Comparison of First, Last, and Longest-Held Jobs as Surrogates for All Jobs in Estimating Cumulative Exposure in Cross-Sectional Studies of Work-Related Asthma

Although last job has been found to be a satisfactory surrogate for all jobs in cancer studies, we do not recommend the use of this metric in studies of chronic diseases where development of disability may occur with early exposure. We found that both first job and longest job held were better metrics in studies where the adverse health effect may influence the job history of subject.