Valuation of EQ-5D health states in Poland: first TTO-based social value set in Central and Eastern Europe.

OBJECTIVE

Currently, there is no EQ-5D value set for Poland. The primary objective of this study was to elicit EQ-5D Polish values using the time trade-off (TTO) method.

METHODS

Face-to-face interviews with visitors of inpatients in eight medical centers in Warsaw, Skierniewice, and Puławy were carried out by trained interviewers. Quota sampling was used to achieve a representative sample of the Polish population with regard to age and sex. Modified protocol from the Measurement and Value of Health study was used. Each respondent ranked 10 health states and valued 4 health states using the visual analog scale and 23 using the TTO. Mean and variance stability tests were performed to determine whether using a larger number of health states per respondent would yield credible results. Modeling included random effects and random parameters models.

RESULTS

Between February and May 2008, 321 interviews were performed. Modeling based on 6777 valuations resulted in an additive model with all coefficients statistically significant, R(2) equal to 0.45, and value -0.523 for the worst possible health state. Means and variance did not differ significantly for states valued in the middle and at the end of the TTO exercise.

CONCLUSIONS

This is the first EQ-5D value set based on TTO in Central and Eastern Europe so far. Because the values differ considerably from those elicited in Western European countries, its use should be recommended for studies in Poland. Increasing the number of health states that each respondent is asked to value using TTO seems feasible and justifiable.