Interactive voice response technology, which uses the telephone to administer survey questions, was used to measure drinking behavior through daily reports (Kranzler et al. 2004). The number of standard drinks of beer, wine, and liquor that patients consumed were summed to create a total number of standard drinks per day. The Timeline Follow-back was administered every two weeks during treatment to augment daily drinking data. Days for which data were missing either because the patient failed to provide data that day despite remaining in the study or after having discontinued study participation prematurely were coded as heavy drinking days. This conservative approach included all patients in the analysis and yielded 12 weekly values for the drinking outcomes (Kranzler et al. 2011).
