OBJECTIVES: To gain utility values for asthmatic patients, self-administered direct TTO questions may seem to be a simple option. This study examined reported TTO values by disease severity groups, and the relationship between other health status measures, and with age. METHODS: 228 consecutive adult outpatients and inpatients at four sites in Hungary participated in the study. Doctors had to report GINA severity group and lung function values. Patients had to fill in three QoL questionnaires and a direct TTO question that offered a choice between 20 years in current health or shorter length of life in perfect health. Statistical analysis applied F-statistics. RESULTS: Mean TTO values were 0.99, 0.96, 0.82, 0.73 in the four severity groups, respectively. These were higher than corresponding EQ-5Dindex results of 0.93, 0.76, 0.65, 0.52. Correlation coefficients between TTO values and EQ-5Dindex, EQ-5Dvas, SF-36(PCS), SF-36(MCS), SGRQ, and FEV1% were 0.40, 0.40, 0.34, 0.25, -0.36, and 0.36, respectively. Age explained 23% of differences in TTO values after controlling for asthma severity. Within severity groups 4 and 3, patients over 50 reported TTO values lower by 0.21 and 0.20 than those below this age. These differences were larger than corresponding differences in EQ-5Dindex values suggesting that direct TTO responses may incorporate different concepts of remaining life years of the older. Results were statistically significant (p<0.0001). CONCLUSIONS: Utility values gained from direct TTO questions can lead to higher scores than generic utility-based questionnaires, low correlation values with other measures, and to biases in patient groups of heterogeneous age.