Gaps in guideline adherence: evaluating HLA-B*57:01 screening for abacavir sensitivity and the implementation of evidence-based HIV care

Objective

Approximately 5–8 % of the population carries the HLA-B*57:01 allele, which increases the risk of severe hypersensitivity reactions to abacavir. Current guidelines and an FDA black box warning recommend HLA-B*57:01 screening for all patients before starting abacavir. We assessed the proportion of patients who undergo screening before initiating abacavir to evaluate adherence to guidelines.

Design

A retrospective cohort study using national IQVIA® PharMetrics Plus reimbursement data.

Methods

Data from the 2014-2022 IQVIA® PharMetrics Plus March 2023 dataset were analyzed. We identified patients aged ≥ 18 years who were newly prescribed abacavir, with ≥ 12 months of continuous enrollment before their first abacavir prescription. We examined the proportion of individuals who received HLA-B*57:01 screening any time before their initial abacavir prescription and conducted a multivariable logistic regression analysis on the receipt of HLA-B*57:01 screening adjusting for sex, age, year, and region.

Results

We identified 7,391 patients newly prescribed abacavir between 2014 and 2022. Approximately 46 % received an HLA-B*57:01 screen before initiation of abacavir. Annual screening rates ranged from 44 % to 50 % between 2015 and 2018 and dropped to 17 % by 2022. Screening was less likely to occur after 2018, compared to earlier in the study period, and more likely for younger as well as male patients.

Conclusions

These findings highlight broader challenges in HIV guideline adherence, emphasizing the need for ongoing evaluation and systematic interventions to improve implementation and patient safety.