A Multi-State Model Examining Patterns of Transitioning Among States of Engagement in Care in HIV-Positive Individuals Initiating Combination Antiretroviral Therapy

Abstract

Background Common measures of engagement in care fail to acknowledge that infrequent follow-up may occur either intentionally among patients with sustained virologic suppression or unintentionally among patients with poor clinical outcomes. Methods Five states of HIV care were defined within the Canadian Observational Cohort (CANOC) Collaboration following combination antiretroviral therapy (cART) initiation: (1) guidelines HIV care (suppressed viral load (VL) and CD4 >200 cells/mm3, no gaps in cART >3 months, no gaps in CD4 or VL measurement >6 months), (2) successful care with decreased frequency of follow-up (as above except no gaps in CD4 or VL measurement >12 months), (3) suboptimal care (unsuppressed VL, CD4<200 cells/mm3 on 2 consecutive visits, ≥1 gap in cART >3 months, or ≥1 gap in CD4 or VL measurement >12 months), (4) loss to follow-up (no contact for 18 months), and (5) death. Multi-state models were used to determine factors associated with transitioning among states. Results 7810 participants were included. Younger age, female gender, Indigenous ethnicity and people who have injected drugs (PWID) were associated with increased likelihoods of transitioning from guidelines to suboptimal care and decreased likelihoods of transitioning from suboptimal to guidelines care. One-fifth of individuals in successful, decreased follow-up after cART initiation (mean sojourn time 0.72 years) were in suboptimal care in subsequent years. Conclusions Using routinely collected data, we have developed a flexible framework that characterizes patient transitions among states of HIV clinical care. We have demonstrated that multi-state models provide a useful approach to supplement ‘cascade of care’ work.

Trends in HIV care cascade engagement among diagnosed people living with HIV in Ontario, Canada: A retrospective, population-based cohort study

“…A recent clinical cohort study found that 10% of participants not defined as being engaged in continuous care were virally suppressed, yet these individuals would be excluded from the numerator of subsequent cascade steps [58]. Future analyses of our cascade will explore longitudinal approaches informed by non-linear cascade frameworks and measure transitions in and out of different stages [59–62]. Finally, all our analyses were descriptive and future research will explore regression analyses to identify predictors of cascade engagement (pending strategies to address missing data).…”

Beyond binary retention in HIV care

“…Recently, multi-state modeling approaches have become prominent in characterizing longitudinal patient dynamics along the phases in the HIV care cascade using cohort data [13, 15–17]. In the current analysis, we use the state transition framework developed by Lee at al.…”

Examining annual transitions in healthcare spending among U.S. medicare beneficiaries using multistate Markov models: Analysis of medicare current beneficiary survey data, 2003–2019

“…Moreover, compared to traditional mean-based regression models relying on the assumption of non-heavy tail distribution, MSM models handle the observations with extremely high cost by categorizing them into a high spending state instead of treating them as outliers, and thus provide more robust estimates. Despite MSM models being commonly used to study disease progression transitions ( Gillis et al, 2016 , Matsena Zingoni et al, 2019 , Shoko and Chikobvu, 2018 , Vasheghani Farahani et al, 2020 , Yu et al, 2012 ), our study demonstrates that this approach could be adopted by health-services researchers and policy makers for cost-containment efforts. These modifiable factors associated with spending state transitions provide potential opportunities for early intervention and may prevent the rise in spending at later stages of life.…”