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What’s New in the Patient Safety World

September 2020

Daylight Savings Time Impacts Patient Safety?



We’ve done multiple columns on how patient safety is impacted by time of day, day of the week, and month of the year. But Daylight Savings Time?


A study, just presented in abstract form at the SLEEP 2020 meeting, found that adverse events resulting from human errors increased by 18.7% in the week after the Spring time change (Kolla 2020).


The Mayo Clinic researchers began with the premise that the “Spring forward” change at the start of Daylight Savings Time (DST) which reduces sleep opportunity by an hour, could result in sleep deprivation in healthcare workers and lead to an increase the potential for medical errors. The researchers looked at 8 years of data of self-reported adverse events (AE’s) in inpatient, outpatient, and ambulatory settings that occurred 7 days prior to and following the Spring and Fall time changes in a large healthcare organization and identified AE’s likely resulting from human error.


They found that adverse events resulting from human errors increased by a statistically significant 18.7% in the week after the Spring time change. A 5% increase in adverse events in the week following the Autumn return to Standard Time from DST was not statistically significant.


The authors conclude there is a significant increase in human error related AE’s following the “Spring forward” clock change which can jeopardize patient safety. They suggest that DST might best be eliminated. Alternatively, they recommend policy makers and healthcare organizations should evaluate measures to mitigate the increased risk during this period.


The study used self-reported AE’s in a single healthcare organization and there was no formal measure of actual sleep deprivation. But the findings are fascinating. The authors note their findings need to be replicated in other healthcare organizations.


However, the American Academy of Sleep Medicine on August 26, 2020 issued a position statement that these seasonal time changes should be abolished in favor of a fixed, national, year-round standard time (Rishi 2020). It cites “an abundance of accumulated evidence indicates that the acute transition from standard time to daylight saving time incurs significant public health and safety risks, including increased risk of adverse cardiovascular events, mood disorders, and motor vehicle crashes.” It also states that daylight saving time is less aligned with human circadian biology and that circadian misalignment may be associated in the longer term with increased cardiovascular disease risk, metabolic syndrome and other health risks.



Some of our other columns on the role of fatigue in Patient Safety:


November 9, 2010      “12-Hour Nursing Shifts and Patient Safety”

April 26, 2011             “Sleeping Air Traffic Controllers: What About Healthcare?”

February 2011             “Update on 12-hour Nursing Shifts”

September 2011          “Shiftwork and Patient Safety

November 2011          “Restricted Housestaff Work Hours and Patient Handoffs”

January 2012               “Joint Commission Sentinel Event Alert: Healthcare Worker Fatigue and Patient Safety

January 3, 2012           “Unintended Consequences of Restricted Housestaff Hours”

June 2012                    “June 2012 Surgeon Fatigue”

November 2012          “The Mid-Day Nap”

November 13, 2012    “The 12-Hour Nursing Shift: More Downsides”

July 29, 2014              “The 12-Hour Nursing Shift: Debate Continues”

October 2014              “Another Rap on the 12-Hour Nursing Shift”

December 2, 2014       “ANA Position Statement on Nurse Fatigue”

August 2015               “Surgical Resident Duty Reform and Postoperative Outcomes”

September 2015          “Surgery Previous Night Does Not Impact Attending Surgeon Next Day”

September 29, 2015    “More on the 12-Hour Nursing Shift”

September 6, 2016      “Napping Debate Rekindled”

April 18, 2017             “Alarm Response and Nurse Shift Duration”

July 11, 2017              “The 12-Hour Shift Takes More Hits”

February 13, 2018       “Interruptions in the ED”

April 2018                   “Radiologists Get Fatigued, Too”

August 2018               “Burnout and Medical Errors”

September 4, 2018      “The 12-Hour Nursing Shift: Another Nail in the Coffin”

August 2020               “New Twist on Resident Work Hours and Patient Safety”

August 25, 2020         “The Off-Hours Effect in Radiology”






Kolla B, Coombes BJ, Morgenthaler TI, Mansukhani MP. 0173 Spring Forward, Fall Back: Increased Patient Safety-Related Adverse Events Following the Spring Time Change. Sleep 2020; 43(Supplement_1): A69

(Kolla 2020)



Rishi MA, Ahmed O, Perez JHB, et al. Daylight saving time: an American Academy of Sleep Medicine position statement. Journal of Clinical Sleep Medicine 2020; Published online August 26, 2020

(Rishi 2020)




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