EFFECT OF RECALL PERIOD ON THE REPORTING OF OCCUPATIONAL INJURIES AMONG OLDER WORKERS IN THE HEALTH AND RETIREMENT STUDY

Studies of injury morbidity often rely on self-reported survey data. I n designing these surveys, researchers must chose between a shorter re call period to minimize recall bias and a longer period to maximize th e precision of rate estimates. Using data from the Health and Retireme nt Study, which employed a recall period of 1 year, we examined the ef fect of the recall period on rates of occupational injuries among olde r workers as well as upon rate ratios of these injuries for nine risk factors. We fit a stochastic model to the occupational injury rates as a function of time before the interview and used this model to estima te what the injury rates would have been had we used a 4-week recall p eriod. The adjusted occupational injury rate of 5.9 injuries per 100 w orkers per year was 36% higher than the rate based on a 1-year recall period. Adjustment for recall period had much less effect on rate rati os, which typically varied by <10%. Our work suggests that self-report ed surveys with longer recall periods may be used to estimate occupati onal injury rates and also may be useful in studying the associations between occupational injuries and a variety of risk factors. (C) 1995 Wiley-Liss, Inc.