JMIR Publications

ABSTRACT

Background:

To monitor the use of tenofovir disoproxil fumarate/emtricitabine (Truvada; TVD) and related medicines for pre-exposure prophylaxis (PrEP) as HIV prevention using commercial pharmacy data, it is necessary to determine whether TVD monotherapy prescriptions are used for PrEP, or for some other clinical indication.

Objective:

An algorithm to classify TVD use as PrEP use was developed using data from a national electronic database on healthcare utilization, and was validated using data from electronic medical records from US providers and medical records abstracted at a large community-based health and wellness center in Washington DC.

Methods:

An algorithm was developed to identify whether TVD prescriptions were for PrEP from large-scale administrative databases. The algorithm identifies TVD monotherapy prescriptions, and then excludes patients with International Classification of Diseases (ICD)-9 diagnostic codes, medications or procedures that suggest indications other than for PrEP (e.g., documentation of HIV infection, chronic hepatitis B (CHB), or use of TVD for post-exposure prophylaxis (PEP)). For evaluation, we collected data by clinician assessment of medical records for patients with monotherapy TVD, and compared the assessed indication identified by the clinician review with the assessed indication identified by the algorithm

Results:

The PrEP algorithm demonstrated high sensitivity and moderate specificity (99.6%, 49.6%) in the electronic medical record database, and high sensitivity and specificity (99%, 87%) in data from the urban community health clinic.

Conclusions:

The PrEP algorithm correctly classified the indication for monotherapy PrEP in most subjects treated with TVD in two separate studies.