Institutional Review Board (IRB) approval was obtained prior to this prospective cohort study. All methods were performed in accordance with the relevant guidelines and regulations. Participants included trainees in two urban anesthesiology training programs within a single health care system. The intervention group consisted of residents from one training program for whom in-person MBSR training was made available; the “active” control consisted of residents from a second training program within the same health care system for whom an online cognitive behavioral therapy (CBT) course and app-based mindfulness resources were made available. This design is based on the body of research on mindfulness and MBSR employing both wait-list and “active” controls.19,20
Inclusion criteria included CA-1 or CA-2 training level (PGY-2 and 3), resulting in 76 total eligible anesthesiology residents. Exclusion criteria included PGY-1 and PGY-4 training level given the inability of interns to consistently attend and the inability of those at the PGY-4 training level to complete the two-year study protocol.
After obtaining consent, study participants were to be followed over a 24-month period including a 3-month pre-intervention phase, 18-month intervention phase and 3-month post-intervention phase. Primary outcome variables included Maslach Burnout Inventory - Human Services Survey (MBI-HSS) scores, hair cortisol level and sleep status level (SSL) collected through Fitbit Alta HR™ (Fitbit Inc., San Francisco, CA) wearable devices.
Intervention: The in-person training cohort was provided a MBSR course every other week over 18 months (January 2018 - June 2019) during morning lecture time (6:30 to 7:00 AM) at a single training program. The MBSR curriculum was based on the original course developed by Jon Kabat-Zinn at the University of Massachusetts.21 The curriculum provided to our participants was modified to consist of 36 half-hour sessions over 18 months (deviating from weekly 2.5 hour sessions over 8 weeks originally described for MSBR), due to scheduling restrictions imposed by operating room staffing requirements. MSBR sessions consisted of instruction in sitting meditation, mindful movement, body scan, and walking meditation. Generally, the aim of the course and these exercises is to learn about and recognize stress to modify its effects by applying mindfulness techniques to daily life. Session attendance was optional and available to all anesthesiology house staff in the program to which it was provided. The instructor was certified to provide instruction in MSBR and was hired through the Graduate Medical Education office to all training programs in our healthcare system.
The control group received access to moodgym® (ehubHealth Pty Ltd., Goulburn, AU), an app-based CBT training product, and InsightTimer© (Insight Network Inc., San Francisco, CA) an app-based source of meditation timers and mindfulness meditation tracks. Use of these products was voluntary and not recorded to preserve subjects’ privacy.
Maslach Burnout Inventory – Human Services Survey (MBI-HSS) and hair cortisol levels were obtained on day 1 of the pre-intervention phase, at which time SSL data collection with Fitbit Alta HR™ devices was also initiated. The proposed data collection schedule is presented in Table 1.
The MBI-HSS, a validated 22-question survey, is the most commonly used tool for measuring burnout in clinicians.22 It consists of 3 scales that assess three domains of burnout: emotional exhaustion, depersonalization, and personal accomplishment.23
Hair cortisol level testing is a surrogate marker of stress, given that stress is associated with increased activity of the hypothalamic-pituitary-adrenal axis. It is an easily accessible means of cortisol testing when examining human cortisol levels over a period of several months, although some studies suggest that in order to detect cortisol levels in a given hair sample the stress must be ongoing.24 Hair was cut as close to the scalp as possible with clean scissors in an amount of hair roughly the width of a pencil from the posterior vertex of the head. Samples 3cm in length representing cortisol deposition over roughly the 3-month period prior to collection were obtained by using a ruler to measure the desired length from the cut end and cut again to yield the correct sample. Samples were wrapped in aluminum foil, labeled with a permanent marker with each participant’s unique identification number, stored at room temperature, then shipped overnight to the University of Massachusetts, to the lab that developed this method for cortisol analysis.25
Sleep State Level was measured through the Fitbit Alta HR™ electronic fitness tracker, which each participant was asked to wear 24 hours a day, except when charging. This device is known to be safe in the operating room without interfering with equipment or monitors. Each participant was asked to download Detalytics© (Detalytics Pte. Ltd, Singapore), an app that would allow data from the Fitbit to be uploaded and analyzed. The Detalytics© proprietary sleep analytics suite analyzes the level and stability of sleep during a single sleep cycle and across multiple episodes of sleep. The three data endpoints comprise the Sleep Status Level: sleep quantity (duration of time the participant is asleep), sleep quality (time required to fall asleep and the number of awakenings experienced in a single sleep cycle), and sleep consistency (overall variability within multiple sleep cycle measurements).
The primary objective of the analysis was to evaluate the effect of MBSR on Maslach results and hair cortisol at three time points or campaigns (baseline, 180 days, and 360 days), and to determine whether there existed a change over time. The secondary objective was to investigate the effect of residency year overall and its trend. A mixed model was used with fixed effects including intervention group, campaign time (baseline, 180 and 360 days), clinical anesthesia year (CA-1 and CA-2), interaction between intervention group and time, and interaction between clinical anesthesia year and time. Random effects included the study subjects. The mixed model accounted for the within-subject correlation of the repeated assessments during the campaign periods.
Data are presented as median [interquartile range] and N (%). For comparisons of Fitbit Alta™ HR and sleep data between the intervention and control groups, the Wilcoxon-Mann Whitney test was used for continuous data and Fisher’s exact test was used for categorical data where appropriate. In general, a 2-sided p-value of < 0.05 signifies statistical differences between the two groups. Although many data points were collected by the Fitbit Alta™ devices, the study sample size was limited. Therefore, we chose to use 0.01 as the significance criterion instead of correcting the p-values for the multiple comparisons. The statistical analysis was performed using SAS Software (Version 9.4, SAS Institute, Cary, NC, USA).