The “weekend effect”
(sometimes also known as the “after hours effect” since many of the same
results apply to patients admitted at night as well as on weekends) in which
increases in mortality, complications or adverse events are seen for patients
admitted on weekends has been demonstrated for a wide range of both surgical
and medical conditions. Our numerous columns on the “weekend effect” have
stressed that there are likely both patient-related and system-related factors
underlying the phenomenon (see, for example, our November 2013 What's New in the Patient Safety World column “The
Weekend Effect: Not One Simple Answer”).
Several recent
articles have challenged the concept of the “weekend effect” and pointed out
deficiencies in case identification methodologies that may give rise to
inaccurate conclusions.
Stroke is one of the
many conditions previously identified as prone to the weekend effect. One new
analysis from the UK (Li 2016),
however, looks at how use of administrative coding to identify stroke cases may
erroneously lead to this conclusion. The authors looked at stroke cases from
the Oxford Vascular Study and found that many patients admitted with a stroke
diagnosis may not, in fact, have had a new stroke. Rather many had a
previous stroke and were admitted for other reason yet administrative coding
made them appear to have had new strokes. Such patients obviously have a lower
likelihood of mortality during that admission and they are disproportionately
admitted on weekdays (often for procedures). Thus, it is not surprising that
patients admitted on weekends (who have new strokes) would appear to have
higher mortality rates. When the authors looked just at those patients with
acute (new) strokes they found no imbalance in baseline stroke severity for
weekends vs. weekdays and no difference in the 30-day mortality rates.
A second UK study on stroke (Bray 2016) focused on the impact of not only day of the week but also time of day of admission. They analyzed data from the Sentinel Stroke National Audit Programme with over 74,000 stroke patients. They found variation from day to day and time of day for several measures of stroke care measures. Overall, they found no difference in 30 day survival between weekends and weekdays but patients admitted overnight on weekdays had lower odds of survival.
Another very interesting study looked at patients presenting
to emergency rooms (Meacock
2016). They postulated that restricted
service availability at weekends on the outpatient side may lead to selection
of patients with greater average severity of illness for admission. They found
that similar numbers of patients attended emergency rooms on weekends and
weekdays and there were similar numbers of deaths amongst patients attending
emergency rooms on weekend days compared with weekdays. Attending emergency
rooms at the weekend overall was not associated with a significantly higher
probability of death. Higher mortality rates at weekends are found only amongst
the subset of patients who are admitted. They conclude that reduced
availability of primary care services and the higher admission threshold at weekends
mean fewer and sicker patients are admitted at weekends than during the week.
And a fourth study, again from the UK, challenged previous studies that had suggested lack of availability of specialists on weekends was responsible for higher mortality rates for patients admitted on weekends. Aldridge and colleagues (Aldridge 2016) found that substantially fewer specialists were present providing care to emergency admissions on Sunday than on Wednesday (11% vs. 42%) but specialists present on Sunday spent 40% more time caring for emergency patients than did those present on Wednesday. Moreover, the median specialist intensity on Sunday was only 48% of that on Wednesday. Thus, their analysis did not detect a correlation between weekend staffing of hospital specialists and mortality risk for emergency admissions.
Our own opinion is
that the “weekend effect” and “after-hours effect” are real phenomena but that
the causes are multifactorial, including both patient-based and system-based
contributing factors. We suspect that, yes, patients admitted at these times
are likely sicker and have a higher severity of illness and therefore are
likely to have a higher mortality rate. However, as we’ve pointed out over and
over, hospitals do not provide the same levels of service 24 hours a day, seven
days a week. Staffing patterns, in terms of volume and even more so in
terms of experience, are the most obvious difference but there are many others
as well. Many diagnostic tests are not as readily available during these times.
On-site physician availability may be different and cross-coverage by
physicians who lack detailed knowledge about individual patients is common. You
also see more verbal orders, which of course are error-prone, at night and on
weekends. But the most
significant difference is nurse workload on weekends. We’ve described the
tremendous increase in nurse responsibilities on weekends due to lack of other
staff (no clerical staff, delayed imaging, physicians not on site) that add
additional responsibilities to their jobs. Our December 15, 2009 Patient Safety
Tip of the Week “The
Weekend Effect” discussed how adding non-clinical administrative tasks to
already overburdened nursing staff on weekends may be detrimental to patient
care. Just do rounds on one of your med/surg floors
or ICU’s on a weekend. You’ll see nurses answering phones all day long, causing
interruptions in some attention-critical nursing activities. Calls from
radiology and the lab that might go directly to physicians now often go first
to the nurse on the floor, who then has to try to track down the physician.
They end up filing lab and radiology reports or faxing medication orders down
to pharmacy, activities often done by clerical staff during daytime hours. Even
in those facilities that have CPOE, nurses off-hours often end up entering those
orders into the computer because the physicians are off-site and are phoning in
verbal orders and this may soon get worse as The Joint Commission is now
allowing orders to be texted in (see our May 24, 2016 Patient Safety Tip of the
Week “Texting
Orders – Is It Really Safe?”).
You’ll also see nurses giving directions to the increased numbers of visitors
typically seen on weekends. They may even end up doing some housekeeping chores
and delivering food trays. All of these interruptions and distractions
obviously interfere with nurses’ ability to attend to their clinically
important tasks (see our Patient Safety Tips of the Week for August 25, 2009 “Interruptions,
Distractions, Inattention…Oops!” and May 4, 2010 “More
on the Impact of Interruptions”). That is why we think that simply
addressing nurse:patient
staffing ratios without addressing nurse workload issues may be short-sighted.
So while the recent
articles may dilute the weekend effect for some conditions, all you have to do
is spend some time in your hospital on weekends and you’ll readily see that
things are different on weekends.
Some of our previous columns on the “weekend effect”:
· February 26, 2008 “Nightmares….The Hospital at Night”
· December 15, 2009 “The Weekend Effect”
· July 20, 2010 “More on the Weekend Effect/After-Hours Effect”
· October 2008 “Hospital at Night Project”
· September 2009 “After-Hours Surgery – Is There a Downside?”
· December 21, 2010 “More Bad News About Off-Hours Care”
·
June
2011 “Another
Study on Dangers of Weekend Admissions”
·
September
2011 “Add
COPD to Perilous Weekends”
·
August
2012 “More
on the Weekend Effect”
·
June
2013 “Oh
No! Not Fridays Too!”
·
November
2013 “The
Weekend Effect: Not One Simple Answer”
·
August
2014 “The
Weekend Effect in Pediatric Surgery”
·
October
2014 “What
Time of Day Do You Want Your Surgery?”
·
December
2014 “Another
Procedure to Avoid Late in the Day or on Weekends”
·
January
2015 “Emergency
Surgery Also Very Costly”
·
May 2015
“HAC’s
and the Weekend Effect”
·
August
2015 “More
Stats on the Weekend Effect”
·
September
2015 “Surgery
Previous Night Does Not Impact Attending Surgeon Next Day”
·
February
23, 2016 “Weekend
Effect Solutions?”
References:
Li L, Rothwell PM on behalf of the Oxford Vascular Study. Biases in detection of apparent “weekend effect” on outcome with administrative coding data: population based study of stroke. BMJ 2016; 353: i2648
http://www.bmj.com/content/bmj/353/bmj.i2648.full.pdf
Bray BD, Cloud GC, James MA, et al. Weekly variation in health-care quality by day and time of admission: a nationwide, registry-based, prospective cohort study of acute stroke care. Lancet 2016; published online first May 10, 2016
http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2816%2930443-3/abstract
Meacock R, Anselmi L, Kristensen SR, et al. Higher mortality rates amongst emergency patients admitted to hospital at weekends reflect a lower probability of admission. J Health Serv Res Policy 2016; Published online before print May 6, 2016
http://hsr.sagepub.com/content/early/2016/05/05/1355819616649630.abstract
Aldridge C, Bion J, Boyal A, et al. Weekend specialist intensity and admission mortality in acute hospital trusts in England: a cross-sectional study. Lancet 2016; published online first May 10, 2016
http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2816%2930442-1/abstract
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