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

Implications of HIV Disease for Oral Health Services

This paper, by means of a quality framework, reviews health services research in relation to people with HIV infection. The relevance of oral health care services to people’s needs is considered in terms of the goal of health services to reduce the burden of disease on the everyday life of the population. Dental services may therefore have a role in primary prevention in the HIV epidemic, passing on information about HIV and promoting health through the early diagnosis and treatment of oral disease. Effectiveness research of oral health care in HIV assesses the usefulness of oral diagnosis, whether care is safe, and whether treatment is clinically effective. Few data are available on the efficiency of services. People with HIV still have problems accessing dental care, due to the volume of care available in relation to their need and acceptability of care. Access problems in the US are compounded by social inequality. Health services research data are particularly sparse in resource-poor countries, and there is a need to translate the available information into treatment guidelines appropriate to these settings. The research community and funding agencies should place greater emphasis on the quality of oral health services for people with HIV.

Routine HIV screening in Portugal: clinical impact and cost-effectiveness

OBJECTIVE

To compare the clinical outcomes and cost-effectiveness of routine HIV screening in Portugal to the current practice of targeted and on-demand screening.

DESIGN

We used Portuguese national clinical and economic data to conduct a model-based assessment.

METHODS

We compared current HIV detection practices to strategies of increasingly frequent routine HIV screening in Portuguese adults aged 18-69. We considered several subpopulations and geographic regions with varying levels of undetected HIV prevalence and incidence. Baseline inputs for the national case included undiagnosed HIV prevalence 0.16%, annual incidence 0.03%, mean population age 43 years, mean CD4 count at care initiation 292 cells/μL, 63% HIV test acceptance, 78% linkage to care, and HIV rapid test cost €6 under the proposed routine screening program. Outcomes included quality-adjusted survival, secondary HIV transmission, cost, and incremental cost-effectiveness.

RESULTS

One-time national HIV screening increased HIV-infected survival from 164.09 quality-adjusted life months (QALMs) to 166.83 QALMs compared to current practice and had an incremental cost-effectiveness ratio (ICER) of €28,000 per quality-adjusted life year (QALY). Screening more frequently in higher-risk groups was cost-effective: for example screening annually in men who have sex with men or screening every three years in regions with higher incidence and prevalence produced ICERs of €21,000/QALY and €34,000/QALY, respectively.

CONCLUSIONS

One-time HIV screening in the Portuguese national population will increase survival and is cost-effective by international standards. More frequent screening in higher-risk regions and subpopulations is also justified. Given Portugal's challenging economic priorities, we recommend prioritizing screening in higher-risk populations and geographic settings.

Cost effectiveness of cryptococcal antigen screening as a strategy to prevent HIV-associated cryptococcal meningitis in South Africa

Objectives

Cryptococcal meningitis (CM)-related mortality may be prevented by screening patients for sub-clinical cryptococcal antigenaemia (CRAG) at antiretroviral-therapy (ART) initiation and pre-emptively treating those testing positive. Prior to programmatic implementation in South Africa we performed a cost-effectiveness analysis of alternative preventive strategies for CM.

Design

Cost-effectiveness analysis.

Methods

Using South African data we modelled the cost-effectiveness of four strategies for patients with CD4 cell-counts <100 cells/µl starting ART 1) no screening or prophylaxis (standard of care), 2) universal primary fluconazole prophylaxis, 3) CRAG screening with fluconazole treatment if antigen-positive, 4) CRAG screening with lumbar puncture if antigen-positive and either amphotericin-B for those with CNS disease or fluconazole for those without. Analysis was limited to the first year of ART.

Results

The least costly strategy was CRAG screening followed by high-dose fluconazole treatment of all CRAG-positive individuals. This strategy dominated the standard of care at CRAG prevalence ≥0.6%. Although CRAG screening followed by lumbar puncture in all antigen-positive individuals was the most effective strategy clinically, the incremental benefit of LPs and amphotericin therapy for those with CNS disease was small and additional costs were large (US$158 versus US$51per person year; incremental cost effectiveness ratio(ICER) US$889,267 per life year gained). Both CRAG screening strategies are less costly and more clinically effective than current practice. Primary prophylaxis is more effective than current practice, but relatively cost-ineffective (ICER US$20,495).

Conclusions

CRAG screening would be a cost-effective strategy to prevent CM-related mortality among patients initiating ART in South Africa. These findings provide further justification for programmatic implementation of CRAG screening.

The potential economic value of a Staphylococcus aureus vaccine among hemodialysis patients

Staphylococcus aureus infections are a substantial problem for hemodialysis patients. Several vaccine candidates are currently under development, with hemodialysis patients being one possible target population. To determine the potential economic value of an S. aureus vaccine among hemodialysis patients, we developed a Markov decision analytic computer simulation model. When S. aureus colonization prevalence was 1%, the incremental cost-effectiveness ratio (ICER) of vaccination was ≤$25,217/quality-adjusted life year (QALY). Vaccination became more cost-effective as colonization prevalence, vaccine efficacy, or vaccine protection duration increased or vaccine cost decreased. Even at 10% colonization prevalence, a 25% efficacious vaccine costing $100 prevented 29 infections, 21 infection-related hospitalizations, and 9 inpatient deaths per 1000 vaccinated HD patients. Our results suggest that an S. aureus vaccine would be cost-effective (i.e., ICERs ≤ $50,000/QALY) among hemodialysis patients over a wide range of S. aureus prevalence, vaccine costs and efficacies, and vaccine protection durations and delineate potential target parameters for such a vaccine.

Newer drugs and earlier treatment: impact on lifetime cost of care for HIV-infected adults

OBJECTIVE

To determine the component costs of care to optimize treatment with limited resources.

DESIGN

We used the Cost-Effectiveness of Preventing AIDS Complications Model of HIV disease and treatment to project life expectancy and both undiscounted and discounted lifetime costs (2010 €).

METHODS

We determined medical resource utilization among HIV-infected adults followed from 1998 to 2005 in northern France. Monthly HIV costs were stratified by CD4 cell count. Costs of CD4, HIV RNA and genotype tests and antiretroviral therapy (ART) were derived from published literature. Model inputs from national data included mean age 38 years, mean initial CD4 cell count 372 cells/μl, ART initiation at CD4 cell counts less than 350 cells/μl, and ART regimen costs ranging from €760 to 2570 per month.

RESULTS

The model projected a mean undiscounted life expectancy of 26.5 years and a lifetime undiscounted cost of €535,000/patient (€320,700 discounted); 73% of costs were ART related. When patients presented to care with mean CD4 cell counts of 510 cells/μl and initiated ART at CD4 cell counts less than 500 cells/μl or HIV RNA more than 100,000 copies/ml, life expectancy was 27.4 years and costs increased 1-2%, to €546,700 (€324,500 discounted). When we assumed introducing generic drugs would result in a 50% decline in first-line ART costs, lifetime costs decreased 4-6%, to €514,200 (€302 ,800 discounted).

CONCLUSION

As HIV disease is treated earlier with more efficacious drugs, survival and thus costs of care will continue to increase. The availability in high-income countries of widely used antiretroviral drugs in generic form could reduce these costs.

Pathogenesis and prevention of immune reconstitution disease during antiretroviral therapy

The risks of unmasking and paradoxical forms of immune reconstitution disease in HIV-infected patients starting antiretroviral therapy (ART) are fuelled by a combination of the late presentation of patients with advanced immunodeficiency, the associated high rates of opportunistic infections (OIs) and the need for rapid initiation of ART to minimize overall mortality risk. We review the risk factors and our current knowledge of the immunopathogenesis of immune reconstitution disease, leading to a discussion of strategies for prevention. Initiation of ART at higher CD4 counts, use of OI-preventive therapies prior to ART eligibility, intensified screening for OIs prior to ART initiation and optimum therapy for OIs are all needed. In addition, use of a range of pharmacological agents with immunosuppressive and immunomodulatory activity is being explored.

Public health and prevention in Europe: is it cost-effective?

Objectives

In the public debate surrounding public health and prevention, it is sometimes assumed that preventive interventions are by definition cost-effective. This paper aims to explore whether preventive pharmaceutical interventions are more cost-effective than a curative approach to diseases.

Methods

A descriptive study identified European economic evaluations in the Tufts Medical Center Cost-Effectiveness Analysis Registry between 2000 and 2007. Data were extracted on publication year, target population, intervention, patient sample, disease, prevention stage and incremental cost-utility ratio of each economic evaluation. Preventive interventions were defined as measures preventing disease onset. Curative interventions related to measures identifying patients with risk factors or preclinical disease or interventions limiting disability after harm has occurred. Results were expressed in terms of costs (valued in Euros at 2008 prices) per quality-adjusted life year. The association between incremental cost-utility ratios and prevention stage was examined by means of the Mann–Whitney U test.

Key findings

The analysis included 231 studies that reported information about 608 incremental cost-effectiveness ratios. Preventive interventions included interventions that were more effective and less expensive than comparators (41% of incremental cost-effectiveness ratios), and interventions that improved outcomes and increased costs (59%). Both preventive and curative interventions covered the full range of cost-effectiveness results. However, preventive interventions had a significantly lower median ratio of €6255 per quality-adjusted life year and were thus more cost-effective than curative interventions (€12 917 per quality-adjusted life year) (P=0.002).

Conclusions

Although the cost-effectiveness of preventive interventions varies substantially, preventive interventions tended to be more cost-effective than curative interventions.

Cost-effectiveness of primary prophylaxis of AIDS associated cryptococcosis in Cambodia

Background

Cryptococcal infection is a frequent cause of mortality in Cambodian HIV-infected patients with CD4+ count ≤100 cells/µl. This study assessed the cost-effectiveness of three strategies for cryptococcosis prevention in HIV-infected patients.

Methods

A Markov decision tree was used to compare the following strategies at the time of HIV diagnosis: no intervention, one time systematic serum cryptococcal antigen (CRAG) screening and treatment of positive patients, and systematic primary prophylaxis with fluconazole. The trajectory of a hypothetical cohort of HIV-infected patients with CD4+ count ≤100 cells/µl initiating care was simulated over a 1-year period (cotrimoxazole initiation at enrollment; antiretroviral therapy within 3 months). Natural history and cost data (US$ 2009) were from Cambodia. Efficacy data were from international literature.

Results

In a population in which 81% of patients had a CD4+ count ≤50 cells/ µl and 19% a CD4+ count between 51–100 cells/µl, the proportion alive 1 year after enrolment was 61% (cost $ 472) with no intervention, 70% (cost $ 483) with screening, and 72% (cost $ 492) with prophylaxis. After one year of follow-up, the cost-effectiveness of screening vs. no intervention was US$ 180/life year gained (LYG). The cost-effectiveness of prophylaxis vs. screening was $ 511/LYG. The cost-effectiveness of prophylaxis vs. screening was estimated at $1538/LYG if the proportion of patients with CD4+ count ≤50 cells/µl decreased by 75%.

Conclusion

In a high endemic area of cryptococcosis and HIV infection, serum CRAG screening and prophylaxis are two cost effective strategies to prevent AIDS associated cryptococcosis in patients with CD4+ count ≤100 cells/µl, at a short-term horizon, screening being more cost-effective but less effective than prophylaxis. Systematic primary prophylaxis may be preferred in patients with CD4+ below 50 cells/µl while systematic serum CRAG screening for early targeted treatment may be preferred in patients with CD4+ between 51–100 cells/µl.

Routine HIV screening in France: clinical impact and cost-effectiveness

BACKGROUND

In France, roughly 40,000 HIV-infected persons are unaware of their HIV infection. Although previous studies have evaluated the cost-effectiveness of routine HIV screening in the United States, differences in both the epidemiology of infection and HIV testing behaviors warrant a setting-specific analysis for France.

METHODS/PRINCIPAL FINDINGS

We estimated the life expectancy (LE), cost and cost-effectiveness of alternative HIV screening strategies in the French general population and high-risk sub-populations using a computer model of HIV detection and treatment, coupled with French national clinical and economic data. We compared risk-factor-based HIV testing ("current practice") to universal routine, voluntary HIV screening in adults aged 18-69. Screening frequencies ranged from once to annually. Input data included mean age (42 years), undiagnosed HIV prevalence (0.10%), annual HIV incidence (0.01%), test acceptance (79%), linkage to care (75%) and cost/test (€43). We performed sensitivity analyses on HIV prevalence and incidence, cost estimates, and the transmission benefits of ART. "Current practice" produced LEs of 242.82 quality-adjusted life months (QALM) among HIV-infected persons and 268.77 QALM in the general population. Adding a one-time HIV screen increased LE by 0.01 QALM in the general population and increased costs by €50/person, for a cost-effectiveness ratio (CER) of €57,400 per quality-adjusted life year (QALY). More frequent screening in the general population increased survival, costs and CERs. Among injection drug users (prevalence 6.17%; incidence 0.17%/year) and in French Guyana (prevalence 0.41%; incidence 0.35%/year), annual screening compared to every five years produced CERs of €51,200 and €46,500/QALY.

CONCLUSIONS/SIGNIFICANCE

One-time routine HIV screening in France improves survival compared to "current practice" and compares favorably to other screening interventions recommended in Western Europe. In higher-risk groups, more frequent screening is economically justifiable.

Assessing the performance of a computer-based policy model of HIV and AIDS

Background

Model-based analyses, conducted within a decision analytic framework, provide a systematic way to combine information about the natural history of disease and effectiveness of clinical management strategies with demographic and epidemiological characteristics of the population. Among the challenges with disease-specific modeling include the need to identify influential assumptions and to assess the face validity and internal consistency of the model.

Methods and Findings

We describe a series of exercises involved in adapting a computer-based simulation model of HIV disease to the Women's Interagency HIV Study (WIHS) cohort and assess model performance as we re-parameterized the model to address policy questions in the U.S. relevant to HIV-infected women using data from the WIHS. Empiric calibration targets included 24-month survival curves stratified by treatment status and CD4 cell count. The most influential assumptions in untreated women included chronic HIV-associated mortality following an opportunistic infection, and in treated women, the ‘clinical effectiveness’ of HAART and the ability of HAART to prevent HIV complications independent of virologic suppression. Good-fitting parameter sets required reductions in the clinical effectiveness of 1^st and 2^nd line HAART and improvements in 3^rd and 4^th line regimens. Projected rates of treatment regimen switching using the calibrated cohort-specific model closely approximated independent analyses published using data from the WIHS.

Conclusions

The model demonstrated good internal consistency and face validity, and supported cohort heterogeneities that have been reported in the literature. Iterative assessment of model performance can provide information about the relative influence of uncertain assumptions and provide insight into heterogeneities within and between cohorts. Description of calibration exercises can enhance the transparency of disease-specific models.

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.

The cost-effectiveness of antiretroviral treatment in Khayelitsha, South Africa--a primary data analysis

Background

Given the size of the HIV epidemic in South Africa and other developing countries, scaling up antiretroviral treatment (ART) represents one of the key public health challenges of the next decade. Appropriate priority setting and budgeting can be assisted by economic data on the costs and cost-effectiveness of ART. The objectives of this research were therefore to estimate HIV healthcare utilisation, the unit costs of HIV services and the cost per life year (LY) and quality adjusted life year (QALY) gained of HIV treatment interventions from a provider's perspective.

Methods

Data on service utilisation, outcomes and costs were collected in the Western Cape Province of South Africa. Utilisation of a full range of HIV healthcare services was estimated from 1,729 patients in the Khayelitsha cohort (1,146 No-ART patient-years, 2,229 ART patient-years) using a before and after study design. Full economic costs of HIV-related services were calculated and were complemented by appropriate secondary data. ART effects (deaths, therapy discontinuation and switching to second-line) were from the same 1,729 patients followed for a maximum of 4 years on ART. No-ART outcomes were estimated from a local natural history cohort. Health-related quality of life was assessed on a sub-sample of 95 patients. Markov modelling was used to calculate lifetime costs, LYs and QALYs and uncertainty was assessed through probabilistic sensitivity analysis on all utilisation and outcome variables. An alternative scenario was constructed to enhance generalizability.

Results

Discounted lifetime costs for No-ART and ART were US$2,743 and US$9,435 over 2 and 8 QALYs respectively. The incremental cost-effectiveness ratio through the use of ART versus No-ART was US$1,102 (95% CI 1,043-1,210) per QALY and US$984 (95% CI 913-1,078) per life year gained. In an alternative scenario where adjustments were made across cost, outcome and utilisation parameters, costs and outcomes were lower, but the ICER was similar.

Conclusion

Decisions to scale-up ART across sub-Saharan Africa have been made in the absence of incremental lifetime cost and cost-effectiveness data which seriously limits attempts to secure funds at the global level for HIV treatment or to set priorities at the country level. This article presents baseline cost-effectiveness data from one of the longest running public healthcare antiretroviral treatment programmes in Africa that could assist in enhancing efficient resource allocation and equitable access to HIV treatment.

Human papillomavirus: the burden of infection

Vaccines for preventing human papillomavirus (HPV) infection are far along in clinical development and testing, and hold great promise for reducing HPV infections and HPV-associated disease. HPV is the most common sexually transmitted infection in the United States, affecting an estimated 75% of the U.S. population. HPV infection is highly prevalent in sexually active adolescents and young adults. Sexual activity is the most important risk factor for infection, with 64% to 82% of sexually active adolescent girls testing positive for HPV. Clinical manifestations of HPV infection include genital warts, cervical intraepithelial neoplasia (CIN), and invasive cervical cancer, all of which cause significant morbidity and, in the case of cervical cancer, mortality. The majority of HPV-associated disease is caused by 4 HPV types: HPV 6 and 11 are responsible for low-grade genital lesions and more than 90% of genital warts, and HPV 16 and 18 both account for approximately 70% of all high-grade CIN or dysplasia and invasive cervical cancer. Although current screening methods have proven effective in reducing cervical cancer incidence and associated mortality, more than 10,000 women are diagnosed annually and 4000 U.S. women die from the disease each year.

Cost-effectiveness of HIV post-exposure prophylaxis in France

OBJECTIVE

To assess the cost-effectiveness of HIV post-exposure prophylaxis (PEP) in France.

METHODS

We used a decision tree to evaluate, from a society's perspective, the cost of PEP per quality-adjusted life-year (QALY) saved. We used 1999-2003 PEP surveillance data and literature-derived data on per event transmission probabilities, PEP efficacy and quality of life with HIV. HIV prevalence and lifetime cost of HIV/AIDS management in the HAART era were derived from French studies. We assumed that mean life expectancy in full health was 65 years among uninfected individuals and that the mean survival time after HIV infection was 22.5 years. The costs of PEP drugs and follow-up were derived from the French public sector. A 3% annual rate was used to discount future costs and effects.

RESULTS

During 1999-2003, PEP was prescribed to 8958 individuals (heterosexual sex: 47.6%; homosexual sex: 28.4%; occupational exposure: 23.4%; drug injection: 0.6%); of those, 2143 were exposed to a known HIV-infected source. PEP was estimated to prevent 7.7 infections and saved 64.5 QALY at a net cost of euro 5.7 million, resulting in an overall cost-effectiveness ratio of euro 88,692 per QALY saved. PEP was cost saving for 4.4% of cases and cost effective (< euro 50,000 per QALY) in a further 11.3% of cases. In contrast, 72 and 52% of prescriptions had a cost-effectiveness ratio exceeding euro 200,000 and euro 2 millions, respectively, per QALY saved.

CONCLUSION

Overall, the French PEP programme is only moderately cost effective. PEP guidelines should be revised to target high-risk exposures better.

Clinical impact and cost-effectiveness of co-trimoxazole prophylaxis in patients with HIV/AIDS in Côte d'Ivoire: a trial-based analysis

BACKGROUND

In 2000, WHO/UNAIDS recommended co-trimoxazole prophylaxis for persons at early stages of HIV infection (WHO stage > or = 2) in sub-Saharan Africa.

OBJECTIVE

To assess the cost-effectiveness of alternative strategies for initiation of co-trimoxazole in Côte d'Ivoire.

DESIGN

Cost-effectiveness analysis with an HIV simulation model using clinical and cost data from a randomized trial of co-trimoxazole in HIV-infected adults.

METHODS

The study included HIV-infected patients in Côte d'Ivoire, with median age 33 years. Thirty-four percent were classified as WHO stage 2, 59% as stage 3, and 7% as stage 4. The mean CD4 cell count was 331 x 10(6) cells/l. The interventions were no prophylaxis, clinical criteria-based co-trimoxazole initiation (early: WHO stage > or = 2; late: WHO stage > or = 3), CD4-based co-trimoxazole initiation (< 500, < 200, < 50 x 10(6) CD4 cells/l). The outcome measures were life expectancy, lifetime costs, and incremental cost-effectiveness.

RESULTS

The most effective strategy, initiation of co-trimoxazole prophylaxis at WHO stage > or = 2, increased undiscounted life expectancy by 5.2 months, discounted life expectancy by 4.4 months, and lifetime costs by US dollars 60, compared with no prophylaxis. Delaying prophylaxis initiation until WHO stage >or = 3 was less costly and less effective. All CD4-based strategies were dominated. The incremental cost-effectiveness of early versus late co-trimoxazole prophylaxis initiation was US dollars 200/year of life gained. Results were stable despite wide variations in plausible assumptions about bacterial resistance and the prophylaxis efficacy on co-trimoxazole-resistant strains.

CONCLUSIONS

For HIV-infected adults in Côte d'Ivoire, co-trimoxazole prophylaxis is reasonably cost-effective and most effective if initiated when WHO stage > or = 2. Early co-trimoxazole prophylaxis will prevent complications prior to antiretroviral therapy initiation and should be considered an essential component of care for early HIV in sub-Saharan Africa.

Antifungal interventions for the primary prevention of cryptococcal disease in adults with HIV

BACKGROUND

Cryptococcal disease is an opportunistic infection that causes significant morbidity and mortality in adults with HIV. Primary prophylaxis with antifungal interventions may decrease cryptococcal disease incidence and associated mortality.

OBJECTIVES

To assess the efficacy of antifungal interventions for the primary prevention of cryptococcal disease in adults with HIV.

SEARCH STRATEGY

We searched the following databases: MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), ClinicalTrials.gov, Database of Abstracts of Reviews of Effectiveness (DARE), Latin American and Caribbean Literature on the Health Sciences (LILACS), and the Cochrane Controlled Trials Register (CCTR). We reviewed abstracts from the following relevant conferences: International AIDS Conference, International AIDS Society Conference on HIV Pathogenesis and Treatment, and Conference on Retroviruses and Opportunistic Infections. We searched reference lists for all primary and other pertinent articles identified. We attempted to contact experts in the field, particularly primary authors of included studies, to better ensure completeness of included studies. We also approached pharmaceutical companies for any available and relevant unpublished data. The time period searched was from 1980 to August 2004. We placed no language restrictions on the search. Key words used include: meningitis, cryptococcal, cryptococcus, cryptococcosis, acquired immunodeficiency syndrome, human immunodeficiency virus, prophylaxis, chemoprevention, antifungal agents, and the Cochrane screen for randomized controlled trials.

SELECTION CRITERIA

Randomized controlled trials using antifungal interventions for the primary prevention of cryptococcal disease in adults with HIV were selected.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial eligibility and quality. Trial authors, experts, and pharmaceutical companies were contacted for additional and/or missing information. Data were abstracted by two reviewers. Data were pooled, where appropriate, to yield summary estimates.

MAIN RESULTS

Five studies (N=1316) were identified. All study patients had CD4 cell counts <300 cells/microl, and the majority of patients had CD4 cell counts <150 cells/microl. When all five studies are analyzed as a single group (N=1316), the incidence of cryptococcal disease was decreased in those taking primary prophylaxis (RR 0.21, 95% CI 0.09, 0.46) compared to those taking placebo. However, there was no significant difference in overall mortality observed (RR 1.01, 95% CI 0.71, 1.44). When the three studies using itraconazole as the intervention were analyzed together (N=798), the incidence of cryptococcal disease was decreased in those taking itraconazole for primary prophylaxis (RR 0.12, 95% CI 0.03, 0.51) compared to those taking placebo; however, there was no significant difference in overall mortality (RR 1.12, 95% CI 0.70, 1.80). When the two studies using fluconazole as the intervention were analyzed together (N=518), the incidence of cryptococcal disease was decreased in those taking fluconazole for primary prophylaxis (RR 0.25, 95% CI 0.07, 0.87) compared to those taking placebo; however, there was no significant difference in overall mortality (RR 0.59, 95% CI 0.14, 2.62).

AUTHORS' CONCLUSIONS

Antifungal primary prophylaxis with either itraconazole or fluconazole is effective in reducing the incidence of cryptococcal disease in adults with advanced HIV disease. However, neither of these interventions has a clear effect on overall mortality. Further research is needed to better understand these interventions and the populations in which they may be most effective.

The economic implications of non-adherence after renal transplantation

BACKGROUND

The economic impact of therapeutic non-adherence in chronic diseases has rarely been examined using qualitative standards for economic evaluation. This study illustrates the impact of non-adherence on the cost utility of renal transplantation versus haemodialysis from the societal perspective and examines the scope for adherence-enhancing interventions.

METHODS

Long-term costs and outcomes in adherent and non-adherent renal transplant patients were simulated in a Markov model. The cost (euros, year 2000 values) and outcome data that were imputed in the model were derived from a prospective study in renal transplantation candidates performed in 2002. Probabilities of adverse events, graft rejection, graft loss and death in adherent and non-adherent renal transplant patients were derived from literature.

RESULTS

Compared with dialysis, renal transplantation offers a better outcome in both adherent and non-adherent patients. Lifetime costs after transplantation in the adherent patient group are higher than lifetime dialysis costs and lifetime costs in the non-adherent patient group, mainly because adherent patients live longer after transplantation. Long-term outcomes after transplantation are better for adherent than for non-adherent patients. The mean cost per QALY gained in adherent patients relative to non-adherent patients was euro 35 021 per QALY (95% CI 26 959, 46 620).

CONCLUSION

Compared with established healthcare interventions, such as haemodialysis, renal transplantation can be considered a cost-effective therapy for patients with end-stage renal disease, even if patients are non-adherent after transplantation. The low incremental cost per QALY calculated in this model for adherent renal transplant patients, suggests there may be scope for adherence-enhancing interventions (provided that such interventions with a sufficiently high effectiveness exist or can be developed). As the findings are based on simulated long-term costs and outcomes, they should not be considered as precise estimates of the impact of non-adherence. This study is rather meant as an illustration of how non-adherence may impact on the results of cost-effectiveness analyses.