Dataset Information

Treating loss-to-follow-up as a missing data problem: a case study using a longitudinal cohort of HIV-infected patients in Haiti.

ABSTRACT:

Background

HIV programs are often assessed by the proportion of patients who are alive and retained in care; however some patients are categorized as lost to follow-up (LTF) and have unknown vital status. LTF is not an outcome but a mixed category of patients who have undocumented death, transfer and disengagement from care. Estimating vital status (dead versus alive) among this category is critical for survival analyses and program evaluation.

Methods

We used three methods to estimate survival in the cohort and to ascertain factors associated with death among the first cohort of HIV positive patients to receive antiretroviral therapy in Haiti: complete case (CC) (drops missing), Inverse Probability Weights (IPW) (uses tracking data) and Multiple Imputation with Chained Equations (MICE) (imputes missing data). Logistic regression was used to calculate odds ratios and 95% confidence intervals for adjusted models for death at 10 years. The logistic regression models controlled for sex, age, severe poverty (living on <$1 USD per day), Port-au-Prince residence and baseline clinical characteristics of weight, CD4, WHO stage and tuberculosis diagnosis.

Results

Age, severe poverty, baseline weight and WHO stage were statistically significant predictors of AIDS related mortality across all models. Gender was only statistically significant in the MICE model but had at least a 10% difference in odds ratios across all models.

Conclusion

Each of these methods had different assumptions and differed in the number of observations included due to how missing values were addressed. We found MICE to be most robust in predicting survival status as it allowed us to impute missing data so that we had the maximum number of observations to perform regression analyses. MICE also provides a complementary alternative for estimating survival among patients with unassigned vital status. Additionally, the results were easier to interpret, less likely to be biased and provided an alternative to a problem that is often commented upon in the extant literature.

SUBMITTER: Jannat-Khah DP

PROVIDER: S-EPMC6245624 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature

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Publications

Treating loss-to-follow-up as a missing data problem: a case study using a longitudinal cohort of HIV-infected patients in Haiti.

Jannat-Khah Deanna P DP Unterbrink Michelle M McNairy Margaret M Pierre Samuel S Fitzgerald Dan W DW Pape Jean J Evans Arthur A

BMC public health 20181119 1

<h4>Background</h4>HIV programs are often assessed by the proportion of patients who are alive and retained in care; however some patients are categorized as lost to follow-up (LTF) and have unknown vital status. LTF is not an outcome but a mixed category of patients who have undocumented death, transfer and disengagement from care. Estimating vital status (dead versus alive) among this category is critical for survival analyses and program evaluation.<h4>Methods</h4>We used three methods to est ...[more]

PMID: 30453995

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Project description:BackgroundThe cross-sectional HIV care continuum is widely used to assess the success of HIV care programmes among populations of people with HIV and the potential for ongoing transmission. We aimed to investigate whether a longitudinal continuum, which incorporates loss to follow-up and mortality, might provide further insights about the performance of care programmes.MethodsIn this longitudinal cohort study, we included individuals who entered the UK Collaborative HIV Cohort (CHIC) study between Jan 1, 2000, and Dec 31, 2004, and were linked to the national HIV cohort database (HIV and AIDS Reporting System). For each month during a 10 year follow up period, we classified individuals into one of ten distinct categories according to engagement in care, antiretroviral therapy (ART) use, viral suppression, loss to cohort follow-up and loss to care, and mortality, and assessed the proportion of person-months of follow-up spent in each stage of the continuum. 5 year longitudinal continuums were also constructed for three separate cohorts (baseline years of entry 2000-03, 2004-07, and 2008-09) to compare changes over time.FindingsWe included 12 811 people contributing 1 537 320 person-months in our analysis. During 10 years of follow-up, individuals spent 811 057 (52·8%) of 1 537 320 person-months on ART. Of the 811 057 person-months spent on ART, individuals had a viral load of 200 copies per mL or less for 607 185 (74·9%) person-months. 10 years after cohort entry, 3612 (28·1%) of 12 811 individuals were lost to follow-up, 954 (26·4%) of whom had transferred to a non-CHIC UK clinic for care. By 10 years, 759 (5·9%) of 12 811 participants who entered the cohort had died. Loss to follow-up decreased and the proportion of person-months that individuals spent virally suppressed increased over calendar time.InterpretationLoss to follow-up in HIV care programmes was high and rates of viral suppression were lower than previously reported. Complementary information provided by a longitudinal continuum might highlight areas for intervention along the HIV care pathway, however, transfers outside the cohort must be accounted for.FundingMedical Research Council, UK.

Project description:IntroductionLong-term survival of HIV patients after initiating highly active antiretroviral therapy (ART) has not been sufficiently described in Latin America and the Caribbean, as compared to other regions. The aim of this study was to describe the incidence of mortality, loss to follow-up (LTFU) and associated risk factors for patients enrolled in the Caribbean, Central and South America Network (CCASAnet).MethodsWe assessed time from ART initiation (baseline) to death or LTFU between 2000 and 2014 among ART-naïve adults (≥18 years) from sites in seven countries included in CCASAnet: Argentina, Brazil, Chile, Haiti, Honduras, Mexico and Peru. Kaplan-Meier techniques were used to estimate the probability of mortality over time. Risk factors for death were assessed using Cox regression models stratified by site and adjusted for sex, baseline age, nadir pre-ART CD4 count, calendar year of ART initiation, clinical AIDS at baseline and type of ART regimen.ResultsA total of 16,996 ART initiators were followed for a median of 3.5 years (interquartile range (IQR): 1.6-6.2). The median age at ART initiation was 36 years (IQR: 30-44), subjects were predominantly male (63%), median CD4 count was 156 cells/µL (IQR: 60-251) and 26% of subjects had clinical AIDS prior to starting ART. Initial ART regimens were predominantly non-nucleoside reverse transcriptase inhibitor based (86%). The cumulative incidence of LTFU five years after ART initiation was 18.2% (95% confidence interval (CI) 17.5-18.8%). A total of 1582 (9.3%) subjects died; the estimated probability of death one, three and five years after ART initiation was 5.4, 8.3 and 10.3%, respectively. The estimated five-year mortality probability varied substantially across sites, from 3.5 to 14.0%. Risk factors for death were clinical AIDS at baseline (adjusted hazard ratio (HR)=1.65 (95% CI 1.47-1.87); p<0.001), lower baseline CD4 (HR=1.95 (95% CI 1.63-2.32) for 50 vs. 350 cells/µL; p<0.001) and older age (HR=1.47 (95% CI 1.29-1.69) for 50 vs. 30 years at ART initiation; p<0.001).ConclusionsIn this large, long-term study of mortality among HIV-positive adults initiating ART in Latin America and the Caribbean, overall estimates of mortality were heterogeneous, generally falling between those reported in high-income countries and sub-Saharan Africa.

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Dataset Information

Treating loss-to-follow-up as a missing data problem: a case study using a longitudinal cohort of HIV-infected patients in Haiti.

Background

Methods

Results

Conclusion

Publications

Treating loss-to-follow-up as a missing data problem: a case study using a longitudinal cohort of HIV-infected patients in Haiti.

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