The 'weekend effect': What is the
evidence?
Paul Aylin
Professor of Epidemiology and Public Health
[email protected] Patient
Safety
Translational
Research Centre
1st June 2016
The ‘weekend effect’
• Background
• My work
• Explanations
• Next steps
Freemantle et al.
• Update of their 2012 paper on 2009/10 admissions for 2013/14
• Compared with Wednesday
• Combines elective and emergency admissions
• Choice of disease specific analyses (Oncology and cardiovascular)
• Day of death analysis
Over 100 papers
1. Abougergi MS, Travis AC, Saltzman JR. Impact of day of admission on
mortality and other outcomes in upper GI hemorrhage: a nationwide analysis.
Gastrointest Endosc. 2014 Aug; 80(2): 228-35
http://www.ncbi.nlm.nih.gov/pubmed/24674354
2. Albright KC, Savitz SI, Raman R, Martin-Schild S, Broderick J, Ernstrom K,
Ford A, Khatri R, Kleindorfer D, Liebeskind D, Marshall R, Merino JG, Meyer
DM, Rost N, Meyer BC. Comprehensive stroke centers and the 'weekend
effect': the SPOTRIAS experience. Cerebrovasc Dis. 2012; 34(5-6): 424-9
http://www.ncbi.nlm.nih.gov/pubmed/23207423
3. Al-Lawati JA, Al-Zakwani I, Sulaiman K, Al-Habib K, Al Suwaidi J,
Panduranga P, Alsheikh-Ali AA, Almahmeed W, Al Faleh H, Al Saif S, Hersi
A, Asaad N, Al-Motarreb A, Mikhailidis DP, Amin H. Weekend versus
weekday, morning versus evening admission in relationship to mortality in
acute coronary syndrome patients in 6 middle eastern countries: results from
gulf race 2 registry. Open Cardiovasc Med J. 2012; 6: 106-12
http://www.ncbi.nlm.nih.gov/pubmed/23002404
4. Ananthakrishnan AN et al. Outcomes of Weekend Admissions for Upper
Gastrointestinal Hemorrhage: A Nationwide Analysis. Clin Gastro Hepatology
2009; 7(3): 296-302.e1 http://www.ncbi.nlm.nih.gov/pubmed/19084483
5. Arabi Y, Alshimemeri A, Taher S.. Weekend and weeknight admissions have
the same outcome of weekday admissions to an intensive care unit with
onsite intensivist coverage. Crit Care Med. 2006 Mar; 34(3): 605-11
http://www.ncbi.nlm.nih.gov/pubmed/16521254
6. Aylin P et al. Day of week of procedure and 30 day mortality for elective
surgery: retrospective analysis of hospital episode statistics.. BMJ 2013; 346:
f2424 http://www.ncbi.nlm.nih.gov/pubmed/23716356
7. Aylin P et al. Weekend mortality for emergency admissions. A large,
multicentre study. Qual Saf Health Care 2010; 19(3): 213-217
http://www.ncbi.nlm.nih.gov/pubmed/20110288
8. Barba R et al. The impact of weekends on outcome for acute exacerbations of
COPD. ERJ 2012; 39(1): 46-50
http://www.ncbi.nlm.nih.gov/pubmed/21659418
9. Barnett MJ et al. Day of the week of intensive care admission and patient
outcomes: a multisite regional evaluation. Med Care 2002; 40(6): 530-9
http://www.ncbi.nlm.nih.gov/pubmed/12021679
10. Bejanyan N, Fu AZ, Lazaryan A, Fu R, Kalaycio M, Advani A, Sobecks R,
Copelan E, Maciejewski JP, Sekeres MA. Impact of weekend admissions on
quality of care and outcomes in patients with acute myeloid leukemia Cancer.
2010 Aug 1; 116(15): 3614-20 http://www.ncbi.nlm.nih.gov/pubmed/20564070
11. Béjot Y, Aboa-Eboulé C, Jacquin A, Troisgros O, Hervieu M, Durier J, Osseby
GV, Giroud M. Eur J Neurol. Stroke care organization overcomes the
deleterious 'weekend effect' on 1-month stroke mortality: a population-based
study. 2013 Aug; 20(8): 1177-83
http://www.ncbi.nlm.nih.gov/pubmed/23551852
12. Bell CM, Redelmeier DA. Mortality among patients admitted to hospitals on
weekends as compared with weekdays. N Engl J Med. 2001 Aug 30; 345(9):
663-8 http://www.ncbi.nlm.nih.gov/pubmed/11547721
13. Bell D, Lambourne A, Percival F, Laverty AA, Ward DK. Consultant input in
acute medical admissions and patient outcomes in hospitals in England: a
multivariate analysis PLoS One. 2013 Apr 17; 8(4): e61476
http://www.ncbi.nlm.nih.gov/pubmed/23613858
14. Bray B, Cloud GC, James MA, Hemmingway H, Paley L, Stewart K, Tyrrell
PJ, Wolfe CDA, Rudd AG. 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; D
15. Bray BD, Ayis S, Campbell J, Cloud GC, James M, Hoffman A, Tyrrell PJ,
Wolfe CD, Rudd AG. Associations between stroke mortality and weekend
working by stroke specialist physicians and registered nurses: prospective
multicentre cohort study. PLoS Med. 2014 Aug 19; 11(8)
http://www.ncbi.nlm.nih.gov/pubmed/25137386?dopt=Abstract
16. Brims FJ, Asiimwe A, Andrews NP, Prytherch D, Higgins BR, Kilburn S,
Chauhan AJ. Weekend admission and mortality from acute exacerbations of
chronic obstructive pulmonary disease in winter. Clin Med. 2011 Aug; 11(4):
334-9 http://www.ncbi.nlm.nih.gov/pubmed/21853828
17. Brims FJ, Asiimwe A, Andrews NP, Prytherch D, Higgins BR, Kilburn S,
Chauhan AJ. Weekend admission and mortality from acute exacerbations of
chronic obstructive pulmonary disease in winter. Clin Med. 2011 Aug; 11(4):
Increased mortality associated with weekend hospital admission: a case for
expanded 7 day services? BMJ 2015;351 :h4596
35. Freemantle, Keogh, Pagano et al. Weekend hospitalization and additional
risk of death: An analysis of inpatient data. N J R Soc Med 2012; 105(2): 74-
84 http://www.ncbi.nlm.nih.gov/pubmed/22307037
36. Gallerani M, Imberti D, Ageno W, Dentali F, Manfredini R. Higher mortality
rate in patients hospitalised for acute pulmonary embolism during weekends.
Thromb Haemost. 2011 Jul; 106(1): 83-9
http://www.ncbi.nlm.nih.gov/pubmed/21544321
37. Gellerani M et al. Aortic rupture. Journal of Vascular Surgery. Volume 55,
Issue 5 , Pages 1247-1254, May 2012. Higher mortality in patients
hospitalized for acute aortic rupture or dissection during weekends
http://www.ncbi.nlm.nih.gov/pubmed/22542339
38. Goldacre MJ, Maisonneuve JJ. Mortality from meningococcal disease by day
of the week: English national linked database study J Public Health (Oxf).
2013 Sep; 35(3): 413-21 http://www.ncbi.nlm.nih.gov/pubmed/23378233
39. Goldstein SD, Papandria DJ, Aboagye J, Salazar JH, Van Arendonk K, Al-
Omar K, Ortega G, Sacco Casamassima MG, Abdullah F. The "weekend
effect" in pediatric surgery - increased mortality for children undergoing urgent
surgery during the weekend. J Pediatr Surg. 2014 Jul; 49(7): 1087-91.
http://www.ncbi.nlm.nih.gov/pubmed/24952794
40. Goodman EK, Reilly AF, Fisher BT, Fitzgerald J, Li Y, Seif AE, Huang YS,
Bagatell R, Aplenc R. Association of weekend admission with hospital length
of stay, time to chemotherapy, and risk for respiratory failure in pediatric
patients with newly diagnosed leukemia at freestanding US children's
hospitals. JAMA Pediatr. 2014 Oct; 168(10): 925-31
http://www.ncbi.nlm.nih.gov/pubmed/25155012
41. Groves EM, Khoshchehreh M, Le C, Malik S. Effects of weekend admission
on the outcomes and management of ruptured aortic aneurysms. J Vasc
Surg. 2014 Aug; 60(2): 318-24
http://www.ncbi.nlm.nih.gov/pubmed/24709439
42. Hamaguchi S, Kinugawa S, Tsuchihashi-Makaya M, Goto D, Tsutsui H.
Weekend versus weekday hospital admission and outcomes during
hospitalization for patients due to worsening heart failure: a report from
Japanese Cardiac Registry of Heart Failure in Cardiology (JCARE-CARD).
Heart Vessels. 2014 May; 29(3): 328-35
http://www.ncbi.nlm.nih.gov/pubmed/23653107
43. Hamilton P et al. Weekend Birth and Higher Neonatal Mortality: A Problem of
Patient Acuity or Quality of Care? Journal of Obstetric, Gynecologic, &
Neonatal Nursing 2003; 32(6): 724–733
http://www.ncbi.nlm.nih.gov/pubmed/14649592
44. Handel EH et al. Weekend admissions as an independent predictor of
mortality: an analysis of Scottish hospital admissions. BMJ Open 2012; 2:
e001789 http://www.ncbi.nlm.nih.gov/pubmed/23135542
45. Hansen KW, Hvelplund A, Abildstrøm SZ, Prescott E, Madsen M, Madsen JK,
Jensen JS, Sørensen R, Galatius S. Prognosis and treatment in patients
admitted with acute myocardial infarction on weekends and weekdays from
1997 to 2009. Int J Cardiol. 2013 Sep 30; 168(2): 1167-73
http://www.ncbi.nlm.nih.gov/pubmed/23199552
46. Hixson ED, Davis S, Morris S, Harrison AM. Do weekends or evenings matter
in a pediatric intensive care unit? Pediatr Crit Care Med. 2005 Sep; 6(5): 523-
30. http://www.ncbi.nlm.nih.gov/pubmed/16148810
47. Hoh BL, Chi YY, Waters MF, Mocco J, Barker FG. Effect of weekend
compared with weekday stroke admission on thrombolytic use, in-hospital
mortality, discharge disposition, hospital charges, and length of stay in the
Nationwide Inpatient Sample Database, 2002 to 2007. 2nd. Stroke. 2010 Oct;
41(10): 2323-8 http://www.ncbi.nlm.nih.gov/pubmed/20724715
48. Hong JS et al. Comparison of Case Fatality Rates for Acute Myocardial
Infarction in Weekday vs Weekend Admissions in South Korea. Circulation
Journal 2010; 74(3): 496-502 http://www.ncbi.nlm.nih.gov/pubmed/20075558
49. Horwich TB et al. Weekend hospital admission and discharge for heart failure:
Association with quality of care and clinical outcomes. American Heart
Journal 2009; 158(3): 451-458
http://www.ncbi.nlm.nih.gov/pubmed/19699870
50. Ibrahimou B, Salihu HM, English G, Anozie C, Lartey G, Dagne G. Twins born
over weekends: are they at risk for elevated infant mortality? Arch Gynecol
Obstet. 2012 Dec; 286(6): 1349-55
68. O'Neill DE, Southern DA, O'Neill BJ, McMurtry MS, Graham MM. Weekend
compared with weekday presentation does not affect outcomes of patients
presenting with non-ST elevation acute coronary syndrome. Eur Heart J
Acute Cardiovasc Care. 2014 Jun; 3(2): 99-104.
http://www.ncbi.nlm.nih.gov/pubmed/24585942
69. Orandi BJ, Selvarajah S, Orion KC, Lum YW, Perler BA, Abularrage CJ.
Outcomes of nonelective weekend admissions for lower extremity ischemia. J
Vasc Surg. 2014 Dec; 60(6): 1572-9
http://www.ncbi.nlm.nih.gov/pubmed/25441678
70. Orman ES, Hayashi PH, Dellon ES, Gerber DA, Barritt AS 4th. Impact of
nighttime and weekend liver transplants on graft and patient outcomes. Liver
Transpl. 2012 May; 18(5): 558-65
http://www.ncbi.nlm.nih.gov/pubmed/22271668
71. Ozdemir BA, Sinha S, Karthesalingham, Poloniecki J, Pearse RM, Grocott
MPW, Thompson MM, Holt P. Mortality of emergency general surgical
patients and associations with hospital structures and processes. British
Journal of Anaesthesia 2016;116 (1):54-62
72. Palmer W, Bottle A, Aylin P. Association between day of delivery and obstetric
outcomes: observational study. BMJ 2015;351:h5774
73. Palmer WL et al. A Retrospective Cohort Study on the Association Between
Day of Hospital Presentation and the Quality and Safety of Stroke Care. Arch
Neurol 2012; 69(10): 1296-1302
http://www.ncbi.nlm.nih.gov/pubmed/22777008
74. Pasupathy D, Wood AM, Pell JP, Fleming M, Smith GC. Time of birth and risk
of neonatal death at term: retrospective cohort study. BMJ 2010;341:c3498.
75. Pederby MA et al. Survival From In-Hospital Cardiac Arrest During Nights
and Weekends. JAMA 2008; 299(7): 785-792
http://www.ncbi.nlm.nih.gov/pubmed/18285590
76. Powell ES, Khare RK, Courtney DM, Feinglass J. The weekend effect for
patients with sepsis presenting to the emergency department . J Emerg Med.
2013 Nov;45(5):641-8. doi: 10.1016/j.jemermed.2013.04.042. Epub 2013 Aug
30. http://www.ncbi.nlm.nih.gov/pubmed/23993937
77. Ricciardi R, Nelson J, Roberts PL, Marcello PW, Read TE, Schoetz DJ. Is the
presence of medical trainees associated with increased mortality with
weekend admission? BMC Med Educ. 2014 Jan 8;14:4. doi: 10.1186/1472-
6920-14-4 http://www.ncbi.nlm.nih.gov/pubmed/24397268
78. Robinson E, Smith G, Power S, Harrison D, Nolan J, Soar J, Spearpoint K,
Gwinnutt C, Rowan K. Risk-adjusted survival for adults following in-hospital
cardiac arrest by day of week and time of day: observational cohort study.
BMJ Qual Saf 2015. http://dx.d
79. Ruiz M, Bottle A, Aylin P. The Global Comparators Project: international
comparison of 30 day in-hospital mortality by day of the week. BMJ Quality
and Safety 2015;0:1-13 doi:10.1136/bmjqs-2014-003467
80. Sakhuja A et al. Outcomes of Patients Receiving Maintenance Dialysis
Admitted Over Weekends. Ankit Sakhuja. AJKD 2013; 62(4): 763-770
http://www.ncbi.nlm.nih.gov/pubmed/23669002
81. Salihu HM, Ibrahimou B, August EM, Dagne G. Risk of infant mortality with
weekend versus weekday births: a population-based study. J Obstet
Gynaecol Res. 2012 Jul; 38(7): 973-9
http://www.ncbi.nlm.nih.gov/pubmed/22487462
82. Saposnik G, Baibergenova A, Bayer N, Hachinski V. Weekends: a dangerous
time for having a stroke? Stroke. 2007 Apr; 38(4): 1211-5
http://www.ncbi.nlm.nih.gov/pubmed/17347472
83. Schmid M, Ghani KR, Choueiri TK, Sood A, Kapoor V, Abdollah F, Chun FK,
Leow JJ, Olugbade K Jr, Sammon JD, Menon M, Kibel AS, Fisch M, Nguyen
PL, Trinh QD. An evaluation of the 'weekend effect' in patients admitted with
metastatic prostate cancer. BJU Int. 2014 Aug 7. doi: 10.1111/bju.12891.
[Epub ahead of print] http://www.ncbi.nlm.nih.gov/pubmed/25099032
84. Schmulewitz L, Proudfoot A, Bell D. The impact of weekends on outcome for
emergency patients. Clin Med 2005;5:621e5
85. Schneider EB et al. Beating the weekend trend: Increased mortality in older
adult traumatic brain injury (TBI) patients admitted on weekends. J Surg Res
2012; 177(2): 295-300 http://www.ncbi.nlm.nih.gov/pubmed/22795343
86. Shaheen AA, Kaplan GG, Myers RP. Clin Gastroenterol Hepatol . Weekend
versus weekday admission and mortality from gastrointestinal hemorrhage
caused by peptic ulcer disease. 2009 Mar; 7(3): 303-10
Bell et al. NEJM 2001
• Mortality among patients admitted to hospital on weekends as
compared with weekdays Canadian study, acute care from ER
departments in Ontario, Canada.
• 3.8 million admissions
• Looked at specific conditions (AAA, acute epiglottis, PE, AMI,
Stroke and #NOF) plus the 100 conditions that were the most
common causes of death.
• Significant weekend effect for AAA (OR 1.28), epiglottis (OR
5.47) and PE (OR 1.19), plus 23 out of the 100 leading causes
of death.
• No conditions associated with significantly lower mortality rates
at the weekend.
Bell CM, Redelmeier DA. Mortality among patients admitted to hospital on weekends as
compared with weekdays. N Engl J Med 2001;345:663e8.
Kostis et al. 2007
• Weekend versus weekday admission and mortality from
myocardial infarction
• Acute Myocardial Infarction, all admissions in New Jersey 1987-
2002
• 231,164 admissions
• In the interval from 1999 to 2002 (59,786 admissions), mortality
at 30 days was significantly higher for patients admitted on
weekends (12.9% vs. 12.0%, P = 0.006).
• Persisted at 1 year (1% absolute difference in mortality).
• Associated with lower rate of invasive procedures
Kostis WJ, Demissie K, Marcella SW, et al. Weekend versus weekday admission and mortality
from myocardial infarction. N Engl J Med 2007;356:1099e109
Barba et al. 2006
• Mortality among adult patients admitted to the hospital on
weekends
• All acute admissions to tertiary acute care hospital in Spain
(1999-2003)
• 35,993 hospital admissions
• All in-hospital deaths OR = 1.1, but not significant. Deaths
within 48 hours OR=1.4
Barba R, Losa JE, Velasco M, et al. Mortality among adult patients admitted to the hospital on
weekends. Eur J Intern Med 2006;17:322e4
Imperial Patient
Safety Translational
Research Centre
Other studies
• Hamilton et al found higher weekend neonatal
mortality (OR= 1.42) in Texas 1999-2000.
• Schmulewitz et al found no weekend effect in a single
Scottish hospital
• Wunsch et al used ICNARC to examine 75,621
admissions to 102 ICUs across England, Wales and
NI and found admissions on weekend days (Friday,
Saturday, Sunday) or in the evening/night were
associated with higher odds of crude hospital death,
but this was accounted for by case mix.
Hamilton P, Resttrepo E. Weekend birth and higher neonatal mortality: a problem of patient acuity or quality? J Obstet Gynecol Neonatal Nurs
2003;32:724e33.
Schmulewitz L, Proudfoot A, Bell D. The impact of weekends on outcome for emergency patients. Clin Med 2005;5:621e5.
Wunsch H, Mapstone J, Brady T, et al. Hospital mortality associated with day and time of admission to intensive care units. Intensive Care
Med 2004;30:895e901.
Literature
• Studies finding no effect tend to be smaller, single
hospital studies or based in intensive care
Mikulich et al
• St. James Hospital, Dublin
• 49,337 episodes of inpatient care
• 30 day in-hospital mortality at the weekend
(9.99% vs. 9.0%)
• Wide confidence intervals (small sample)
• Unadjusted OR 1.11 (CI 0.99-1.23)
• Adjusted OR 1.05 (CI 0.88-1.24)
• Entirely consistent with other papers showing
weekend effects
Weekend mortality for emergency admissions
• All emergency admissions in England for 2005/6
• Examined top 50 diagnoses leading to death and all
cause admissions.
• Adjusted for age, sex, socioeconomic deprivation,
comorbidity and diagnosis
• Odds of death were calculated for admissions at the
weekend compared to admissions during the week
Imperial Patient
Safety
Translational
Research Centre
Weekend mortality for emergency admissions
• 4,317,866 admissions with 215,054 in-hospital
deaths
• Crude mortality
• 5.2% for weekend admissions
• 4.9% for weekday admissions
• 17 out of 50 diagnosis groups associated with
significantly higher odds of death (p<0.001) including
stroke (OR 1.13), AMI (OR1.08)
• Overall adjusted odds of death was 10% higher
(OR=1.10, 95% CI 1.08-1.11) in those patients
admitted at the weekend compared with patients
admitted during a weekday (p<0.001)
Results
Limitations
• Multiple statistical tests
• No out of hospital deaths
• Fewer admissions at weekend, so casemix
might be different
Methods
• All acute and specialist English hospitals carrying out
elective surgery over three financial years, from 2008-09 to
2010-11
• Planned operating room planned procedures based on
AHRQ patient safety indicator1
• Exclude day cases
• 30 day post op deaths (including out of hospital deaths
linked to ONS death data)
• Adjusted for age, sex, ethnic group, socio-economic
deprivation, co-morbidities, number of emergency
admissions in the last 12 months, year and procedure risk
quintile
1 Bottle A, Aylin P, 2009, Application of AHRQ patient safety indicators to English hospital data, Quality & Safety in Health
Care, Vol:18, ISSN:1475-3898, Pages:303-308
Results
• 27,582 deaths within 30 days following 4,133,346
inpatient admissions for elective operating room
procedures (6.7 per 1000).
• Compared with Monday, adjusted odds of death
were 44% and 82% higher, respectively, if the
procedures were carried out on Friday (odds ratio
1.44, 95% confidence interval 1.39 to 1.50) or a
weekend (1.82, 1.71 to 1.94)
1 Bottle A, Aylin P, 2009, Application of AHRQ patient safety indicators to English hospital data, Quality & Safety in Health
Care, Vol:18, ISSN:1475-3898, Pages:303-308
Adjusted odds of death and 95% confidence intervals by day of procedure in English
hospitals for 2008-9 to 2010-11. (Crude rate 0.67%)
Aylin P, Alexandrescu R, Jen MH, et al., 2013, Day of week of procedure and 30 day mortality for elective surgery:
retrospective analysis of hospital episode statistics, British Medical Journal, Vol:346, ISSN:1756-1833,
Pages:f2424-f2424
©2013 by British Medical Journal Publishing Group
(exc. day cases and
deliveries)
Discussion
• Not able to use more recent data
• Mortality low for elective procedures (6.7 per 1000)
• Monday benchmark
• Hypothesis that post-op care may have contributed to
mortality• Same picture in 2 day mortality
• Fall in Sunday mortality
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
Mon Tues Wed Thu Fri Sat Sun
OR
an
d 95%
CI
Days of week
Adjusted odds of death and 95% confidence intervals by day of procedure in English hospitals for 2008-9 to 2010-11.
(exc. day cases and deliveries)
Discussion
• Not able to use more recent data
• Mortality low for elective procedures (6.7 per 1000)
• Monday benchmark
• Hypothesis that post-op care may have contributed
to mortality• Same picture in 2 day mortality
• Fall in Sunday mortality
• Are junior consultants more likely to operate on a
Friday?
Proportions of procedures carried out by consultant experience
by day of procedure in English hospitals for 2008-9 to 2010-11.
12 11.7 12.3 12.2 15.5 13.3 12.1
45.5 44.6 45 4546.1 48.5 45.5
42.5 43.7 42.7 42.8 38.4 38.2 42.4
Monday Tuesday Wednesday Thursday Friday Saturday Sunday
0-2 yrs 3-10 yrs ≥ 11 yrs
Ruiz M, Bottle A, Aylin PP, 2015, Exploring the impact of consultants' experience on hospital mortality by day of the week: a retrospective analysis of hospital episode statistics. 2015 BMJ Qual Saf. Published Online First: doi:10.1136/bmjqs-2015-004105
Additional adjustment by consultant experience
• Adjustment makes little difference.
• Friday effect increases from OR = 1.44
to 1.48
Interpretation
• Key is higher mortality on Friday with no
apparent difference in casemix
• 48 hours following surgery
• Frailer patients, with a high burden of
co-morbidity are at higher risk of
mortality at the weekend.
Rapid Response
“…….The biggest increase in mortality in those
operated on over Friday through to Sunday
may perhaps be due to the seemingly
ubiquitous practice of drastically reducing the
number of doctors, in particular junior doctors,
working out of hours and at weekends. A single
foundation year 1 (FY1) doctor may cover a
number of wards, as many as 60-100 patients.
Their immediate senior, the SHO may cover
twice that number or more, and so on up the
ladder.”
Methods
• English patients admitted to hospital with a stroke
(ICD I60-I64) from April 2009 to March 2010
• Look at 6 process and outcome indicators• Brain scan on day of admission
• Thrombolysis treatment
• Aspiration pneumonia
• Seven-day in-hospital mortality
• Discharge to usual place of residence within 56 days
• Thirty day emergency readmission (all cause)
• Adjusted for age, sex, socio-economic deprivation,
previous emergency admissions, co-morbidities,
ethnic group, source of admissions and stroke type.
Results
• 93,621 stroke admissions
• 9.3% died within 7 days, and 17.1% died within
30 days
• 46.5% had same day brain scan
• 2.6% received thrombolysis
• 5.2% had aspiration pneumonia
• 72.6% were discharged to their normal place of
residence
• 11% readmitted within 30 days
Adjusted odds of stroke indicators and 95% CIs weekend
versus weekday, England 2009/10
0.60
0.70
0.80
0.90
1.00
1.10
1.20
1.30
Same dayscanning
Thrombolysis Aspirationpneumonia
7-day in-hospitalmortality
Discharge tousual place of
admissionwithin 56 days
30-dayemergency
readmissionswithin
OR
an
d 9
5%
CI
Association between weekday/weekend delivery and indicators of
quality and safety of care – England 1st April 2010 and 31st March 2012
0.80
0.85
0.90
0.95
1.00
1.05
1.10
1.15
1.20
Perineal tear Puerperalinfection
3-daymaternal
readmission
In-hospitalperinatalmortality
Injury toneonate
Selectedneonatalinfections
3-dayneonatal
rradmissions
Od
ds R
ati
o (9
5%
CI)
Daily trends
Summary
• Babies born at the weekend have an
increased risk of being still born or dying in
hospital within the first 7 days.
• Increased complication rates at weekends,
with higher rates of puerperal infection, injury
to neonate and 3-day neonatal emergency
readmissions
• “No consistent association between outcomes
and staffing was identified”
Indicator Adjusted OR (95%
CI) – original paper Excluding elective caesareans
Adjusting for induction labour
Excluding antenatal stillbirths
Perineal tear 1.00
(0.98 to 1.03)
- 1.00
(0.98 to 1.02)
-
Puerperal infection 1.06
(1.01 to 1.11)
1.05
(1.00 to 1.09)
1.07
(1.02 to 1.12)
-
3-day maternal readmissions
0.93
(0.84 to 1.02)
0.92
(0.83 to 1.02)
0.93
(0.84 to 1.03)
-
In-hospital perinatal mortality
1.07
(1.02 to 1.13)
1.07
(1.02 to 1.12)
- 1.09
(1.02 to 1.16)
Injury to neonate 1.06
(1.02 to 1.09)
1.05
(1.02 to 1.08)
- -
Selected neonatal infections
1.01
(0.98 to 1.04)
1.00
(0.97 to 1.03)
- -
3-day neonatal readmissions
1.04
(1.00 to 1.08)
1.03
(0.99 to 1.07)
- -
Re-analysis following comments
After excluding elective caesareans
Odds of death if born at the weekend compared with weekdays OR = 1.3 (1.0-1.7)
Odds of dying from anoxia at weekend compared with weekdays OR = 1.5 (1.1-2.1)
“About one in four deaths from intrapartum anoxia at term could be prevented if all women attempting vaginal birth had the same risk of this event as women delivering during the normal working week”
What’s the explanation?
• Conflicting evidence?
4,317,866
14,217,640 14,818,374
5,271,327
4,133,346
93,621
1,349,599
49,337 29498758
6,92336,734
1,578
0.8
1
1.2
1.4
1.6
1.8
2
weekend (
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ency)
Sa
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ay (
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Su
nday (
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ns)
Sa
turd
ay (
All
adm
issio
ns)
Su
nday (
All
adm
issio
ns)
weekend (
Em
erg
ency)
Weeke
nd (
Ele
ctive)
Friday (
Ele
ctive)
Weeke
nd (
Str
oke)
Weeke
nd (
Birth
s)
weekend (
Em
erg
ency)
Weeke
nd (
EV
H)
Weeke
nd (
Str
oke)
Weeke
nd (
Infe
ction
)
Weeke
nd (
EV
H)
Weeke
nd (
Str
oke)
Aylin 2010(England)
Freemantle 2010(England)
Freemantle 2015(England)
Handel(Scotland)
Aylin 2013 (England) Palmer2012
Palmer2015
Mikulich2010
(Dublin)
Byun 2012(Korea)
Kazley2010 (US)
Kevin 2010(Canada)
Myers2009 (US)
Turin 2008(Japan)
Od
ds/H
azard
/Rate
Rati
o
UK studiesStudies cited for no weekend
effect (all non-UK)
What’s the explanation?
• Conflicting evidence?
• Coding?
• Statistical artefact?
Imperial Patient
Safety
Translational
Research Centre
“His team studied 1,693 stroke hospital admissions and found 638 (38%) were
lower-level incidents that had been put in the wrong category.”
“The new research based on the Oxford Vascular Study - which has been
sent to the British Medical Journal but not published - comes as the BMA
union starts five days of fresh talks over the junior doctors' contract”
Rothwell et al. Administrative classification
Classification
• Hospital admissions
• Elective admissions
• Subdural/extradural haemorrhage
• Inpatient events after emergency
admission
• Inpatient events after elective
admission
• Transfers from hospital
• Episodes?
• Spells?
• Superspells?
Apparent “incorrect coding”
• Only admitted patients
• Elective admissions (293)
• Subdural/extradural haemorrhage (55)
• Inpatient events after emergency
admission (9)
• Inpatient events after elective
admission (39)
• Transfers from hospital (34)
• Admission date wrong (24)
• GP information wrong (20)
• Unknown (12)
• Cancelled admission (15)
4,317,866
14,217,640 14,818,374
5,271,327
4,133,346
93,621
1,349,59949,337 294
987586,923
36,7341,578
1,292
3,715,727
0.6
0.8
1
1.2
1.4
1.6
1.8
2
wee
ken
d (
Emer
gen
cy)
Satu
rday
(A
ll ad
mis
sio
ns)
Sun
day
(A
ll ad
mis
sio
ns)
Satu
rday
(A
ll ad
mis
sio
ns)
Sun
day
(A
ll ad
mis
sio
ns)
wee
ken
d (
Emer
gen
cy)
Wee
ken
d (
Elec
tive
)
Frid
ay (
Ele
ctiv
e)
Wee
ken
d (
Stro
ke)
Wee
ken
d (
Bir
ths)
wee
ken
d (
Emer
gen
cy)
Wee
ken
d (
EVH
)
Wee
ken
d (
Stro
ke)
Wee
ken
d (
Infe
ctio
n)
Wee
ken
d (
EVH
)
Wee
ken
d (
Stro
ke)
Wee
ken
d (
Stro
ke)
Wee
ken
d (
via
A&
E)
Wee
ken
d (
Dir
ect
adm
issi
on
s)
Aylin 2010(England)
Freemantle 2010(England)
Freemantle 2015(England)
Handel(Scotland)
Aylin 2013 (England) Palmer2012
Palmer2015
Mikulich2010
(Dublin)
Byun2012
(Korea)
Kazley2010 (US)
Kevin2010
(Canada)
Myers2009 (US)
Turin2008
(Japan)
Rothwell2016 (UK)
Meacock 2016 (UK)
Od
ds/
Haz
ard
/Rat
e R
atio
UK studies Studies cited for noweekend effect
940,859
Meacock et al.
• Examined A&E attendances as well as admitted
patients.
• “There are fewer deaths following hospital admission
at weekends. “
• “Higher mortality rates at weekends are found only
amongst the subset of patients who are admitted.”
• “Fewer and sicker patients are admitted at weekends
than during the week.”
Imperial Patient
Safety
Translational
Research Centre
Meacock et al.
• Paper shows a higher mortality rate for patients
admitted at the weekend
• True for both admissions via A & E and direct
admissions from the community. In line with previous
work.
• “Fewer and sicker patients are admitted at weekends
than during the week.
• Their own figures suggest patients admitted at
weekend not sicker - younger, fewer co-morbidities
etc.
• A&E attendances - a questionable choice of
denominatorImperial Patient
Safety
Translational
Research Centre
What other explanations are there?
Nursing and outcomes
• “An increase in a nurses' workload by one patient increased the
likelihood of an inpatient dying within 30 days of admission by 7% (odds
ratio 1·068, 95% CI 1·031–1·106), and every 10% increase in
bachelor's degree nurses was associated with a decrease in this
likelihood by 7% (0·929, 0·886–0·973).”
• “These associations imply that patients in hospitals in which 60% of
nurses had bachelor's degrees and nurses cared for an average of six
patients would have almost 30% lower mortality than patients in
hospitals in which only 30% of nurses had bachelor's degrees and
nurses cared for an average of eight patients.”
Conclusions
• “Mortality outcomes after stroke are
associated with the intensity of weekend
staffing by registered nurses but not 7-d/wk
ward rounds by stroke specialist physicians”
• “The findings have implications for quality
improvement and resource allocation in
stroke care”
Summary
• Lots of literature supporting the weekend effect (using
variety of clinical and administrative data)
• Not explained away by casemix or data quality
• Clinical datasets
• Relationships with other factors
• Pattern not just in mortality
• Differences in patterns of care
• Mechanism still unclear
• Failure to rescue?
• Further work required on staffing levels (difficult to
do), and other contributing factors.
• Interventions Imperial Patient
Safety
Translational
Research Centre
• National Cardiac Arrest Audit (NCAA)
• 27,700 in-hospital cardiac arrest
• Odds of survival weekend daytime vs. weekday daytime = 0.72 (0.68-76)
Stroke mortality England 2008-2014
Acknowledgements
Dr Alex Bottle
Prof Derek Bell
Dr Roxana Alexandrescu
Dr William Palmer
Dr Min Hua Jen
Dr Milagros Ruiz
Prof Azeem Majeed