Utilization Trends of Antiretroviral Therapy in Manitoba, Canada: A Population-based Study Between 2007 and 2022

Background: Antiretroviral therapy (ART) has evolved substantially over years; however, the COVID-19 pandemic has disrupted access to healthcare which might have influenced the patterns of ART use.

Objectives: To examine the trends in Antiretroviral therapy (ART) use among individuals living in Manitoba. We also aimed to investigate the immediate and lagged impact of the COVID-19 pandemic on the trend of ART use.

Methods: We conducted population-based study using the provincial Health databases including all individuals in Manitoba from January 2007 to March 2022. We examined all ART and the 4 core classes: protease inhibitors (PI), integrase inhibitors, nucleotide reverse transcriptase inhibitors (NRTIs), and non-nucleoside reverse transcriptase inhibitors (NNRTIs). In addition, we evaluated the first-line ART combination regimens including 2 NRTIs plus integrase inhibitors, 2 NRTIs plus PI, 2NRTIs plus NNRTIs, and 1 NRTIs plus integrase inhibitors. We assessed the quarterly prevalence of ART and evaluated the trends in ART using linear regression. Interrupted time series using autoregressive models were conducted to examine the immediate and lagged changes of COVID-19 pandemic in the quarterly rates of any ART and first line regimens.

Results: Among 5,749 ART users examined, the mean age was 27.9 years (SD=15.67), 49.5% were males, and 58.9% were among lower income group. The prevalence of any ART use increased more than 3-fold, from 0.04% in Q1-2007 to 0.14% in Q1-2022 (p < 0.001). Males had higher rates of ART use compared with females (0.11% vs. 0.05%) and lower-income groups had higher rates of use than higher-income groups (0.13% vs. 0.05%). Use of first-line regimens increased by an average of 8.5% (0.007% in 2007, 0.09% in 2022), with higher prevalence among males and lower-income groups. We observed a 79-fold increase in the use of 2 NRTIs plus integrase inhibitors from 0.0008% to 0.07% (p < 0.001). In contrast, the use of 2NRTIs plus NNRTIs peaked in 2014 at 0.013% then steadily declined, reaching 0.005% in 2021/2022 (p=0.002). The use of 2 NRTIs plus PI increased by 4% in 2014 followed by a decline to 0.014% in 2021/2022(p=0.03). The COVID-19 pandemic was associated with a non-significant immediate decline (β2=-0.003, p=0.48) followed by a slight increase (β3=0.0001, p=0.77) in the use of ART during the pandemic compared to pre-pandemic period. Among first-line regimen, the pandemic was associated with non-significant changes (β2=-0.03, p=0.29 and β3=-0.001, p=0.22).

Conclusions: Our findings demonstrated a marked increase in the use of ART over the 15-year study period, attributed to the use of 2 NRTIs plus integrase inhibitors and decrease in 2NRTIs plus PI and 2NRTIs plus NNRTIs. COVID-19 was not associated with significant impacts on the overall utilization trends.