Differences in Stress Level between Nurses Working Two-Shift and Three-Shift Rotations

Research Article

Austin Med Sci. 2021; 6(1): 1046.

Differences in Stress Level between Nurses Working Two-Shift and Three-Shift Rotations

Yu SJ1,2, Wang SS3,4, Ma DD1,5, He LA1,2, Liu Y6 and Cao YJ1,7*

1Department of Rescpiratory and Critical Care Medicine, Qilu Hospital of Shandong University, China

2Nursing Theory & Practice Innovation Research Center of Shandong University, China

3University of Shandong, Center for Health Management and Policy Research, Shandong, China

4University of Massachusetts Boston, Gerontology Institute, Boston, USA

5University of Shandong, Key Laboratory of Otolaryngology, National Health and Health Commission Shandong, China

6University of First Affiliated Hospital of Jinzhou Medical, China

7Department of Nursing, Qilu Hospital of Shandong University, China

*Corresponding author: Cao YJ, Department of Nursing, Qilu Hospital of Shandong University; Nursing Theory & Practice Innovation Research Center of Shandong University, 107 West Wenhua Rd Jinan, Shandong, China 250012 China

Received: April 26, 2021; Accepted: May 18, 2021; Published: May 25, 2021


Background: Shift work has been widely documented to affect stress among nurses; however, it is not clear how different shift work schedules are associated with nurses’ levels of stress.

Objective: This study aimed to compare levels of stress among Chinese nurses working on different shift work schedules by examining their salivary amylase and cortisol.

Design: A cross-sectional survey design. Saliva samples were collected from nurses who had been working in two-shift modes (shift at 5pm or 8pm) or three-shift modes (shift at 11pm, 12am, or 1am) for at least one year. Data collection was conducted from March 1, 2017 to May 31, 2017.

Setting: Participants were recruited from a public tertiary teaching medical center in eastern China.

Participants: A total of 216 nurses were included in the final analysis, including 55 working in two-shift modes and 161 working in three-shift modes.

Method: Stress level was assessed using the amylase and cortisol profiles. Logistic regression analyses for amylase and cortisol profiles were adjusted for marriage, age, working years, education background, professional title.

Conclusion: Our findings suggested that nurses’ stress was contingent on night-shift schedules. Three-shift rotations may be superior than two-shift rotations in keeping nurses’ stress levels low. Nurse managers may take nurses’ potential stress levels into consideration when design work schedules.

Keywords: Salivary amylase; Salivary cortisol; Stress; Nurses; Shift rotations


Stress can affect individuals’ health and work efficiency [1-3]. Nurses tend to have high levels of stress, due to heavy workload and high concentration of attention [4,5]. Nurses with high levels of stress have been reported suffering various health problems, ranging from physical problems, such as gastrointestinal and musculoskeletal symptoms, sleep disorders, and physical exhaustion, to psychological disorders, including anxiety and depression [6,7]. Moreover, studies found that high stress was associated with prolonged response time and decreased attention among nurses, which further led to issues related to patients’ safety and care quality [8-12].

Shift work is common in the healthcare field and is necessary to guarantee the continuity and quality of care [13]. However, studies have suggested that shift work was strongly associated with stress [14]. For example, compared with day-shift workers, night-shift workers reported greater stress [15]. Shift rotation among nurses mainly includes two modes: the two-shift mode (i.e., day shift and night shift) and the three-shift mode (i.e., day shift, early-night shift, and late-night shift) [16] Most hospitals in the United States, Britain, Australia implement the two-shift mode [17-20], whereas in China, a variety of two-shift and three-shift working schedules exist [21,22]. Researchers have not yet explored stress among nurses working in different shift modes; therefore, the aim of this study is to compare night-shift nurses’ stress between two- and three-shift modes, and further among 5 different shift schedules.

In the literature of stress, most studies used subjective measures – surveys or observations to quantify stress level; such measures are subject to response biases [23-25]. Individuals’ saliva samples could be a more accurate indicator of stress. According to Niu and colleagues (2015), it takes longer for night shift nurses to adjust to the circadian rhythm of cortisol secretion than day shift nurses [11]. Salivary amylase and cortisol amylase are biomarkers that reflect the activities of the two major stress response systems in human body, the Sympathetic-Adrenomedullary (SAM) axis and the Hypothalamic- Pituitary-Adrenal (HPA) axis [26]. Human bodies experiencing stress will activate the SAM axis and HPA axis, and promote the synthesis and secretion of salivary and cortisol hormone [27-29]. Studies using saliva biochemical indexes as measures of stress found that the concentration of salivary amylase and cortisol increased as the stress level was increasing [11,28,30,31]. Therefore, salivary amylase and cortisol are both considered as sensitive indicators of stress [32]. To our knowledge, no study has used salivary indicators to compare stress levels between two-shift nurses and three-shift nurses in China.

To expand on the literature regarding stress among nurses in China, this study aims to explore how different shift modes are associated with nurses’ stress, measured by salivary amylase and cortisol. Evidence from this study will help nursing managers in restrategizing nurse shift schedules and keep nurses’ stress at the lowest possible levels.


Study design

Data were collected from nurses working in either two-shift or three-shift modes, including 5 different shift schedules. There were 2 types of schedules in the two-shift modes: 1) night shift between 5pm and 8am (next day) and 2) night shift between 8pm and 8am (next day). The three-shift mode included 3 types of schedules: 1) night shift between 11pm and 8am (next day), 2) night shift between 12am and 8am, and 3) night shift between 1am and 8am. Nurses recruited in this study were thereafter categorized into 5 groups (i.e., 5pm, 8pm, 11pm, 12am, and 1am) based on their rotation schedules. All nurses worked a total of 40 hours per week, including day and night work. They usually take a two-day rest after night work.


From March 1, 2017 to May 31, 2017, shift working nurses employed in a public tertiary hospital in Jinan City Shandong Province in China were invited to participate in this study. The inclusion criteria were: shift working nurses aged ≤40 years old who had been providing direct care to patients in wards for more than one year. Nurses in the following conditions were excluded: with oral diseases, upper respiratory tract infections, endocrine diseases, immune system diseases, under menstruation cycle, or pregnancy.

A total of 220 participants were recruited by research assistants who were not aware of the study design. Of these, 217 nurses agreed to complete the baseline assessment and then screen. One participant withdrew from the study due to personal reasons, leaving a final sample size of 216. The sample included 61 participants working in the two-shift modes (34 in 5pm and 27 in 8pm group) and 155 participants working in the three-shift modes (42 in 11pm, 64 in 12am, and 49 in 1am group).

Data collection

Salivary amylase and cortisol. Saliva samples were collected by the participants using a salivary device. Prior to saliva collection, the following instructions were provided to each participant: 1) set an alarm and collect the saliva sample between 7am and 8:30am on the day after they had rested for two days; 2) collect the sample at awakening before brushing teeth to avoid any micro-wounds in the oral cavity; 3) do not smoke, eat, or do strenuous exercise within 60 minutes prior to collecting saliva sample; 4) chew the sterile cotton ball for 5 min, and collect approximately 2-3ml saliva sample; and 5) store the saliva sample in refrigerator (2oC~8oC). Cold packs and bags were provided for sample transportation. Saliva specimens were placed in a refrigerator for 24 hours with a constant temperature at 2oC~8oC. After 24 hours, the specimens were centrifuged at 3000 rpm for 15 minutes to remove mucin and residue. The processed filtrate was kept in freezer for a month before testing. Salivary amylase was measured using the Human Alpha-Amylase (AMY1) ELISA kit (batch number: CSB-E14075h) and salivary cortisol was measured using the R&D SYSTEMS, A bio-techno brand cortisol Assay (batch number: KGE008B) under the manufacturer instructions (China Cusabio and American R&D system).

Demographic and night-shift information. Demographics included gender (male vs. female), age (<30 years vs. 30-40 years), length of service (<10 years vs. 10-20 years), education (junior college vs. college and above), professional title (nurses vs. nurse practitioner and above), marital status (married vs. single), shift modes (two-shift vs. three-shift), and shift schedules (5pm, 8pm, 11pm, 12am, or 1am).

Statistical analysis

SPSS22.0 statistical software was used for data entry and statistical analysis. Salivary amylase and cortisol levels were firstly compared between the two shift modes using independent sample t-test, and then compared among different shift schedules using one-way ANOVA. Further, multiple linear regression models were conducted to examine the associations between shift modes/schedules and salivary amylase and cortisol levels.

Ethical considerations

Ethical approval for the study was obtained from Qilu Hospital of Shandong University Ethics Committee (No.2017080). Participants were aware of the purpose and methodology of the study. Participants also understood that their participation was voluntary, and they were able to withdraw at any stage with no negative consequences. Participants who were willing to join this study signed an informed consent form. Confidentiality of the participants was protected by discarding salivary samples and de-identifying collected data. Data was only used for academic research purpose.


Demographic backgrounds of the two-shift and three-shift nurses are provided in Table 1. The average age was 28 years (SD=4.04), and the percentage of females was 93%. Half of the nurses were married, and half had college or higher degree. About 56% of the participants were nurse practitioners or above. No significant differences were found between two-shift and three-shift nurses’ demographic characteristics.