Pharmacotherapy assessment in chronic kidney disease: validation of the PAIR instrument for use in Brazil.

Individuals with chronic kidney disease (CKD) use polypharmacy, which, in combination with renal impairment, exposes them to the risk of drug-related problems (DRPs). There are no available tools in Brazil to systematically assess the pharmacotherapy and management of DRPs in this population. Therefore, the objective of this work was to validate the PAIR instrument (Pharmacotherapy Assessment in Chronic Renal Disease) for use in Brazilian Portuguese. This is a retrospective longitudinal observational study. Medical records from 100 CKD patients under conservative treatment, between 2016 and 2017, in a nephrology clinic, were analyzed. PAIR was applied by pharmacists in two consultations of the same patient, with an interval of 6 months. Reliability, conceptual validity, responsiveness of the instrument and prevalence of DRPs in the studied sample were assessed. A mean of 1.26 ± 0.96 DRPs/patient was identified. Inter-rater reliability coefficients (k) ranged from 0.58 to 0.94 and from 0.79 to 1.00 for test-retest, revealing moderate to perfect level of agreement. In conceptual validity, a mean of 1.60 ± 1.24 DRPs/patient was identified by the nephrologist through clinical judgment, compared to 1.33±0.76 DRPs/patient identified by the pharmacist using PAIR (p = 0.07). Therefore PAIR allowed the identification of clinically significant DRPs. In responsiveness, a mean of 1.26 ± 0.96 DRPs/patient was identified at the first consultation and 1.11 ± 1.02 DRPs/patient at the subsequent consultation (p = 0.17) by the pharmacist using PAIR. The number of DRPs between the periods did not change. As a conclusion, the PAIR allowed the identification of clinically significant DRPs in CKD, constituting a new validated instrument to be used in Brazil.