 - Clinical signs and symptoms corresponding to hip andor knee OA OR radiologically diagnosed OA OR Registered in the medical journal with the ICPC codes L89 osteoarthritis of the hip, L90 osteoarthritis of knee, L91 osteoarthritis not classified elsewhere, L13 hip symptomscomplaints, L15 knee symptomscomplaints andor L20 joint symptomscomplaints not classified elsewhere. 