HIV AIDS

Highly active retroviral therapy (HAART) which consists of inhibitor of viral enz5mie (reverse transcriptase (RT) and proteases) which is also a part of biosensor, i.e., induction of inhibitor viral enz mie into host and its use as biosensor against HIV [6], In field of medicine there are nucleic acid biosensor, which helps, in medical diagnosis [7], 

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Pommier Y, Johnson AA, Marchand C (2005) Integrase inhibitors to treat HIV/AIDS, Nat Rev Drug Discov 4 236-248... 

The cost-effectiveness analysis of antiviral therapy has to be seen under the precondition that no long-term effects, such as drug resistance, occnr. Future analysis might show that we strongly underestimated the long-term costs of HIV/AIDS. 

The proceeding chapters give wimess of an overwhelming scientific development. Antiviral intervention has become a standard, and the worldwide availability of this innovation is perceived as a humanitarian matter of course with a value of its own. However, such an important therapy progress has to be seen in competition with other allocations of scarce funds. Health care resources are Umited - in one country more than in another, but in principle funds invested to antiretroviral intervention will not be available for prevention of HIV/AIDS or for the cure of other diseases. This fundamental scarcity calls for a rational utilization of existing resources and a scientific calculation of the socio-economic impact of antiretroviral intervention. 

This chapter adds the socio-economic dimension to the medical or technical perspectives of the proceeding contributions of this book. As its health economic terminology and approach might be unfamiliar to some readers, we start with a section on methodology. In particular, we present an overview of the concept of Cost-of-Illness (COI) and of relevant health economic evaluation techniques. In Sect. 2, we present the basic findings of a meta-analysis of the socio-economic costs of HIV/AIDS and of the socio-economic impact of antiviral intervention. The major findings are reflected in Sect. 3. The chapter closes with a speculation on long-term socio-economic costs of antiviral intervention. 

The studies presented in the Sect. 2 of this paper give a comprehensive picture of the Cost-of-Illness (COI) of HIV/AIDS. In a broad sense, these COI are the difference... 

In countries with an existing (social) health insurance system, it is usually rather simple do receive a close-to-reality estimate of the provider Costs-of-Illness. The insurance pays the bills of general practitioners, specialists, hospitals, pharmacies, laboratories, etc. so that the total costs per patient can easily be determined. However, in some countries we cannot receive this data, and sometimes confidentiality regulations do not permit the transfer of insurance data, so that, for instance, provider costs of difference phases of HIV/AIDS can be calculated. In this case, a sample of patient files has to be analyzed with permission of the patients so that the provider costs can be recorded. 

The calculation of direct household costs of HIV/AIDS is quite difficult. First, resource consumption is hardly documented, so that patients have to be interviewed or be asked to keep household diaries for all expenditure due to their disease. Second, it is frequently not easy to allot a certain expenditure to a specific disease. Co-payments for drugs, practitioner, and hospital services as well as transport to and from the provider are easily allocated to the COI of this disease. But other direct household costs might be even higher, such as the costs of a special diet, but it is very difficult to analyze whether these costs are really incurred due to this illness. Studies demonstrate that direct household costs might be small in developed countries, but they might make up to 50% of the total COI in developing countries (Su et al. 2006). 

Consequently, there is no golden standard of calculating indirect Costs-of-Illness. The estimates based on different methodologies might differ significantly, and so will the total Costs-of-Illness of HIV/AIDS. It is possible to analyze the quality of studies whether all components (such as indirect costs of caring relatives etc.) have been included. Whether the methodology applied is best cannot always be determined. 

HIV/AIDS-patient to mortahty, progression. to increase of gross national... 

Output return on investment, cost recovery, sustainability, coverage, sales etc. care workers per fife year gained Admission of HIV/AIDS Speciahst... 

The following chapter will analysis a number of published studies on COl on HIV/AIDS and on antiviral intervention. For each study we analyse whether it can... 

From the early beginning of treating HIV/AIDS, most health economic studies focussed on the calculation of provider costs. During the first years there had been a clear dominance of research on hospital costs for patients with AIDS, in particular,... 

The economic impacts of HIV/AIDS disease have also been analyzed in Europe. Beck (1995) studied the AIDS-related costs in a national AIDS referral center in London. He concluded that share of total drug cost increased between 1985 and 1989 from 5.0% to 30.0%. The median survival time from the date of the diagnosis of AIDS was 14.6 months before the introduction of Zidovudine (1987) and 21.0 months afterwards. 

Kyriopoulos et al. (1995) compared different estimates of HIV/AIDS healthcare expenditure in Greece based on study years 1987-1993. Average annual cost per... 

The number of studies for other countries is limited. Krentz et al. (2003) analyzed the provider costs of providing medical care to patients with HIV/AIDS in Southern Alberta Canada) between April 1995 and April 2001. The authors collected all patient-specific provider costs including the cost of drugs (HIV and non-HIV drugs), outpatient care (including physician costs and laboratory testing), and... 

Caekelbergh et al. calculated the direct costs of HIV/AIDS in Belgium from the health care pay perspective. On the basis of 150 patients, they determined the costs of antiretrovirals, outpatient and inpatient resource use for the year 2005. They realize that the costs strongly depend on the CD4- - T-cell count, that is, the annual costs per patient are on average about US 2,900 for a patient with a CD4+ T-cell count >500, US 3,200 (CD4 351-500), US 8,650 (CD4 210-350), US 16,600 (CD4 101-200), US 31,300 (CD4 51-100), and US 49,400 (CD4 0-50), respectively. Consequently, the early detection of an HIV-infection as well as proper management that prohibits disease transition is of high cost-importance. 

Finally, Kimura (2002) estimated the socio-economic impact of HIV/AIDS in Japan and estimated the inpatient and outpatient costs of beating HIV-infected adults. He calculated costs of US 17,858 to US 21,431 p.a. for outpatients, whereas 83% were due to antiretrovirals. The cost estimates for inpatients with Aids varies strongly. Inpatients with a CD4+ count from 200-499 had costs of US 37,007 p.a., inpatients with a CD4- - count between 50 and 199 had costs of US 76,197 p.a., and inpatients with a CD4+ count of less then 50 had average cost of US 170,155 p.a. 

Estimates of the lifetime COl are needed for temporal and international comparisons and for assessment of the efficiency of prevention strategies. During the first years of HIV/AIDS treatment, direct lifetime costs were only estimated by simple projections based on retrospective data. Later, specific statistical tools were adopted to estimate life expectancy and lifetime costs. The results of lifetime estimates are very sensitive to imputed assumptions. Table 4 demonstrates some studies in this field. 

A final assessment is difficult as the number of studies on lifetime costs of HIV/AIDS is very small, and the last few years have seen only few publications in that field. However, with an increasing life expectancy due to HAART, we can expect that the provider lifetime COI will strongly increase. 

In a nut-shell Out knowledge of the direct COI of HIV/AIDS has strongly increased in the last 10 years. Depending on the level of care in a particular country, provider cost per case might be as high as US 25,000 p.a., and the discounted lifetime costs in the HAART era will be more than 100,000 US per case. There can be no doubt that AIDS will cause higher costs for the patients and his household, but we know almost nothing about these costs. 

Hanvelt et al. (1994) estimated the nationwide indirect costs of mortality due to HIV/AIDS in Canada. A descriptive, population-based economic evaluation study was conducted. Data from Statistics Canada were used, which contained information about aU men aged 25-64 years for whom HIV/AIDS or another selected disease was listed as the underlying cause of death from 1987 to 1991. Based on the human capital approach, the present value of future earnings lost for men was calculated. The estimated total loss from 1987 to 1991 was US 2.11 billion, with an average cost of US 558,000 per death associated with HIV/AIDS. Future production loss due to HIV/AIDS was more than double during the period 1987 to 1991, from US 0.27 to US 0.60 billion. A more comprehensive update of this smdy was presented by Hanvelt et al. (1996). The same database and the same data section but for the calendar years 1987-1993 was used. The indirect cost of future production due to HIV/AIDS in Canada based on the human capital approach for that period was estimated to be US 3.28 billion. The authors also calculated the willingness-to-pay to prevent premature death due to HIV/AIDS, which was estimated based on... 

HIV/AIDS-induced mortality and morbidity of workers can result in significant economic loss to business, including direct cost due to increased insurance premiums paid by employers, costs due to increased benefits paid by employers, indirect costs due to lost time due to illness, lost and reduced productivity, and other costs, like cost to new training and hiring of staff. Famham and Gorsky (1994) used a Markov model to calculate the expected medical, disability, employee replacement, life insurance, and pension costs to a business firm in the US for an HIV-infected... 

In the early period of the pandemic, before the development of sensitive and reliable instruments to diagnose early infection, only patients with advanced AIDS presented to health care facilities. As a result, the estimates and projects of the costs for HIV/AIDS patients based on observed health care utilization were high. For example, Scitovsky and Rice estimated the annual costs of AIDS care in the United States in 1985, 1986, and 1991 to be US 630 million, US 1.1 billion, and US 8.5 billion, respectively these costs represented the direct and indirect costs of HIV infections (Scitovsky and Rice 1987 Scitovsky 1988, 1989). More than 80% of these costs stemmed from losses in productivity, a reflection of the fact that AIDS has afflicted primarily working-age adults. The great increase in total costs by 1991 is caused by a projected increase in the prevalence. 

There is a growing body of literature on the costs of HIV/AIDS (Homberger et al. 2007), but all studies address only one branch of the COI tree (Fig. 1). Until now there is not a single publication fully covering all aspects of COI of HIV/AIDS, and different methodologies (such as human capital approach vs. friction cost method) make comparison difficult. In addition, the time lag between the year of the study and the publication is between 3 and 10 years. That is one reason why we know so little about the costs of the last 5 years results are not yet published. 

Compared with the standard health economic methodology applied in COI studies for other diseases (e.g. Keith and Shackleton 2006 Welte et al. 2000 Leidl et al. 1999 Henke et al. 1997 Xie et al. 1996), the quality of health economic analysis of HIV/AIDS is not always satisfactory as far as costs are concerned (Levy et al. 2006). Sometimes it is not clear whether researchers included both inpatient and outpatient medications in their analyses. Equally important, many of the early studies used costs and charges interchangeably data using charges may not accurately reflect true costs. Drummond and Davis (1988) also argued that there have been incorrect estimates of the survival times and costs in aU these early studies, since there were no explicit adjustments made for disease severity. 

In a long-term perspective, a number of important feedback loops might exist, with tremendous consequences on the COl and the cost-effectiveness of intervention programmes. Some of these loops were discussed in the Special Issue on HIV/AIDS of the Lancet (Vol. 368, August 5-11, 2006), but we would like to stress their importance for the long-term socio-economic impact of antiviral intervention. 

Second, sexual behavior might change if the good message of a treatment of HIV/AIDS spreads. Already today we have an increase of incidence in some countries, such as Germany. This might be partly due to the long-term consequence of a reduced horror. ... 

Becker R, Shakur U (2001) The impact of drug comphance on the cost of treating HIV/AIDS in Africa, Value Health 4 439 140... 

Caekelbergh K et al (2007) Cost of care for HIV/AIDS in Belgium according to disease stage. Poster presented at the 11th European AIDS Conference/EACS, 24-27 October 2007, Code P19,5/01... 

Goodman MR (1988) Study notes in system dynamics, Cambridge, London Haburchak DR (1997) The economics of AIDS in America, AIDS Read 7 155-160 Hanvelt RA, Ruedy NS, Hogg RS et al (1994) Indirect costs of HIV/AIDS mortality in Canada, AIDS 8 F7-F11... 

Hornberger J, Holodniy M, Robertus K, Winnike M, Gibson E, Verhulst E (2007) A systematic review of cost-utility analyses in HIV/AIDS imphcations for public pohcy, Med Decis Making 27(6) 789-821... 

Moatti JP, Spire B, Kazatchkine M (2004) Drug resistance and adherence to HIV/AIDS antiretroviral treatment against a double standard between the north and the south, AIDS I8 S55-S6I Moore RD, Chaisson RE (1997) Costs to Medicaid of advancing immunosuppression in an urban HIV-infected patient population in Maryland, J Acquir Immune Defic Syndr Hum Retrovirol 16 223-231... 

Rovura J, Leidl R (1995) Projecting individual healthcare costs of HIV/AIDS patients in Catalonia, in FitzSimons D, Hardy V, Tolley K (eds) The economic and social impact of AIDS in Europe. Cassell, London, pp 82-89... 

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