Abstract
OBJECTIVES: Recall error biases reporting of earlier life experiences, even potentially traumatic experiences (PTEs). Better tools for accurate retrospective reporting of PTEs and other health risk factors have the potential for broad scientific and health intervention benefits. METHODS: We designed a life history calendar (LHC) to support this task and randomized more than 1000 individuals to each arm of a retrospective diagnostic interview, including detailed measures of PTEs, with and without the LHC. This is one of the largest experiments ever done to assess the benefit of an LHC approach and the only large-scale experiment done in a poor, agrarian, non-Western setting (rural Nepal). RESULTS: Results demonstrate use of an LHC in retrospective measurement can significantly increase lifetime reports of PTEs, especially reports of two or more PTEs. The LHC increases PTE reporting more for men and those with less education. CONCLUSIONS: The LHC approach is practical for many uses ranging from large surveys of the general population to clinical intake of new patients. It significantly increases reporting of health risk factors.