Paired t-tests were used to test for differences between pre-test and post-test scores. To test for differences in the background variables of participants in the RCTs and the implementation study, the t-test for means of two groups and the c2-test for nominal variables were used. A stepwise regression analysis for each programme was carried out to identify the characteristics of participants which may have predicted the effects. For the Knee programme, a combined outcome parameter was constructed from the parameters knowledge, pain (IRGL and VAS), self-efficacy and mobility (IRGL) with a range from 6 (no effect) to 12 (positive effect). For the Hip programme, a similar procedure was followed for the parameters pain and mobility. Independent variables in the analysis for the Knee programme were age, civil status,income, education and number of chronic conditions. In the Hip programme all variables were included, except for income (not measured in the RCT). An individual effect size was used to assess the changes in the outcome parameters in the Knee programme. It was also used to compare the effect sizes of the RCT of this programme. The effect size of the Hip programme and that of the RCT was not compared, because in the RCT the outcome parameters mobility and pain were not measured with the IRGL and VAS, but with the Harris Hip Score. For all analyses, a significance level of a < 0.05 was used.