Errors in recall of age at first sex

To measure the degree and direction of errors in recall of age at first sex.

Participants were initially recruited in 1994-1995 (Wave I) with 3 subsequent follow-ups in: 1996 (Wave II); 2001- 2002 (Wave III); and 2007-2008 (Wave IV). Participants' individual errors in recall of their age at first sex at Wave IV were estimated by the paired difference between responses given for age at first sex in Wave I and Wave IV (recalled age at first sex obtained at Wave IV minus the age at first sex obtained at Wave I).

The mean of the recall-estimation of age at first sex at Wave IV was found to be slightly increased comparing to the age at first sex at Wave I (less than 1 year). The errors in the recalled age at first sex tended to increase in participants who had their first sex younger or older than the average, and the recalled age at first sex tended to bias towards the mean (i.e. participants who had first sex younger than the average were more likely to recall an age at first sex that was older than the age, and vice versa).

In this U.S. population-based sample, the average recall error for age at first sex was small. However, the accuracy of recalled information varied significantly among subgroup populations.