Drug-related problems and pharmacotherapeutic advisory intervention at a medicine clinic

Objective To describe the scenario and frequency of drug-related problems (DRPs) in in-patients and to determine whether a pharmacotherapeutic advisory intervention aiming at reducing DRPs could affect rates of re-hospitalisation and/or death within 6 months. Methods This prospective, randomised, controlled advisory intervention study was carried out at the Clinic of Internal Medicine at Stockholm Soder Hospital. Three hundred patients from four wards took part in the study. Patients taking two drugs or more were included. In the intervention arm, potential drug interactions were found using a computer system. Medical symptoms were estimated by a nurse together with the patient. Creatinine clearance was calculated. Thereafter a clinical pharmacologist scrutinised the patient's medical record for DRPs together with the nurse. DRPs judged to be clinically relevant resulted in written advice to the physician in charge of the patient. The control group received usual care. Results In the intervention group, a total of 299 DRPs were found among 71% of the patients (106/150). The number of written letters of advice to the physicians in charge was 106. Of these, 63% were accepted. After 6 months, the proportion of re-hospitalisations or death in the intervention group was 49% (73/150) compared to 46% (69/150) in the control group. The difference was not significant. Conclusions DRPs were common. Potential drug interactions and adverse drug reactions dominated. Hospital-based medication review by a clinical pharmacologist was not associated with reduced rates of re-hospitalisation and/or death. The clinical relevancy of DRPs might be overestimated as a risk for re-hospitalisation or death. It is of great importance to clarify if and how drug-related problems can be prevented. In designing such studies, one should consider choosing inclusion criteria that accumulate risk.