Age

User Notes

The user is encouraged to carefully examine all age and birth date variables when performing any age-related analysis. Birth data collected at the time of screening may have been provided by a family member, giving rise to possible inconsistencies when comparing a respondent's reported age with age calculated from date of birth. In cases where age was unknown, interviewers were directed to obtain a "best estimate" of a respondent's "exact age" at the time of screening and to make corrections later if possible. Furthermore, a respondent may be inconsistent in different interviews in reporting his age. The date of birth inconsistencies are documented in the codebook. Birth date corrections were made in 1981. The birth date corrections should be used carefully and the user is advised to make any additional corrections on a case-by-case basis.

There are varying numbers of out-of-scope cases in the Original Cohorts for two reasons: (1) the birth date variables in a handful of cases are inconsistent with the stated age of the respondent, and (2) some borderline cases that may actually be in scope for the calendar year of the survey are not necessarily in scope at the time the interview took place. CHRR has investigated causes of birth date inconsistencies and has discovered that they arise from birth data originally provided by Census. Unfortunately, these data are generally not recoverable since many of the affected respondents have since attrited. An additional difficulty is that the date of birth for some cases is not reported.

It may be to the user's advantage to calculate his or her own variable for age based on the reported date of birth. When birth date variables are either unavailable or out of scope, the user may wish to investigate other age-related variables in order to establish age.

In the 1981 survey year, there are duplicate date of birth variables for this cohort. One series, R06823., R08068., and R08069. (not depicted on the chart), includes values for individuals interviewed as well as for some who were not interviewed in 1981. It is advisable to use the series of birth date variables R07441.-R07443. for this survey year.