AbstractObjectiveFirst‐line treatment for patients with knee osteoarthritis should ideally prescribe patient education, exercise, and if needed, weight loss. In practice, however, adjunctive treatments, including painkillers and referrals to specialists, are typically introduced before these measures. This study evaluated interventions to sustainably improve general practitioner delivered care for patients with knee osteoarthritis.DesignComparison of impacts of knee osteoarthritis care during four half‐year periods: before, 6, 12, and 18 months after primary intervention based on electronic medical records (EMR) and patient questionnaires.SettingDanish general practitioners (GPs) treating 6240 patients.ParticipantsFour GPs, two GP trainees, and six staff members.InterventionsSix pre‐planned primary interventions: patient leaflet, GP and staff educational session, knee osteoarthritis consultation, two functional tests monitoring patient function, EMR phrase aiding consultation, and waiting room advertisement and three supportive follow‐up interventions.Main outcome measuresUsage of first‐line and adjunctive treatment elements, the functional tests, and the EMR phrase.ResultsApproximately 50 knee osteoarthritis cases participated in each of the four half‐year periods. Primary interventions had only transient effects lasting <12 months on the knee osteoarthritis care. Functional tests and EMR phrases were used predominantly during the first 6 months, where a transient drop in the referral rate to orthopedics was observed. Use of educational elements was moderate and without significant change during follow‐up.ConclusionMore routine use of the primary or inclusion of novel increased‐adherence interventions is needed to sustainably improve care for knee osteoarthritis patients in Danish general practice.