Comparison of drinking patterns measured by daily reports and timeline follow back

The major objective of this study was to compare near real-time daily alcohol consumption data over the course of 366 consecutive days with retrospective reports by means of the timeline follow-back (TLFB). Participants (N = 33) responded for 366 days on an interactive voice response (IVR) system by entering alcohol consumption data daily using the touch-tone pads of their telephones. In-person interviews were conducted every 13 weeks during which participants were administered the TLFB. The correlations between the IVR and TLFB for amount consumed, drinking days, and heavy drinking days were modest. There was a wide variability across participants in their individual correlations for these variables. Participants who were diagnosable with a lifetime DSM-IV alcohol disorder at baseline significantly underreported their drinking compared with participants who were not diagnosable. The authors were unable to ascertain variables that influenced accurate reporting on the TLFB.