Reliability of a questionnaire and an ergonomic checklist for assessing working conditions and health at call centres.

BACKGROUND The purpose was to study the test-retest reliability and internal consistency of questions in a questionnaire concerning working conditions and health and the inter-rater reliability of observations and measurements according to an ergonomic checklist. METHOD Fifty-seven operators participated in a retest questionnaire 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 ergonomic checklist were classified as having fair to good or higher reliability. CONCLUSIONS About half of the questions had fair to good or higher reliability and can be recommended for further analyses. The majority of variables in the ergonomic checklist were classified as having fair to good or higher reliability. Low reliability does not necessarily indicate that the reliability of the test, per se, is low but may signify that the conditions measured vary over time or that the answers are aggregated in one part of the scale.