Screening for early detection of parkinsonism using a self-administered questionnaire: a cross-sectional epidemiologic study.

BACKGROUND: Manganese (Mn) is a common component of welding fume. Exposure to Mn fume has been associated with parkinsonism. A simple and reliable screening tool to evaluate Mn exposed workers for neurotoxic injury would have broad occupational health application. METHODS: This study investigated 490 occupational welders recruited from a trade union list. Subjects were examined by a movement disorders specialist using the Unified Parkinson Disease Rating Scale motor subsection 3 (UPDRS3). Parkinsonism, intermediate, and normal groups were defined as UPDRS3 score ≥ 15, 6-15, and <6, respectively. Workers completed a health status questionnaire (PDQ39) and a Parkinson disease (PD) Symptoms Questionnaire. Areas under receiver operator curve (AUC) were analyzed based on these scores, adjusted for age, smoking, race, gender, and neurologist, using normal as the reference. RESULTS: The AUC was 0.79 (95% confidence interval [CI]=0.73-0.84) for PDQ39 and 0.78 (95% CI=0.72-0.85) for PD Symptoms Questionnaire score. At 70% sensitivity, the specificity for PDQ39 score and PD Symptoms Questionnaire score for the prediction of parkinsonism was 73.1% and 80.1%, respectively. CONCLUSIONS: These results suggest the questionnaires have reasonably good sensitivity and specificity to predict parkinsonism in Mn exposed workers. These questionnaires could be a valuable first step in a tiered screening approach for Mn exposed workers.

Validity and reliability of an occupational exposure questionnaire for parkinsonism in welders.

This study assessed the validity and test-retest reliability of a medical and occupational history questionnaire for workers performing welding in the shipyard industry. This self-report questionnaire was developed for an epidemiologic study of the risk of parkinsonism in welders. Validity participants recruited from three similar shipyards were asked to give consent for access to personnel files and complete the questionnaire. Responses on the questionnaire were compared with information extracted from personnel records. Reliability participants were recruited from the same shipyards and were asked to complete the questionnaire at two different times approximately 4 weeks apart. Percent agreement, kappa, intraclass correlation coefficient (ICC), and sensitivity and specificity were used as measures of validity and/or reliability. Personnel files were obtained for 101 of 143 participants (70%) in the validity study, and 56 of the 95 (58.9%) participants in the reliability study completed the retest of the questionnaire. Validity scores for items extracted from personnel files were high. Percent agreement for employment dates and job titles ranged from 83-100%, while ICC for start and stop dates ranged from 0.93-0.99. Sensitivity and specificity for current job title ranged from 0.5-1.0. Reliability scores for demographic, medical and health behavior items were mainly moderate or high, but ranged from 0.19 to 1.0. Most recent job/title items such as title, types of welding performed, and material used showed substantial to perfect agreement. Certain determinants of exposure such as days and hours per week exposed to welding fumes demonstrated mainly moderate agreement (kappa= 0.42-0.47, percent agreement 63-77%); however, mean days and hours reported did not differ between test and retest. The results of this study suggest that participants' self-report for job title and dates employed are valid compared with employer records. While kappa scores were low for some medical conditions and for caffeine consumption, high kappa scores for job title, dates worked, types of welding, and materials welded suggest participants generated reproducible answers important for occupational exposure assessment.