Table 1.

Characteristics of included studies.

First author, yearref	Region	Year of patient cohort	Cause for UGIH	Total admissions	Definition of off-hours	Study design	Outcomes measured	Adjusted variables
Mohammed, 201622	UK	April 2008 ∼ June 2012	Variceal +  nonvariceal	507	Weekends, or nighttime	Retrospective	30-day mortality
Serrao, 201617	USA	2000 ∼ 2011	Gastroduodenal angiodysplasia	85,971	Weekends	Retrospective	In-hospital mortality; delay endoscopy; LOS; surgery rate	Demographic and covariate variables
Weeda, 201716	USA	2010 ∼ 2012	Variceal +  nonvariceal	119,353	Weekends	Retrospective	In-hospital mortality; LOS	Age (75 years), gender, race, primary payer, the presence of Agency for Healthcare Research and Quality-29 comorbidities (excluding peptic ulcer disease), and hospital teaching status/location, region and bed size
Ahmed, 201521	Scotland	January 2000 ∼ October 2009	Variceal +  nonvariceal	60,643	Weekends	Retrospective	30-day mortality; LOS
Al-Qahatani, 201513	Saudi Arabia	January 2005 ∼ July 2013	Variceal	937	Weekends	Retrospective	In-hospital mortality; endoscopy within 24 hours; need for surgery; rebleeding; LOS
Wu, 201412	Taiwan	January 2009 ∼ March 2011	Peptic ulcer	744	Weekends +  public holiday	Retrospective	30-day mortality, need for surgery, rebleeding rate, LOS
Abougergi, 20146	USA	January 2009 ∼ December 2009	Variceal +  nonvariceal	202,259	Weekends	Retrospective	In-hospital mortality, endoscopy within 24 hours, need for angiographic embolization, LOS	Age, sex, race/ethnicity, median yearly income, patient's comorbidities, hospital location, geographic region, hospital teaching status, and hospital bed size
Tufegdzic, 20145	Serbia	January 2002 ∼ January 2012	Variceal +  nonvariceal	493	Weekends	Retrospective	In-hospital mortality, need for surgery, rebleeding rate, LOS	Weekend admission, age, symptoms and treatment
Haas, 201214	USA	January 2008 ∼ October 2008	Variceal +  nonvariceal	174	Weekends	Retrospective	In-hospital and 30-day mortality, need for surgery, LOS
de Groot, 20122	the Netherlands	October 2009 ∼ September 2011	Variceal +  nonvariceal	571	Weekends + holiday, or evening + night	Prospective	30-day mortality, need for s urgery, rebleeding rate	Age, GI cancer, DM, rectal blood loss, collapse, systolic blood pressure, diastolic blood pressure, hemoglobin, urea, intervention needed, pre- and post-endoscopic blood transfusion
Youn, 201210	South Korea	January 2007 ∼ December 2009	Peptic ulcer	388	Weekends, or nighttime	Retrospective	In-hospital mortality, need for surgery and angiographic embolization, rebleeding rate, LOS	Age
Tsoi, 20118	Hong Kong	January 1993 ∼ December 2005	Peptic ulcer	8222	Weekends +  public holiday	Retrospective	30-day mortality, need for surgery	Waiting time, age, hemodynamic status, and comorbid illness
Byun, 201211	South Korea	January 2005 ∼ February 2009	Variceal	294	Weekends	Retrospective	In-hospital mortality, rebleeding rate
Jairath, 20117	UK	May 2007 ∼ July 2007	Variceal +  nonvariceal	6749	Weekends	Retrospective	30-day mortality, endoscopy within 24 hours, need for surgery and angiographic embolization, rebleeding rate, LOS	Clinical Rockall score, hematemesis, melena, hemoglobin and urea concentration on admission, use of aspirin, NSAID, proton pump inhibitors, gender, variceal bleeding, peptic ulcer bleeding, whether received endoscopy during 24 hours, admission status
Button, 20113	UK	April 1999 ∼ March 2007	Variceal +  nonvariceal	24,421	Weekends +  public holiday	Retrospective	30-day mortality	Age, gender, malignancies, circulatory diseases, renal failure, diabetes, COPD and liver disease
Myers, 200915	USA	January 1998 ∼ December 2005	Variceal	36,734	Weekends	Retrospective	In-hospital mortality	Age, sex, race, health insurance, liver-related variables, comorbidities, hospital and admission characteristics, year and procedures
Shaheen, 20094	USA	January 1993 ∼ December 2005	Peptic ulcer	237,412	Weekends	Retrospective	In-hospital mortality, need for surgery	Age, sex, race, health insurance, comorbidities, hospital and admission characteristics, year and procedures
Schmulewitz, 200518	UK	January 2001 ∼ December 2001	Variceal +  nonvariceal	584	Weekends +  public holiday	Retrospective	In-hospital mortality	Age, sex
Parente, 200519	Italy	July 2001 ∼ July 2003	Peptic ulcer	272	Night	Prospective	30-day mortality, need for surgery, rebleeding rate	Age, sex, Rockall and Forrest score, blood transfusion, and experience of endoscopists
Choudari, 199320	UK	October 1991 ∼ September 1992	Peptic ulcer	114	Weekends + night	Prospective	30-day mortality, need for surgery, rebleeding rate

UGIH: upper gastrointestinal hemorrhage; DM: diabetes mellitus; GI: gastrointestinal; LOS: length of hospital stay; COPD: chronic obstructive pulmonary disease; NSAID: nonsteroidal anti-inflammatory drug; UK: United Kingdom; USA: United States of America.