Upregulation of CD26 expression in epithelial cells and stromal cells during wound-induced skin tumour formation.

We have previously described InvEE transgenic mice in which non-dividing, differentiating epidermal cells express oncogenically activated MAPK kinase 1 (MEK1). Skin wounding triggers tumour formation in InvEE mice via a mechanism that involves epidermal release of IL-1α and attraction of a pro-tumorigenic inflammatory infiltrate. To look for potential effects on the underlying connective tissue, we screened InvEE and wild-type epidermis for differential expression of cytokines and immune modulators. We identified a single protein, CD26 (dipeptidyl peptidase-4). CD26 serum levels were not increased in InvEE mice. In contrast, CD26 was upregulated in keratinocytes expressing mutant MEK1 and in the epithelial compartment of InvEE tumours, where it accumulated at cell-cell borders. CD26 expression was increased in dermal fibroblasts following skin wounding but was downregulated in tumour stroma. CD26 activity was stimulated by calcium-induced intercellular adhesion in keratinocytes, suggesting that the upregulation of CD26 in InvEE epidermis is due to expansion of the differentiated cell layers. IL-1α treatment of dermal fibroblasts stimulated CD26 activity, and therefore epidermal IL-1α release may contribute to the upregulation of CD26 expression in wounded dermis. Pharmacological blockade of CD26, via Sitagliptin, reduced growth of InvEE tumours, while combined inhibition of IL-1α and CD26 delayed tumour onset and reduced tumour incidence. Our results demonstrate that inappropriate activation of MEK1 in the epidermis leads to changes in dermal fibroblasts that, like the skin inflammatory infiltrate, contribute to tumour formation.

Quantifying the risks and benefits of efavirenz use in HIV-infected women of childbearing age in the USA.

OBJECTIVES: The aim of the study was to quantify the benefits (life expectancy gains) and risks (efavirenz-related teratogenicity) associated with using efavirenz in HIV-infected women of childbearing age in the USA. METHODS: We used data from the Women's Interagency HIV Study in an HIV disease simulation model to estimate life expectancy in women who receive an efavirenz-based initial antiretroviral regimen compared with those who delay efavirenz use and receive a boosted protease inhibitor-based initial regimen. To estimate excess risk of teratogenic events with and without efavirenz exposure per 100,000 women, we incorporated literature-based rates of pregnancy, live births, and teratogenic events into a decision analytic model. We assumed a teratogenicity risk of 2.90 events/100 live births in women exposed to efavirenz during pregnancy and 2.68/100 live births in unexposed women. RESULTS: Survival for HIV-infected women who received an efavirenz-based initial antiretroviral therapy (ART) regimen was 0.89 years greater than for women receiving non-efavirenz-based initial therapy (28.91 vs. 28.02 years). The rate of teratogenic events was 77.26/100,000 exposed women, compared with 72.46/100,000 unexposed women. Survival estimates were sensitive to variations in treatment efficacy and AIDS-related mortality. Estimates of excess teratogenic events were most sensitive to pregnancy rates and number of teratogenic events/100 live births in efavirenz-exposed women. CONCLUSIONS: Use of non-efavirenz-based initial ART in HIV-infected women of childbearing age may reduce life expectancy gains from antiretroviral treatment, but may also prevent teratogenic events. Decision-making regarding efavirenz use presents a trade-off between these two risks; this study can inform discussions between patients and health care providers.

Cost-effectiveness analysis of alternative first-trimester pregnancy termination strategies in Mexico City.

OBJECTIVE: To assess the comparative health and economic outcomes associated with three alternative first-trimester abortion techniques in Mexico City and to examine the policy implications of increasing access to safe abortion modalities within a restrictive setting. DESIGN: Cost-effectiveness analysis. SETTING: Mexico City. POPULATION: Reproductive-aged women with unintended pregnancy seeking first-trimester abortion. METHODS: Synthesising the best available data, a computer-based model simulates induced abortion and its potential complications and is used to assess the cost-effectiveness of alternative safe modalities for first-trimester pregnancy termination: (1) hospital-based dilatation and curettage (D&C), (2) hospital-based manual vacuum aspiration (MVA), (3) clinic-based MVA and (4) medical abortion using vaginal misoprostol. MAIN OUTCOME MEASURES: Number of complications, lifetime costs, life expectancy, quality-adjusted life expectancy. RESULTS: In comparison to the magnitude of health gains associated with all safe abortion modalities, the relative differences between strategies were more pronounced in terms of their economic costs. Assuming all options were equally available, clinic-based MVA was the least costly and most effective. Medical abortion with misoprostol provided comparable benefits to D&C, but cost substantially less. Enhanced access to safe abortion was always more influential than shifting between safe abortion modalities. CONCLUSIONS: This study demonstrates that the provision of safe abortion is cost-effective and will result in reduced complications, decreased mortality and substantial cost savings compared with unsafe abortion. In Mexico City, shifting from a practice of hospital-based D&C to clinic-based MVA and enhancing access to medical abortion will have the best chance to minimise abortion-related morbidity and mortality.

Health and economic impact of HPV 16 and 18 vaccination and cervical cancer screening in India.

Cervical cancer is a leading cause of cancer death among women in low-income countries, with approximately 25% of cases worldwide occurring in India. We estimated the potential health and economic impact of different cervical cancer prevention strategies. After empirically calibrating a cervical cancer model to country-specific epidemiologic data, we projected cancer incidence, life expectancy, and lifetime costs (I$2005), and calculated incremental cost-effectiveness ratios (I$/YLS) for the following strategies: pre-adolescent vaccination of girls before age 12, screening of women over age 30, and combined vaccination and screening. Screening differed by test (cytology, visual inspection, HPV DNA testing), number of clinical visits (1, 2 or 3), frequency (1 x , 2 x , 3 x per lifetime), and age range (35-45). Vaccine efficacy, coverage, and costs were varied in sensitivity analyses. Assuming 70% coverage, mean reduction in lifetime cancer risk was 44% (range, 28-57%) with HPV 16,18 vaccination alone, and 21-33% with screening three times per lifetime. Combining vaccination and screening three times per lifetime provided a mean reduction of 56% (vaccination plus 3-visit conventional cytology) to 63% (vaccination plus 2-visit HPV DNA testing). At a cost per vaccinated girl of I$10 (per dose cost of $2), pre-adolescent vaccination followed by screening three times per lifetime using either VIA or HPV DNA testing, would be considered cost-effective using the country's per capita gross domestic product (I$3452) as a threshold. In India, if high coverage of pre-adolescent girls with a low-cost HPV vaccine that provides long-term protection is achievable, vaccination followed by screening three times per lifetime is expected to reduce cancer deaths by half, and be cost-effective.

The value of including boys in an HPV vaccination programme: a cost-effectiveness analysis in a low-resource setting.

We assessed the cost-effectiveness of including boys vs girls alone in a pre-adolescent vaccination programme against human papillomavirus (HPV) types 16 and 18 in Brazil. Using demographic, epidemiological, and cancer data from Brazil, we developed a dynamic transmission model of HPV infection between males and females. Model-projected reductions in HPV incidence under different vaccination scenarios were applied to a stochastic model of cervical carcinogenesis to project lifetime costs and benefits. We assumed vaccination prevented HPV-16 and -18 infections in individuals not previously infected, and protection was lifelong. Coverage was varied from 0-90% in both genders, and cost per-vaccinated individual was varied from IUSD 25 to 400. At 90% coverage, vaccinating girls alone reduced cancer risk by 63%; including boys at this coverage level provided only 4% further cancer reduction. At a cost per-vaccinated individual of USD 50, vaccinating girls alone was

The long-term benefits of genotypic resistance testing in patients with extensive prior antiretroviral therapy: a model-based approach.

OBJECTIVES: Resistance testing in HIV disease may provide long-term benefits that are not evident from short-term data. Our objectives were to estimate the long-term effectiveness, cost and cost-effectiveness of genotype testing in patients with extensive antiretroviral exposure. METHODS: We used an HIV simulation model to estimate the long-term effectiveness and cost-effectiveness of genotype testing. Clinical data incorporated into the model were from NARVAL, a randomized trial of resistance testing in patients with extensive antiretroviral exposure, and other randomized trials. Each simulated patient was eligible for up to three sequential regimens of antiretroviral therapy (i.e. two additional regimens beyond the trial-based regimen) using drugs not available at the time of the study, such as lopinavir/ritonavir, darunavir/ritonavir and enfuvirtide. RESULTS: In the long term, projected undiscounted life expectancy increased from 132.2 months with clinical judgement alone to 147.9 months with genotype testing. Median survival was estimated at 11.9 years in the resistance testing arm vs 10.4 years in the clinical judgement alone arm. Because of increased survival, the projected lifetime discounted cost of genotype testing was greater than for clinical judgement alone (euro313,900 vs euro263,100; US$399,000 vs US$334,400). Genotype testing cost euro69,600 (US$88,500) per quality-adjusted life year gained compared with clinical judgement alone. CONCLUSIONS: In patients with extensive prior antiretroviral exposure, genotype testing is likely to increase life expectancy in the long term as a result of the increased likelihood of receiving two active new drugs. Genotype testing is associated with cost-effectiveness comparable to that of strategies accepted in patients with advanced HIV disease, such as enfuvirtide use.

Impact of opportunistic diseases on chronic mortality in HIV-infected adults in Côte d'Ivoire.

OBJECTIVE: To estimate incidence rates of opportunistic diseases (ODs) and mortality for patients with and without a history of OD among HIV-infected patients in Côte d'Ivoire. METHODS: Using incidence density analysis, we estimated rates of ODs and chronic mortality by CD4 count in patients in a cotrimoxazole prophylaxis trial in Abidjan before the highly active antiretroviral therapy (HAART) era. Chronic mortality was defined as death without a history of OD or death more than 30 days after an OD diagnosis. We used Poisson's regression to examine the effect of OD history on chronic mortality after adjusting for age, gender, and current CD4 count. RESULTS: Two hundred and seventy patients (40% male, mean age 33 years, median baseline CD4 count 261 cells/microl) were followed up for a median of 9.5 months. Bacterial infections and tuberculosis were the most common severe ODs. Of 47 patients who died, 9 (19%) died within 30 days of an OD, 26 (55%) died more than 30 days after an OD, and 12 (26%) died with no OD history. The chronic mortality rate was 31.0/100 person-years for those with an OD history, and 11.1/100 person-years for those with no OD history (rate ratio (RR) 2.81, 95% confidence interval (CI): 1.43 - 5.54). Multivariate analysis revealed that OD history remained an independent predictor of mortality (RR 2.15, 95% CI: 1.07 - 4.33) after adjusting for CD4 count, age and gender. CONCLUSIONS: Before the HAART era, a history of OD was associated with increased chronic HIV mortality in Côte d'Ivoire, even after adjusting for CD4 count. These results provide further evidence supporting OD prophylaxis in HIV-infected patients.

Estimating the costs and benefits of screening monogamous, heterosexual couples for unrecognised infection with herpes simplex virus type 2.

OBJECTIVES: Herpes simplex virus type 2 (HSV-2) is the most common cause of ulcerative genital disease in the United States, but infection is commonly unrecognised. Serological screening tests could identify discordantly infected couples and permit targeted interventions to limit HSV-2 transmission. Our objective was to evaluate the projected cost effectiveness of strategies to prevent HSV-2 transmission in couples with no history of HSV-2 infection. METHODS: We created a mathematical model to simulate the natural history and costs of HSV-2 transmission, and the expected impact of HSV-2 prevention strategies in monogamous, heterosexual couples. Strategies evaluated included (i) no screening; (ii) universal condom use; and (iii) serological screening for HSV-2 with condom use targeted to discordant couples. Screening tests considered included western blot (WB), ELISA, and ELISA with confirmation of positive test results using WB (ELISA-->WB). RESULTS: Compared to no screening, the use of ELISA-->WB prevented 38 future infections per 1000 couples, with a cost effectiveness ratio of $8200 per infection averted. The use of WB in all couples had an incremental cost effectiveness ratio of $63 600 per infection averted. Strategies of ELISA alone and universal condom use were not cost effective. The cost effectiveness of ELISA-->WB improved with increasing prevalence of HSV-2, but worsened with decreasing condom compliance. Screening with ELISA alone was a reasonable strategy only when ELISA specificity increased to 99%. CONCLUSIONS: Serological screening for unrecognised HSV-2 infection in monogamous, heterosexual couples is expected to decrease the incidence of HSV-2 infection, but increase healthcare costs. For couples choosing to be screened, a two step testing strategy (ELISA-->WB) is recommended. Recommendations for a national policy to conduct serological screening will depend on the value placed on averting an incident HSV-2 infection.

Prevention of human immunodeficiency virus-related opportunistic infections in France: a cost-effectiveness analysis.

A simulation model of human immunodeficiency virus (HIV) disease, which incorporated French data on the progression of HIV disease in the absence of antiretroviral therapy and on cost, was used to determine the clinical impact and cost-effectiveness of different strategies for the prevention of opportunistic infections in French patients who receive highly active antiretroviral therapy (HAART). Compared with use of no prophylaxis, use of trimethoprim-sulfamethoxazole (TMP-SMZ) increased per-person lifetime costs from euro 185,600 to euro 187,900 and quality-adjusted life expectancy from 112.2 to 113.7 months, for an incremental cost-effectiveness ratio of euro 18,700 per quality-adjusted life-year (euro/QALY) gained. Compared with use of TMP-SMZ alone, use of TMP-SMZ plus azithromycin cost euro 23,900/QALY gained; adding fluconazole cost an additional euro 54,500/QALY gained. All strategies that included oral ganciclovir had cost-effectiveness ratios that exceeded euro 100,000/QALY gained. In the era of HAART, on the basis of French data, prophylaxis against Pneumocystis carinii pneumonia, toxoplasmic encephalitis, and Mycobacterium avium complex bacteremia is cost-effective. Prophylaxis against fungal and cytomegalovirus infections is less cost-effective than are other therapeutic options for HIV disease and should remain of lower priority.

Clinical consequences and cost of limiting use of vancomycin for perioperative prophylaxis: example of coronary artery bypass surgery.

Routine us of vancomycin for perioperative prophylaxis is discouraged, principally to minimize microbial resistance to it. However, outcomes and costs of this recommendation have not been assessed. We used decision-analytic models to compare clinical results and cost-effectiveness of no prophylaxis, cefazolin, and vancomycin, in coronary artery bypass graft surgery. In the base case, vancomycin resulted in 7% fewer surgical site infections and 1% lower all-cause mortality and saved $117 per procedure, compared with cefazolin. Cefazolin, in turn, resulted in substantially fewer infections and deaths and lower costs than no prophylaxis. We conclude that perioperative antibiotic prophylaxis with vancomycin is usually more effective and less expensive than cefazolin. Data on vancomycin's impact on resistance are needed to quantify the trade-off between individual patients' improved clinical outcomes and lower costs and the future long-term consequences to society.

Incidence of primary opportunistic infections in two human immunodeficiency virus-infected French clinical cohorts.

BACKGROUND: Clinical guidelines for the prevention of opportunistic infections in human immunodeficiency virus (HIV)-infected individuals have been developed on the basis of natural history data collected in the USA. The objective of this study was to estimate the incidence of primary opportunistic infections in HIV-infected individuals in geographically distinct cohorts in France. METHODS: We conducted our study on 2664 HIV-infected patients from the Tourcoing AIDS Reference Centre and the hospital-based information system of the Groupe d'Epidémiologie Clinique du SIDA en Aquitaine enrolled from January 1987 to September 1995 and followed through December 1995. We estimated: (1) CD4-adjusted incidence rates of seven primary opportunistic infections in the absence of prophylaxis for that specific infection or any antiretroviral drugs other than zidovudine; and (2) CD4 lymphocyte count decline. RESULTS: The highest incidence rates for all opportunistic infections studied occurred in patients with CD4 counts < 200/microl. With CD4 counts < 50/microl, the most common opportunistic infections were toxoplasmic encephalitis (12.6 per 100 person-years) and Pneumocystis carinii pneumonia (11.4 per 100 person-years). Mycobacterium tuberculosis was the least common opportunistic infection (< 5.0/100 person-years). Even with CD4 counts > 300/microl, cases of Pneumocystis carinii pneumonia and toxoplasmic encephalitis were reported. The mean CD4 lymphocyte decline per month was 4.6 cells/microl. There was a significant association between HIV risk behaviour and the incidence of cytomegalovirus infection, between calendar year and the incidence of Pneumocystis carinii pneumonia, toxoplasmic encephalitis and Candida esophagitis, and between geographical area and the incidence of Pneumocystis carinii pneumonia and cytomegalovirus infection. CONCLUSIONS: Geographical differences exist in the incidence of HIV-related opportunistic infections. These results can be used to define local priorities for prophylaxis of opportunistic infections.

Cost-effectiveness of earlier initiation of antiretroviral therapy for uninsured HIV-infected adults.

OBJECTIVES: This study was designed to examine the societal cost-effectiveness and the impact on government payers of earlier initiation of antiretroviral therapy for uninsured HIV-infected adults. METHODS: A state-transition simulation model of HIV disease was used. Data were derived from the Multicenter AIDS Cohort Study, published randomized trials, and medical care cost estimates for all government payers and for Massachusetts, NewYork, and Florida. RESULTS: Quality-adjusted life expectancy increased from 7.64 years with therapy initiated at 200 CD4 cells/microL to 8.21 years with therapy initiated at 500 CD4 cells/microL. Initiating therapy at 500 CD4/microL was a more efficient use of resources than initiating therapy at 200 CD4/microL and had an incremental cost-effectiveness ratio of $17,300 per quality-adjusted life-year gained, compared with no therapy. Costs to state payers in the first 5 years ranged from $5,500 to $24,900 because of differences among the states in the availability of federal funds forAIDS drug assistance programs. CONCLUSIONS: Antiretroviral therapy initiated at 500 CD4 cells/microL is cost-effective from a societal: perspective compared with therapy initiated later. States should consider Medicaid waivers to expand access to early therapy.

Cost effectiveness of human papillomavirus testing to augment cervical cancer screening in women infected with the human immunodeficiency virus.

PURPOSE: To determine the cost effectiveness of incorporating molecular testing for high-risk types of human papillomavirus into a cervical cancer screening program for women infected with the human immunodeficiency virus (HIV). SUBJECTS AND METHODS: We developed a Markov model to simulate the natural history of cervical cancer precursor lesions in HIV-infected women. Probabilities of progression and regression of cervical lesions were conditional on transient or persistent infection with human papillomavirus, as well as stage of HIV and effectiveness of antiretroviral therapy. Incorporating data from prospective cohort studies, national databases, and published literature, the model was used to calculate quality-adjusted life expectancy, life expectancy, lifetime costs, and incremental cost-effectiveness ratios for two main strategies: targeted screening-human papillomavirus testing is added to the initial two cervical cytology smears obtained after an HIV diagnosis and subsequent screening intervals are modified based on the test results; and universal screening-no testing for human papillomavirus is performed, and a single cytology screening interval is applied to all women. RESULTS: In HIV-infected women on anti-retroviral therapy, a targeted screening strategy in which cervical cytology screening was conducted every 6 months for women with detected human papillomavirus DNA, and annually for all others, cost $10,000 to $14,000 per quality-adjusted life year gained compared with no screening. A universal screening strategy consisting of annual cervical cytology for all women was 15% less effective and had a less attractive cost-effectiveness ratio. Targeted screening remained economically attractive in multiple sensitivity analyses, although when the overall incidence of cervical cancer precursor lesions was lowered by 75%, the screening interval for women with detected human papillomavirus DNA could be widened to 1 year. CONCLUSIONS: Adding human papillomavirus testing to the two cervical cytology smears obtained in the year after an HIV diagnosis, and modifying subsequent cytology screening intervals based on the results, appears to be an effective and cost-effective modification to current recommendations for annual cytology screening in HIV-infected women.

Predictors of hazardous child seating behavior in fatal motor vehicle crashes: 1990 to 1998.

OBJECTIVE: Motor vehicle crashes are the leading cause of death in children ages 5 to 14. Children seated in the front seats of vehicles are at increased risk of death and injury in crashes, particularly in vehicles with passenger-side air bags. This study identifies factors associated with the seating of children in the front seats of vehicles involved in fatal crashes between 1990 and 1998. METHODS: Using 1990 to 1998 data from the Fatal Analysis Reporting System, a US census of motor vehicle crashes involving a fatality, multivariable logistic regression was used to model the association between child seating behavior and vehicle, driver, and occupant characteristics. RESULTS: The proportion of vehicles carrying children in the front declined from 42% to 31% over the 9-year period. Controlling for driver and vehicle characteristics, the risk of front-seating declined between 1990 and 1998, and this risk was smaller in vehicles carrying only younger children (

Policy analysis of cervical cancer screening strategies in low-resource settings: clinical benefits and cost-effectiveness.

CONTEXT: Cervical cancer is a leading cause of cancer-related death among women in developing countries. In such low-resource settings, cytology-based screening is difficult to implement, and less complex strategies may offer additional options. OBJECTIVE: To assess the cost-effectiveness of several cervical cancer screening strategies using population-specific data. DESIGN AND SETTING: Cost-effectiveness analysis using a mathematical model and a hypothetical cohort of previously unscreened 30-year-old black South African women. Screening tests included direct visual inspection (DVI) of the cervix, cytologic methods, and testing for high-risk types of human papillomavirus (HPV) DNA. Strategies differed by number of clinical visits, screening frequency, and response to a positive test result. Data sources included a South African screening study, national surveys and fee schedules, and published literature. MAIN OUTCOME MEASURES: Years of life saved (YLS), lifetime costs in US dollars, and incremental cost-effectiveness ratios (cost per YLS). RESULTS: When analyzing all strategies performed as a single lifetime screen at age 35 years compared with no screening, HPV testing followed by treatment of screen-positive women at a second visit, cost $39/YLS (27% cancer incidence reduction); DVI, coupled with immediate treatment of screen-positive women at the first visit was next most effective (26% cancer incidence reduction) and was cost saving; cytology, followed by treatment of screen-positive women at a second visit was least effective (19% cancer incidence reduction) at a cost of $81/YLS. For any given screening frequency, when strategies were compared incrementally, HPV DNA testing generally was more effective but also more costly than DVI, and always was more effective and less costly than cytology. When comparing all strategies simultaneously across screening frequencies, DVI was the nondominated strategy up to a frequency of every 3 years (incremental cost-effectiveness ratio, $460/YLS), and HPV testing every 3 years (incremental cost-effectiveness ratio, $11 500/YLS) was the most effective strategy. CONCLUSION: Cervical cancer screening strategies that incorporate DVI or HPV DNA testing and eliminate colposcopy may offer attractive alternatives to cytology-based screening programs in low-resource settings.

Time costs associated with cervical cancer screening.

OBJECTIVES: Time costs borne by women when undergoing cervical cancer screening have rarely been elucidated, although such costs may pose substantial barriers to care. The purpose of this project was to quantify the opportunity costs associated with cervical cancer screening in young women attending Planned Parenthood Clinics. METHODS: We conducted a self-report survey of 105 women from six clinics to measure travel, waiting, and exam times associated with cervical cancer screening. Respondents recorded their time of arrival and departure, length of time in the waiting room, age, income level, and hours per week they worked outside of the home. Time costs were valued three ways: through self-reported hourly wage, age- and gender-adjusted minimum earnings, and national age- and gender-adjusted hourly wages. RESULTS: Respondents were on average 24 years old, worked 29 hours per week outside the home, and earned less than $20,000 per year. Mean time for one-way travel was 18.7 minutes; waiting room time was 16.9 minutes; and exam time was 50.8 minutes. Time costs were estimated to be $14.08 per visit based upon the self-reported hourly wage; $16.46 per visit based upon age- and gender-adjusted minimum earnings; and $19.63 per visit based upon age- and gender-adjusted national wage rates. CONCLUSIONS: Time costs associated with cervical cancer screening represent an important opportunity cost and should be considered in studies attempting to identify barriers to screening adherence. Our results indicate that time costs accounted for up to 25% of cervical cancer screening costs. Time costs should be identified, measured, valued, and included in cost-effectiveness analyses of cervical cancer screening.

Use of genotypic resistance testing to guide hiv therapy: clinical impact and cost-effectiveness.

BACKGROUND: Genotypic sequencing for drug-resistant strains of HIV can guide the choice of antiretroviral therapy. OBJECTIVE: To assess the cost-effectiveness of genotypic resistance testing for patients acquiring drug resistance through failed treatment (secondary resistance) and those infected with resistant virus (primary resistance). DESIGN: Cost-effectiveness analysis with an HIV simulation model incorporating CD4 cell count and HIV RNA level as predictors of disease progression. DATA SOURCES: Published randomized trials and data from the Multicenter AIDS Cohort Study, the national AIDS Cost and Services Utilization Survey, the Red Book, and an institutional cost-accounting system. TARGET POPULATION: HIV-infected patients in the United States with baseline CD4 counts of 0.250 x 10(9) cells/L. TIME HORIZON: Lifetime. PERSPECTIVE: Societal. INTERVENTIONS: Genotypic resistance testing and clinical judgment, compared with clinical judgment alone, in two contexts: after initial treatment failure (secondary resistance testing) and before initiation of antiretroviral therapy (primary resistance testing). OUTCOME MEASURES: Life expectancy, quality-adjusted life expectancy, and cost-effectiveness in dollars per quality-adjusted life-year (QALY) gained. RESULTS OF BASE-CASE ANALYSIS: Secondary resistance testing increased life expectancy by 3 months, at a cost of $17 900 per QALY gained. The cost-effectiveness of primary resistance testing was $22 300 per QALY gained with a 20% prevalence of primary resistance but increased to $69 000 per QALY gained with 4% prevalence. RESULTS OF SENSITIVITY ANALYSIS: The cost-effectiveness ratio for secondary resistance testing remained under $25 000 per QALY gained, even when effectiveness and cost of testing and antiretroviral therapy, quality-of-life weights, and discount rate were varied. CONCLUSIONS: Genotypic antiretroviral resistance testing following antiretroviral failure is cost-effective. Primary resistance testing also seems to be reasonably cost-effective and will become more so as the prevalence of primary resistance increases.

Preevaluation of clinical trial data: the case of preemptive cytomegalovirus therapy in patients with human immunodeficiency virus.

We developed a mathematical simulation model to anticipate outcomes from an upcoming trial of targeted, preemptive cytomegalovirus (CMV) therapy in high-risk, human immunodeficiency virus (HIV)-infected patients identified by means of CMV polymerase chain reaction screening. We estimated the costs and consequences of CMV prophylaxis in patients with CD4(+) counts < or =100 cells/microL under various assumptions regarding disease progression, complication rates, drug effects, and costs. Without CMV preemptive therapy, lifetime costs average $44,600 with expected duration of survival of 19.16 quality-adjusted life-months and 213 CMV cases per 1000 patients. Targeted preemptive therapy with orally administered valganciclovir increases costs and duration of survival to $46,900 and 19.63 quality-adjusted life-months, respectively. CMV cases decrease to 174 per 1000 patients. The cost per quality-adjusted life-year gained is $59,000. This result compares favorably with other strategies in end-stage HIV disease but hinges on valganciclovir cost and efficacy assumptions and the absence of minimally effective salvage antiretroviral therapy for HIV. The upcoming trial should resolve the clinical uncertainty surrounding some of these assumptions.