44: A Pilot Study of Electronic Diary Self Reports of Affect in Adolsecents with Anorexia

Abstract

Anorexia nervosa (AN) causes significant morbidity in adolescents, but the influences of affect on behaviors are poorly understood. Collection of real time data from patients using Ecologic Momentary Assessment (EMA) allows temporal association of state affect with behavioral events. This pilot study uses a novel cell phone tool to establish feasibility of EMA in adolescents with AN and to evaluate inter- and intra-day variations in affect. Subjects (n = 8) were AN patients (ages 13–26) of an outpatient eating disorders center. Subjects used the personal digital assistant portion of the Treo 650 cell phone to complete daily and random-signal electronic diary questionnaires daily for up to 28 days. Immediately after completion, subjects synchronized data directly into the research database using the wireless phone network. State affect was measured 6 times daily (T1 [8 – 10:19 am]; T2 [10:20 – 12:39 pm]; etc., until 9:59 pm) using 3-positive (Happy, Energetic, Excited) and 3-negative (Sad, Angry, Upset) items from the Positive and Negative Affect Scale (PANAS). Average daily affect was measured with the full 20-item PANAS. An exit questionnaire and interview assessed reactions to the experience. Preliminary analysis of the first 4 subjects revealed 2 completed 28 days of data collection and 2 completed 24 days. One subject was withdrawn due to an admission scheduled after study entry and one was confused about start/stop dates. Subjects reported that the cell phones were easy to use (mean = 4.2; 1 = very hard to 5 = very easy). Daily electronic diary compliance rates were high (92%). Within the random-signal diaries, compliance ranged from 83-100% for the first 3 weeks, but dropped to 79% for days 23-28 (total rate 88%). Within days, the first time interval (T1) had a compliance rate of only 78%, mostly due to one subject who completed only 46% of the T1 diaries. The remaining subjects completed 88%, similar to the rates in the remaining intervals. Average daily (full PANAS) affect scores across subjects and days was 10.57 (SD 6.11) for positive and 7.53 (SD 5.51) for negative. Within days, random-signal (6-item PANAS) positive affect was lowest in period T6 (2.59, SD 2.18) and highest in period T5 (3.83, SD 2.39). Negative affect was lowest in period T1 (1.72, SD 1.87) and highest in period T3 (2.05, SD 2.16). These data show feasibility of this method to capture expected variations in affect in adolescents with AN. We found greater variation in positive affect at relatively higher levels than negative affect. Overall, negative affect was somewhat flat. Demonstration of mood variation may be useful in understanding eating and exercise behaviors characteristic of AN.