Dimensions and domains to assess secondhand tobacco smoke exposure: insights from a Delphi study

To identify the dimensions and domains to be included in questionnaires when assessing self-reported secondhand tobacco smoke (SHS) exposure in etiological studies and in population health surveys.

A qualitative study was conducted in two stages. In stage one, based on a Delphi methodology, 16 experts in tobacco epidemiology completed two questionnaires and attended a group session. In stage two, triangulation interviews were conducted with six experts from the Delphi study to provided in-depth reflection on the domains identified in stage one. The recorded transcriptions were analyzed using a thematic approach.

The experts discussed the importance of assessing SHS exposure in specific scenarios, highlighting the home, workplace, leisure venues, and private transport. They discussed the importance of asking about cohabiting with smokers when assessing exposure at home. The experts stressed the importance of differentiating between leisure venues, by prioritizing closed over open spaces. In population-based health surveys, the experts recommended that the recall time should be recent, referring to the last seven days. In etiological studies, they suggested that lifetime exposures should be explored.

This study marks the first step toward identifying the dimensions and domains for assessing self-reported SHS exposure. Question standardization when ascertaining SHS exposure is critical to permit cross study comparisons and to analyze trends in the evolution of SHS exposure.