Tuesday, October 8, 2013

Can we measure smoking behavior?

In any survey, we must consider the issue of imperfect recall or misrepresentation in self-reported assessments. People do not remember precisely how much they spent on this or that, and they they may not recall how long they have been unemployed. For some questions, social pressure may also be a factor. For example, one may not concede on using illegal drugs or one may misreport smoking behavior. The extend of such biases can be measured though, if one has access to administrative data or some other objective measure. The results are often disappointing (Examples discussed here: 1, 2).

Vidhura Tennekoon and Robert Rosenman criticize the fact that the measures against which surveys responses are compared are taken as perfect gold standards. Specifically they look at the biochemical assessment of smoking status, whose results the literature never doubts and which makes self-reported smoking status look really unreliable. Once you use statistical methods that concede that the biochemical assessment may also include some measurement error, they realize that it may be just as bad as the self-assessment. One can thus not exclude that the self-assessment may actually be a better indicator that an independently recorded measure.

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