Examining the treatment gap between expert and semi-expert patients in obstetrics using a difference-in-differences approach

Using detailed patient-level data, we show that patients who enjoyed relevant medical training (physicians and midwives) are 3.1 percentage points less likely to receive a C-section than semi-expert patients (nurses and physiotherapists). We examined whether this treatment gap diminishes after a Dutch law reform that aimed to (1) strengthen patients’ position in health care processes and (2) increase quality of care through more openness about clinical decisions and learning from medical incidents. We hypothesize that prescriptions of the law, such as more internal debates about appropriate treatment and improved communication of clinical decisions and potential complications during consultations, are expected to make semi-expert patients more informed. Exploiting the reform in a difference-in-differences approach, in which semi-expert patients constitute the treatment group and expert patients the control group, we show that the likelihood of semi-expert patients receiving a C-section after the reform is eight percentage points lower than the changes in C-section rates among expert patients. Given that the reform especially impacted the information level of semi-experts, these findings seem to support the idea that the treatment gap is driven, at least to some extent, by agency discrimination.