Previous estimates of potential cost savings from the de-implementation of low-value care have been calculated using simple modeling approaches that focus on direct medical costs and do not account for substitution. Therefore, this study aimed to develop and evaluate a modeling approach to calculate a more realistic estimate of the societal costs and benefits of de-implanting low-value care. The modelling approach was developed and evaluated in three steps: (1) reviewing studies to identify aspects that may affect the costs and benefits of de-implementation, (2) selecting three low-value care cases, (3) developing and evaluating the modelling approach for each case. Desk research and interviews with stakeholders were conducted in step 3 to define the input parameters. The modelling approach was built and evaluated for the following cases: (1) surgery for achilles tendon rupture, (2) mammography for women < 30 years with focal breast complaints, and (3) imaging for non-specific low back pain. From the interviews, it appeared that case 2 had already been fully disinvested. Hence, calculating the societal costs and benefits for this case was not considered valuable. For cases 1 and 3, it was deemed valid and feasible to calculate the societal costs and benefits. Compared to the adapted societal business case approach used in Case 1, the adapted societal cost-benefit analysis approach used in Case 3 provided a more realistic and accurate estimate of the benefits. It is feasible to calculate a more elaborate and realistic estimate of the societal costs and benefits of de-implanting low-value care than previous estimates. However, it was not possible to include the expenses of de-implementation itself as these are highly reliant on the specific de-implementation strategy employed, which is context-specific. Furthermore, the time required to calculate a more elaborate and realistic estimate underscores the need to carefully select low-value care cases for which the value of calculating such an estimate outweighs the effort involved.
