Eva Rodríguez-Míguez

Measuring the impact of alcohol-related disorders on quality of life through general population preferences

OBJECTIVE To estimate the intangible effects of alcohol misuse on the drinkers quality of life, based on general population preferences METHODS: The most important effects (dimensions) were identified by means of two focus groups conducted with patients and specialists. The levels of these dimensions were combined to yield different scenarios. A sample of 300 people taken from the general Spanish population evaluated a subset of these scenarios, selected by using a fractional factorial design. We used the probability lottery equivalent method to derive the utility score for the evaluated scenarios, and the random-effects regression model to estimate the relative importance of each dimension and to derive the utility score for the rest of scenarios not directly evaluated. RESULTS Four main dimensions were identified (family, physical health, psychological health and social) and divided into three levels of intensity. We found a wide variation in the utilities associated with the scenarios directly evaluated (ranging from 0.09 to 0.78). The dimensions with the greatest relative importance were physical health (36.4%) and family consequences (31.3%), followed by psychological (20.5%) and social consequences (11.8%). CONCLUSIONS Our findings confirm the benefits of adopting a heterogeneous approach to measure the effects of alcohol misuse. The estimated utilities could have both clinical and economic applications.

Using the SF-6D to measure the impact of alcohol dependence on health-related quality of life.

Alcohol dependence not only reduces life expectancy, but also causes considerable loss of quality of life of the dependents of and persons around those with alcohol dependence. This article presents new evidence on the impact of alcohol dependence on health-related quality of life in Spain. Three samples were recruited: 150 alcoholics and 64 family members of alcoholics, with both samples taken from an alcoholism treatment unit, and 600 persons from the general population. We used the short form 6D, a preference-based generic instrument, applying the utility scores estimated for Spain. It was found that the annual mean loss of quality-adjusted life years associated with alcohol dependence was 0.144 and 0.083 for the alcoholics and their close family members, respectively. This impact becomes more notable after controlling for socio economic variables and was higher than that estimated in similar studies. Possible explanations for these differences are discussed. The results from this work can be applied to economic evaluation studies measuring benefits from policies targeted at reducing the prevalence of alcohol dependence.

The Lead Time Tradeoff The Case of Health States Better Than Dead

Background. Lead time tradeoff (L-TTO) is a variant of the time tradeoff (TTO). L-TTO introduces a lead period in full health before illness onset, avoiding the need to use 2 different procedures for states better and worse than dead. To estimate utilities, additive separability is assumed. We tested to what extent violations of this assumption can bias utilities estimated with L-TTO. Methods. A sample of 500 members of the Spanish general population evaluated 24 health states, using face-to-face interviews. A total of 188 subjects were interviewed with L-TTO and the rest with TTO. Both samples evaluated the same set of 24 health states, divided into 4 groups with 6 health states per set. Each subject evaluated 1 of the sets. A random effects regression model was fitted to our data. Only health states better than dead were included in the regression since it is in this subset where additive separability can be tested clearly. Results. Utilities were higher in L-TTO in relation to TTO (on average L-TTO adds about 0.2 points to the utility of health states), suggesting that additive separability is violated. The difference between methods increased with the severity of the health state. Thus, L-TTO adds about 0.14 points to the average utility of the less severe states, 0.23 to the intermediate states, and 0.28 points to the more severe estates. Conclusions. L-TTO produced higher utilities than TTO. Health problems are perceived as less severe if a lead period in full health is added upfront, implying that there are interactions between disjointed time periods. The advantages of this method have to be compared with the cost of modeling the interaction between periods.