The agreement between workers and within workers in regard to occupational exposure to mercury in dental practice assessed from a questionnaire and an interview
Tóm tắt
The correct assessment and classification of exposure is essential in epidemiology. The validity of exposure data obtained by the use of questionnaires is, however, seldom evaluated. When conducting a study on the possible health effects from mercury exposure in dental practice, we compared answers on exposure from a job-specific questionnaire with answers to the same questions given at an interview 6 to 18 months later. We examined the concordance between workers by comparing answers to the questionnaire given by persons working in the same clinics during the same time spans and the agreement within workers by comparing answers to the same questions from a questionnaire and from an interview. Other aims were to see if there was a difference in the answers to the questionnaire across job titles and to study the impact of missing information on the response rate in a detailed questionnaire. There was a marked difference between the pairs of employees working in the same clinic regarding the start and termination years for the different preparation methods, and this was partly independent of their occupation. Kappa values for using different preparation methods in the questionnaire and at the interview varied between 0.41(moderate) to 0.88(very good). The results of this study indicate that a mailed questionnaire will cause misclassification of exposure. The observed occurrence of false positive exposure classifications from the questionnaire compared to the interview was higher than for false negative. This is important and may result in serious bias if the prevalence of exposure is low. Due to missing information, detailed questionnaires may also be inefficient if the goal is to construct exposure measures from combinations of several answers in the questionnaire.
Tài liệu tham khảo
Kauppinen T: Assessment of exposure in occupational epidemiology. Scand J Work Environ Health 1994, 20(special issue):19–29.
Flegal K, Brownie C, Haas JD: The effects of exposure misclassification on estimates of relative risk. Am J Epidemiol 1986, 123(4):736–751.
Tielemans E, Heederik D, Burdof A, Vermeulen R, Vermeulen H, Kromhout H, Hartog K: Assessment of occupational exposures in a general population: comparison of different methods. Occup Environ Med 1999, 56: 45–51. 10.1136/oem.56.3.145
Holmes E, Garschick E: The reproducibility of the self-report of occupational exposure to asbestos and dust. J Occup Med 1991, 33(2):134–138.
Hilt B, Langård S, Andersen A, Rosenberg J: Asbestos exposure, smoking habits, and cancer incidence among production and maintenance workers in an electrochemical plant. Am J Ind Med 1985, 8(6):565–77. 10.1002/ajim.4700080608
Ahlborg GA: Validity of exposure data obtained by questionnaire. Two examples from occupational reproductive studies. Scand J Work Environ Health 1990, 16: 284–288.
Teschke K, Olshan AF, Daniels JL, De Roos AJ, Parks CG, Schulz M, Vaughan TL, Kromhout H: Occupational exposure assessment in case-control studies: opportunities for improvement. Occup Environ Med 2002, 59: 575–594. 10.1136/oem.59.9.575
Svendsen K, Syversen T, Melø I, Hilt B: Historical exposure to mercury in Norwegian dental personnel. Scand J Work Environ Health 2010, 36(3):231–41.
Hilt B, Svendsen K, Syversen T, Aas O, Qvenild T, Sletvold H, Melø I: Occurrence of cognitive symptoms in dental assistants with previous occupational exposure to metallic mercury. NeuroToxicology 2009, 30: 1202–6. 10.1016/j.neuro.2009.04.012
Altman DG: Practical Statistics for Medical Research. Chapman & Hall, London UK; 1991.
Fritchi L, Siemiatycki J, Richardson L: Self-assessed versus expert-assessed occupational exposures. Am J Epidemiol 1996, 144: 521–527.
Hobson AJ, Sterling DA, Emo B, Evanoff BA, Sterling CS, Good L, Seixas N, Checkoway H, Racette BA: Validity and reliability of an occupational exposure questionnaire for parkinsonism in welders. J Occup Environ Hyg 2009, 6(6):324–31. 10.1080/15459620902836856