Factors related with the appropriateness of pharmacological treatment in polypathological patients.

Objective: To evaluate the association between the number of pharmacological inappropriateness and possible factors related with it.

Methods: All polyphatological patients of the IMPACTO project in a tertiary hospital were included (July 2010-March 2012). The pharmacist performed the interventions based on a combined strategy that included the modified MAI and the STOPP-START criteria. A greater number of interventions indicated smaller treatment appropriateness. In the analysis of the strength of association between two continuous variables the Pearson correlation coefficient was used. Test of Student's t or Mann-Whitney comparisons of quantitative data between two groups were applied. Subsequently, a multivariate analysis was performed to study possible variables which explain the inappropriateness of the pharmacological treatment.

Results: 242 patients were included. 838 inappropriateness were detected (average per patient of 3±2). The appropriateness was associated with: number of diagnoses, medications, and categories of polypathology, Charlson Comorbidity Index, sex, and categories A1 and B2. When diagnosing collinearity in the multivariate model, we observed that there was collinearity between "Charlson Comorbidity Index" and "number of categories of polypathological patients", so it was decided to conduct two multivariate models variables, one each. The number of drugs, the number of diagnoses and the gender remained significant in both multivariate models.

Conclusions: The appropriateness of pharmacological treatment decreases with increasing number of drugs and number of diagnoses, as well as female gender. However, both multi variate models explain a low percentage of variability in the number of inappropriateness.