The multidimensionality of the psychological demands scale should be considered in psychometric analysis and interpretation, occupational epidemiologic studies, and future scale extension.

Relatively little is known about the short-term test-retest reliability of the Job Content Questionnaire (JCQ) and Effort-Reward Imbalance Questionnaire (ERIQ). Seventeen JCQ and six ERIQ items were qualitatively reviewed by 19 firefighters in focus groups. The items were then administered twice to 81 firefighters with a time interval of 1-8 weeks. The short-term reliability of the JCQ and ERIQ items and scales with the four-point Likert item responses was at least fair or moderate with several complementary statistical methods. It improved substantially when the four-point responses were simplified into the two ('agree' or 'disagree') responses. The JCQ psychological demands and the ERIQ effort scales were among the least reliable scales and their items were most frequently indicated by the firefighters to be clarified. The responses of professional firefighters to the JCQ and ERIQ items and scales were stable during an 8-week period, particularly when dichotomous item responses were used.

No abstract

HRR, a simple cardiovascular fitness measure, was inversely associated with MetS among middle-aged professional firefighters.