Reliability of retrospective survey data on infant feeding.

This article examines retest reliability and digit preference in retrospective survey data on breastfeeding duration and type of supplementary food, covering three decades and reported by more than 1200 Malaysian women. Women with little or no education, rural residents, and those of Malay ethnicity are found to give less reliable data. In a logistic regression analysis, these respondent characteristics are more important determinants of data quality than the length of the recall period.