Cost-effectiveness of improved treatment services for sexually transmitted diseases in preventing HIV-1 infection in Mwanza Region, Tanzania

Improved management of sexually transmitted diseases (STDs) is consistently advocated as an effective strategy for HIV prevention. The impact, cost, and cost-effectiveness of this approach were evaluated in a prospective, comparative study of six communities in Tanzania's Mwanza Region in which primary health care center workers were trained to provide improved STD treatment and six matched non-intervention communities. The baseline prevalence of HIV was 4% in both groups. During the 2-year study period, 11,632 cases of STDs were treated in the intervention health units. The HIV seroconversion rate was 1.16% in the intervention communities and 1.86% in the comparison communities--a difference in HIV incidence of 0.70 (95% confidence interval, 0.37-1.09) and a reduction of about 40%. The total annual cost of the intervention was US$59,060 ($0.39 per person served). The cost of STD treatment was $10.15 per case. An estimated 252 HIV-1 infections were averted each year. The incremental annual cost of the program was $54,839, equivalent to $217.62 per HIV infection averted and $10.33 per disability-adjusted-life-year (DALY) saved. The estimated cost-effectiveness compares favorably with that of childhood immunization programs ($12-17 per DALY saved) and could be further enhanced through implementation of the intervention on a wider scale. The intervention subsequently has been expanded to encompass 65 health units in Mwanza Region, with no increase in investment costs.     

Cost-effectiveness of HIV-prevention skills training for men who have sex with men

OBJECTIVE: A previous study empirically compared the effects of two HIV-prevention interventions for men who have sex with men: (i) a safer sex lecture, and (ii) the same lecture coupled with a 1.5 h skills-training group session. The skills-training intervention led to a significant increase in condom use at 12-month follow-up, compared with the lecture-only condition. The current study retrospectively assesses the incremental cost-effectiveness of skills training to determine whether it is worth the extra cost to add this component to an HIV-prevention intervention that would otherwise consist of a safer sex lecture only. DESIGN: Standard techniques of incremental cost-utility analysis were employed. METHODS: A societal perspective and a 5% discount rate were used. Cost categories assessed included: staff salary, fringe benefits, quality assurance, session materials, client transportation, client time valuation, and costs shared with other programs. A Bernoulli-process model of HIV transmission was used to estimate the number of HIV infections averted by the skills-training intervention component. For each infection averted, the discounted medical costs and quality-adjusted life years (QALY) saved were estimated. One- and multi-way sensitivity analyses were performed to assess the robustness of base-case results to changes in modeling assumptions. RESULTS: Under base-case assumptions, the incremental cost of the skills training was less than $13,000 (or about $40 per person). The discounted medical costs averted by incrementally preventing HIV infections were over $170,000; more than 21 discounted QALY were saved. The cost per QALY saved was negative, indicating cost-savings. These results are robust to changes in most modeling assumptions. However, the model is moderately sensitive to changes in the per-contact risk of HIV transmission. CONCLUSIONS: Under most reasonable assumptions, the incremental costs of the skills training were outweighed by the medical costs saved. Thus, not only is skills training effective in reducing risky behavior, it is also cost-saving.     

Preventing perinatal transmission of HIV--costs and effectiveness of a recommended intervention

OBJECTIVE: To calculate the national costs of reducing perinatal transmission of human immunodeficiency virus through counseling and voluntary testing of pregnant women and zidovudine treatment of infected women and their infants, as recommended by the Public Health Service, and to compare these costs with the savings from reducing the number of pediatric infections. METHOD: The authors analyzed the estimated costs of the intervention and the estimated cost savings from reducing the number of pediatric infections. The outcome measures are the number of infections prevented by the intervention and the net cost (cost of intervention minus the savings from a reduced number of pediatric HIV infections). The base model assumed that intervention participation and outcomes would resemble those found in the AIDS Clinical Trials Group Protocol 076. Assumptions were varied regarding maternal seroprevalence, participation by HIV-infected women, the proportion of infected women who accepted and completed the treatment, and the efficacy of zidovudine to illustrate the effect of these assumptions on infections prevented and net cost. RESULTS: Without the intervention, a perinatal HIV transmission rate of 25% would result in 1750 HIV-infected infants born annually in the United States, with lifetime medical-care costs estimated at $282 million. The cost of the intervention (counseling, testing, and zidovudine treatment) was estimated to be $ 67.6 million. In the base model, the intervention would prevent 656 pediatric HIV infections with a medical care cost saving of $105.6 million. The net cost saving of the intervention was $38.1 million. CONCLUSION: Voluntary HIV screening of pregnant women and ziovudine treatment for infected women and their infants resulted in cost savings under most of the assumptions used in this analysis. These results strongly support implementation of the Public Health Service recommendations for this intervention.     

Human immunodeficiency virus partner notification. Cost and effectiveness data from an attempted randomized controlled trial

OBJECTIVE: Determine the cost and effectiveness of partner notification for human immunodeficiency virus (HIV) infection. METHODS: Persons testing HIV positive in three areas were randomly assigned one of four approaches to partner notification. Analysis plans changed because disease intervention specialists notified many partners from the patient referral group. We dropped the patient referral group and combined the others to assess the cost and effectiveness of provider referral. RESULTS: The 1,070 patients reported 8,633 partners. Of those 1,035 were located via record search or in person. A previous positive test was reported by 248 partners. Of the 787 others, 560 were tested: 438 were HIV negative and 122 were newly identified as HIV positive. The intervention specialist's time totaled 197 minutes per index patient. The cost of the intervention specialist's time, travel, and overhead was $268,425: $251 per index patient, $427 per partner notified, or $2,200 per new HIV infection identified. No demographic characteristic of the index patient strongly predicted the likelihood of finding an infected partner. CONCLUSION: We could not compare the effectiveness of different partner notification approaches because of frequent crossover between randomized groups. The cost of partner notification can be compared with other approaches to acquired immunodeficiency syndrome prevention, but the benefits are not easily measured. We do not know the number of HIV cases prevented or the value of fulfilling the ethical obligation to warn partners of a potential threat to their health.     

Cost-effectiveness of chemoprophylaxis after occupational exposure to HIV

OBJECTIVES: To assess the economic efficiency of recent US Public Health Service recommendations for chemoprophylaxis with a combination of antiretroviral drugs following high-risk occupational exposure to human immunodeficiency virus (HIV). To provide a framework for evaluating the relative effectiveness and costs associated with candidate postexposure prophylaxis (PEP) regimens. METHODS: Standard techniques of cost-effectiveness and cost-utility analysis were used. The analysis compares the costs and consequences of a hypothetical, voluntary combination-drug PEP program consisting of counseling for all HIV-exposed health care workers, followed by chemoprophylaxis for those who elect it vs an alternative in which PEP is not offered. A societal perspective was adopted and a 5% discount rate was used. Hospital costs of recommended treatment regimens (zidovudine alone or in combination with lamivudine and indinavir) were used, following the dosing schedules recommended by the US Public Health Service. Estimates of lifetime treatment costs for HIV and acquired immunodeficiency syndrome were obtained from the literature. Because the effectiveness of combination PEP has not been established, the effectiveness of zidovudine PEP was used in the base-case analyses. MAIN OUTCOME MEASURES: Net PEP program costs, number of HIV infections averted, cost per HIV infection averted, and cost-utility ratio (net cost per discounted quality-adjusted life-year saved) for zidovudine, lamivudine, and indinavir combination PEP. Lower bounds on the effectiveness required for combination regimens to be considered incrementally cost saving, relative to zidovudine PEP alone, were calculated. Multiple sensitivity and threshold analyses were performed to assess the impact of uncertainty in key parameters. RESULTS: Under base-case assumptions, the net cost of a combination PEP program for a hypothetical cohort of 10,000 HIV-exposed health care workers is about $4.8 million. Nearly 18 HIV infections are prevented. The net cost per averted infection is just less than $400,000, which exceeds estimated lifetime HIV and acquired immunodeficiency syndrome treatment costs. Although combination PEP is not cost saving, the cost-utility ratio (about $37,000 per quality-adjusted life-year in the base case) is within the range conventionally considered cost-effective, provided that chemoprophylaxis is delivered in accordance with Public Health Service guidelines. Small incremental improvements in the effectiveness of PEP are associated with large overall societal savings. CONCLUSIONS: Under most reasonable assumptions, chemoprophylaxis with zidovudine, lamivudine, and indinavir following moderate- to high-risk occupational exposures is cost-effective for society. If combination PEP is minimally more effective than zidovudine PEP, then the added expense of including lamivudine and indinavir in the drug regimen is clearly justified.     

Antiretroviral drugs as a public health intervention for pregnant HIV-infected women in rural South Africa: an issue of cost-effectiveness and capacity

OBJECTIVE: To estimate cost-effectiveness and capacity requirements for providing antiretroviral drugs to pregnant HIV-infected women in rural South Africa. SETTING: Hlabisa health district, where HIV prevalence among pregnant women was 26.0% in 1997. METHODS: Calculation of the number of paediatric HIV infections averted under three scenarios, and their cost. No intervention was compared with scenario A (zidovudine delivered within current infrastructure), scenario B (zidovudine delivered through enhanced infrastructure), and scenario C (short-course zidovudine plus lamivudine delivered through enhanced infrastructure). Cost-effectiveness was defined as cost per infection averted and cost per potential life-year gained. Capacity was determined in terms of staff and infrastructure required to effectively implement the scenarios. RESULTS: With no intervention, 657 paediatric HIV infections were projected for 1997. In scenario A this could be reduced by 15% at a cost of US$ 574 825, in scenario B by 42% at US$ 1520770, and in scenario C by 47% at US$ 764901. In scenario C, drugs accounted for 76% of costs, whereas additional staff accounted for 18%. Cost per infection averted was US$ 2492 and cost per potential life-year gained (discounted at 3%) was US$ 88. Cost of scenario C was equivalent to 14% of the 1997 district health budget. At least 12 extra counsellors and nurses and one laboratory technician, together with substantial logistical and managerial support, would be needed to deliver an effective intervention. CONCLUSION: Although antiretrovirals may be relatively cost-effective in this setting, the budget required is currently unaffordable. Developing the capacity required to deliver the intervention would pose both a major challenge, and an opportunity, to improve health services.     

Cost-effectiveness of thrombolytic therapy for acute myocardial infarction

OBJECTIVE: To estimate the cost-effectiveness of thrombolytic therapy versus no thrombolytic therapy for patients following acute myocardial infarction, focusing on the impact of time to treatment on outcome. METHODS: A decision model was developed to assess the benefits, risks, and costs associated with thrombolytic therapy for treatment of acute myocardial infarction compared with standard nonthrombolytic therapy. The model used pooled data from a recent study of nine large randomized, controlled clinical trials and 12-month outcome data from a recently published meta-analysis of thrombolytic therapy trial data. Outcomes were expressed in terms of survival to hospital discharge and survival to 1 year after discharge. The risks of treatment that led to death, morbidity, or added costs were estimated. The model determined excess and marginal costs per death averted to hospital discharge and at 1 year. Results were also estimated in terms of cost per year of life saved. Sensitivity analyses included variations in time to treatment and drug cost. RESULTS: The marginal cost of thrombolytic therapy per death averted at 1 year was $222,344, or $14,438 per year of life saved. For patients treated within 6 hours of acute myocardial infarction, the marginal cost per death averted was $181,536 at 1 year, or $11,788 per year of life saved. CONCLUSIONS: Thrombolytic therapy is significantly more cost-effective than many other cardiovascular interventions and compares favorably with other forms of medical therapy. Results suggest that shortening the time to treatment has a critical impact on the cost-effectiveness of thrombolytic therapy.     

Anesthesia of wild red howler monkeys (Alouatta seniculus) with medetomidine/ketamine and reversal by atipamezole

The cost-effectiveness of two different methods of prevention of morbidity and mortality due to Plasmodium falciparum malaria, vaccination and impregnation of mosquito nets with permethrin, was compared. The analysis was performed with reference to the cohort of all children born in The Gambia in 1990 and protected for 5 years, using estimates of costs from studies in The Gambia. The vaccine was assumed to be given in three doses before the age of 6 months, through the Expanded Programme of Immunization, and to remain effective up to the age of 5 years. The bednets were assumed to be impregnated at 6-monthly intervals over the 5-year period. The expected number of deaths and attacks due to P. falciparum in the first 5 years of the 1990 cohort's lives were estimated from published literature. The numbers of deaths and attacks averted by the two strategies were then estimated by decision analysis, using the best estimates of effectiveness available in the literature. The vaccine strategy would have averted an estimated 743 deaths and 50,502 malaria attacks, whereas the net impregnation would have averted 1537 deaths and 69,415 attacks. The estimated cost per death averted was U.S. $252 for the vaccine and U.S. $711 for net impregnation. The estimated cost per P. falciparum attack averted was U.S. $3.71 for the vaccine and U.S. $15.75 for net impregnation. Sensitivity analysis, examining the effect of varying the vaccine cost or insecticide cost, the efficacy of the vaccine or net impregnation, and the percentage coverage of the population, confirmed the greater cost-effectiveness of the vaccine strategy for either of the outcomes examined under the conditions of the model. However, limitations on the absolute number of deaths and malaria attacks which can averted by currently available vaccines demonstrate that a vaccine of higher efficacy would be highly desirable.     

Prenatal screening for cystic fibrosis carriers: an economic evaluation

The cloning of the CFTR gene has made it technically possible to avert the unwanted birth of a child with cystic fibrosis (CF). Several large trials offering prenatal CF carrier screening suggest that such screening is practical and that identified carriers generally use the information obtained. Therefore, a critical question is whether the cost of such screening is justified. Decision analysis was performed that used information about choices that pregnant women were observed to make at each stage in the Rochester prenatal carrier-screening trial. The cost of screening per CF birth voluntarily averted was estimated to be $1,320,000-$1,400,000. However, the lifetime medical cost of the care of a CF child in today's dollars was estimated to be slightly>$1,000,000. Therefore, despite both the high cost of carrier testing and the relative infrequency of CF conceptions in the general population, the averted medical-care cost resulting from choices freely made are estimated to offset approximately 74%-78% of the costs of a screening program. At present, if it is assumed that a pregnancy terminated because of CF is replaced, the marginal cost for prenatal CF carrier screening is estimated to be $8,290 per quality-adjusted life-year. This value compares favorably with that of many accepted medical services. The cost of prenatal CF carrier screening could fall to equal the averted costs of CF patient care if the cost of carrier testing were to fall to $100.     

Vestibular hypersensitivity to clicks is characteristic of the Tullio phenomenon

OBJECTIVES: This study evaluated the cost-effectiveness of a smoking cessation and relapse-prevention program for hospitalized adult smokers from the perspective of an implementing hospital. It is an economic analysis of a two-group, controlled clinical trial in two acute care hospitals owned by a large group-model health maintenance organization. The intervention included a 20-minute bedside counseling session with an experienced health counselor, a 12-minute video, self-help materials, and one or two follow-up calls. METHODS: Outcome measures were incremental cost (above usual care) per quit attributable to the intervention and incremental cost per discounted life-year saved attributable to the intervention. RESULTS: Cost of the research intervention was $159 per smoker, and incremental cost per incremental quit was $3,697. Incremental cost per incremental discounted life-year saved ranged between $1,691 and $7,444, much less than most other routine medical procedures. Replication scenarios suggest that, with realistic implementation assumptions, total intervention costs would decline significantly and incremental cost per incremental discounted life-year saved would be reduced by more than 90%, to approximately $380. CONCLUSIONS: Providing brief smoking cessation advice to hospitalized smokers is relatively inexpensive, cost-effective, and should become a part of the standard of inpatient care.     

The cost-effectiveness of a multifactorial targeted prevention program for falls among community elderly persons

OBJECTIVES: Falls and fall injuries are common-potentially preventable-causes of morbidity, functional decline, and increased health-care use among elderly persons. The current analyses, performed on data obtained as part of a randomized controlled trial conducted within a health maintenance organization, describe the costs of a multifactorial, targeted prevention program for falls, present total net health-care costs, estimate the cost per fall prevented, and describe acute fall-related health-care costs. METHODS: The 301 participants were at least 70 years of age and possessed at least one of eight targeted risk factors for falling. The 153 participants randomized to the targeted intervention (TI) group received a combination of medication adjustment, behavioral recommendations, and exercises as determined by their baseline assessment. The 148 participants randomized to the usual care (UC) group received a series of home visits by a social work student. RESULTS: The mean intervention cost per TI participant was $925 (range $588 to $1,346). Total mean health-care costs were approximately $2,000 less in the TI than UC group, whereas median costs were approximately $1,100 higher in the TI than UC group. The TI strategy was unequivocally cost effective when mean costs were used because the intervention was associated with both lowered total health-care costs and fewer total and medical care falls. In sensitivity analyses, the cost-effectiveness of the TI strategy appeared robust to widely differing assumptions about total health-care costs (25th to 75th percentile of the actual distribution) and intervention costs (minimum to maximum costs). In subgroup analyses, the TI strategy showed its strongest effect among individuals at high risk of falling, defined as possession of at least four of the eight targeted risk factors. CONCLUSIONS: Consideration should be given toward incorporating and reimbursing the cost of fall-prevention programs within the usual health care of community-living elderly persons, particularly for those persons at high risk for falling.     

Cost analysis and HIV prevention interventions.

Comments on the review by J. A. Kelly et al (see record 1994-10963-001) regarding public health interventions designed to prevent, reduce, or eliminate behavior that put individuals at risk for becoming HIV-infected. D. R. Holtgrave expands on the review by discussing important economic policy issues, including the cost of HIV prevention interventions and the societal economic benefits of prevention programs. Methods for estimating the cost of an HIV prevention intervention are described. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Advanced HIV infection treated with zidovudine monotherapy: lifetime values of absolute cost-effectiveness as a pharmacoeconomic reference for future studies evaluating antiretroviral combination treatments. The Osservatorio SIFO sui Farmaci

OBJECTIVE: This study was undertaken to evaluate the cost and the effectiveness of zidovudine monotherapy in patients with advanced HIV infection and to derive preliminary data on the cost-effectiveness of the triple treatment with saquinavir plus zalcitabine plus zidovudine compared with zidovudine alone. DESIGN: We used a combined method of survival analysis utilizing both the quality-adjusted time without symptoms or toxicity (Q-TWIST) method and the Gompertz approach. This combined method was applied to assess the absolute cost-effectiveness and cost-utility ratios of zidovudine monotherapy and to perform a preliminary incremental cost-effectiveness comparison of saquinavir plus zalcitabine plus zidovudine versus zidovudine alone. The clinical material used in our study was derived from two reports on the treatment of advanced HIV infection. Data of lifetime costs of HIV infection were obtained from published information. RESULTS: In patients with advanced HIV infection treated with zidovudine monotherapy, lifetime survival was 252.1 discounted person-years per 100 patients. Using an average lifetime cost of $93,000 (discounted) per individual, the absolute ratio of cost-effectiveness for zidovudine monotherapy was $36,980 per life-year, while the absolute cost-utility ratio was $47,112 per quality-adjusted life-year. In the comparative analysis of saquinavir plus zalcitabine plus zidovudine versus zidovudine alone, our calculations showed that the administration of the triple treatment can have an "average" cost-effectiveness, provided that mean lifetime survival per patient (discounted) is improved to at least 3.68 years (with an average survival gain of at least 14 mo per patient). CONCLUSIONS: The values of absolute cost-effectiveness and cost-utility ratios for zidovudine monotherapy are a useful reference point for further pharmacoeconomic studies in the area of antiretroviral drugs.     

The role of reactive nitrogen intermediates in modulation of gametocyte infectivity of rodent malaria parasites

Two hundred and fourteen young women received acquired immunodeficiency syndrome (AIDS) prevention interventions at an inner-city family health center serving minority patients predominantly. The community in which the health center is located has a high incidence of intravenous (IV) drug abuse. Either a peer or a health care provider delivered the intervention. In the peer-delivered intervention, a trained peer educator reviewed with patients an AIDS "Rap" videotape and several AIDS brochures, which imparted information about human immunodeficiency virus (HIV), its transmission, and prevention. In the provider-delivered intervention, family practice residents, attending physicians, and nurse practitioners used a patient-centered counseling approach to convey the same information. Questionnaires administered immediately before and after the intervention and at one month follow-up evaluated changes in knowledge, attitudes, and behavior. Analyses of data from both combined intervention groups revealed significant improvements in several areas of knowledge, including the effectiveness of using a condom and cleaning IV drug implements with bleach to prevent transmission of HIV. Many improvements were retained at the one-month follow-up. In addition, subjects in both groups who were sexually active stated immediately after the intervention that asking a sexual partner about past sexual experience would now be less difficult, and at one-month follow-up they reported a significant decrease in the frequency of vaginal sex. Our findings suggest that counseling by physicians can achieve more changes in knowledge of sexual risks, whereas peer education can achieve greater changes in knowledge about IV drug use. Results show that both approaches to AIDS prevention used in this study can significantly affect knowledge, attitudes, and sexual behavior.     

Modelling the spread of HIV in social networks of injecting drug users

OBJECTIVE: To explore the risk of a future rise of HIV prevalence in populations of injecting drug users (IDU) with low HIV prevalence but continuing risk behaviour, and to study the potential influence of prevention measures on HIV incidence. METHODS: A stochastic simulation model was used to describe a network of long-term buddy relationships in a population of IDU. HIV transmission took place when borrowing injecting equipment from an infected buddy or stranger. The probability of transmission depended on the duration of infection. Individuals remained in the population on average for 10 years. Two surveys amongst IDU in The Netherlands containing information about risk behaviour were used to estimate model parameters. We investigated the effect of different prevention strategies. RESULTS: Below a threshold sharing frequency the epidemic never takes off; above the threshold there is a large stochastic variation in prevalence. After reduction of risk behaviour, HIV prevalence decreases very slowly. Reducing sharing with strangers is more effective than reducing the overall sharing frequency. Prevention focused on new IDU greatly reduces HIV incidence. Reduction of sharing frequency in HIV-positive IDU has no significant influence on HIV incidence at HIV testing rates of 10 and 50% per year, if infectivity is highest during primary infection. CONCLUSIONS: A stabilization of HIV prevalence does not exclude the possibility of a future rise. Predictions about the future course of an epidemic are inherently uncertain. The effect of prevention programmes on HIV prevalence only becomes visible on a long time-scale. Social networks of IDU play an important role in transmission dynamics and success of prevention.     

Effects and generalizability of communally oriented HIV-AIDS prevention versus general health promotion groups for single, inner-city women in urban clinics.

A primary prevention, behavioral intervention designed to reduce HIV risk behavior was tested in a randomized, controlled trial with single, inner-city women. A total of 935 women were randomly assigned to 1 of 3 conditions: a small group, 6-session communally oriented HIV prevention intervention; a yoked general health promotion intervention control; or a standard care control. Both interventions involved the interactive use of videotapes by live group leaders. The HIV prevention intervention, in particular, resulted in significant positive effects on self-reported and behaviorally assessed safer-sex behavior. Women in the HIV prevention group showed reduced point prevalences of medically tested sexually transmitted diseases at follow-up in some comparisons. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Australia's role in HIV prevention in the developing world

A scientist with the National Centre in HIV Epidemiology and Clinical Research at the University of New South Wales in Sydney, Australia, addresses the fact that Australians working in the area of HIV infection have been very successful in prevention, treatment, and care. In the early 1980s, a bipartisan political decision was made to foster an effective partnership between HIV-infected communities, health care providers, and governments. HIV-infected communities included sex workers, prisoners, Aboriginal people, and high profile gay community activists. These three different groups succeeded in forming such a partnership, as reflected in the fact that the annual number of new HIV cases is down to 500 from a peak of 3000 in 1984. A key method used to contain HIV infection was needle-and-syringe exchange programs and continuing access to needles to prevent HIV transmission in the injecting drug community. Even though Australia has all this experience and success, it had a backseat role in ushering in the UNAIDS program because Australia did not contribute a significant share of the agency's relatively small budget (US$100 million/year). If Australia were to give just 10%, it would acquire a front row seat along with the Netherlands, Sweden, Belgium, France, and the UK. These nations have the greatest say as to where UNAIDS funds go. The Australian international aid organization has recently received an increase in funds, $110 million for 4 years to spend on four areas, one of which is HIV/AIDS. Australia has just allocated $25 million for a 5-year program for HIV/STD (sexually transmitted disease) prevention in Indonesia. This money would have been able to buy Australia a leading role in UNAIDS. Australians need to reassess their priorities. Australians can help their neighbors in the Asia-Pacific region move away from their denial of HIV to HIV prevention and care. They can conduct clinical trials of shorter and more user-friendly regimens of antiviral drugs that may lead to reduced perinatal transmission and research on microbicides. They can prevent tuberculosis and introduce manageable methods of securing safe blood supplies and mass screening.     

Perinatal intervention trial in Africa: effect of a birth canal cleansing intervention to prevent HIV transmission

BACKGROUND: Perinatal transmission of human immunodeficiency virus (HIV) type 1 contributes significantly to infant mortality. Exposure in the birth canal may account for some transmission. We examined the efficacy of a birth canal washing procedure in reducing perinatal transmission in Malawi. METHODS: The infection status of infants of 3327 control women (conventional delivery procedures) was compared with that of 3637 infants of intervention-delivered women. The infants' HIV status was determined by polymerase chain reaction on dried blood spots collected at 6 and 12 weeks of age. The intervention consisted of manual cleansing of the birth canal with a cotton pad soaked in 0.25% chlorhexidine, which was done on admission in labour and every 4 h until delivery. FINDINGS: No adverse reactions to the intervention procedure were seen. 2094 (30%) of the enrolled women were HIV-infected, and 59% of their infants were seen in follow-up. Among 982 vaginal vertex singleton deliveries to HIV-infected women, 269 (27%) infants were infected. The intervention had no significant impact on HIV transmission rates (27% in 505 intervention women compared with 28% in 477 control women), except when membranes were ruptured more than 4 h before delivery (transmission 25% in the intervention group vs 39% in the control group). INTERPRETATION: If birth canal exposure is an important risk factor, different or additional methods to reduce the risk of perinatal HIV transmission should be tested. Alternatively, perhaps birth canal exposure is not a major contributor to perinatal infection risk.     

Accounting for time-dependent covariates whose levels are influenced by exposure status

Injury sustained through falling is a significant risk for the elderly and a significant burden on the health service. Although many risk factors have been detected and interventions proposed, there remains limited evidence concerning the cost-effectiveness of fall prevention. This study addressed the cost-effectiveness of a home assessment and modification program hypothesised to reduce risk of falling for the independent elderly. Due to a lack of direct clinical trial evidence concerning such an intervention, a decision analytic model was developed to simulate the potential costs and outcomes of the intervention. The model was developed using available published literature concerning injury in the elderly, focusing on Australian data where possible. Cost-effectiveness was estimated as the cost per fall prevented and cost per injury prevented. Over a one-year period, the incremental cost of introducing the intervention was $172 per person, resulting in an incremental cost per fall prevented of $1,721 and cost per injury prevented of $17,208. Over a 10-year period, the intervention resulted in a cost saving of $92 per person (i.e. dominance, with cost savings in addition to reduced falls and injuries). This analysis indicates that there is potential for considerable benefit to be gained from this intervention, in terms of less morbidity, fewer hospitalisations and, possibly, improved quality of life. However, these results are based on a model constructed from various data sources and assumptions so, although results are indicative, further research is required to provide firm data before definitive policy conclusions and recommendations may be made.