Would somebody please help me with the English?
Similar mystery shoppers’ methods have been used in several studies and approved by ethics committees. For example, X had used this method in evaluating purchasing restricted medicines in New Zealand's pharmacies. Informed consent was not obtained from the pharmacists participated to the study. However, the researcher had informed them through the Pharmaceutical Society newsletter, that the studies was taking place but were not given details about the areas, pharmacies or medicines included, or the timing of the study. Mystery shoppers also have been used by other researchers in evaluating influence of the patient's race on the dentist's decision to extract or retain a decayed tooth, types of information physicians provide when prescribing antidepressants and in health service evaluation .
X had used- X used
participated to- participating in
newsletter, that- no comma
evaluating influence - the
tooth, types- tooth and the