April 1999, Volume 9, Issue 2, Pages 150 – 157

Article

Time lines and computer-based visual editing: new techniques for assessing exposure in epidemiologic studies JANET LAWLER-HEAVNER, A. JAMES RUTTENBER, MING YIN & TED D. WADE Department of Preventive Medicine and Biometrics, University of Colorado School of Medicine, Denver, Colorado     Correspondence to: JANET LAWLER-HEAVNER , MSPH. Department of Preventive Medicine and Biometrics, Campus Box C-245, University of Colorado Health Sciences Center, 4200 East Ninth Avenue Denver, CO 80262. Tel.: (303)315-7595. E-mail: janet.lawler-heavner@uchsc.edu

Keywords

environmental epidemiology;   epidemiologic methods;   exposure assessment;   interviews;   occupational epidemiology;   questionnaires

Abstract

We describe a time-line-based methodology for collecting exposure data for epidemiologic studies and for processing these data for statistical analysis with readily available software for the personal computer. The four components to this approach are: (1) collecting data in a memory-enhancing time-line format; (2) entering data from time lines into a computer database and editing them; (3) making a quantitative estimate of exposure, intake, or dose for each exposure event; and (4) creating analysis datasets by `slicing’ the quantified time lines based on desired exposure intervals or disease latent periods. Compared with fixed-format interviews, time-line-based interviews help subjects organize remembered events, thereby reducing confusion. They do not restrict responses to predetermined categorical exposure responses. The time-line methodology also facilitates the collection of supplementary data necessary for computing doses for complex exposures and the packaging of quantified exposures into analysis datasets for any time period of interest.

Received 11 December 1997; Accepted 18 September 1998

^© Macmillan Publishers Ltd 1997