Does switching from multiple to single-tablet regimen containing the same antiretroviral drugs improve adherence? A group-based trajectory modeling analysis

ABSTRACT

Combination Antiretroviral Therapy (cART) in single-tablet regimens (STR) is a simplification strategy that can potentially improve medication adherence and clinical outcomes. We conducted a retrospective cohort study of 1206 patients using efavirenz, tenofovir and lamivudine in multiple-tablet regimen who switched to the STR containing the same active ingredients in a southeast metropolis in Brazil. We measured adherence using the proportion of days covered (PDC≥95%) and evaluated this outcome before and after the switch using paired non-parametric statistics. Additionally, we used group-based trajectory modeling to identify adherence patterns to cART for each period and evaluate the migration behavior of patients between the trajectory groups. We observed a 14% increase in the proportion of adherent patients after switching to STR and a 6.2% increase in the proportion of patients with CD4 count>500 cells/μl (p < 0.001), without changes in viral load outcomes. We identified four adherence trajectories in each period. Most patients (60%, n = 722) migrated towards a group with better adherence trajectory or remained in the trajectory group with the highest probability of adherence after the switch. Our findings suggest that the implementation of the STR had a positive impact on adherence and CD4 count. This may potentially improve virologic outcomes later on treatment.

KEYWORDS:

• HIV infections
• antiretroviral therapy
• medication adherence
• cohort studies

Acknowledgements

All authors have contributed significantly to this study and are aware of and agree with this submission. Santos SF, Almeida-Brasil CC and Costa JO participated in study design, analysis and interpretation of data, and were responsible for drafting the paper. Cruz M was responsible for data management (data access and cleaning) and provided support in drafting the paper. Reis EA participated in analysis and interpretation of data, and critically reviewed the paper. Silveira MR contributed to study conception and design, acquisition of data, and critically reviewed the paper. Ceccato MGB contributed to study conception and design, acquisition of data, data interpretation, and critically reviewed the paper. All authors read and approved the final version of the paper.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was funded by the Fundação de Amparo à Pesquisa de Minas Gerais (Fapemig) (CDS-APQ-03938-16). Almeida-Brasil CC and Costa JO received a national Doctoral Scholarship from the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Finance Code 001.