What were the data analysis methods used in the study?

Methods:In this two-hospital pilot implementation project, napping on the night shift was offered to six nursing units for which the executive nursing leadership had given approval. Unit nurse managers' approval was sought, and where granted, further explanation was given to the unit's staff nurses. A nap experience form, which included the Karolinska Sleepiness Scale, was used to assess pre-nap sleepiness level, nap duration and perceived sleep experience, post-nap sleep inertia, and the perceived helpfulness of the nap. Nurse managers and staff nurses were also interviewed at the end of the three-month study period.

Results:Successful implementation occurred on only one of the six units, with partial success seen on a second unit. Barriers primarily occurred at the point of seeking the unit nurse managers' approval. On the successful unit, 153 30-minutes naps were taken during the study period. A high level of sleepiness was present at the beginning of 44% of the naps. For more than half the naps, nurses reported achieving either light (43%) or deep (14%) sleep. Sleep inertia was rare. The average score of helpfulness of napping was high (7.3 on a 1-to-10 scale). Nurses who napped reported being less drowsy while driving home after their shift.

Setting.This pilot study of a napping implementation project was one component of a study of fatigue risk management implementation initiatives in two mid-Atlantic hospitals. One is a 380-bed community teaching hospital, and the other a 313-bed children's hospital. Both hospitals have received Magnet recognition from the American Nurses Credentialing Center. Procedures.Initial study approval was obtained from the directors of nursing research, the nursing research councils, and the vice presidents for nursing at each hospital. Approval was also obtained from each hospital's institutional review board (IRB) and from the University of Maryland's IRB. Six nursing units were then selected collaboratively by the nursing research directors and executive nursing leadership. Unit selection took place between October 2011 and May 2012. The selected units included medical-surgical, critical care, and ED units.

The process of engaging the units was the same in both settings. Between January and October 2012, the principal investigator (JGB) met with each nurse manager and her designates (nurse educators, senior nurses, or a staff nurse designated as the project "point person"), and provided information about the risks of sleepiness on the night shift, the scientific evidence supporting napping, and methods to avoid post-nap sleep inertia. Each unit was encouraged to develop its own evidence-based method of implementing napping (seeTable 1,7, 22, 24, 25, 30-35). Nurse managers often delegated implementation to their senior nursing staff. When requested, the principal investigator introduced the study to nurses verbally during change of shift meetings. Data collection with staff nurses took place between February 2012 and May 2013. Nurse managers were interviewed at the end of the data collection period, and night-shift nurses were also interviewed as a group on the unit where napping was successful. These interviews took place during February 2014, and written notes were taken.

Measures.A single-page nap experience form was used by napping nurses to document aspects of the nap. Nurses were asked to complete the form each time they took a nap. Data gathered included the timing and duration of the nap, sleepiness level immediately before the nap, sleep ability during the nap, sleep inertia upon arising, and helpfulness of the nap. No unique identifiers were collected. The nap experience form incorporated the following tools. Sleepiness levels immediately before napping were assessed using the Karolinska Sleepiness Scale (KSS). This scale rates sleepiness on an ordinal scale ranging from 1 to 9, with 1 representing extremely alert, 5 representing neither alert nor sleepy, and 9 representing very sleepy, great effort to keep awake, fighting sleep. Ratings of 7 to 9 indicate levels of sleepiness that can impair workplace safety. The KSS is widely used in sleep science to describe state of sleepiness,36and has been validated against performance and electroencephalographic variables.37Sleep ability during the nap was assessed using an investigator-developed four-point ordinal scale (1, awake, eyes closed; 2, eyes closed, not sure if I fell asleep; 3, slept lightly; 4, slept deeply). Sleep inertia on arising was measured using an investigator-developed four-point scale (1, very groggy or sluggish; 2, a little groggy or sluggish; 3, alert, not refreshed; 4, alert and refreshed). The perceived helpfulness of the nap was assessed using an investigator-developed visual analog scale in which participants marked a line to rate their nap somewhere between "not at all helpful" (rated 0) and "extremely helpful" (rated 10).In order to ensure participants' anonymity, we did not collect demographic data.

Data analysis.Data were described based on the level of measurement, and graphs were produced to display the relative proportions of the variables.

Nap experience form data.A total of 153 nap experience forms were collected and analyzed. The average nap duration was 31 minutes (SD, 5.4 minutes). Most participants reported some sleepiness immediately before the nap (mean KSS score, 6.1; SD, 1.8), which is to be expected on the night shift. For 44.2% of naps, nurses reported KSS scores between 7 and 9. For more than half of naps, nurses reported actual sleep, with 43% reporting that they slept lightly and 14% reporting that they slept deeply. Sleep inertia was relatively rare, with 1.3% of naps ending in the nurse feeling "very groggy or sluggish" and 20.3% of naps ending in the nurse feeling "a little groggy or sluggish." Nurses reported feeling "alert and refreshed" at the end of 56.2% of naps. Regarding the helpfulness of napping, the average score was 7.3 out of 10 (SD, 2.2).During the subsequent group interview, several night-shift nurses commented that napping had eliminated drowsy driving on the way home from work. Many of them also thought that having the napping implementation project on their unit made it more desirable for other night-shift nurses to "float" there so that they could take a nap.