Cost-effectiveness of routine and low-cost CD4 T-cell count compared with WHO clinical staging of HIV to guide initiation of antiretroviral therapy in resource-limited settings

Does directly administered antiretroviral therapy represent good value for money in sub-Saharan Africa? A cost-utility and value of information analysis

BACKGROUND

Successful antiretroviral therapy (ART) relies on the optimal level of ART adherence to achieve reliable viral suppression, avert HIV drug resistance, and prevent avoidable deaths. It has been shown that there are various groups of people living with HIV at high-risk of non-adherence to ART in sub-Saharan Africa. The objective of this study was to examine the cost effectiveness and value-of-information of directly administered antiretroviral therapy (DAART) versus self-administered ART among people living with HIV, at high risk of non-adherence to ART in sub-Saharan Africa.

METHODS AND FINDINGS

A Markov model was developed that describes the transition between HIV stages based on the CD4 count, along with direct costs, quality of life and the mortality rate associated with DAART in comparison with self-administered ART. Data used in the model were derived from the published literature. A health system perspective was employed using a life-time time horizon. Probabilistic sensitivity analysis was performed to determine the impact of parameter uncertainty. Value of information analysis was also conducted. The expected cost of self-administered ART and DAART were $5,200 and $15,500 and the expected QALYs gained were 8.52 and 9.75 respectively, giving an incremental cost effectiveness ratio of $8,400 per QALY gained. The analysis demonstrated that the annual cost DAART needs to be priced below $200 per patient to be cost-effective. The probability that DAART was cost-effective was 1% for a willingness to pay threshold of $5,096 for sub-Saharan Africa. The value of information associated with the cost of DAART and its effectiveness was substantial.

CONCLUSIONS

From the perspective of the health care payer in sub-Saharan Africa, DAART cannot be regarded as cost-effective based on current information. The value of information analysis showed that further research will be worthwhile and potentially cost-effective in resolving the uncertainty about whether or not to adopt DAART.

Optimal starting point for antiretroviral HIV treatment in a town in Cameroon: a randomised controlled study

Background

Optimal starting point for antiretroviral treatment (ART) has been uncertain.

Methods

Parallel group, single blind, randomised controlled study of adult HIV positive patients consulting at the Protestant Hospital, Ngaoundere, Cameroon in 2007-8. Simple randomisation of patients in WHO clinical stage 1-2 to start of ART early or deferred, i.e. when CD4 counts dropped below 350 versus 250 cells/mm³, or when they reached clinical stage 3-4. Clinical follow-up every three months were offered for all patients. Main outcomes were clinical stage, CD4 differences and mortality. Of 424 consulting patients, most were excluded, mainly because they were already in WHO stage 3-4. Forty-four patients were randomised.

Results

In the ‘early’ group two patients died and five were lost to follow-up. In the ‘deferred’ group, six patients died and nine were lost to follow-up (Hazard ratio for death by early compared to deferred treatment 0.26, 95% confidence interval 0.05-1.29). Of the patients lost to follow-up, three patients in the ‘early’ group and four patients in the ‘deferred’ group were known to be alive when the study ended. Fourteen patients in the early group and 11 in the deferred group started ART. Twenty-two patients were evaluated clinically six to seven months after the study period was terminated. Except for one patient with AIDS, these were all still in clinical stage 1-2.

Conclusions

In our small sample, relative risk for death did not differ significantly, but deferred treatment seemed to carry no increased survival or other clinical advantage. During the study period, other studies made WHO change its guidelines to conform to our early treatment. The tendency in our study lends support to this policy.

Trial registration

ISRCTN22114173

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2458-14-828) contains supplementary material, which is available to authorized users.

Diagnostic accuracy of the WHO clinical staging system for defining eligibility for ART in sub-Saharan Africa: a systematic review and meta-analysis

INTRODUCTION

The World Health Organization (WHO) recommends that HIV-positive adults with CD4 count ≤500 cells/mm(3) initiate antiretroviral therapy (ART). In many countries of sub-Saharan Africa, CD4 count is not widely available or consistently used and instead the WHO clinical staging system is used to determine ART eligibility. However, concerns have been raised regarding its discriminatory ability to identify patients eligible to start ART. We therefore reviewed the accuracy of WHO stage 3 or 4 assessment in identifying ART eligibility according to CD4 count thresholds for ART initiation.

METHODS

We systematically searched PubMed and Global Health databases and conference abstracts using a comprehensive strategy for studies that compared the results of WHO clinical staging with CD4 count thresholds. Studies performed in sub-Saharan Africa and published in English between 1998 and 2013 were eligible for inclusion according to our predefined study protocol. Two authors independently extracted data and assessed methodological quality and risk of bias using the Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS-2) tool. Summary estimates of sensitivity and specificity were derived for each CD4 count threshold and hierarchical summary receiver operator characteristic curves were plotted.

RESULTS

Fifteen studies met the inclusion criteria, including 25,032 participants from 14 countries. Most studies assessed individuals attending ART clinics prior to treatment initiation. WHO clinical stage 3 or 4 disease had a sensitivity of 60% (95% CI: 45-73%, Q=914.26, p<0.001) and specificity of 73% (95% CI: 60-83%, Q=1439.43, p<0.001) for a CD4 threshold of ≤200 cells/mm(3) (11 studies); sensitivity and specificity for a threshold of CD4 count ≤350 cells/mm(3) were 45% (95% CI: 26-66%, Q=1607.31, p<0.001) and 85% (95% CI: 69-93%, Q=896.70, p<0.001), respectively (six studies). For the threshold of CD4 count ≤500 cells/mm(3) sensitivity was 14% (95% CI: 13-15%) and specificity was 95% (95% CI: 94-96%) (one study).

CONCLUSIONS

When used for individual treatment decisions, WHO clinical staging misses a high proportion of individuals who are ART eligible by CD4 count, with sensitivity falling as CD4 count criteria rises. Access to accurate, accessible, robust and affordable CD4 count testing methods will be a pressing need for as long as ART initiation decisions are based on criteria other than seropositivity.

A novel community health worker tool outperforms WHO clinical staging for assessment of antiretroviral therapy eligibility in a resource-limited setting

The accuracy of a novel community health worker antiretroviral therapy eligibility assessment tool was examined in community members in Blantyre, Malawi. Nurses independently performed World Health Organization (WHO) staging and CD4 counts. One hundred ten (55.6%) of 198 HIV-positive participants had a CD4 count of <350 cells per cubic millimeter. The community health worker tool significantly outperformed WHO clinical staging in identifying CD4 count of <350 cells per cubic millimeter in terms of sensitivity (41% vs. 19%), positive predictive value (75% vs. 68%), negative predictive values (53% vs. 47%), and area under the receiver-operator curve (0.62 vs. 0.54; P = 0.017). Reliance on WHO staging is likely to result in missed and delayed antiretroviral therapy initiation.

GP73 is a potential marker for evaluating AIDS progression and antiretroviral therapy efficacy

Golgi protein-73 (GP73) is upregulated in cancers and viral infections; however, its role in human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) remains undetermined. GP73 was evaluated as a biomarker of HIV progression and AIDS treatment efficacy. Forty-eight HIV patients (≤ 350 CD4 + T cells/μL) undergoing highly active antiretroviral therapy (HAART group) and 18 HIV patients expected to undergo HAART within 9 months (>350 CD4 + T cells/μL) (control group) were enrolled in a prospective, single center, cohort study from May 2009 to Jun 2012. Blood aspartate aminotransferase, alanine aminotransferase (ALT), cholesterol, triglycerides, and total bilirubin were assessed at baseline, 2 weeks, and 1, 3, 6, 9, and 12 months (HAART group) or 3 month intervals (control group). Serum HIV RNA level (viral load) was determined by reverse-transcriptase polymerase chain reaction (RT-PCR), and serum and peripheral blood mononuclear cell (PBMC) GP73 concentration were determined by chemiluminescent immunoassay kit and western blot, respectively. Significant positive and negative correlations in baseline serum GP73 concentration and HIV viral load (r = 0.39, P < 0.001) and CD4 + T cell count (r = -0.501, P < 0.001) were observed, respectively. In receiver operator characteristic (ROC) analysis, area under the curve (AUC) was 0.79 (95 % CI 0.66-0.92). The sensitivity and specificity of GP73 for correct identification of patients with ≤350 CD4 + T cells/μL were 76.09 and 75.0 %, respectively, with an ROC-derived cut-off of 100.6 ng/mL. For HIV patients undergoing antiretroviral therapy, GP73 may be a potential biomarker treatment efficacy useful in AIDS management.

Cost-effectiveness analysis of Option B+ for HIV prevention and treatment of mothers and children in Malawi

Background

The Ministry of Health in Malawi is implementing a pragmatic and innovative approach for the management of all HIV-infected pregnant women, termed Option B+, which consists of providing life-long antiretroviral treatment, regardless of their CD4 count or clinical stage. Our objective was to determine if Option B+ represents a cost-effective option.

Methods

A decision model simulates the disease progression of a cohort of HIV-infected pregnant women receiving prophylaxis and antiretroviral therapy, and estimates the number of paediatric infections averted and maternal life years gained over a ten-year time horizon. We assess the cost-effectiveness from the Ministry of Health perspective while taking into account the practical realities of implementing ART services in Malawi.

Results

If implemented as recommended by the World Health Organization, options A, B and B+ are equivalent in preventing new infant infections, yielding cost effectiveness ratios between US$ 37 and US$ 69 per disability adjusted life year averted in children. However, when the three options are compared to the current practice, the provision of antiretroviral therapy to all mothers (Option B+) not only prevents infant infections, but also improves the ten-year survival in mothers more than four-fold. This translates into saving more than 250,000 maternal life years, as compared to mothers receiving only Option A or B, with savings of 153,000 and 172,000 life years respectively. Option B+ also yields favourable incremental cost effectiveness ratios (ICER) of US$ 455 per life year gained over the current practice.

Conclusion

In Malawi, Option B+ represents a favorable policy option from a cost-effectiveness perspective to prevent future infant infections, save mothers' lives and reduce orphanhood. Although Option B+ would require more financial resources initially, it would save societal resources in the long-term and represents a strategic option to simplify and integrate HIV services into maternal, newborn and child health programmes.

HIV in the tropics: staging in the resource-limited setting

PURPOSE OF REVIEW

In 2010, the WHO updated HIV treatment guidelines for adults and children, expanding the eligibility of HIV-infected individuals for antiretroviral therapy (ART) on the basis of immunological staging. We discuss the barriers to HIV staging in under-resourced settings.

RECENT FINDINGS

In industrialized countries, HIV-infected patients are immunologically staged using CD4 lymphocyte counts measured using flow cytometry, but reliable and timely CD4 testing is still not readily available for all patients in many poorly resourced countries. Often CD4 testing is only available in central hospitals and clinics and depends upon availability of reagents. This leaves clinical staging as the standard of care in many places. Significant discrepancies exist between clinical and immunologic staging. Lack of immunologic staging can lead to delayed or inappropriate initiation of ART, increased attrition before ART, and overall poorer outcomes as patients often initiate ART at lower CD4 cell count baselines. This has led to intensive efforts to develop cost-effective laboratory testing, particularly for accurate low-cost CD4 testing.

SUMMARY

Simplified, low-cost alternatives for immunologic staging are vital to continued scale up of ART programs globally. Point-of-care CD4 testing in particular has shown promise in decreasing attrition rates before ART and improving overall mortality in resource-limited settings.

Validation of World Health Organisation HIV/AIDS clinical staging in predicting initiation of antiretroviral therapy and clinical predictors of low CD4 cell count in Uganda

Introduction

The WHO clinical guidelines for HIV/AIDS are widely used in resource limited settings to represent the gold standard of CD4 counts for antiviral therapy initiation. The utility of the WHO-defined stage 1 and 2 clinical factors used in WHO HIV/AIDS clinical staging in predicting low CD4 cell count has not been established in Uganda. Although the WHO staging has shown low sensitivity for predicting CD4<200cells/mm³, it has not been evaluated at for CD4 cut-offs of <250cells/mm³ or <350 cells/mm³.

Objective

To validate the World Health Organisation HIV/AIDS clinical staging in predicting initiation of antiretroviral therapy in a low-resource setting and to determine the clinical predictors of low CD4 cell count in Uganda.

Results

Data was collected on 395 participants from the Joint Clinical Research Centre, of whom 242 (61.3%) were classified as in stages 1 and 2 and 262 (68%) were females. Participants had a mean age of 36.8 years (SD 8.5). We found a significant inverse correlation between the CD4 lymphocyte count and WHO clinical stages. The sensitivity the WHO clinical staging at CD4 cell count of 250 cells/mm³ and 350cells/mm³ was 53.5% and 49.1% respectively. Angular cheilitis, papular pruritic eruptions and recurrent upper respiratory tract infections were found to be significant predictors of low CD4 cell count among participants in WHO stage 1 and 2.

Conclusion

The WHO HIV/AIDS clinical staging guidelines have a low sensitivity and about half of the participants in stages 1 and 2 would be eligible for ART initiation if they had been tested for CD4 count. Angular cheilitis and papular pruritic eruptions and recurrent upper respiratory tract infections may be used, in addition to the WHO staging, to improve sensitivity in the interim, as access to CD4 machines increases in Uganda.