Drug-related problems reported by patients with rheumatic diseases: an observational study.

Background: Drug-related problems can negatively influence treatment outcome and well-being for patients with rheumatic diseases. Thus, it is important to support patients in preventing or resolving drug-related problems as quickly as possible. To effectively develop interventions for this purpose, knowledge on the frequency and character of drug-related problems is needed. Therefore, this study aims to quantify and characterize drug-related problems reported by patients with inflammatory rheumatic diseases along their treatment process.

Methods: A prospective observational study was conducted in a Dutch outpatient pharmacy. Adult patients with rheumatic diseases that were prescribed medication by a rheumatologist were questioned about experienced DRPs by telephone 4 times in 8 weeks using a structured interview-guide. Patient-reported DRPs were scored on uniqueness (i.e., if a specific DRP was reported in multiple interviews by one individual, this was counted as one unique DRP) and were categorized using a classification for patient-reported DRPs and analysed descriptively.

Results: In total, 52 participants (median age 68 years (interquartile range (IQR) 62-74), 52% male) completed 192 interviews with 45 (87%) participants completing all 4 interviews. The majority of patients (65%) were diagnosed with rheumatoid arthritis. Patients reported a median number of 3 (IQR 2-5) unique DRPs during interview 1. In subsequent interviews, patients reported median numbers of 1 (IQR 0-2), 1 (IQR 0-2) and 0 (IQR 0-1) unique DRPs for interviews 2-4 respectively. Participants reported a median number of 5 (IQR 3-9) unique DRPs over all completed interviews. Unique patient-reported DRPs were most frequently categorized into (suspected) side effects (28%), medication management (e.g., medication administering or adherence) (26%), medication concerns (e.g., concerns regarding long-term side-effects or effectiveness) (19%) and medication effectiveness (17%).

Conclusions: Patients with rheumatic diseases report various unique DRPs with intervals as short as two weeks. These patients might therefore benefit from more continuous support in-between contact moments with their healthcare provider.