title: The Knee Clinical Assessment Study--CAS(K). A prospective study of knee pain and knee osteoarthritis in the general population.
abstract: BACKGROUND
  Knee pain affects an estimated 25% of the adult population aged 50 years and over. Osteoarthritis is the most common diagnosis made in older adults consulting with knee pain in primary care. However, the relationship between this diagnosis and both the current disease-based definition of osteoarthritis and the regional pain syndrome of knee pain and disability is unclear. Expert consensus, based on current evidence, views the disease and the syndrome as distinct entities but the clinical usefulness of these two approaches to classifying knee pain in older adults has not been established. We plan to conduct a prospective, population-based, observational cohort study to investigate the relative merits of disease-based and regional pain syndrome-based approaches to classification and prognosis of knee pain in older adults.
  
  
  METHODS
  All patients aged 50 years and over registered with three general practices in North Staffordshire will be invited to take part in a two-stage postal survey. Respondents to this survey phase who indicate that they have experienced knee pain within the previous 12 months will be invited to attend a research clinic for a detailed assessment. This will consist of clinical interview, physical examination, digital photography, plain x-rays, anthropometric measurement and a brief self-complete questionnaire. All consenting clinic attenders will be followed up by (i) general practice medical record review, (ii) repeat postal questionnaire at 18-months.
authors.affiliation: Primary Care Sciences Research Centre, Keele University, Keele, North Staffordshire, United Kingdom ST5 5BG. g.m.peat@cphc.keele.ac.uk
authors.forename: George
authors.initials: G
authors.lastname: Peat
authors.forename: Elaine
authors.initials: E
authors.lastname: Thomas
authors.forename: June
authors.initials: J
authors.lastname: Handy
authors.forename: Laurence
authors.initials: L
authors.lastname: Wood
authors.forename: Krysia
authors.initials: K
authors.lastname: Dziedzic
authors.forename: Helen
authors.initials: H
authors.lastname: Myers
authors.forename: Ross
authors.initials: R
authors.lastname: Wilkie
authors.forename: Rachel
authors.initials: R
authors.lastname: Duncan
authors.forename: Elaine
authors.initials: E
authors.lastname: Hay
authors.forename: Jonathan
authors.initials: J
authors.lastname: Hill
authors.forename: Peter
authors.initials: P
authors.lastname: Croft
mesh_terms: D000368:Aged; D003625:Data Collection; D006801:Humans; D007717:Knee; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications / Q000175:diagnosis*; D010146:Pain / Q000145:classification* / Q000209:etiology; D011446:Prospective Studies