Impact of ambulatory clinical pharmacist interventions on outcomes in the HIV population

Abstract

Background: Previous studies have demonstrated the benefit of clinical pharmacist intervention in the care of patients with human immunodeficiency virus (HIV) in an ambulatory care setting. Patients who receive interprofessional care that includes a clinical pharmacist are more likely to see clinical benefit including improved adherence and reduced HIV viral load. With recent improvements in virologic testing and HIV medications, it is useful to identify which types of pharmacist interventions are significantly improving clinical outcomes in the most difficult-to-treat patients. Aims: Determine the impact of clinical pharmacy interventions and specialty pharmacy involvement in an uncontrolled HIV population. Methods: HIV patients with a detectable HIV viral load (>20 copies/mL) were retrospectively included in the study if they had at least one visit with a clinical pharmacist and at least one follow-up HIV viral load documented after the visit between January 1, 2017 and March 1, 2019. Patient charts were reviewed to obtain information regarding HIV history, relevant interventions made by the clinical pharmacist, and adherence rates. The primary outcome was the proportion of patients who achieved an undetectable viral load (<20 copies/mL) after seeing a pharmacist in clinic. Secondary outcomes included types of pharmacist interventions, and specialty pharmacy capture rate. Results: Fifty-one patients were included in the primary analysis. The median baseline viral load was 22,900 copies/mL and 68.6% of patients were able to achieve an undetectable HIV viral load after meeting with a pharmacist. The most common pharmacist intervention was compliance counseling, followed by medication change and medication initiation. In this cohort where 30% of patients were uninsured and unable to fill medications at the associated specialty pharmacy, the specialty pharmacy capture rate was 39%. Conclusions: The clinical pharmacists within the Regional Center for Infectious Disease care for a large proportion of the clinic’s difficult-to-treat HIV patients with uncontrolled viral loads. Within this population, patients whose care included clinical pharmacist interventions were able to achieve an undetectable viral load more than two-thirds of the time. Clinical pharmacists are also uniquely positioned to encourage utilization of specialty pharmacies to improve delivery and adherence. Utilization of skilled pharmacists will be vitally important in achieving new viral suppression rate targets, particularly within difficult-to-treat patient populations.