Assessment of panic frequency: Reliability and validity of a time-line follow-back method

The purpose of this study was to investigate the reliability and validity of a Panic Attack Frequency Calendar (PAFC), modeled after a time-line follow-back (TLFB) procedure e.g., Sobell & Sobell, 1979). The latter has been used for years to reliably and validly assess daily alcohol use through self-report over extended periods of time. Seventy-four adult individuals (ages 18-57) who had experienced a panic attack within the past 2 weeks completed a battery of self-report questionnaires, including retrospective frequency measures, and were administered an 8-week PAFC initially and a 10-week PAFC 2 weeks later. Half the participants self-monitored their panic attacks in a diary. The PAFC showed high stability over 2 weeks across several panic behavior variables. The PAFC was also shown to be a valid instrument in assessing panic frequency when compared with panic data obtained from the diary and the retrospective frequency measure.