Why medicines are used differently from prescribed: a protocol for a prospective patient-oriented observational case study to investigate reasons for non-adherence in primary care

Introduction Patients do not always tell the physician if they have used medicines differently from prescribed. The challenges that patients experience in medication self-management and adherence have been prioritised globally as among the most crucial factors influencing the effectiveness and safety of pharmacotherapies. Methods and analysis This study protocol presents a new patient-oriented method to investigate reasons for non-adherence using pharmacist-conducted medication reconciliation in a primary care clinic as data collection point. By interviewing, the pharmacist will learn how the patient has been taking the prescribed medicines and whether any non-prescription medicines and food supplements have been used for self-medication. The pharmacist will document the findings of the conversation to the electronic patient record in a structured format. The pharmacist will collect data related to the characteristics of the patients and outpatient clinics, patients’ diseases and medications, and medication discrepancies. These data will be analysed for descriptive statistics to identify (1) the number of discrepancies between the physician’s prescription orders and the patient’s self-reported use of the medicines, (2) what kind of discrepancies there are, (3) which are high-risk medicines in terms of non-adherence and (4) why medicines were taken differently from prescribed; based on the results, (5) a preliminary conceptual model of patient-reported reasons for non-adherence will be constructed. Trial registration number NCT05167578.