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Test‐retest reliability of an icon/calendar‐based questionnaire used to assess occupational history †
Author(s) -
Engel Lawrence S.,
Keifer Matthew C.,
Thompson Mary Lou,
Zahm Shelia H.
Publication year - 2001
Publication title -
american journal of industrial medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.7
H-Index - 104
eISSN - 1097-0274
pISSN - 0271-3586
DOI - 10.1002/ajim.1119
Subject(s) - medicine , icon , work (physics) , test (biology) , demography , recall , occupational medicine , reliability (semiconductor) , gerontology , environmental health , occupational exposure , psychology , computer science , mechanical engineering , paleontology , power (physics) , physics , quantum mechanics , sociology , engineering , cognitive psychology , biology , programming language
Background Self‐reported work histories can be critical for both epidemiologic and clinical purposes. However, the complexity of some work histories, such as those of migrant farm workers, can hamper recall, resulting in inaccurate reporting. Memory aids may reduce such error. This study assesses the reliability of work histories collected using such aids in the form of an icon/calendar‐based questionnaire. Methods Thirty‐one males engaged in farmwork and other manual labor for a median 28 years (range: 10–64) were interviewed twice, 8–14 months apart, about their lifetime employment. In each interview, subjects were asked about important life events, which were recorded with icons on a calendar. They were then asked to recount their work history, including for each job the tasks, crops or products handled, starting and ending dates, and location. This information was recorded, job‐by‐job, on the calendar with icons. Results Interquestionnaire agreement of cumulative reported employment duration (as measured by the correlation coefficient) was moderate to high across all time periods for certain crops (e.g., r = 0.69–0.92 for apple‐related work), by location (e.g., r = 0.76–0.95 for Washington State), and for agricultural work in general (r = 0.67–0.94), but was lower for specific tasks. Agreement of job counts was high for total work history for certain crops (e.g., r = 0.93 for apple‐related work), by location (e.g., r = 0.90 for Washington State), and for agricultural work in general (r = 0.89), but paradoxically decreased with proximity to the interview date. Agreement of both measures tended to be highest for those tasks and crops in which subjects reported spending the most time. Categorization of subjects into tertiles on the basis of either cumulative duration or counts produced results similar to those observed for job counts. Conclusions The icon‐calendar questionnaire is an effective tool for estimating cumulative duration of certain work categorizations among subjects with complex work histories. Am. J. Ind. Med. 40:512–522, 2001. Published 2001 Wiley‐Liss, Inc.