Background: Clinical pharmacists are increasingly involved in detecting and solving drug-related problems. To document their performance, a convenient tool to code pharmaceutical interventions in daily practice is desirable. The Swiss Society of Public Health Administration and Hospital Pharmacists (GSASA) proposed to implement a new classification system for pharmaceutical interventions.
Objectives: To develop and validate a classification system for pharmaceutical interventions and to compare it with the well-established Pharmaceutical Care Network Europe (PCNE) system.
Setting: Rehabilitation clinic, geriatric and orthopaedic wards of a 427-bed teaching hospital.
Methods: Development of the GSASA classification started with expert panel discussions and the validation of the first version (GSASA V1). To assess appropriateness, interpretability, and validity, clinical pharmacists documented during a 6-week period all interventions using GSASA V1 and PCNE version 6.2 (V6.2). Acceptability and feasibility were tested by an 8-item questionnaire with 5-point Likert scale (1 = strongly disagree, 5 = strongly agree), and inter-rater reliability (Fleiss-Kappa coefficients κ) was determined. After revision, the second version (V2) was assessed again for reliability.
Mean outcome measures: User's agreement/satisfaction, comprehensiveness/reliability of the classification system.
Results: The GSASA V1 includes 4 categories and 35 subcategories. Of 115 interventions classified with GSASA V1, 93 (80.9 %) could be completely classified in all categories. This explains that 3 of 6 users could be not satisfied with the comprehensiveness of GSASA V1 (mean user agreement 2.7 ± 0.8). The questionnaire showed that all users could find GSASA V1 (4.0 ± 0.0) easier to use than PCNE V6.2 (3.0 ± 0.9). Users were generally satisfied with the GSASA V1 (3.5 ± 0.8), especially with the adequate time expenditure (4.0 ± 0.7). Inter-rater reliability and acceptability of GSASA V1 were comparable to those of the PCNE V6.2. The agreement among the GSASA V1 users was substantial for the categories 'problem' (κ = 0.66), 'intervention' (κ = 0.74), and 'outcome' (κ = 0.63), while moderate agreement for the category 'cause' was obtained (κ = 0.53). The final system GSASA V2 includes 5 categories (addition of 'type of problem') and 41 subcategories. Total inter-rater reliability was moderate (κ = 0.52).
Conclusion: The GSASA classification system appeared to be reliable and promising for documentation of pharmaceutical interventions in daily practice (practical and less time-consuming). The system is validated in terms of appropriateness, interpretability, validity, acceptability, feasibility, and reliability.
Keywords: Classification system; Clinical pharmacy; Drug-related problems; Pharmaceutical care; Pharmaceutical interventions; Validation.