What statistical analysis did the researchers use? and why?

Background: Fatigue associated with shiftwork can threaten the safety and health of nurses and the patients in their care. Napping during night shift breaks has been shown to be an effective strategy to decrease fatigue and enhance performance in a variety of work environments, but appears to have mixed support within health care.

Methods: A survey design was used. Forty-seven Canadian critical care unit managers who were members of the Canadian Association of Critical Care Nurses responded to the web-based survey. Data analysis involved calculation of frequencies and percentages for demographic data, use of the Friedman rank test for comparison of managers' perceptions, and content analysis for responses to open-ended questions. Results: The findings of this study offer valuable insights into the complexities and confticts perceived by managers with respect to napping on night shift breaks by nursing staff. Staff and patient health and safety issues, work and break expectations and experiences, and strengths and deficits related to organizational napping resources and policy are considerations that will be instrumental in the development of effective napping strategies and guideline

Purpose: The purpose of this study was to explore critical care unit managers' perceptions of and experiences with their nursing staff's napping practices on night shift, including their perceptions of the benefits and barriers to napping/not napping in terms of patient safety and nurses' personal health and safety. Methods: A survey design was used. Forty-seven Canadian critical care unit managers who were members of the Canadian Association of Critical Care Nurses responded to the web-based survey. Data analysis involved calculation of frequencies and percentages for demographic data, use of the Friedman rank test for comparison of managers' perceptions, and content analysis for responses to open-ended questions. Results: The findings of this study offer valuable insights into the complexities and confticts perceived by managers with respect to napping on night shift breaks by nursing staff. Staff and patient health and safety issues, work and break expectations and experiences, and strengths and deficits related to organizational napping resources and policy are considerations that will be instrumental in the development of effective napping strategies and guidelines.

Significant variability was found across reports in terms of the duration and timing of naps during the night shift, with most naps lasting between 20 and 120 minutes and falling somewhere between midnight and four a.m. Sleep inertia, defined as "the state of impaired cognition, grogginess, and disorientation commonly experienced on awakening from sleep" (Wertz, Ronda, Czeisler, & Wright, 2006, p. 163), is identified as a safety concern in some napping studies (Kubo et al., 2010; Takahashi, Arito, & Fukuda, 1999; Takeyama et al., 2004). Two small studies have examined nurses' napping behaviours on night shifts. A group of eight intensive care unit (ICU) nurses in France kept a sleep diary for one month (Daurat & Foret, 2004). Four of the nurses napped at work, recording naps on 75% of their night shifts, with an average nap length of 150 minutes. The researchers concluded that whether or not the nurses napped on night shift appeared to be determined by circadian influences. In a study exploring emergency department (n = 9) and intensive care (n = 4) nurses' experiences with napping during breaks on night shift (Fallis, McMlan, & Edwards, 2011), 10 of 13 nurses reported regularly napping on breaks. Although performance or practice outcomes were not measured, nurses identified benefits of feeling energized or refreshed after a brief nap.

The web-based survey was developed by the research team founded on a review of the literature, the results of a qualitative study on napping/non-napping experiences of critical care nurses (Fallis et al, 2011), and the clinical experience of the research team. To assess content validity, three individuals with management experience piloted the survey and provided feedback regarding clarity and completeness. In addition, three experts in survey development reviewed the questions and made suggestions for revisions. The final survey consisted of 28 questions. Twelve questions elicited information to describe the sample. The remainder of the survey was divided into three sections: night shift routines (seven questions), perceptions of napping on night shift (five questions), and knowledge of incidents related to fatigue (three questions). The section on night shift routines included five yes/no questions on the presence of a napping policy, availability of a nap room, and the practice of napping in the manager's unit, and two Likert-scale questions on frequency of getting or combining breaks on night shift. The next section included three Likert-scale questions on perceptions of napping and two yes/no questions on whether or not there were benefits or drawbacks to napping on breaks, with an option to list perceived benefits or drawbacks. The questions on fatigue-related patient safety issues, nurse injury, and accidents on the drive home from work were yes/no in nature, with space provided to describe any incidents. The final question provided an opportunity for additional comment. Data analysis Data were identified by code only and downloaded from SurveyMonkey and entered into a Microsoft Excel spreadsheet and SPSS software for analysis. Quantitative data analysis involved descriptive and inferential analysis of closed-item responses using SPSS version 18. Descriptive statistics were used to report numerical data relating to the managers' age and nurses' break duration. Relative frequencies expressed as percentages were employed to describe data such as gender, years of experience in a critical care setting and as a manager, and type of facility. The Friedman rank test was used to examine differences in the managers' own perceptions of napping and their perceptions of colleagues' and administrators' views of napping. Open-ended responses were downloaded into a Word document and entered into Ethnograph 6.0, a software program for data management, then analyzed using content analysis (Weber, 1990). Two team members independently reviewed the responses on a question-by-question basis and grouped the responses into broad categories and then met to agree on and collapse the categories to organize data. Results Forty-seven managers, representing nine provinces, responded to the survey (Table 1). The mean age of the managers was 49.5 7.2 years, with 45% (21) identifying a baccalaureate degree and 28% (13) a graduate degree as their highest level of education. Most (77%) had more than 20 years of experience as a registered nurse, 60% (28) had worked in critical care for more than 20 years and the majority (58%) had at least six years of experience as a manager. Almost all (92%) had worked night shifts as a critical care nurse during their career. The managers were drawn nearly evenly from tertiary (55%) and community hospital settings (45%), with the majority managing a mixed ICU (72%) in which nurses worked 12-hour shifts (85%).