OBJECTIVES: Conflicting evidence exists regarding whether very short recall periods are required for making valid judgments about the effectiveness of health care interventions. This analysis explored the influence of two factors thought to impact recall, recency and significance of events, on caregiver recall of symptoms of infant gastroesophageal reflux disease (GERD). METHODS: Retrospective analyses were conducted on 185 infants with GERD from a multi-national validation study of the Revised Infant-Gastroesophageal Reflux Questionnaire (I-GERG-R), a measure of symptom severity. Primary caregivers completed a 12-item I-GERQ-R weekly and a 5-item diary daily during the three-week study period. Due to word limitations, this abstract only reports results from the ‘frequency of spit-up' item during the first week. RESULTS: Overall, a moderately high Pearson correlation (r=0.636) was observed between the diary and the I-GERQ-R item. When the open-ended diary responses were recoded into the same structured format as the I-GERQ-R item, the correlation improved significantly (r=0.829), indicating that initial moderate correlation was largely due to the different response format rather than recall bias. The correlations between the I-GERQ-R item and the average of the diary item were about equal between the last two days and the first two days of the first week (original: r=0.585 and 0.589; recoded: r=0.758 and 0.745), indicating that the I-GERQ-R response was not largely influenced by the most recent 2-day experience. The correlations between the I-GERQ-R item and the diary item on the day with the largest number of reported spit-ups were not larger than that between I-GERQ-R and the average diary score of other 6 days (original: r=0.627 and 0.630; recoded: 0.767 and 0.821), indicating that I-GERQ-R was not largely influenced by the most symptomatic day. CONCLUSION: Overall, we found that recency and high frequency of the event did not unduly influence parent's recall of infant GERD symptoms.