07/08. tbl. 100. árg. 2014

Needle Exchange Programs are a cost-effective preventative measure against HIV in Iceland

Nálaskiptiþjónusta er kostnaðarvirk forvörn gegn HIV á Íslandi

Objective: In 2007 there was a sudden increase in HIV cases among intravenous drug users (IDUs) in Iceland. In 2007 - 2011 there were 34 new HIV cases among IDUs compared to four in the previous four year period. The purpose of this study was to assess whether needle exchange programs (NEPs) were cost-effective in preventing the spread of HIV among IDUs in Iceland. 

Materials and methods: Cost-utility analysis was conducted from a societal perspective. Costs are presented at the 2011 price level and values were discounted using a 3% discount rate. A ten year period, 2011 - 2020 was compared with and without NEPs. The Incremental Cost-Utility Ratio (ICUR) was calculated as societal cost per quality adjusted life year (QALY). Sensitivity analysis was performed on study assumptions.

Results: The estimated societal costs associated with HIV infections among IDUs from 2011 - 2020 was 914.369.621 ISK without NEP and 947.653.758 ISK with NEP. Excess societal cost due to NEP was 33.284.137 ISK. Societal utility from NEP was 7,39 QALYs. Additionally, NEP prevented 4-5 HIV infections. The ICUR of providing NEP was 4.506.720 ISK.

Conclusion: According to WHO an intervention is considered cost-effective if the ICUR is less than three-fold national GDP per capita. In 2011 the GDP per capita in Iceland was 15.315.000 ISK. Sensitivity analysis on study assumptions yielded a societal cost within the WHO limit. Therefore, the results indicate that NEPs are cost-effective in preventing the spread of HIV among IDUs in Iceland.

Table I. Main study assumptions.

Study assumption:
A difference in HRQL exists between IDUs with and without HIV infection. The study assumed a 3,5 point HRQL difference.
NEPs lower the incidence of HIV among IDUs. The study assumed a decrease of 0,12 cases/100 person-years/year.
The yearly societal cost associated with the HIV treatment of a single IDU in 2011 was an estimated to be 2.338.350 kr.
The yearly societal cost associated with a NEP in Iceland in 2011 was an estimated 9.013.437 kr.
The number of IDUs in Iceland in 2011 was estimated to be 386.
The study assumed a 3% discount rate.

Figure 1
. Estimated
number of active IDUs in Iceland 20012020. Values within the blue shadowed area are calculated from the number of induviduals who were admitted to Vogur hospital for treatment for intravenous drug addiction.5 Linear regression analysis was used to extrapolate the number of active IDUs during the timeperiod 2010–2020.

Figure 2.Reletive change in the number of new HIV cases among IDUs in HIV epidemics in four countries.6–8The Y axis is calibrated as multiples of the average number of new HIV cases in the three years preoceeding an epidemic.

Figure 3.Sensitivity analysis on study assumptions. The resultof the cost-effectiveness analysis is represented by a green vertical line. The upper limit for cost-effectivenessof an interventionaccording to WHOcriteriaisrepresented by a red vertical line. The input value of each assumptionusedin the sensitivity analysis is denoted next toeach bar.

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