The Clinical and Economic Impact of Attaining National HIV/AIDS Strategy Treatment Targets in the United States.

Background: The US National HIV/AIDS Strategy (NHAS) aims for 72% (90% diagnosed times 80% of those virally suppressed) viral suppression among persons with human immunodeficiency virus (HIV) by 2020. We examined the clinical and economic impact of reaching this target, in the general US population and among black men who have sex with men (MSM), the group with the highest HIV prevalence. Methods: Using a mathematical simulation, we project the 5- and 20-year clinical outcomes, costs, and incremental cost-effectiveness ratios for (1) Current Pace of detection, linkage, retention, and virologic suppression and (2) NHAS investments in expanded testing ($24-$74 per test) and adherence ($400 per person-year), calibrated to achieve 72% suppression by 2020. We examined alternative rates of testing, retention, and suppression and the efficacy and cost of adherence interventions. Results: Compared with Current Pace over 20 years, NHAS averted 280000 HIV transmissions (80000 in black MSM) and 199000 (45000) deaths and saved 2138000 (453000) years of life, while increasing costs by 23%. The incremental cost-effectiveness ratio for NHAS compared with Current Pace was $68900 per quality-adjusted life-year ($38300 for black MSM) and was most sensitive to antiretroviral therapy costs. Conclusions: Reaching NHAS targets would yield substantial clinical benefits and be cost-effective in both the general US and black MSM populations.

The Impact of Reporting a Prior Penicillin Allergy on the Treatment of Methicillin-Sensitive Staphylococcus aureus Bacteremia.

BACKGROUND: Methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia is a morbid infection with mortality benefit from receipt of parenteral ß-lactam therapy. A substantial portion of MSSA bacteremia patients report penicillin allergy, but infrequently have true allergy. OBJECTIVE: To determine the frequency and predictors of optimal and adequate therapy in patients with MSSA bacteremia. DESIGN: Retrospective cohort. PARTICIPANTS: Adult inpatients with MSSA bacteremia, January 2009 through October 2013. MAIN MEASURES: The primary measure was a trial of optimal therapy (OT), defined as ≥3 inpatient days or discharge on any first-line agents (nafcillin, oxacillin, cefazolin, or penicillin G, if susceptible). The secondary measure was completion of adequate therapy (AT), defined as ≥10 inpatient days or discharge on an agent appropriate for MSSA bacteremia. Data were electronically gathered with key variables manually validated through chart review. Log-binomial regression models were used to determine the frequency and predictors of outcomes. KEY RESULTS: Of 456 patients, 346 (76%) received a trial of OT. Patients reporting penicillin allergy (13%) were less likely to receive OT trial than those without penicillin allergy (47% vs. 80%, p <0.001). Adjusting for other factors, penicillin allergy was the largest negative predictor of OT trial (RR 0.64 [0.49, 0.83]). Infectious Disease (ID) consultation was the largest positive predictor of OT trial across all patients (RR 1.34 [1.14, 1.57]). Allergy/Immunology consultation was the single most important predictor of OT trial among patients reporting penicillin allergy (RR 2.33 [1.44, 3.77]). Of 440 patients, 391 (89%) completed AT, with ID consultation the largest positive predictor of the outcome (RR 1.28 [1.15, 1.43]). CONCLUSIONS: Nearly 25% of patients with MSSA bacteremia did not receive OT trial and about 10% did not receive AT completion. Reported penicillin allergy reduced, and ID consult increased, the likelihood of OT. Allergy evaluation, coupled with ID consultation, may improve outcomes in MSSA bacteremic patients.

Cost-effectiveness of genotype testing for primary resistance in Brazil.

OBJECTIVE: HIV genotype-resistance testing can help identify more effective antiretroviral treatment (ART) regimens for patients, substantially increasing the likelihood of viral suppression and immune recovery. We sought to evaluate the cost-effectiveness of genotype-resistance testing before first-line ART initiation in Brazil. DESIGN: We used a previously published microsimulation model of HIV disease (CEPAC-International) and data from Brazil to compare the clinical impact, costs, and cost-effectiveness of initial genotype testing (Genotype) with no initial genotype testing (No genotype). METHODS: Model parameters were derived from the HIV Clinical Cohort at the Evandro Chagas Clinical Research Institute and from published data, using Brazilian sources whenever possible. Baseline patient characteristics included 69% male, mean age of 36 years (SD, 10 years), mean CD4 count of 347 per microliter (SD, 300/µL) at ART initiation, annual ART costs from 2012 US $1400 to US $13,400, genotype test cost of US $230, and primary resistance prevalence of 4.4%. Life expectancy and costs were discounted 3% per year. Genotype was defined as "cost-effective" compared with No Genotype if its incremental cost-effectiveness ratio was less than 3 times the 2012 Brazilian per capita GDP of US $12,300. RESULTS: Compared with No genotype, Genotype increased life expectancy from 18.45 to 18.47 years and reduced lifetime cost from US $45,000 to $44,770; thus, in the base case, Genotype was cost saving. Genotype was cost-effective at primary resistance prevalence as low as 1.4% and remained cost-effective when subsequent-line ART costs decreased to 30% of baseline value. Cost-inefficient results were observed only when simultaneously holding multiple parameters to extremes of their plausible ranges. CONCLUSIONS: Genotype-resistance testing in ART-naive individuals in Brazil will improve survival and decrease costs and should be incorporated into HIV treatment guidelines in Brazil.

High frequency of hypothalamic-pituitary-adrenal axis dysfunction after local corticosteroid injection in HIV-infected patients on protease inhibitor therapy.

BACKGROUND: The frequency of hypothalamic-pituitary-adrenal axis dysfunction among HIV-infected patients receiving steroid injections has not been reported, and the risk factors for this adverse event are poorly characterized. METHODS: We conducted a retrospective analysis of data from HIV-infected patients in the Partners HealthCare system (Boston, MA) who received corticosteroid injection(s) between 2002 and 2011. Chart review focused on HIV status, antiretroviral therapy [eg, protease inhibitors (PI)], steroid injection(s), and adrenal axis dysfunction (eg, adrenal insufficiency and/or Cushing syndrome). Because all cases occurred among patients on PIs, we performed additional detailed data extraction and conducted univariate and multivariate analyses to identify risk factors in this group. RESULTS: One hundred seventy-one HIV-infected patients received ≥1 corticosteroid injection(s) in the study period. Nine cases (event frequency: 5.3%; 95% confidence interval: 2.4% to 9.8%) of secondary adrenal insufficiency were diagnosed; 5 (55%) of these 9 patients also had clinical evidence of Cushing syndrome. All cases occurred among the 81 patients on PIs (event frequency among those on PIs: 11.1%; 95% confidence interval: 5.2% to 20.0%). Among patients on PIs, the major risk factor for hypothalamic-pituitary-adrenal axis dysfunction was having ≥2 injections within 6 months. CONCLUSIONS: In this retrospective cohort study, 11% of HIV-infected patients on PIs at the time of steroid injection were later diagnosed with hypothalamic-pituitary-adrenal axis dysfunction. Corticosteroid injections in HIV-infected patients on PIs should only be used with great caution and close monitoring.

The cost-effectiveness of routine tuberculosis screening with Xpert MTB/RIF prior to initiation of antiretroviral therapy: a model-based analysis.

BACKGROUND: In settings with high tuberculosis (TB) prevalence, 15-30% of HIV-infected individuals initiating antiretroviral therapy (ART) have undiagnosed TB. Such patients are usually screened by symptoms and sputum smear, which have poor sensitivity. OBJECTIVE: To project the clinical and economic outcomes of using Xpert MTB/RIF(Xpert), a rapid TB/rifampicin-resistance diagnostic, to screen individuals initiating ART. DESIGN: We used a microsimulation model to evaluate the clinical impact and cost-effectiveness of alternative TB screening modalities - in all patients or only symptomatic patients - for hypothetical cohorts of individuals initiating ART in South Africa (mean CD4 cell count = 171 cells/µl; TB prevalence 22%). We simulated no active screening and four diagnostic strategies, smear microscopy (sensitivity 23%); smear and culture (sensitivity, 100%); one Xpert sample (sensitivity in smear-negative TB: 43%); two Xpert samples (sensitivity in smear-negative TB: 62%). Outcomes included projected life expectancy, lifetime costs (2010 US$), and incremental cost-effectiveness ratios (ICERs). Strategies with ICERs less than $7100 (South African gross domestic product per capita) were considered very cost-effective. RESULTS: Compared with no screening, life expectancy in TB-infected patients increased by 1.6 months using smear in symptomatic patients and by 6.6 months with two Xpert samples in all patients. At 22% TB prevalence, the ICER of smear for all patients was $2800 per year of life saved (YLS), and of Xpert (two samples) for all patients was $5100/YLS. Strategies involving one Xpert sample or symptom screening were less efficient. CONCLUSION: Model-based analysis suggests that screening all individuals initiating ART in South Africa with two Xpert samples is very cost-effective.

WHO 2010 guidelines for prevention of mother-to-child HIV transmission in Zimbabwe: modeling clinical outcomes in infants and mothers.

BACKGROUND: The Zimbabwean national prevention of mother-to-child HIV transmission (PMTCT) program provided primarily single-dose nevirapine (sdNVP) from 2002-2009 and is currently replacing sdNVP with more effective antiretroviral (ARV) regimens. METHODS: Published HIV and PMTCT models, with local trial and programmatic data, were used to simulate a cohort of HIV-infected, pregnant/breastfeeding women in Zimbabwe (mean age 24.0 years, mean CD4 451 cells/µL). We compared five PMTCT regimens at a fixed level of PMTCT medication uptake: 1) no antenatal ARVs (comparator); 2) sdNVP; 3) WHO 2010 guidelines using "Option A" (zidovudine during pregnancy/infant NVP during breastfeeding for women without advanced HIV disease; lifelong 3-drug antiretroviral therapy (ART) for women with advanced disease); 4) WHO "Option B" (ART during pregnancy/breastfeeding without advanced disease; lifelong ART with advanced disease); and 5) "Option B+:" lifelong ART for all pregnant/breastfeeding, HIV-infected women. Pediatric (4-6 week and 18-month infection risk, 2-year survival) and maternal (2- and 5-year survival, life expectancy from delivery) outcomes were projected. RESULTS: Eighteen-month pediatric infection risks ranged from 25.8% (no antenatal ARVs) to 10.9% (Options B/B+). Although maternal short-term outcomes (2- and 5-year survival) varied only slightly by regimen, maternal life expectancy was reduced after receipt of sdNVP (13.8 years) or Option B (13.9 years) compared to no antenatal ARVs (14.0 years), Option A (14.0 years), or Option B+ (14.5 years). CONCLUSIONS: Replacement of sdNVP with currently recommended regimens for PMTCT (WHO Options A, B, or B+) is necessary to reduce infant HIV infection risk in Zimbabwe. The planned transition to Option A may also improve both pediatric and maternal outcomes.

Should resistance testing be performed for treatment-naive HIV-infected patients? A cost-effectiveness analysis.

BACKGROUND: Data from the United States and Europe show a population prevalence of baseline drug resistance of 8%-10% among human immunodeficiency virus (HIV)-infected patients who are antiretroviral naive. Our objective was to determine the clinical impact and cost-effectiveness of genotype resistance testing for treatment-naive patients with chronic HIV infection. METHODS: We utilized a state-transition model of HIV disease to project life expectancy, costs, and cost-effectiveness in a hypothetical cohort of antiretroviral-naive patients with chronic HIV infection. On the basis of a US survey of treatment-naive patients from the Centers for Disease Control and Prevention, we used a baseline prevalence of drug resistance of 8.3%. RESULTS: A strategy of genotype-resistance testing at initial diagnosis of HIV infection increased per-person quality-adjusted life expectancy by 1.0 months, with an incremental cost-effectiveness ratio of 23,900 dollars per quality-adjusted life-year gained, compared with no genotype testing. The cost-effectiveness ratio for resistance testing remained less than 50,000 dollars per quality-adjusted life-year gained, unless the prevalence of resistance was < or =1%, a level lower than those reported in most regions of the United States and Europe. In sensitivity analyses, the cost-effectiveness remained favorable through wide variations in baseline assumptions, including variations in genotype cost, prevalence of resistance overall and to individual drug classes, and sensitivity of resistance testing. CONCLUSIONS: Genotype-resistance testing of chronically HIV-infected, antiretroviral-naive patients is likely to improve clinical outcomes and is cost-effective, compared with other HIV care in the United States. Resistance testing at the time of diagnosis should be the standard of care.

Optimal allocation of testing dollars: the example of HIV counseling, testing, and referral.

BACKGROUND: Health screening programs can be represented as a pathway of sequential processes: offering a test, obtaining consent, conducting the test, providing results, and linking to appropriate care. Using the example of HIV testing, the authors explore the optimal targeting of funds within this pathway. METHODS: The authors develop a microsimulation of HIV testing services and decompose the likelihood that an unidentified HIV-infected person will receive care into the probability of testing [P(test)] and the probability of follow-up [P(follow)] defined as returning for results and linking to care. The authors examine the clinical impact and cost-effectiveness of alternative investments in these component probabilities. RESULTS: At 1% undiagnosed HIV prevalence, cost-effectiveness ratios for HIV testing cluster around $33,000/QALY (quality-adjusted life year) gained. A program with a yield of 0.16 via P(test)=0.20 and P(follow)=0.80 has a cost-effectiveness ratio of $32,900/QALY compared with $36,300/QALY for a program where P(test)=0.80 and P(follow)=0.20. Interventions that improve the probability of success in later stages in the testing pathway [P(follow)] are more cost-effective than investments devoted to earlier stages [P(test)]. CONCLUSIONS: Equivalent pathway outcomes in a screening program do not confer equal value. Limited screening resources are best targeted toward returning for results and linkage among those already identified with disease rather than offering testing to additional people.