Cognitive impairment predicts medication discrepancies in Huntington's Disease: patient self-report compared to pharmacy records.

BACKGROUND

Proper medication reconciliation (= comparing the accuracy of patient-reported medication use with pharmacy records) could prevent potentially dangerous situations such as drug-drug interactions and hospitalization. This is particularly important when patients rely on multiple medications, such as in neurodegenerative disorders like Huntington's Disease (HD). Currently, it is unknown how often medication discrepancies occur in HD patients and which factors contribute to the discrepancies.

OBJECTIVE

Identify prognostic factors of medication discrepancies in HD, using patient-reported medication use and local pharmacy records.

METHODS

With 134 pre- and manifest HD patients, we performed a multivariable logistic regression analysis with medication discrepancy as dependent variable (pharmacy records as reference value) and sex, CAP score, disease status (pre- or manifest HD), number of concomitant medications taken, presence of an informal caregiver, Unified Huntington's Disease Rating Scale-Total Functioning Capacity, unified cognitive Z-score and Problem Behaviors Assessment-short characteristic scores for depression, anxiety, and apathy as independent variables.

RESULTS

Medication discrepancies were reported frequently, both in premanifest (43.2%) and manifest HD subjects (36.7%). Impaired cognition significantly predicted medication discrepancies (beta = -0.688, SE 0.27, p = 0.011). All other variables were non-significant.

CONCLUSIONS

Regardless of HD disease status and stage, patient self-reported medication use is not a reliable source, especially in those with impaired cognitive function. The presence of an informal caregiver and the absence of polypharmacy, depression, anxiety and apathy do not influence self-reported medication accuracy. Objective verification of medication use with HD patients' local pharmacy is recommended.

TRIAL REGISTRATION NUMBER: ICTRP-NL-OMON55123, HD-med, registered 26-Nov-2019.