The Spectrum of Clinical Pharmacy Services in a Non-University Hospital—A Comprehensive Characterization Including a Risk Assessment for Drug-Related Problems and Adverse Drug Reactions

<i>Background:</i> Clinical pharmacy services (CPS) have been shown to confer significant advantages in patient care. It remains to be clarified how CPS resources are allocated across routine care settings. It remains to be clarified which recommendations are made to resolve the drug-related problems (DRP) identified by CPS and which adverse drug reactions (ADR) actually arise from the identified DRP. <i>Methods:</i> Following positive ethical approval, patient chart analyses, evaluation of pharmacy documentation on CPS and pharmacist interviews were performed to characterize CPS at all medical departments of the Bundeswehr Hospital Hamburg. We developed and pre-tested instruments for standardization: A Standard Operating Procedure (SOP) for the practical exercise and documentation of CPS by the pharmacists performing them, a standardized form (checklist) for retrospective data collection as part of this study, and a standardized questionnaire for conducting the pharmacist interviews including a risk assessment according to the NCC-MERP score. <i>Results:</i> In total, 1000 CPS were documented in 504 patients (mean age: 69.95 years; 229 female) on 16,705 treatment days. A total of 66.87% CPS was initiated when pharmacists participated in ward rounds. In all CPS, "Indications" was the topic addressed most frequently (37.70%). "Agents for obstructive respiratory diseases" was the most frequently involved drug class (11.32%). The most frequent processing time per CPS was 16-30 min (48.61%). The number of CPS ranged from 0.36/100 treatment days in dermatology to 12.47 in oncology. Severity of 358 DRP was classified "very severe" (5.03%), "severe" (42.74%), "moderate" (34.36%), "low" (15.08%), "very low" (1.40%), or "without impact" (1.40%). The probability of DRP occurrence was classified as "high" in 13.13% and "very high" in 3.35%. In 15.36% of the DRP, an ADR actually occurred. In 504 patients, 932 specific recommendations were forwarded to solve the DRP identified during CPS. Of those, 53.97% were implemented. <i>Conclusions:</i> In almost all CPS, a considerable number of DRP with serious clinical consequences were identified. Half of the forwarded recommendations were implemented.