Night shift work in resident physicians: does it affect mood states and cognitive levels?

The effects of night shift work on health status have been widely studied. Night workers seem to smoke more, eat badly and show a low propensity to physical activity. Night work can be associated with an increase in cardiovascular and gastrointestinal disorders, alterations in immune response, diabetes, aging, hormonal imbalance, and premature death; alteration of circadian rhythm is also regarded as a risk factor for breast cancer and neuropsychiatric disorders. Moreover, several studies have highlighted the effects of sleep deprivation on clinical performance, quality of care and personal safety of healthcare personnel. No studies have investigated the effects of night work on Italian resident physicians and compared its effect across specialties. This study aims to assess the prevalence of sleep disorders, possible cognitive impairment and mood states, in relation to night shift work among resident physicians.

80 resident physicians, attending the postgraduate training into an Hospital located in the South of Italy, were divided into 4 areas (medical, surgical, services and anaesthesia). They were recruited from July 2017 to June 2018 and participated to a survey consisting of 4 questionnaires to investigate the presence of sleep deprivation and sleep quality (Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index), their cognitive status (Mini Mental State examination) and mood profiles (Profile of Mood States, POMS). Analysis of variance was used for comparison of questionnaires scores across specialties.

Authors reported no sleep deprivation, no sleep disorders and their outcomes, no changes in intellectual efficiency and no cognitive impairment in this population, neither in the areas performing night shifts nor in those involving only day shifts. Mood states measured by POMS showed a borderline level of Anger-Hostility (A) value among the residents of the medical area and services, and an increase slightly beyond the physiological levels of the T-score 50 of Fatigue-Inertia (F) always in the same groups. An increase in the Vigour-Activity (V) value beyond T-score 50 levels was also observed among residents of all the areas considered.

Emotional involvement could be attributed to the gap between high professional demand and lack of experience and knowledge among trainees. Tutors should help their students in order to identify earlier changes in the mood. Improvement in the organization of the trainee's activity could reduce the emotional overload.