Objective. The aim of the present study was to assess the effects of a community intervention aimed at general practitioners (GPs) by comparing Medicare claims data from patients with severe mental illness (SMI) of GPs exposed to the intervention and controls that were not.Methods. A comparison was made of primary care consultation and pathology data of people with SMI from intervention and control areas. Negative binomial regression models were used to compare the frequency and length of GP consultations, as well as the number and type of pathology examinations.Results. Records of 103 people from intervention area and 98 controls were obtained. Intervention and control areas were not different at baseline in terms of age and claims data, but females had higher consultation rates. After adjusting for gender, people from intervention areas had more GP consultations, especially long consultations (adjusted incidence rate ratio 1.56; 95% confidence interval 1.28-1.91). They also had more pathology screening for chronic diseases, in accordance with implemented guideline recommendations. These benefits persisted after the end of the intervention.Conclusion. These findings suggest that the ACTIVATE program aimed at training GPs to screen and better manage chronic diseases in adults with SMI had a positive effect up to 6 months after the trial, with demonstrated desired changes in medical management practices by GPs in the intervention area during that time.What is known about the topic? People with an SMI have higher mortality and poorer physical health than the general population. What does this paper add? The community intervention had a significant and sustained effect, with demonstrated desired changes in screening and medical management by GPs for adults with SMI in the intervention area. What are the implications for practitioners? GPs are ideally placed to assist in the prevention and better management of health conditions, thereby reducing avoidable illness and deaths in vulnerable populations, such as adults with SMI. HEALTH SERVICE RESEARCHOngoing professional training and dissemination of clinical guidelines are critical for raising awareness about the physical and oral health care needs of people with SMI.Additional keyword: health services research.