Adherence to Antiretroviral Regimens in Australia: A Nationwide Cohort Study

Juliana De Oliveira Costa*, Andrea L. Schaffer, Nicholas A. Medland, Melisa Litchfield, Sujita W. Narayan, Rebecca Guy, Hamish McManus, Sallie Anne Pearson

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


The lifetime use of combination antiretroviral therapy (cART) highlights the need to understand patterns of and factors associated with adherence to cART. In this cohort study using a 10% random sample of dispensing claims data for eligible Australians, we identified 2042 people dispensed cART between January 2016 and December 2017 (mean age 48.0 ± 12.0 years old, 88.6% male, and 85.9% treatment experienced). We considered people to be adherent if the proportion of treatment coverage days was ≥80% in the 360 days after their first observed cART dispensing. We also used group-based trajectory modeling (GBTM) to examine different patterns of adherence for 360 days from first observed cART dispensing. Most commonly, people receiving cART were treated with two nucleoside/nucleotide reverse transcriptase inhibitors with an integrase strand transfer inhibitors (INSTI - 46.6%). Overall, 1708 people [83.6% (95% confidential interval 82.0-85.3%)] remained adherent over 360 days. GBTM identified three distinct adherence patterns: nearly always adherent [67.8% (63.7-71.9%) of the cohort], moderate adherence [26.6% (23.0-30.1%)], and low adherence [5.6% (4.1-7.2%)]. People were more likely to belong to the "nearly always adherent" trajectory if they were older (per additional year of age), treated with an INSTI regimen, and on treatment for more than 6 months. Our study demonstrates that the 360-day adherence to cART is generally high, but approximately one-third maintain a moderate or low adherence pattern. The use of INSTI regimens and additional support of treatment adherence, especially among younger people and those initiating therapy, may further improve adherence.

Original languageEnglish
Pages (from-to)81-91
Number of pages11
JournalAIDS Patient Care and STDs
Issue number2
Publication statusPublished - Feb 2020
Externally publishedYes

Bibliographical note

Funding Information:
This research is supported by the National Health and Medical Research Council (NHMRC) Centre of Research Excellence in Medicines and Ageing (ID: 1060407) and a Cooperative Research Centre Project (CRC-P) Grant from the Australian Government Department of Industry, Innovation and Science (ID: CRC-P-439). JOC received a PhD visiting student scholarship from the CAPES Foundation (Process 88881.188410/2018-01) and an Endeavor Research Fellowship from the Australia Awards-Endeavour Scholarships and Fellowships. A.L.S. is supported by an NHMRC Early Career Fellowship (ID: 1158763).

Publisher Copyright:
© Copyright 2020, Mary Ann Liebert, Inc., publishers 2020.


  • antiretroviral therapy
  • highly active
  • HIV
  • medication adherence


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