In many countries, policies have explicitly encouraged the integration of primary care organisations and interprofessional cooperation to improve the productive and allocative efficiency of care provision and to address the unequal geographical distribution of physicians. In France, the Social Security Department of the Ministry of Health (DSS) and a not-for-profit organisation called Asalee ("Action de sante libérale en équipe" meaning Teamwork in self-employed medical practice) set up an experiment to promote vertical integration and teamwork between general practitioners and nurses, notably based on nurses' staffing and training as well as authorisation of task substitution between general practitioners and nurses and new remuneration schemes. This article evaluates the extension of this experiment over the period 2010-2016 by studying the joint effect of the cooperation between general practitioners and nurses, the specific organization of Asalee and the underlying economic incentives on general practitioners' activity based on the following: number of working days, patients seen at least once or listed and visits delivered (office and/or home). We control, as much as possible, for endogeneity and reduce selection biases by using a case-control design, using exact matching method and difference-indifferences estimation methods on panel data. We highlight a positive but relatively modest effect of entering into the Asalee pilot on the number of GPs' working days (+1.2%) and a more pronounced effect on the number of patients seen (+7.55%) or listed (+6.87%). Yet, we find no effect on the number of office and home visits.