BackgroundThe Dutch Health and Youth Care Inspectorate has organized a study investigating whether there are benefits to using claim data in the risk-based supervision of general practitioner (GP) practices. MethodsWe identified and selected signals of risks based on interviews with experts. Next, we selected 3 indicators that could be measured in the claim database. These were: the expected and actual costs of the GP practice; the percentage of reserve antibiotics prescribed; and the percentage of patients undergoing an emergency admission during the weekend. We corrected the scores of the GP practices based on their casemix and identified practices with the most unfavorable scores, ‘red flags,’ in 2015, or the trend between 2013-2015. Finally, we analysed the data of GP practices already identified as delivering substandard care by the Health and Youth Care Inspectorate and calculated the sensitivity and specificity of using the indicators to identify poor performing GP practices. ResultsBy combining the 3 indicators, we identified 1 GP practice with 3 red flags and 24 GP practices with 2 red flags. The a priori chance of identifying a GP practice that shows substandard care is 0.3%. Using the indicators, this improved to 1.0%. The sensitivity was 26.7%, the specificity was 92.8%. ConclusionThe Dutch Health and Youth Care Inspectorate might use claim data to calculate indicators on costs, the prescribing of reserve antibiotics and emergency admissions during the weekend, when setting priorities for its visits to GP practices. Visiting more GP practices by the Health and Youth Care Inspectorate, and identifying substandard care, is necessary to validate the use of these indicators.