Abstract
Background. The purpose was to study the test-retest reliability and internal consistency of questions in aquestionnaire concerning working conditions and health and the inter-rater reliability of observations andmeasurements according to an ergonomic checklist. Method. Fifty-seven operators participated in a retestquestionnaire and 58 operators participated in an inter-observer test. Results. The questions had fair to good or higher reliability in 142 of the total of 312. Twenty-seven of the total of 44 variables in the ergonomicchecklist were classified as having fair to good or higher reliability. Conclusions. About half of the questionshad fair to good or higher reliability and can be recommended for further analyses. The majority of variablesin the ergonomic checklist were classified as having fair to good or higher reliability. Low reliability does notnecessarily indicate that the reliability of the test, per se, is low but may signify that the conditions measuredvary over time or that the answers are aggregated in one part of the scale.