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Point-of-care CD4 testing to inform selection of antiretroviral medications in south african antenatal clinics: a cost-effectiveness analysis.

Ciaranello AL, Myer L, Kelly K, Christensen S, Daskilewicz K, Doherty K, Bekker LG, Hou T, Wood R, Francke JA, Wools-Kaloustian K, Freedberg KA, Walensky RP - PLoS ONE (2015)

Bottom Line: Outcomes included MTCT risk at weaning (age 6 months), maternal and pediatric life expectancy (LE), maternal and pediatric lifetime healthcare costs (2013 USD), and cost-effectiveness ($/life-year saved).POC led to lower modeled MTCT risk (5.3%), greater pediatric LE (53.4 years) and lower PMTCT plus pediatric lifetime costs ($1,040/infant).Compared to laboratory, POC improved clinical outcomes and reduced healthcare costs.

View Article: PubMed Central - PubMed

Affiliation: Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America; Medical Practice Evaluation Center, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America.

ABSTRACT

Background: Many prevention of mother-to-child HIV transmission (PMTCT) programs currently prioritize antiretroviral therapy (ART) for women with advanced HIV. Point-of-care (POC) CD4 assays may expedite the selection of three-drug ART instead of zidovudine, but are costlier than traditional laboratory assays.

Methods: We used validated models of HIV infection to simulate pregnant, HIV-infected women (mean age 26 years, gestational age 26 weeks) in a general antenatal clinic in South Africa, and their infants. We examined two strategies for CD4 testing after HIV diagnosis: laboratory (test rate: 96%, result-return rate: 87%, cost: $14) and POC (test rate: 99%, result-return rate: 95%, cost: $26). We modeled South African PMTCT guidelines during the study period (WHO "Option A"): antenatal zidovudine (CD4 ≤350/μL) or ART (CD4>350/μL). Outcomes included MTCT risk at weaning (age 6 months), maternal and pediatric life expectancy (LE), maternal and pediatric lifetime healthcare costs (2013 USD), and cost-effectiveness ($/life-year saved).

Results: In the base case, laboratory led to projected MTCT risks of 5.7%, undiscounted pediatric LE of 53.2 years, and undiscounted PMTCT plus pediatric lifetime costs of $1,070/infant. POC led to lower modeled MTCT risk (5.3%), greater pediatric LE (53.4 years) and lower PMTCT plus pediatric lifetime costs ($1,040/infant). Maternal outcomes following laboratory were similar to POC (LE: 21.2 years; lifetime costs: $23,860/person). Compared to laboratory, POC improved clinical outcomes and reduced healthcare costs.

Conclusions: In antenatal clinics implementing Option A, the higher initial cost of a one-time POC CD4 assay will be offset by cost-savings from prevention of pediatric HIV infection.

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Related in: MedlinePlus

Univariate sensitivity analyses: Pediatric life expectancy.Undiscounted pediatric life expectancies for laboratory and POC testing are shown (maternal life expectancies do not differ substantially by testing strategy, and so are excluded from the figure). POC “test and result return” is defined as the product of (proportion of HIV-identified women undergoing CD4 testing) * (proportion of CD4-tested women receiving CD4 results). For POC sensitivity and POC “test and result return,” life expectancies are shown at the threshold values at which POC testing no longer results in a higher life expectancy compared to laboratory testing. For POC specificity, life expectancy increases as specificity decreases, so no such threshold exists; results are shown at 50%, 80%, and 100%, as examples. The horizontal dotted line shows the undiscounted pediatric life expectancy under the base case laboratory conditions. Left panel: base case; middle panel: low laboratory access scenario; right panel: sensitivity analyses on POC parameters. Abbreviations: POC: point-of-care testing.
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pone.0117751.g002: Univariate sensitivity analyses: Pediatric life expectancy.Undiscounted pediatric life expectancies for laboratory and POC testing are shown (maternal life expectancies do not differ substantially by testing strategy, and so are excluded from the figure). POC “test and result return” is defined as the product of (proportion of HIV-identified women undergoing CD4 testing) * (proportion of CD4-tested women receiving CD4 results). For POC sensitivity and POC “test and result return,” life expectancies are shown at the threshold values at which POC testing no longer results in a higher life expectancy compared to laboratory testing. For POC specificity, life expectancy increases as specificity decreases, so no such threshold exists; results are shown at 50%, 80%, and 100%, as examples. The horizontal dotted line shows the undiscounted pediatric life expectancy under the base case laboratory conditions. Left panel: base case; middle panel: low laboratory access scenario; right panel: sensitivity analyses on POC parameters. Abbreviations: POC: point-of-care testing.

Mentions: Holding test specificity at the base-case value of 86%, POC CD4 testing remained cost-saving (greater life expectancy and lower costs) compared to laboratory unless POC test sensitivity was ≤89%. POC resulted in a higher combined life expectancy compared to laboratory unless POC test sensitivity was ≤84% (Fig. 2: right panel). Holding test sensitivity at the base-case value of 93%, POC life expectancy increased compared to the base-case as the specificity of the POC assay decreased (i.e., more women with high CD4 were “incorrectly” assigned to ART than to AZT), and POC life expectancy never fell below laboratory life expectancy even at POC specificity of 100%. POC remained cost-saving (greater life expectancy and lower costs) compared to laboratory at all POC assay specificities.


Point-of-care CD4 testing to inform selection of antiretroviral medications in south african antenatal clinics: a cost-effectiveness analysis.

Ciaranello AL, Myer L, Kelly K, Christensen S, Daskilewicz K, Doherty K, Bekker LG, Hou T, Wood R, Francke JA, Wools-Kaloustian K, Freedberg KA, Walensky RP - PLoS ONE (2015)

Univariate sensitivity analyses: Pediatric life expectancy.Undiscounted pediatric life expectancies for laboratory and POC testing are shown (maternal life expectancies do not differ substantially by testing strategy, and so are excluded from the figure). POC “test and result return” is defined as the product of (proportion of HIV-identified women undergoing CD4 testing) * (proportion of CD4-tested women receiving CD4 results). For POC sensitivity and POC “test and result return,” life expectancies are shown at the threshold values at which POC testing no longer results in a higher life expectancy compared to laboratory testing. For POC specificity, life expectancy increases as specificity decreases, so no such threshold exists; results are shown at 50%, 80%, and 100%, as examples. The horizontal dotted line shows the undiscounted pediatric life expectancy under the base case laboratory conditions. Left panel: base case; middle panel: low laboratory access scenario; right panel: sensitivity analyses on POC parameters. Abbreviations: POC: point-of-care testing.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4355621&req=5

pone.0117751.g002: Univariate sensitivity analyses: Pediatric life expectancy.Undiscounted pediatric life expectancies for laboratory and POC testing are shown (maternal life expectancies do not differ substantially by testing strategy, and so are excluded from the figure). POC “test and result return” is defined as the product of (proportion of HIV-identified women undergoing CD4 testing) * (proportion of CD4-tested women receiving CD4 results). For POC sensitivity and POC “test and result return,” life expectancies are shown at the threshold values at which POC testing no longer results in a higher life expectancy compared to laboratory testing. For POC specificity, life expectancy increases as specificity decreases, so no such threshold exists; results are shown at 50%, 80%, and 100%, as examples. The horizontal dotted line shows the undiscounted pediatric life expectancy under the base case laboratory conditions. Left panel: base case; middle panel: low laboratory access scenario; right panel: sensitivity analyses on POC parameters. Abbreviations: POC: point-of-care testing.
Mentions: Holding test specificity at the base-case value of 86%, POC CD4 testing remained cost-saving (greater life expectancy and lower costs) compared to laboratory unless POC test sensitivity was ≤89%. POC resulted in a higher combined life expectancy compared to laboratory unless POC test sensitivity was ≤84% (Fig. 2: right panel). Holding test sensitivity at the base-case value of 93%, POC life expectancy increased compared to the base-case as the specificity of the POC assay decreased (i.e., more women with high CD4 were “incorrectly” assigned to ART than to AZT), and POC life expectancy never fell below laboratory life expectancy even at POC specificity of 100%. POC remained cost-saving (greater life expectancy and lower costs) compared to laboratory at all POC assay specificities.

Bottom Line: Outcomes included MTCT risk at weaning (age 6 months), maternal and pediatric life expectancy (LE), maternal and pediatric lifetime healthcare costs (2013 USD), and cost-effectiveness ($/life-year saved).POC led to lower modeled MTCT risk (5.3%), greater pediatric LE (53.4 years) and lower PMTCT plus pediatric lifetime costs ($1,040/infant).Compared to laboratory, POC improved clinical outcomes and reduced healthcare costs.

View Article: PubMed Central - PubMed

Affiliation: Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America; Medical Practice Evaluation Center, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America.

ABSTRACT

Background: Many prevention of mother-to-child HIV transmission (PMTCT) programs currently prioritize antiretroviral therapy (ART) for women with advanced HIV. Point-of-care (POC) CD4 assays may expedite the selection of three-drug ART instead of zidovudine, but are costlier than traditional laboratory assays.

Methods: We used validated models of HIV infection to simulate pregnant, HIV-infected women (mean age 26 years, gestational age 26 weeks) in a general antenatal clinic in South Africa, and their infants. We examined two strategies for CD4 testing after HIV diagnosis: laboratory (test rate: 96%, result-return rate: 87%, cost: $14) and POC (test rate: 99%, result-return rate: 95%, cost: $26). We modeled South African PMTCT guidelines during the study period (WHO "Option A"): antenatal zidovudine (CD4 ≤350/μL) or ART (CD4>350/μL). Outcomes included MTCT risk at weaning (age 6 months), maternal and pediatric life expectancy (LE), maternal and pediatric lifetime healthcare costs (2013 USD), and cost-effectiveness ($/life-year saved).

Results: In the base case, laboratory led to projected MTCT risks of 5.7%, undiscounted pediatric LE of 53.2 years, and undiscounted PMTCT plus pediatric lifetime costs of $1,070/infant. POC led to lower modeled MTCT risk (5.3%), greater pediatric LE (53.4 years) and lower PMTCT plus pediatric lifetime costs ($1,040/infant). Maternal outcomes following laboratory were similar to POC (LE: 21.2 years; lifetime costs: $23,860/person). Compared to laboratory, POC improved clinical outcomes and reduced healthcare costs.

Conclusions: In antenatal clinics implementing Option A, the higher initial cost of a one-time POC CD4 assay will be offset by cost-savings from prevention of pediatric HIV infection.

Show MeSH
Related in: MedlinePlus