Such a correspondence of reports, however, does not necessarily imply that this reported age is, in fact, accurate as both reports may be incorrect. Our results may have direct implications about choosing among alternative measures Fluoro-Sorafenib in analyses of tobacco use, for example, for estimating the total duration of smoking fairly regularly among former smokers. Given that the reliability of the age of initiation of fairly regular smoking (reported by former and current smokers), and that of the time since completely quitting smoking, were higher than the reliability for the number of years a former smoker smoked every day, our findings suggest that it may be preferable to construct the duration of total smoking by using the former two measures, rather than depending solely on former smokers�� direct reports of the number of years smoked every day��even allowing that there may be gaps of nonsmoking within this computed period for some people.

Future research on the reliability of survey reports of tobacco use can be targeted toward further examination of the odds of strict agreement, as a function of demographic or other respondent characteristics. For example, we observed that males were less likely to provide consistent answers than were females when reporting the time since completely quitting smoking. Therefore, it is essential to identify the underlying reasons for this observed gender effect, for example, it could be that males are more likely to satisfice than are females when answering smoking-related questions.

It is also important to investigate other criteria for defining agreement, such as through relaxing requirements for strict agreement (e.g., allowing a difference of up to 2 years between test and retest responses regarding the number of years smoked everyday by former smokers, when establishing matching rules). One problem with this type of relaxation, however, is that such a definition may not be reasonable across all population groups. For example, a 2-year difference in responses for older populations might not be as meaningful as it is for young adults. Thus, suitable definitions should be constructed with respect to subgroups if one wishes to examine the odds of such an agreement. In addition, it would be of interest to investigate factors that may contribute to the odds of producing highly contradictory responses at two time points.

There could be a set of sociodemographic, smoking behavioral, or survey administration characteristics associated with response discordance. For example, it might be the case that more cigarettes smoked per day, more Batimastat discrepant responses about the number of cigarettes smoked per day are provided. For never smoked reporting, it could be the length of time since completely quit smoking among former smokers that effects the reliability of reporting former versus never smoking.