Smoking, health related quality of life and economic evaluation

Abstract

Background and aims The economic evaluation of tobacco control policies requires the adoption of assumptions about the impact of changes in smoking status on health related quality of life (HRQOL). Estimates for such impacts are necessary for different populations. This paper aims to test whether smoking status has an independent effect on HRQOL over and above the effect derived from the increased likelihood of suffering a tobacco related disease and to calculate utility values for the Spanish population. Methods Using data from the Spanish Encuesta Nacional de Salud of 2011-12, we estimate statistical models for HRQOL as measured by the EQ5D5L instrument as a function of smoking status. We include a comprehensive set of controls for biological clinical, lifestyle and socioeconomic characteristics. Results Smoking status has an independent, statistically significant effect on HRQOL. However, the size of the effect is small. The typical smoking related disease, such as lung cancer, is associated to a reduction in HRQOL about 5 times larger than the difference between current smokers and never smokers. Conclusion A realistic representation of the effects of smoking on HRQOL in economic evaluation should shy away from attributing large independent changes to quitting smoking or avoiding starting to smoke, since such changes are small once clinical conditions are controlled for. On the other hand, it is necessary to expand the set of classical smoking related diseases used in economic evaluation with other diseases for which new evidence showing a causal link to smoking exists.