Stress and salivary cortisol in emergency medical dispatchers: A randomized shifts control trial.

Stress at work is a public health concern. Phone operators in emergency medical dispatch centers are particularly at risk. We aimed to demonstrate that the most stressful time for emergency medical dispatchers is the shift when they receive emergency incoming calls, with cortisol as a biomarker of stress. For each emergency medical dispatcher, we measured outcomes over a control day and during three types of shift: Incoming emergency call, Dispatch and Re-assessment. The pattern of shifts was randomized. Saliva was sampled every 15 minutes for 2 hours, i.e. 6 consecutive times, starting 15 minutes after the first life-and-death incoming emergency call between 2 and 5 pm during three types of shift. We measured saliva cortisol every 2 hours over a control day, from 7am to 9pm. Perceived stress was assessed by a visual analog scale. We recruited 22 phone operators aged 36.4+/-10.8 years old (14 women and 8 men). Cortisol values were higher during the Incoming emergency call shift than during the Dispatch (p = .04) and Re-assessment (p = .04) shifts. The increase in cortisol levels was greater in men than in women (p = .009). There were no differences between control values and those of the three shifts. The kinetics of cortisol increased with greater perceived stress overall (p < .001) and for each type of shift (Incoming emergency call, p = .02; Dispatch p = .03; Re-assessment: p < .001). The kinetics of cortisol in response to incoming emergency calls was greater when the call was an absolute emergency (p = .03), and also tended to further increase when a subsequent absolute incoming emergency call was received (p = 0.07). In conclusion, the incoming emergency call shift carries particular risk for dispatchers, who have greater perceived stress and a greater increase in cortisol levels.

Work-related stress in an emergency medical dispatch center.

STUDY OBJECTIVE: Stress is an emergent occupational problem in modern societies. Among workers, medical practitioners are particularly exposed. However, data objectifying stress levels during work time are scarce. The aim of this study was to establish diurnal salivary cortisol levels in a highly stressful work environment, the medical dispatch center of an emergency care unit. METHODS: Eight emergency medical dispatchers agreed to be sampled every 2 hours from 9 AM to 7 PM during a usual day of work. Eight matched control subjects sampled during their leisure time were used as a control group. RESULTS: Whatever the time of the day, emergency medical dispatchers showed significantly increased cortisol levels during their work time compared with levels found in the control group. There was a significant difference in the amount of daytime cortisol secretion between control subjects and emergency medical dispatchers (0.345 nmol/L; 95% confidence interval [CI] 0.04 to 0.93 nmol/L), with a mean daytime augmentation of 22.8% in emergency medical dispatchers compared with that in control subjects. In addition, among emergency medical dispatchers, the subjective perception of emotional stress was positively correlated with total cortisol concentrations per day (r =0.78; 95% CI 0.39 to 1). CONCLUSION: Our data show that work tasks of emergency medical dispatchers led to a hypersecretion of cortisol. Because the damaging effects of persistent cortisol increases on health and cognitive functions are well recognized in human beings, it seems necessary to rapidly identify stressful work situations and targets for organizational improvements to minimize stress in these situations.