NPS analysis of medications for PrEP using MedicineInsight Data
Page last updated: 24 March 2022
Drug utilisation sub-committee (DUSC)
October 2021
Abstract
Purpose
DUSC requested a review of the utilisation of medicines used for the treatment of Human Immunodeficiency Virus (HIV) and for pre-exposure prophylaxis (PrEP) of HIV at its June 2021 meeting. The analyses in this report are for PrEP and are based on general practice data from MedicineInsight.
Data Source / methodology
This study is a descriptive analysis of MedicineInsight data exploring the prescribing of PrEP for HIV in general practice. It uses de-identified patient data from the clinical information systems (CIS) of 488 participating general practices and 2.2 million adult patients in the general study population. The study covered the period between 1 April 2018 to 31 March 2021.
Key Findings
- Of the 2.2 million eligible patients in the MedicineInsight program, 4,055 (0.2%) patients were prescribed PrEP at least once between 1 April 2018 and 31 March 2021.
- · 221 patients had a prescription for PrEP recorded in the first month of listing (April 2018), and by 31 March 2021, 4,055 patients had at least one prescription for PrEP recorded. An average of 110 patients per month were prescribed PrEP for the first time.
- Of the 4,055 patients prescribed PrEP at least once during the study period, the majority were male (98.2%), aged 18 to 39 years (63.4%), and resided in Victoria (47.8%) or New South Wales (39.3%), in major cities (88.4%) and in the two most socioeconomically advantaged areas (77.4%).
- Sociodemographic characteristics were similar for patients prescribed PrEP during the first 18 months since PBS listing and during the last 18 months of the study period. There was a slight increase in the proportion of younger patients (18–29), those with a concession/healthcare card and Aboriginal and Torres Strait Islander patients in the second 18 months compared with the first 18 months, however these differences were not statistically significant.
- The majority of high PrEP caseload practices (in the top 5% according to number of patients prescribed PrEP) were in major cities (95.5%) or located in NSW or Victoria (77.3%), In contrast, approximately half of low PrEP caseload practices were in major cities (57.8%) or in NSW or Victoria (50.5%).
- High PrEP caseload practices had higher numbers of people living with HIV.
- Patients prescribed PrEP at low PrEP caseload practices were younger, more likely to live in regional and more socioeconomically disadvantaged areas and more likely to have a concession/healthcare card than patients prescribed PrEP at high caseload practices.
- A total of 52,935 prescriptions (originals + repeats) for PrEP were recorded for 4055 patients. The mean average number of scripts was 9.7 per person-year. Assuming one prescription covers one month’s supply, this equates to a medication possession ratio (MPR) of 80.8%.
- The mean duration of exposure to PrEP therapy was 541 days. Among 1,242 people identified as having a gap in therapy, the mean time to first discontinuation of PrEP was 307 days.
- Among patients who received more than one original prescription for PrEP, just over half had continuous use (52.0%) and just under half had non-continuous use (48.0%).
- Non-continuous PrEP use was associated with PrEP caseload of the patient’s practice, anxiety and having a concession/healthcare card. The odds of non-continuous PrEP use was:
- 40% lower among patients at low PrEP caseload practices (adjusted OR 0.6; 95% CI: 0.5–0.7, p < 0.0001) compared to high caseload practices;
- 30% higher among patients with a recorded diagnosis of anxiety (adjusted OR 1.3; 95% CI:1.1–1.5, p=0.0002); and
- 20% lower among patients with a concession/healthcare card (adjusted OR 0.8; 95% CI:0.6–0.9, p=0.0034) than not.
- At the end of the study (31 March 2021) 48.8% of patients were on active therapy, 19.8% had discontinued therapy and 31.4% were lost to follow-up. Some of this loss to follow-up may reflect patients moving to a new clinic.
- Stopping PrEP was associated with the PrEP caseload of the practice, sex, depression and anxiety. The odds of stopping PrEP was:
- 2.4 times higher among patients at low PrEP caseload practices (adjusted OR 2.4; 95% CI: 1.7–3.4, p < 0.0001) compared to high caseload practices;
- 3.4 times higher among females (adjusted OR 3.4; 95% CI:1.5–7.8, p=0.012) than males, although the confidence interval for sex is wide;
- 50% higher among patients with a recorded diagnosis of depression (adjusted OR 1.5; 95% CI: 1.2–1.8, p < 0.0001); and
- 30% higher among patients with a recorded diagnosis of anxiety (adjusted OR 1.3; 95% CI:1.0–1.5, p=0.0158).
