Evaluation of a combined lifestyle intervention for overweight and obese patients in primary health care: a quasi-experimental design

Background. Combined lifestyle interventions (CLIs) are designed to reduce risk factors for lifestyle-related diseases through increasing physical activity and improvement of dietary behaviour. Objective. To evaluate the effects of a CLI for overweight and obese patients on lifestyle-related risk factors and health care consumption, in comparison to usual care. Methods. Data on anthropometric and metabolic measurements, morbidity, drugs prescriptions and general practitioner (GP) consultations were extracted from electronic health records (timeframe: July 2009-August 2013). Using a quasi-experimental design, health outcomes of 127 patients who participated in a 1-year CLI were compared to a group of 254 matched patients that received usual care. Baseline to post-intervention changes in health outcomes between intervention and comparison group were evaluated using mixed model analyses. Results. Compared to baseline, both groups showed reductions in body mass index (BMI), blood pressure, total cholesterol and low density lipoprotein cholesterol in year post-intervention. For these outcome measures, no significant differences in changes were observed between intervention and comparison group. A significant improvement of 0.08 mmol/l in high density lipoprotein (HDL) cholesterol was observed for the intervention group above the comparison group (P <0.01). No significant intergroup differences were shown in drugs prescriptions and number of GP consultations. Conclusion. A CLI for overweight and obese patients in primary health care resulted in similar effects on health outcomes compared to usual care. Only an improvement on HDL cholesterol was shown. This study indicates that implementation and evaluation of a lifestyle intervention in primary health care is challenging due to political and financial barriers.