This study showed that collaborative pharmacist–physician geriatric MMS for older adults with polypharmacy visiting the nephrology clinic had a significant impact on improving the quality of medication use with regard to reducing polypharmacy, PIM use, CNS-active drug use, and anticholinergic burden. These results were in line with previous findings that showed a positive benefit of a collaborative care approach offering medication review by clinical pharmacists, in that the approach improved the quality of pharmacotherapy .
Because we targeted patients for providing geriatric MMS and considered all medications including OTC drugs and nutritional supplements, the high prevalence of excessive polypharmacy and inappropriate polypharmacy was as expected and similar that reported previously in patients with CKD . Approximately 85% of the patients were taking 10 or more medications and 77% of the patients were taking at least one PIM or had therapeutic duplications at baseline. However, the total number of medications and PIMs decreased significantly after geriatric MMS.
The acceptance rate of recommendations was 81.7%, which was higher than that reported in a community setting  and similar to that in a hospital setting for patients with CKD . The most frequent DRP in this study was “missing patient documentation,” which in most cases consisted of missed medication history, and could be explained by the ambulatory clinical setting, where documenting a patient’s best possible medication history was impossible due to short durations of consultations with physicians. Performing medication reconciliation (MR) in ambulatory care settings could increase the possibility of safe medication use despite its unknown clinical outcome [17, 18].
The most prevalent pharmacist intervention in this study was drug discontinuation (31.4%). In some cases, this intervention was directly communicated to the physician, whereas in others, it was communicated through patients because prescribing physicians were out of the institution and it was difficult to directly communicate with them. Unlike this study, some previous studies showed that only a small proportion of interventions by clinical pharmacists’ were related to drug discontinuation . This difference might be explained by the difference in the patient population between the studies, because we selected older patients receiving polypharmacy. In addition, because most of our patients had impaired renal function or were on dialysis, OTC drugs or dietary supplements needed to be discontinued. This type of intervention resulted in a significant reduction in the number of medications.
In this study, we evaluated the effectiveness of geriatric MMS for ambulatory older adults with CKD or at risk of CKD. While previous pharmacy practices focused on the management of CKD complications , geriatric MMS in this study focused on the use of PIMs for older adults for whom MR was performed, patient education regarding medication use including the use of OTC drugs and dietary supplements, general precautions about PIMs, duplicated medications from visiting multiple physicians, and strategies to reduce inappropriate polypharmacy.
There are many important limitations of this study, which should be addressed. First, this study had no control group to determine the clinical outcomes of geriatric MMS due to the retrospective nature of the study design. However, this study evaluated the benefit of collaborative geriatric MMS by comparing the quality of medication use among patients before and after geriatric MMS. Second, a certain degree of recall bias might have existed because we did not limit data gathering on medication use to medicines prescribed in our institution and patients may have under-reported the medications taken. Third, all our patients were treated by a specialist nephrologist; therefore, our findings may not be generalizable to community-dwelling geriatric patients. Finally, the number of patients included in this analysis was small and follow-up was not long enough to evaluate the long-term outcome of geriatric MMS.
There is a global trend to involve pharmacists in MMS because of their specific medication-related knowledge. However, pharmacist-led geriatric MMS is not a common practice in Korea or covered by health insurance. The findings of this study offer new insights into the benefits of collaborative geriatric MMS, and this study is one of the first to investigate geriatric MMS for ambulatory patients in Korea.