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The impact of new antiretroic therapeutic schemes on the cost for AIDS treatment in Greece |
Kyriopoulos J E, Geitona M A, Paparizos V A, Kyriakis K K, Botsi C A, Stavrianeas N G |
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Record Status This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn. Health technology The study examined triple antiretroviral therapy for the treatment of human immunodeficiency virus (HIV) and the prevention of acquired immunodeficiency syndrome (AIDS) events. The therapy consisted of two reverse transcriptase inhibitors and one protease inhibitor.
Economic study type Cost-effectiveness analysis.
Study population The study population comprised patients being treated for HIV at various stages of their disease.
Setting The setting was secondary care. The economic study was carried out in Athens, Greece.
Dates to which data relate The effectiveness and resource use data related to 1996 and 1997. The unit costs were derived from public health sector prices and related to data published in 1995 and 1996.
Source of effectiveness data The effectiveness data were derived from a single study.
Link between effectiveness and cost data The costing was undertaken on a random sample of 60 of the patients in the effectiveness study. It was not stated whether the cost analysis was performed prospectively or retrospectively.
Study sample The effectiveness data appear to have been derived both from all HIV-positive patients who were treated at one particular hospital in 1996 and 1997, and from a randomised sample of 60. The entire study sample consisted of 349 patients in 1996 (the control group) and 436 patients in 1997 (the intervention group). The randomised sample of 60 patients were presumably acting as their own controls. Likewise, in the entire cohort of patients, many are likely to have appeared in both the 1996 and 1997 groups. No power calculations to determine the sample size were reported.
Study design This was a before-and-after study on a similar group of patients. All the patients were treated with dual therapy in 1996 and triple therapy in 1997. The study was carried out at a single centre. The patients appear to have been followed for a maximum of 2 years. No loss to follow-up was explicitly reported, but the entire cohort size was larger in 1997 than in 1996, so it is clear the samples were not exactly the same.
Analysis of effectiveness It would appear that all patients in the study were accounted for in the analysis. The authors did not compare the two patient samples at baseline, but, as many of them acted as their own controls, this is less of a drawback. The primary health outcomes used in the analysis were days in hospital, AIDS-events including opportunistic infections, and deaths.
Effectiveness results Results for the entire cohort.
Seventy-six of the 349 patients in 1996 were hospitalised compared with 52 of the 436 patients in 1997, (p=0.0003).
The patients spent a total of 3,485 days in hospital in 1996 versus 1,780 days in 1997, (p<0.00001).
There were 129 AIDS-events in 1996 compared with 40 in 1997, (p<0.00001).
There were 28 new patients in the advanced disease stage in 1996 compared with 11 in 1997, (p=0.00078). Forty-one patients died in 1996 versus only 16 in 1997, (p=0.00011).
Results for the randomised sample of 60.
Thirteen were hospitalised in 1996 versus 5 in 1997, (p=0.07).
There was a total of 542 hospital days in 1996 versus 178 in 1997, (p<0.00001).
The average length of in-patient stay was 41.7 days in 1996 versus 35.6 in 1997, (p-value not stated).
There were 281 outpatient visits in 1996 versus 252 in 1997, (p-value not stated).
There were 24 AIDS-related events (infections, neoplasms etc.) in 1996 versus 5 in 1997, (p=0.003), and no deaths were reported in either year.
Clinical conclusions This study demonstrated superior health outcomes with triple therapy in comparison with dual therapy for the treatment of HIV. The main benefit was fewer AIDS-events, which resulted in significantly less time in hospital and significantly fewer deaths.
Measure of benefits used in the economic analysis The clinical outcomes were left disaggregated. This was therefore classified as a cost-consequences study.
Direct costs The analysis included hospital days, clinic visits, physician salaries, laboratory tests, day care services, medications and "other extra expenses" as the direct health service costs. The quantities of hospital days and clinic visits were reported separately. The public health sector prices were used as the unit costs. These related to 1995 and 1996. The resource use data related to 1996 and 1997. The costs were inflated to 1998 values using the consumer price index of the National Statistical Office of Greece, and were converted to US dollars. Discounting was not required in this study.
Statistical analysis of costs The authors used statistical tests to compare the use of hospital days for the 60 patients in the costing study in 1996 and 1997. In 1996, these patients spent a total of 542 days in hospital compared with 178 in 1997, (p<0.00001).
Indirect Costs The indirect costs were not included in the analysis, though the authors mention that patients on triple therapy were more able to continue working. Also, 26 of the patients in 1996 collected disability benefits, compared with 14 in 1997, (p=0.011).
Sensitivity analysis No sensitivity analyses were carried out.
Estimated benefits used in the economic analysis See the 'Effectiveness Results' section.
Cost results The annual cost of treatment was $14,737 in 1996.
The annual cost of treatment in 1997 was slightly less at $13,403.
The results of the statistical test were not provided, but the authors stated that the results were not significant.
These costs did not include the costs of dealing with any side effects of the drugs. The decline in total costs was due to a reduction in every cost component (hospitalisations, laboratory tests, operational costs) except for medications, which were more costly in 1997. Within the medication category, there was a shift away from drugs to treat infectious disease and other drugs, and towards antiretroviral medication.
Synthesis of costs and benefits The costs and benefits were not combined.
Authors' conclusions This study showed that triple therapy provides better clinical outcomes at a slightly lower cost. This lower cost is the result of a substitution of antiretroviral costs for the costs of treating acquired immunodeficiency syndrome (AIDS)-events such as infections.
CRD COMMENTARY - Selection of comparators The comparator of dual therapy represented what used to be current practice in the setting of this study. In the NHS (and other health care systems), triple therapy is routinely offered to some patients. Thus, this comparison may be of limited use to decision-makers in some health care systems. Further, the authors did not, at any point, specify which reverse transcriptase inhibitors and protease inhibitors were routinely used in their setting for dual or triple therapy.
Validity of estimate of measure of effectiveness This study used a before-and-after design on the same patient population and was, therefore, non-randomised. There are, however, factors that justify the conclusion that triple therapy was clinically superior in this study. Firstly, the differences in the clinical outcomes were large and definitely statistically significant. Second, the outcomes in the control and intervention groups were measured only a year apart, so there are less likely to have been changes in treatment other than the switch from dual to triple therapy. On a related note, the pragmatic design of this study enhances its external validity.
In describing the selection of patients for the effectiveness study, the authors state "clinical data are derived from all HIV-positive patients hospitalised in 1996 and 1997". However, the data they report suggest that fewer than one quarter of patients in the study were hospitalised. Thus, there is some confusion about whether the study included all patients who were treated in hospital, or merely those who were inpatients. Given this uncertainty, it is difficult to say whether the study sample was representative of the study population.
Moreover, since the sample size in 1997 was 25% larger than in 1996, it would appear that the study included patients who were treated in 1996 and/or 1997. Given that the two study groups were obviously not the same, and the study was not randomised, it would have been useful to have seen a comparison of the baseline characteristics of the two groups.
Validity of estimate of measure of benefit No summary measure of benefit was used since this was a cost-consequences study.
Validity of estimate of costs This study included all the major costs relevant to the perspective of a publicly funded health care system. Other public costs were discussed but not measured. Some of the resource use quantities were reported separately and could, therefore, be generalisable to other settings. The resource use quantities were derived from a single study and some of the results were subjected to statistical tests.
The authors cited, as limitations of their study, the exclusion of indirect and intangible costs, and the belief that the public sector prices (on which the costing was based) are an underestimate of the true value of the resources.
Other issues The authors stated that the cost-effectiveness of triple therapy has been shown in international studies. They suggested that these findings confirm this result for the Greek public health care system. The authors also acknowledged that antiretroviral treatment at their centre may change, in which case the current study would be out-of-date.
Implications of the study The authors recommend the development of guidelines for the treatment of HIV and AIDS in Greece.
Bibliographic details Kyriopoulos J E, Geitona M A, Paparizos V A, Kyriakis K K, Botsi C A, Stavrianeas N G. The impact of new antiretroic therapeutic schemes on the cost for AIDS treatment in Greece. Journal of Medical Systems 2001; 25(1): 73-80 Other publications of related interest Paparizos V, Danaka G, Kornarou E, Kyriopoulos J, Stavrianeas N, Baretzidis A. The cost of AIDS according to the patient classification in Greece. Hellenic Rev Dermatol 1996;7:92-9.
Indexing Status Subject indexing assigned by NLM MeSH Acquired Immunodeficiency Syndrome /economics; Anti-HIV Agents /economics /therapeutic use; Antiretroviral Therapy, Highly Active /economics; Cost-Benefit Analysis; Drug Costs; Greece; Health Care Costs; Humans; Prescription Fees AccessionNumber 22001006495 Date bibliographic record published 28/02/2003 Date abstract record published 28/02/2003 |
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