PharmacoEconomics & Outcomes News 670 - 26 Jan 2013

Putting willingness to pay incontext

When estimating willingness to pay (WTP), "a singleceiling threshold should not be used for the resourceallocation of all types of interventions", according toresearchers in Thailand. Their findings show that "thevalue of a QALY varies widely, depending on the contextof health gain".

A community-based survey of 1191 participants wasused to elicit health state preferences for three pairs ofhealth conditions (blindness, paralysis and allergenscenarios, each with two levels of severity). Utilitieswere measured by visual analogue scale and time tradeoff (TTO), followed by a bidding-game technique todetermine WTP for the treatment and prevention of eachset of health conditions.

Results showed a significantly higher WTP per QALYin the context of treatment than prevention. Using theTTO method, the WTP per QALY derived from thetreatment of the hypothetical health conditions rangedfrom Bt59 000 to Bt285 000* across scenarioscompared with Bt26 000 to Bt137 000 per QALY interms of prevention. Household income, gender andhypothetical heath scenario also had a significant effecton the WTP per QALY.

Across the scenarios, values for WTP per QALY were0.4 to 2 times the GDP for Thailand in 2008, which wasdeemed by the study authors to be "in line with previousstudies conducted in several different settings".* Thai baht; Bt16.49 = $US1 (based on US dollar purchasing powerparity)

Thavorncharoensap M, et al. Estimating the willingness to pay for a quality-adjusted life year in Thailand: does the context of health gain matter?ClinicoEconomics and Outcomes Research : Jan 2013. Available from: URL: http://dx.doi.org/10.2147/CEOR.S38062 803082346

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PharmacoEconomics & Outcomes News 26 Jan 2013 No. 6701173-5503/10/0670-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved