The aim of this study is to improve the referral rates to physiotherapy of patients with knee osteoarthritis. The intervention consists of one academic detailing visit directed to general practitioners (GPs)

In Belgium, referral rates to physiotherapy of patients with knee osteoarthritis are low. A surveys shows that only 11% of the patients with knee osteoarthritis are referred for physiotherapy in an early stage of the disease process. Referral to physiotherapy is common after arthroplasty for revalidation, but not in early stage of the disease process. The aim of this study is to increase the referral rate for physiotherapy in an early stage of the disease process.

One to three times a year, a large part of Belgian GPs receive an academic detailing visit by an independent medical visitors of Farmaka. Farmaka is a non-profit organization, which is sponsored by the government. Each year, three medical and medication-related themes are developed to provide evidence-based and independent information for primary care management. A visit takes about 20 minutes.

The medical visitors of Farmaka will spend 5 minutes of their standard visit to inform GPs about the evidence-based conservative management of knee osteoarthritis with physiotherapy. The information will focus on the referral of patients with knee osteoarthritis to a physiotherapist in an early stage of the disease. To optimize the effect of the referral to physiotherapists, GPs are asked to specify their prescription by adding a clear therapy description 'exercise therapy with aerobic, muscle strengthening and functional exercises'.

This information will be summarized on a flyer. This flyer will be distributed to the GPs at the end of the academic detailing visit. The flyer gives more extended information about the approach and treatment of knee osteoarthritis. The information and flyer will only be distributed to the intervention group.

For the sample size calculation we want to optimize the referral rate to physiotherapists with 15%.

To detect an absolute difference of 15% in referral rate to physiotherapists we need 100 patients in each group ( with significance level of 5%, 1 on 1 allocation and power of 80%). The control group is composed of GPs, visited by Farmaka, who will not receive the additional information on knee osteoarthritis management.

After 6 months the GPs of the intervention and control group will receive two case vignettes on the management of knee osteoarthritis.

The number of referrals to a physiotherapist of the intervention group and the control group will be compared, as well as the number of specified well-directed prescriptions.

Inclusion Criteria:

• active GP setting
• visited by independent medical visitors for academic detailing

Exclusion Criteria:

• not willing to participate
• not visited by independent medical visitors for academic detailing