The reliability of telephone interviews compared with in-person interviews using memory aids.

PURPOSE: Information obtained by telephone interviews and in-person interviews is generally considered comparable, but it is unclear if extensive memory aids can be used effectively with telephone interviews. We compared a telephone interview to an in-person interview using the same questionnaire and memory aids in both.

METHODS

A convenience sample of 103 women, aged 25 to 69 years, completed a telephone interview and at least four weeks later, completed an in-person interview. Memory aids included a life events calendar, cue lists, and worksheets.

RESULTS

Agreement values, measured by kappa/weighted kappa, were as follows: parity (1.00), age at menarche (0.76), menopausal status (0.95), a history of reproductive organ surgery (0.98) or tubal ligation (0.91), self-reported infertility (0.76), and a first degree family history of breast/ovarian cancer (0.90). Agreement values for duration variables, measured by the intraclass correlation, were as follows: lactation (0.96), oral contraceptive use (0.98), any hormone replacement therapy (0.98), exclusive estrogen and progesterone therapy (0.83), and exclusive estrogen therapy (0.99).

CONCLUSIONS

The good to excellent level of agreement found in this study indicates that telephone administration of our questionnaire with extensive memory aids is a reliable method of obtaining detailed exposure information relative to in-person interviews.