Indirect cost of HIV infection in England

Are intersectoral costs considered in economic evaluations of interventions relating to sexually transmitted infections (STIs)? A systematic review

BACKGROUND/OBJECTIVE

Sexually transmitted infections (STIs) not only have an impact on the health sector but also the private resources of those affected, their families and other sectors of society (i.e. labour, education). This study aimed to i) review and identify economic evaluations of interventions relating to STIs, which aimed to include a societal perspective; ii) analyse the intersectoral costs (i.e. costs broader than healthcare) included; iii) categorise these costs by sector; and iv) assess the impact of intersectoral costs on the overall study results.

METHODS

Seven databases were searched: MEDLINE (PubMed), EMBASE (Ovid), Web of Science, CINAHL, PsycINFO, EconLit and NHS EED. Key search terms included terms for economic evaluation, STIs and specific infections. This review considered trial- and model-based economic evaluations conducted in an OECD member country. Studies were included that assessed intersectoral costs. Intersectoral costs were extracted and categorised by sector using Drummond's cost classification scheme (i.e. patient/family, productivity, costs in other sectors). A narrative synthesis was performed.

RESULTS

Twenty-nine studies qualified for data extraction and narrative synthesis. Twenty-eight studies applied a societal perspective of which 8 additionally adopted a healthcare or payer perspective, or both. One study used a modified payer perspective. The following sectors were identified: patient/family, informal care, paid labour (productivity), non-paid opportunity costs, education, and consumption. Patient/family costs were captured in 11 studies and included patient time, travel expenses, out-of-pocket costs and premature burial costs. Informal caregiver support (non-family) and unpaid help by family/friends was captured in three studies. Paid labour losses were assessed in all but three studies. Three studies also captured the costs and inability to perform non-paid work. Educational costs and future non-health consumption costs were each captured in one study. The inclusion of intersectoral costs resulted in more favourable cost estimates.

CONCLUSIONS

This systematic review suggests that economic evaluations of interventions relating to STIs that adopt a societal perspective tend to be limited in scope. There is an urgent need for economic evaluations to be more comprehensive in order to allow policy/decision-makers to make better-informed decisions.

The Direct Medical Costs of Late Presentation (<350/mm) of HIV Infection over a 15-Year Period

We describe the immediate- and longer-term direct medical costs of care for individuals diagnosed with HIV at CD4 counts <350/mm(3) ("late presenters"). We collected and stratified by initial CD4 count all inpatient, outpatient, and drug costs for all newly diagnosed patients accessing HIV care within Southern Alberta from 1/1/1995 to 1/1/2010. 59% of new patients were late presenters. We found significantly higher costs for late presenters, especially inpatient costs, during the first year after accessing care. Direct medical costs remained almost twice as high for late presenters in subsequent years compared to patients presenting with CD4 counts >350/mm(3) despite significantly their improved CD4 counts. The sustained high cost for late presenters has implications for recent recommendations for wider routine HIV testing and the earlier initiation of cART. Earlier diagnosis and treatment, while increasing the immediate expenditures within a population, may produce both direct and indirect cost savings in the longer term.

Mental health treatment to reduce HIV transmission risk behavior: a positive prevention model

Secondary HIV prevention, or "positive prevention," is concerned with reducing HIV transmission risk behavior and optimizing the health and quality of life of people living with HIV/AIDS (PLWHA). The association between mental health and HIV transmission risk (i.e., sexual risk and poor medication adherence) is well established, although most of this evidence is observational. Further, a number of efficacious mental health treatments are available for PLWHA yet few positive prevention interventions integrate mental health treatment. We propose that mental health treatment, including behavioral and pharmacologic interventions, can lead to reductions in HIV transmission risk behavior and should be a core component of secondary HIV prevention. We present a conceptual model and recommendations to guide future research on the effect of mental health treatment on HIV transmission risk behavior among PLWHA.

The impact of disease stage on direct medical costs of HIV management: a review of the international literature

The global prevalence of HIV infection continues to grow, as a result of increasing incidence in some countries and improved survival where highly active antiretroviral therapy (HAART) is available. Growing healthcare expenditure and shifts in the types of medical resources used have created a greater need for accurate information on the costs of treatment. The objectives of this review were to compare published estimates of direct medical costs for treating HIV and to determine the impact of disease stage on such costs, based on CD4 cell count and plasma viral load. A literature review was conducted to identify studies meeting prespecified criteria for information content, including an original estimate of the direct medical costs of treating an HIV-infected individual, stratified based on markers of disease progression. Three unpublished cost-of-care studies were also included, which were applied in the economic analyses published in this supplement. A two-step procedure was used to convert costs into a common price year (2004) using country-specific health expenditure inflators and, to account for differences in currency, using health-specific purchasing power parities to express all cost estimates in US dollars. In all nine studies meeting the eligibility criteria, infected individuals were followed longitudinally and a 'bottom-up' approach was used to estimate costs. The same patterns were observed in all studies: the lowest CD4 categories had the highest cost; there was a sharp decrease in costs as CD4 cell counts rose towards 100 cells/mm³; and there was a more gradual decline in costs as CD4 cell counts rose above 100 cells/mm³. In the single study reporting cost according to viral load, it was shown that higher plasma viral load level (> 100,000 HIV-RNA copies/mL) was associated with higher costs of care. The results demonstrate that the cost of treating HIV disease increases with disease progression, particularly at CD4 cell counts below 100 cells/mm³. The suggestion that costs increase as the plasma viral load rises needs independent verification. This review of the literature further suggests that publicly available information on the cost of HAART by disease stage is inadequate. To address the information gap, multiple stakeholders (governments, pharmaceutical industry, private insurers and non-governmental organizations) have begun to establish and support an independent, high quality and standardized multicountry data collection for evaluating the cost of HIV management. An accurate, representative and relevant cost-estimate data resource would provide a valuable asset to healthcare planners that may lead to improved policy and decision-making in managing the HIV epidemic.

Treatment Outcome and Cost-Effectiveness of Different Highly Active Antiretroviral Therapy Regimens in the Uk (1996–2002)

The aim of this study was to estimate the outcome and cost-effectiveness per life-year-gained (LYG) of first-, second- and third-line non-nucleoside reverse transcriptase inhibitors (NNRTI) versus protease inhibitor (PI) containing highly active antiretroviral therapy regimens. Hospital care costs (2002 US dollars discounted 3.5% per annum) were linked to treatment failure times. Results show that the median time-to-treatment failure for first-line (nucleoside reverse transcriptase inhibitors) 2NRTIs + NNRTI was substantially longer than that for 2NRTIs + PIboosted, 2NRTIs + PI and 2NRTIs + 2PIs, whereas for second- and third-line they were similar. Comparing first-line 2NRTIs + NNRTI with 2NRTIs + PIboosted cost per LYG was US$ 12,375; US$ 12,139 per LYG when compared with 2NRTIs + PI and US$ 2948 per LYG when compared with 2NRTIs + 2PIs. For second-line cost per LYG comparing 2NRTIs + NNRTI with 2NRTIs + PIboosted was US$ 19,501; US$ 18,364 per LYG when compared with 2NRTIs + PI and cost-saving when compared with 2NRTIs + 2PIs. For third-line cost per LYG comparing 2NRTIs + NNRTI with 2NRTIs + PIboosted was US$ 2708; US$ 11,559 per LYG when compared with 2NRTIs + PI and cost-saving when compared with 2NRTIs + 2PIs. In conclusion, first-line 2NRTIs + NNRTI was cost-effective or cost-saving when compared with PI-containing regimens for all lines of therapy. Such information is required by clinicians and managers of HIV services to make appropriate treatment decisions based on clinical and financial grounds, and given the increasing number of people living with HIV, such information will become more important over time.

When time is more than money: The allocation of time between work and leisure in HIV-infected patients

Time is a limited resource and individuals have to decide how many hours they should allocate to work and to leisure activities. Differences in wage rate or availability of non-labour income (financial support from families and savings) may influence how individuals allocate their time between work and leisure. An increase in wage rate may induce income effects (leisure time demanded increases) and substitution effects (leisure time demanded decreases) whereas an increase in non-labour income only induces income effects. We explored the effects of differences in wage rate and non-labour income on the allocation of time in HIV-infected patients. Patients enrolled in the Swiss HIV Cohort Study (SHCS) provided information on their time allocation, i.e. number of hours worked in 1998. A multinomial logistic regression model was used to test for income and substitution effects. Our results indicate that (i) the allocation of time in HIV-infected patients does not differ with level of education (i.e., wage rate), and that (ii) availability of non-labour income induces income effects, i.e. individuals demand more leisure time.

Indirect costs and cost-effectiveness analysis

This article examines the methodological implications of the societal perspective in cost-effectiveness analyses in which the costs of health-care interventions are defined as the sums of direct and indirect costs. In the model of cost-effectiveness analysis in which the planner distributes patients among many treatments for many illnesses, the definition requires that total indirect costs be constrained, and the article proposes an iterative computational procedure for choosing a constraint under the assumption that the planner maintains a target trade-off rate between losses of health benefits and reductions in indirect costs. In the more common model in which the planner decides which of two treatments for one illness to provide to patients, the adoption of a societal perspective introduces ambiguities into the welfare properties of the decision rule, and in general the conclusion that a treatment is cost-effective is valid only if switching or assigning patients to the cost-effective treatment does not increase the planner's total direct costs.

Cost-of-illness studies : a review of current methods

The number of cost-of-illness (COI) studies has expanded considerably over time. One outcome of this growth is that the reported COI estimates are inconsistent across studies, thereby raising concerns over the validity of the estimates and methods. Several factors have been identified in the literature as reasons for the observed variation in COI estimates. To date, the variation in the methods used to calculate costs has not been examined in great detail even though the variations in methods are a major driver of variation in COI estimates. The objective of this review was to document the variation in the methodologies employed in COI studies and to highlight the benefits and limitations of these methods. The review of COI studies was implemented following a four-step procedure: (i) a structured literature search of MEDLINE, JSTOR and EconLit; (ii) a review of abstracts using pre-defined inclusion and exclusion criteria; (iii) a full-text review using pre-defined inclusion and exclusion criteria; and (iv) classification of articles according to the methods used to calculate costs. This review identified four COI estimation methods (Sum_All Medical, Sum_Diagnosis Specific, Matched Control and Regression) that were used in categorising articles. Also, six components of direct medical costs and five components of indirect/non-medical costs were identified and used in categorising articles.365 full-length articles were reflected in the current review following the structured literature search. The top five cost components were emergency room/inpatient hospital costs, outpatient physician costs, drug costs, productivity losses and laboratory costs. The dominant method, Sum_Diagnosis Specific, was a total costing approach that restricted the summation of medical expenditures to those related to a diagnosis of the disease of interest. There was considerable variation in the methods used within disease subcategories. In several disease subcategories (e.g. asthma, dementia, diabetes mellitus), all four estimation methods were represented, and in other cases (e.g. HIV/AIDS, obesity, stroke, urinary incontinence, schizophrenia), three of the four estimation methods were represented. There was also evidence to suggest that the strengths and weaknesses of each method were considered when applying a method to a specific illness. Comparisons and assessments of COI estimates should consider the method used to estimate costs both as an important source of variation in the reported COI estimates and as a marker of the reliability of the COI estimate.

Productivity costs and determinants of productivity in HIV-infected patients

BACKGROUND

In HIV-infected patients, reduced ability to work may be an important component of the societal costs of this disease. Few data about productivity costs in HIV-infected patients are available.

OBJECTIVE

The goals of this study were to estimate productivity costs in the HIV-infected population in Switzerland and to identify characteristics that may influence patient productivity.

METHODS

This cross-sectional study included all patients younger than retirement age (65 years for men and 62 years for women) who were enrolled in the Swiss HIV Cohort Study in 2002. Measures of productivity losses in this population were based on patients' ability to work and the median monthly wage rates adjusted for age, sex, and educational level in Switzerland. Factors associated with ability to work were analyzed in a multivariate ordinary logistic regression (proportional odds) model. As of July 1, 2002, the exchange rate for US dollars to Swiss francs (CHF) was US $1.00 approximately equal to CHF 1.48.

RESULTS

A total of 5319 HIV-infected patients (3665 men [68.9%] and 1655 women [31.1%]; mean [SD] age, 40.6 [8.4] years; range, 17-64 years) were included in the study. The mean annual productivity loss per patient was estimated at CHF 22,910 (95% CI, CHF 22,064-CHF 23, 756). Ability to work was independently associated with the following (P < 0.001 for all): age (10-year increase: odds ratio [OR], 0.60 [95% CI, 0.54-0.62]), sex (female/male: OR, 0.73 [95% CI, 0.63-0.84]), history of IV drug use (OR, 0.22 [95% CI, 0.19-0.26]), time since first positive HIV test (>10 years vs < or = 10 years: OR, 0.66 [95% CI, 0.58-0.76]), CD4 cell count (201-500 vs 0-200 cells/microL: OR, 1.68 [95% CI, 1.38-2.46]; > or =501 vs 0-200 cells/microL: OR, 2.01 [95%, CI, 1.64-2.46]), history of AIDS-indicator disease (OR, 0.47 [95% CI, 0.41-0.55]), stable partnership during the last 6 months (OR, 1.63 [95% CI, 1.43-1.86]), and educational level (higher vs basic: OR, 1.68 [95% CI, 1.45-1.95]).

CONCLUSIONS

Productivity losses to society for the HIV-infected population appeared to be substantial in this analysis. Given a patient's clinical health status, a higher education level and a stable partnership were associated with greater ability to work. Socioeconomic characteristics may influence the cost-effectiveness of health care interventions in HIV-infected patients.

An economic model of haemophilia in Mexico

A model was developed to assess the lifetime costs and outcomes associated with haemophilia in Mexico. A retrospective chart review of 182 type A haemophiliacs was conducted for patients aged 0-34 years receiving one of three treatments: (i) cryoprecipitate at clinic; (ii) concentrate at home; or (iii) concentrate at clinic. Patients treated at home experienced 30% less joint damage, used 13-54% less factor VIII, had four times fewer clinic visits, and utilized half as many hospital days than those treated at a clinic. For cryoprecipitate at clinic patients, the annual incidence rates of HCV and HIV were calculated to be 3.6% and 1.4% respectively. The life expectancy for patients receiving cryoprecipitate and those receiving concentrate was estimated to be 49 years and 69 years respectively, with 58% of cryoprecipitate patients predicted to die of AIDS before age 69. Across the lifespan, the average annual cost of care was US$11,677 (MN$110,464) for cryoprecipitate at clinic patients, US$10,104 (M$95,580) for concentrate at home patients and US$18,819 (MN$178,027) for concentrate at clinic patients. Using a 5% discount rate, the incremental lifetime cost per year of life added for treatment with concentrate at home compared with cryoprecipitate at a clinic was US$738 (MN$6981). Rank order stability analysis demonstrated that the model was most sensitive to the cost of fVIII. These results indicate that treatment with concentrate at home compared with cryoprecipitate at a clinic substantially improves clinical outcomes at reduced annual cost levels.

Economic costs to business of the HIV/AIDS epidemic

HIV infection is a devastating disease for individuals and society. The economic burden of employees with HIV infection is a matter of increasing concern for employers. The purpose of this paper was to conduct a comprehensive review of published studies which measured/estimated economic costs incurred by HIV-infected employees, and evaluate the potential economic impact of the HIV/AIDS epidemic on business in different countries. This review finds a conceptual consensus in the literature that suggests that the HIV/AIDS epidemic has a potentially sizable economic cost to business, primarily due to increased costs for employment-based insurance premiums, welfare benefits, lost productivity, new hiring and training, and a downsized economy and labour market. Based on published data in the US, accounting for the first three major cost items, in 2002 an HIV-infected worker would cost an employer in the US an estimated 37,320 US dollars for asymptomatic individuals and 50,374 US dollars for symptomatic individuals per person-year. However, this review found little consistent empirical data in the literature regarding the scale of disease costs specific to businesses in different settings. In addition, the current literature offers little guidance in terms of well designed, validated, and easily replicated analytical frameworks for conducting a comprehensive cost analysis from a business perspective. Future research is needed to improve both the theoretical modelling and empirical work in assessing the full economic impact of the HIV/ADIS epidemic on patients, businesses and society at large.

The cost-effectiveness of the WINGS intervention: a program to prevent HIV and sexually transmitted diseases among high-risk urban women

BACKGROUND

We evaluated the cost-effectiveness of the WINGS project, an intervention to prevent HIV and other sexually transmitted diseases among urban women at high risk for sexual acquisition of HIV.

METHODS

We used standard methods of cost-effectiveness analysis. We conducted a retrospective analysis of the intervention's cost and we used a simplified model of HIV transmission to estimate the number of HIV infections averted by the intervention. We calculated cost-effectiveness ratios for the complete intervention and for the condom use skills component of the intervention.

RESULTS

Under base case assumptions, the intervention prevented an estimated 0.2195 new cases of HIV at a cost of $215,690 per case of HIV averted. When indirect costs of HIV were excluded from the analysis, the intervention's cost-effectiveness ratios were $357,690 per case of HIV averted and $31,851 per quality-adjusted life year (QALY) saved. Under base case assumptions, the condom use skills component of the intervention prevented an estimated 0.1756 HIV infections and was cost-saving. When indirect HIV costs were excluded, the cost-effectiveness ratios for the condom use skills component of the intervention were $97,404 per case of HIV averted and $8,674 per QALY saved.

CONCLUSIONS

The WINGS intervention, particularly the two sessions of the intervention which focussed on condom use skills, could be cost-effective in preventing HIV among women.