Medical Research: What is the background for this study? What are the main findings?
Response: The main findings from our study are that patients with a low number of prescribed drugs benefited more from a comprehensive clinical pharmacist intervention than patients with a higher number of drugs. There was no difference in effect between the patients with higher and lower levels of inappropriate prescribing, as measured by two validated tools for inappropriate prescribing.
Clinical pharmacist interventions have in several studies shown positive effects on inappropriate prescribing and clinical outcomes. Since the concomitant use of a large number of drugs is associated with an increased risk of adverse drug events, it is often assumed that patients receiving a larger number of drugs would benefit most from interventions aiming to improve the quality of drug use. However, differences in the effects of clinical pharmacist intervention between different subgroups of patients have rarely been analyzed.
We have, in a randomized controlled trial, previously demonstrated that a clinical pharmacist intervention at an acute internal medicine hospital ward reduces emergency department visits by 47%, revisits to hospital by 16%, and drug-related readmissions by 80% for patients aged 80 years or older. We aimed to investigate whether there was any difference in treatment effect of the clinical pharmacist interventions on number of subsequent revisits to the emergency department between the patients with less than five drugs and those with five or more drugs on admission to hospital. We also explored whether the effect of the intervention was consistent for patients with a high or low level of inappropriate prescribing.
Medical Research: What should clinicians and patients take away from your report?
Response: Drug-related issues occur in patients irrespective of low or high numbers of prescribed drugs. Accordingly, patients receiving fewer drugs on admission to hospital should not be automatically dismissed when prioritizing who should be targeted for efforts to improve the quality of drug treatment. Further, the results of this study do not support prioritization of patients with inappropriate prescribing (as measured with tools for inappropriate prescribing) for comprehensive pharmacist intervention.
One plausible explanation for the results is that the subgroup of patients who received a lower number of drugs lived in their own homes (alone or with a partner) to a higher degree than the patients receiving more drugs. Patients living in their own homes were most likely more engaged in their drug therapy, and thus more accepting of the parts of the pharmacist intervention that aimed to improve the patient knowledge and compliance to drug therapy, than patients living in nursing homes. Arguably, these patients were also better able to communicate any drug therapy issues, which would improve the quality of the pharmacist intervention. A greater involvement of primary care nurses and/or caretakers would presumably have made the intervention more effective for the patients with more medications and a higher co-morbidity burden.
Medical Research: What recommendations do you have for future research as a result of this study?
Response: Research studies focusing on the improvement of quality and safety of drug use should not exclude patients prescribed a low number of drugs.
Further research is needed to test the hypothesis generated by this study in another group of patients.