drawn with recruitment procedures and age/sex distributions similar to those in the other studies. The EPOSA study is representative of older adults in the general population. The EPOSA project, therefore, provides the opportunity to study both persons with mild and severe OA, and those seeking care and not seeking care.
Design
Data collection took place twice with 12 to 18 months between the baseline (2010/2011) and the follow-up (2011/2012) measurement. At baseline and at follow-up, a total of 2,942 and 2,455 persons, respectively, participated in the EPOSA project. All participants were interviewed by a trained researcher at home or in a clinical center, using a standardized questionnaire and a clinical examination. In all six countries, the same measurement instruments were used and data were collected on a variety of domains (Table 1). During the interviews, data were collected on demographics, health characteristics, lifestyle characteristics, social characteristics, psychological characteristics, well-being, health care utilization and the physical environment. During the clinical exam, data were collected on anthropometry, muscle strength and physical performance. At baseline, OA was assessed in the knee, hip and the hand by using the clinical classification criteria of the American College of Rheumatology. In the UK part of the EPOSA project, radiographs of the knees and hips were obtained at baseline. At the end of the baseline interview, after six months and after the follow-up measurement, data on joint pain were collected by using pain calendars. In 2015/2016, a 5-year EPOSA follow-up measurement took place in the Netherlands. In this follow-up measurement, clinical knee and hip OA was assessed in 379 Dutch EPOSA respondents. Additional questions were asked to these respondents about pain and functional limitations.
Results
So far, the EPOSA study resulted in dozens of papers and several PhD dissertations. Among other papers, studies have been published about the association between OA and (1) physical performance, (2) frailty, (3) comorbidity, pain and functional limitations, (4) self-reported health, (5) physical activity, (6) use of neighbourhood resources, (7) weather sensitivity and pain, (8) drug utilization. Furthermore, EPOSA papers have been published about the concordance between clinical, self-reported and radiographic evaluations of OA. An overview of all EPOSA publications can be found here. Factsheets about these EPOSA publications, including the main results, can be found here.