Towards a Predictive Test of Adjustment to Shift Work

TLDR

The study aimed to create a questionnaire that differentiates individuals by how well their circadian rhythms adapt to night work. The questionnaire was administered to 48 permanent night nurses in a large shift‑work study, and factor and correlation analyses linked factor scores to measures of circadian adjustment. Three factors emerged—sleep‑habit flexibility, drowsiness‑overcoming ability, and morningness/eveningness—and significant correlations with psychological and physiological adjustment metrics confirmed the factors’ concurrent validity, indicating the questionnaire could predict shift‑work adaptation.

Abstract

A questionnaire was developed to distinguish between people who differed in the degree to which their circadian rhythms adjusted to night work. This was administered to 48 ' permanent ' night nurses taking part in a large shift work study. Factor analyses indicated that there were three main factors. These were (I) rigidity/flexibility of sleeping habits, (ii) ability/inability to overcome drowsiness, and (iii) morningness/eveningness. Correlations were computed between the nurses'scores on each of these factors and a range of measures of adjustment of circadian rhythm. A number of significant correlations were found with both psychological and physiological measures, thus indicating that the factors had at least concurrent validity. It is concluded that it may prove feasible to develop a questionnaire that would predict the degree to which people's rhythms would adjust to shift work, and that flexibility of sleeping habits and the ability to overcome drowsiness should be components of such a questionnaire.