A one-item subjective work stress assessment tool is associated with cortisol secretion levels in critical care nurses.

BACKGROUND: Stress-related diseases are increasing in prevalence, with workplace interventions targeting stress receiving greater attention. Cortisol levels, a marker of physiological stress reaction, can be used to evaluate intervention effects, but measurement can be challenging to implement. Objective workload and subjective stress measures are alternatives previously related to cortisol secretion. We evaluated the validity of a one-item subjective stress measure based on its association with cortisol levels.

METHODS: Eighty-two pediatric critical care nurses participated in a prospective cohort study in Switzerland between September 2004 and March 2005. Salivary cortisol samples were collected during three, nine-day periods. Sampling occurred at shift start, repeating every two hours. Subjective stress was recorded with each sample and at shift end. Objective workload for each shift and nursing unit was derived from the hospital's LEP Nursing Workload Management System. Multilevel regression models were employed in the analysis.

RESULTS: Subjective stress, measured contemporaneously (beta=0.098, p=0.044), but not retrospectively (beta=0.012, p=0.556), was significantly related to increased cortisol secretion. Objective workload was not significantly associated with cortisol levels.

CONCLUSIONS: The one-item summary measure of subjective work stress, administered contemporaneously,may be a valid tool for evaluation of workplace interventions. Future study is needed to establish reliability and generalizability