Hand, hip and knee osteoarthritis in a Norwegian population-based study--the MUST protocol.

backgroundKnowledge about the prevalence and consequences of osteoarthritis (OA) in the Norwegian population is limited. This study has been designed to gain a greater understanding of musculoskeletal pain in the general population with a focus on clinically and radiologically confirmed OA, as well as risk factors, consequences, and management of OA. METHODS/

designThe Musculoskeletal pain in Ullensaker STudy (MUST) has been designed as an observational study comprising a population-based postal survey and a comprehensive clinical examination of a sub-sample with self-reported OA (MUST OA cohort). All inhabitants in Ullensaker municipality, Norway, aged 40 to 79 years receive the initial population-based postal survey questionnaire with questions about life style, general health, musculoskeletal pain, self-reported OA, comorbidities, health care utilisation, medication use, and functional ability. Participants who self-report OA in their hip, knee and/or hand joints are asked to attend a comprehensive clinical examination at Diakonhjemmet Hospital, Oslo, including a comprehensive medical examination, performance-based functional tests, different imaging modalities, cardiovascular assessment, blood and urine samples, and a number of patient-reported questionnaires including five OA disease specific instruments. Data will be merged with six national data registries. A subsample of those who receive the questionnaire has previously participated in postal surveys conducted in 1990, 1994, and 2004 with data on musculoskeletal pain and functional ability in addition to demographic characteristics and a number of health related factors. This subsample constitutes a population based cohort with 20 years follow-up. DISCUSSION: This protocol describes the design of an observational population-based study that will involve the collection of data from a postal survey on musculoskeletal pain, and a comprehensive clinical examination on those with self-reported hand, hip and/or knee OA. These data, in addition to data from national registries, will provide unique insights into clinically and radiologically confirmed OA with respect to risk factors, consequences, and management.