The impact of perceived intensity and frequency of police work occupational stressors on the cortisol awakening response (CAR): Findings from the BCOPS study.

Police officers encounter unpredictable, evolving, and escalating stressful demands in their work. Utilizing the Spielberger Police Stress Survey (60-item instrument for assessing specific conditions or events considered to be stressors in police work), the present study examined the association of the top five highly rated and bottom five least rated work stressors among police officers with their awakening cortisol pattern. Participants were police officers enrolled in the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) study (n=338). For each group, the total stress index (product of rating and frequency of the stressor) was calculated. Participants collected saliva by means of Salivettes at four time points: on awakening, 15, 30 and 45min after waking to examine the cortisol awakening response (CAR). Saliva samples were analyzed for free cortisol concentrations. A slope reflecting the awakening pattern of cortisol over time was estimated by fitting a linear regression model relating cortisol in log-scale to time of collection. The slope served as the outcome variable. Analysis of covariance, regression, and repeated measures models were used to determine if there was an association of the stress index with the waking cortisol pattern. There was a significant negative linear association between total stress index of the five highest stressful events and slope of the awakening cortisol regression line (trend p-value=0.0024). As the stress index increased, the pattern of the awakening cortisol regression line tended to flatten. Officers with a zero stress index showed a steep and steady increase in cortisol from baseline (which is often observed) while officers with a moderate or high stress index showed a dampened or flatter response over time. Conversely, the total stress index of the five least rated events was not significantly associated with the awakening cortisol pattern. The study suggests that police events or conditions considered highly stressful by the officers may be associated with disturbances of the typical awakening cortisol pattern. The results are consistent with previous research where chronic exposure to stressors is associated with a diminished awakening cortisol response pattern.