Richard Kaplan

Changing mortality risk associated with CD4 cell response to antiretroviral therapy in South Africa.

Objective:To determine the relationship between mortality risk and the CD4 cell response to antiretroviral therapy (ART). Design:Observational community-based ART cohort in South Africa. Methods:CD4 cell counts were measured 4 monthly, and deaths were prospectively ascertained. Cumulative person-time accrued within a range of updated CD4 cell count strata (CD4 cell-strata) was calculated and used to derive CD4 cell-stratified mortality rates. Results:Patients (2423) (median baseline CD4 cell count of 105 cells/μl) were observed for up to 5 years of ART. One hundred and ninety-seven patients died during 3155 person-years of observation. In multivariate analysis, mortality rate ratios associated with 0–49, 50–99, 100–199, 200–299, 300–399, 400–499 and at least 500 cells/μl updated CD4 cell-strata were 11.6, 4.9, 2.6, 1.7, 1.5, 1.4 and 1.0, respectively. Analysis of CD4 cell count recovery permitted calculations of person-time accrued within these CD4 cell-strata. Despite rapid immune recovery, high mortality in the first year of ART was related to the large proportion of person-time accrued within CD4 cell-strata less than 200 cells/μl. Moreover, patients with baseline CD4 cell counts less than 100 cells/μl had much higher cumulative mortality estimates at 1 and 4 years (11.6 and 16.7%) compared with those of patients with baseline counts of at least 100 cells/μl (5.2 and 9.5%) largely because of greater cumulative person-time at CD4 cell counts less than 200 cells/μl. Conclusion:Updated CD4 cell counts are the variable most strongly associated with mortality risk during ART. High cumulative mortality risk is associated with person-time accrued at low CD4 cell counts. National HIV programmes in resource-limited settings should be designed to minimize the time patients spend with CD4 cell counts less than 200 cells/μl both before and during ART.

The impact of gender and income on survival and retention in a South African antiretroviral therapy programme.

Objectives  Despite the rapid expansion of antiretroviral therapy (ART) services in Africa, there are few data on whether outcomes differ for women and men and what factors may drive such variation. We investigated the association of gender and income with survival and retention in a South African ART programme.

Changes in programmatic outcomes during 7 years of scale-up at a community-based antiretroviral treatment service in South Africa.

Objectives:To assess sustainability of programmatic outcomes in a community-based antiretroviral therapy (ART) service in South Africa during 7 years of scale-up. Methods:Prospective cohort of treatment-naive patients aged ≥15 years enrolled between 2002 and 2008. Data were analyzed by calendar period of ART initiation using time-to-event analysis and logistic regression. Results:ART was initiated by 3162 patients (67% women; median age, 34 years) who were followed-up for a median of 2.4 years (interquartile range, 1.2-3.8). After 6 years, the cumulative probability of death and loss to follow-up (LTFU) was 37.4%. The probabilities of transfer-out to another ART service and of virological failure were 21.6% and 23.1%, respectively. Low mortality risk and excellent virological and immunological responses during the first year of ART were not associated with calendar period of ART initiation. In contrast, risk of LTFU and virological failure both increased between successive calendar periods in unadjusted and adjusted analyses. The number of patients per member of clinic staff increased markedly over time. Conclusions:Successful early outcomes (low mortality and good immunological and virological responses) were sustained between sequential calendar periods during 7 years of scale-up. In contrast, the increasing cumulative probabilities of LTFU or virological failure may reflect decreasing capacity to adequately support patients during long-term therapy as clinic caseload escalated.

Tuberculosis incidence rates during 8 years of follow-up of an antiretroviral treatment cohort in South Africa: comparison with rates in the community.

Background Although antiretroviral therapy (ART) is known to be associated with time-dependent reductions in tuberculosis (TB) incidence, the long-term impact of ART on incidence remains imprecisely defined due to limited duration of follow-up and incomplete CD4 cell count recovery in existing studies. We determined TB incidence in a South African ART cohort with up to 8 years of follow-up and stratified rates according to CD4 cell count recovery. We compared these rates with those of HIV-uninfected individuals living in the same community. Methodology/Principal Findings Prospectively collected clinical data on patients receiving ART in a community-based cohort in Cape Town were analysed. 1544 patients with a median follow-up of 5.0 years (IQR 2.4–5.8) were included in the analysis. 484 episodes of incident TB (73.6% culture-confirmed) were diagnosed in 424 patients during 6506 person-years (PYs) of follow-up. The TB incidence rate during the first year of ART was 12.4 (95% CI 10.8–14.4) cases/100PYs and decreased to 4.92 (95% CI 3.64–8.62) cases/100PYs between 5 and 8 years of ART. During person-time accrued within CD4 cell strata 0–100, 101–200, 201–300, 301–400, 401–500, 501–700 and ≥700 cells/µL, TB incidence rates (95% CI) were 25.5 (21.6–30.3), 11.2 (9.4–13.5), 7.9 (6.4–9.7), 5.0 (3.9–6.6), 5.1 (3.8–6.8), 4.1 (3.1–5.4) and 2.7 (1.7–4.5) cases/100PYs, respectively. Overall, 75% (95% CI 70.9–78.8) of TB episodes were recurrent cases. Updated CD4 cell count and viral load measurements were independently associated with long-term TB risk. TB rates during person-time accrued in the highest CD4 cell count stratum (>700 cells/µL) were 4.4-fold higher that the rate in HIV uninfected individuals living in the same community (2.7 versus 0.62 cases/100PYs; 95%CI 0.58–0.65). Conclusions/Significance TB rates during long-term ART remained substantially greater than rates in the local HIV uninfected populations regardless of duration of ART or attainment of CD4 cell counts exceeding 700 cells/µL.

Loss to follow-up and mortality among pregnant women referred to a community clinic for antiretroviral treatment.

In a retrospective cohort analysis, loss to follow-up and mortality rates were compared between pregnant and nonpregnant women referred to a community-based antiretroviral treatment program in South Africa. Although there was no significant difference in adjusted mortality rates between the two groups, the pregnant women had a substantially higher risk of loss to follow-up both pretreatment and on-treatment. This finding highlights the need for programmatic interventions to address retention in care for this patient population.

Treatment outcomes in HIV-infected adolescents attending a community-based antiretroviral therapy clinic in South Africa

BackgroundVery few data are available on treatment outcomes of adolescents living with HIV infection (whether perinatally acquired or sexually acquired) in sub-Saharan Africa. The present study therefore compared the treatment outcomes in adolescents with those of young adults at a public sector community-based ART programme in Cape Town, South Africa.MethodsTreatment outcomes of adolescents (9-19 years) were compared with those of young adults (20-28 years), enrolled in a prospective cohort between September 2002 and June 2009. Kaplan-Meier estimates and Cox proportional hazard models were used to assess outcomes and determine associations with age, while adjusting for potential confounders. The treatment outcomes were mortality, loss to follow-up (LTFU), immunological response, virological suppression and virological failure.Results883 patients, including 65 adolescents (47 perinatally infected and 17 sexually infected) and 818 young adults, received ART. There was no difference in median baseline CD4 cell count between adolescents and young adults (133.5 vs 116 cells/μL; p = 0.31). Overall mortality rates in adolescents and young adults were 1.2 (0.3-4.8) and 3.1 (2.4-3.9) deaths per 100 person-years, respectively. Adolescents had lower rates of virological suppression (< 400 copies/mL) at 48 weeks (27.3% vs 63.1%; p < 0.001). Despite this, however, the median change in CD4 count from baseline at 48 weeks of ART was significantly greater for adolescents than young adults (373 vs 187 cells/μL; p = 0.0001). Treatment failure rates were 8.2 (4.6-14.4) and 5.0 (4.1-6.1) per 100 person-years in the two groups. In multivariate analyses, there was no significant difference in LTFU and mortality between age groups but increased risk in virological failure [AHR 2.06 (95% CI 1.11-3.81; p = 0.002)] in adolescents.ConclusionsDespite lower virological suppression rates and higher rates of virological failure, immunological responses were nevertheless greater in adolescents than young adults whereas rates of mortality and LTFU were similar. Further studies to determine the reasons for poorer virological outcomes are needed.

Burden of New and Recurrent Tuberculosis in a Major South African City Stratified by Age and HIV-Status

Aim To describe the burden of tuberculosis (TB) in Cape Town by calculating TB incidence rates stratified by age and HIV-status, assessing the contribution of retreatment disease and estimating the cumulative lifetime TB risk in HIV-negative individuals. Methods Details of TB cases were abstracted from the 2009 electronic TB register. Population denominators were estimated from census data and actuarial estimates of HIV prevalence, allowing calculation of age-specific and HIV-stratified TB notification rates. Results The 2009 mid-year population was 3,443,010 (3,241,508 HIV-negative and 201,502 HIV-positive individuals). There were 29,478 newly notified TB cases of which 56% were laboratory confirmed. HIV status was recorded for 87% of cases and of those with known HIV-status 49% were HIV-negative and 51% were positive. Discrete peaks in the incidence of non-HIV-associated TB occurred at three ages: 511/100,000 at 0–4 years of age, 553/100,000 at 20–24 years and 628/100,000 at 45–49 years with 1.5%, 19% and 45% being due to retreatment TB, respectively. Only 15.5% of recurrent cases had a history of TB treatment failure or default. The cumulative lifetime risks in the HIV-negative population of all new TB episodes and new smear-positive TB episodes were 24% and 12%, respectively; the lifetime risk of retreatment disease was 9%. The HIV-positive notification rate was 6,567/100,000 (HIV-associated TB rate ratio = 17). Although retreatment cases comprised 30% of the HIV-associated TB burden, 88% of these patients had no history of prior treatment failure or default. Conclusions The annual burden of TB in this city is huge. TB in the HIV-negative population contributed almost half of the overall disease burden and cumulative lifetime risks were similar to those reported in the pre-chemotherapy era. Retreatment TB contributed significantly to both HIV-associated and non-HIV-associated TB but infrequently followed prior inadequate treatment. This likely reflects ongoing TB transmission to both HIV-negative and positive individuals.

Prevalent and Incident Tuberculosis Are Independent Risk Factors for Mortality among Patients Accessing Antiretroviral Therapy in South Africa.

Background Patients with prevalent or incident tuberculosis (TB) in antiretroviral treatment (ART) programmes in sub-Saharan Africa have high mortality risk. However, published data are contradictory as to whether TB is a risk factor for mortality that is independent of CD4 cell counts and other patient characteristics. Methods/Findings This observational ART cohort study was based in Cape Town, South Africa. Deaths from all causes were ascertained among patients receiving ART for up to 8 years. TB diagnoses and 4-monthly CD4 cell counts were recorded. Mortality rates were calculated and Poisson regression models were used to calculate incidence rate ratios (IRR) and identify risk factors for mortality. Of 1544 patients starting ART, 464 patients had prevalent TB at baseline and 424 developed incident TB during a median of 5.0 years follow-up. Most TB diagnoses (73.6%) were culture-confirmed. A total of 208 (13.5%) patients died during ART and mortality rates were 8.84 deaths/100 person-years during the first year of ART and decreased to 1.14 deaths/100 person-years after 5 years. In multivariate analyses adjusted for baseline and time-updated risk factors, both prevalent and incident TB were independent risk factors for mortality (IRR 1.7 [95% CI, 1.2–2.3] and 2.7 [95% CI, 1.9–3.8], respectively). Adjusted mortality risks were higher in the first 6 months of ART for those with prevalent TB at baseline (IRR 2.33; 95% CI, 1.5–3.5) and within the 6 months following diagnoses of incident TB (IRR 3.8; 95% CI, 2.6–5.7). Conclusions Prevalent TB at baseline and incident TB during ART were strongly associated with increased mortality risk. This effect was time-dependent, suggesting that TB and mortality are likely to be causally related and that TB is not simply an epiphenomenon among highly immunocompromised patients. Strategies to rapidly diagnose, treat and prevent TB prior to and during ART urgently need to be implemented.

Delays in starting antiretroviral therapy in patients with HIV-associated tuberculosis accessing non-integrated clinical services in a South African township

BackgroundDelays in the initiation of antiretroviral therapy (ART) in patients with HIV-associated tuberculosis (TB) are associated with increased mortality risk. We examined the timing of ART among patients receiving care provided by non-integrated TB and ART services in Cape Town, South Africa.MethodsIn an observational cohort study, we determined the overall time delay between starting treatment for TB and starting ART in patients treated in Gugulethu township between 2002 and 2008. For patients referred from TB clinics to the separate ART clinic, we quantified and identified risk factors associated with the two component delays between starting TB treatment, enrolment in the ART clinic and subsequent initiation of ART.ResultsAmong 893 TB patients studied (median CD4 count, 81 cells/μL), the delay between starting TB treatment and starting ART was prolonged (median, 95 days; IQR = 49-155). Delays were shorter in more recent calendar periods and among those with lower CD4 cell counts. However, the median delay was almost three-fold longer for patients referred from separate TB clinics compared to patients whose TB was diagnosed in the ART clinic (116 days versus 41 days, respectively; P < 0.001). In the most recent calendar period, the proportions of patients with CD4 cell counts < 50 cells/μL who started ART within 4 weeks of TB diagnosis were 11.1% for patients referred from TB clinics compared to 54.6% of patients with TB diagnosed in the ART service (P < 0.001).ConclusionsDelays in starting ART were prolonged, especially for patients referred from separate TB clinics. Non-integration of TB and ART services is likely to be a substantial obstacle to timely initiation of ART.

An electronic medical record-based model to predict 30-day risk of readmission and death among HIV-infected inpatients.

Background:Readmission after hospitalization is costly, time-consuming, and remains common among HIV-infected individuals. We sought to use data from the Electronic Medical Record (EMR) to create a clinical, robust, multivariable model for predicting readmission risk in hospitalized HIV-infected patients. Methods:We extracted clinical and nonclinical data from the EMR of HIV-infected patients admitted to a large urban hospital between March 2006 and November 2008. These data were used to build automated predictive models for 30-day risk of readmission and death. Results:We identified 2476 index admissions among HIV-infected inpatients who were 73% males, 57% African American, with a mean age of 43 years. One-quarter were readmitted, and 3% died within 30 days of discharge. Those with a primary diagnosis during the index admission of HIV/AIDS accounted for the largest proportion of readmissions (41%), followed by those initially admitted for other infections (10%) or for oncologic (6%), pulmonary (5%), gastrointestinal (4%), and renal (3%) causes. Factors associated with readmission risk include: AIDS defining illness, CD4 ⩽ 92, laboratory abnormalities, insurance status, homelessness, distance from the hospital, and prior emergency department visits and hospitalizations (c = 0.72; 95% confidence interval: 0.70 to 0.75). The multivariable predictors of death were CD4 < 132, abnormal liver function tests, creatinine >1.66, and hematocrit <30.8 (c = 0.79; 95% confidence interval: 0.74 to 0.84) for death. Conclusions:Readmission rates among HIV-infected patients were high. An automated model composed of factors accessible from the EMR in the first 48 hours of admission performed well in predicting the 30-day risk of readmission among HIV patients. Such a model could be used in real-time to identify HIV patients at highest risk so readmission prevention resources could be targeted most efficiently.