Effect of training, education, professional experience, and need for cognition on accuracy of exposure assessment...

Results are presented from a study that investigated the effect of characteristics of occupational hygienists relating to educational and professional experience and task-specific experience on the accuracy of occupational exposure judgments. A total of 49 occupational hygienists from six companies participated in the study and 22 tasks were evaluated. Participating companies provided monitoring data on specific tasks. Information on nine educational and professional experience determinants (e.g. educational background, years of occupational hygiene and exposure assessment experience, professional certifications, statistical training and experience, and the 'need for cognition (NFC)', which is a measure of an individual's motivation for thinking) and four task-specific determinants was also collected from each occupational hygienist. Hygienists had a wide range of educational and professional backgrounds for tasks across a range of industries with different workplace and task characteristics. The American Industrial Hygiene Association exposure assessment strategy was used to make exposure judgments on the probability of the 95th percentile of the underlying exposure distribution being located in one of four exposure categories relative to the occupational exposure limit. After reviewing all available job/task/chemical information, hygienists were asked to provide their judgment in probabilistic terms. Both qualitative (judgments without monitoring data) and quantitative judgments (judgments with monitoring data) were recorded. Ninety-three qualitative judgments and 2142 quantitative judgments were obtained. Data interpretation training, with simple rules of thumb for estimating the 95th percentiles of lognormal distributions, was provided to all hygienists. A data interpretation test (DIT) was also administered and judgments were elicited before and after training. General linear models and cumulative logit models were used to analyze the relationship between accuracy of judgments and the various characteristics describing the participants. Data interpretation training (P < 0.0001), the company that the hygienist worked for (P < 0.0001), the total number of years hygienists had experience doing exposure assessments (P < 0.0001), and professional certifications (P < 0.0001) held by hygienists were found to be significant determinants of accurately predicting the correct exposure category for DITs as well as for task-specific judgment accuracy. Years of experience with a particular task (P < 0.0001), task evaluated, and the number of datapoints used for making judgments were found to be significant predictors of task-specific judgment accuracy. The NFC score was a predictor of the improvement in task judgment accuracy after training. The NFC score was itself predicted by determinants, such as company, years on current job, years of exposure assessment experience, and professional certifications. The results of this study are relevant not only for the case of industrial hygienists making exposure judgments prospectively but also possibly for those hygienists engaged in retrospective exposure assessments for epidemiological studies.