Open AccessAn apparently incongruous exposure-response relationship resulting from the use of job description to assess magnetic field exposure.
Author(s) -
Delpizzo
Publication year - 1992
Publication title -
scandinavian journal of work, environment and health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.621
H-Index - 103
eISSN - 1795-990X
pISSN - 0355-3140
DOI - 10.5271/sjweh.1583
Subject(s) - referent , occupational exposure , ordinal scale , statistics , basis (linear algebra) , psychology , econometrics , mathematics , medicine , environmental health , philosophy , linguistics , geometry
Empirical data are presented to support the observation that nondifferential misclassification of subjects classified according to an ordinal scale can result in an artifactual nonmonotonic exposure-response curve. This phenomenon can be interpreted erroneously as an indication that an observed relationship is not causal. The occupational exposure of 40 subjects to extremely low-frequency magnetic fields was estimated on the basis of their job description while their "true" exposure was determined by direct dosimetry. A "true" risk was assumed to exist, and estimates of risk that could be obtained through hypothetical case-referent or cohort studies were calculated.