Table 2

Characteristics of included studies regarding the second study aim: determinants of revisits

Author Year Country	Study design	Article/abstract	Disease/working diagnosis	Primary outcome: revisits	N total, male % of total population	N outcome (revisits), male %	Age inclusion Median (IQR)/mean age (SD)	Follow-up* (days)	Type of revisit	Risk of bias† (high/low)
Alessandrini 2004 USA	CR	Article	All	Yes	54 784 NR	1893 NR	All 4.6 years ±4.9‡	2	suR	Low
Ali 2012 USA	CP	Article	All	Yes	8742 NR	124 52%	All 3.0 years (1.1–12)‡	3	suR	High
Angoulvant 2012 France	CP	Article	All§	Yes	501 NR	206 51%	<6 years 18 months (7–39)	7	suR	High
Augustine 2013 USA	CS	Abstract	All	Yes	13 NR	13 NR	All 4.2 years¶	2	uR	High
Berry 2013 USA	CR	Article	All	Yes	568 845 NR	36 734** NR	≤18 years 3 years (0–10)	30	uR	Low
Black 2010 UK	CR	Abstract	All	Yes	2345 NR	91 NR	<17 years 76% <5 years	3	uR	High
Callery 2010 UK	CR	Article	All	Yes	43 372 NR	2433 NR	<15 years NR	7	suR	Low
Chang 2008 Taiwan	CR	Article	All	No	3216 58%	188 NR	<18 years 5 years ±0.1	3	suR	Low
DePiero 2002 USA	CR	Article	All	Yes	51 195 NR	261** NR	All NR	3	suR	Low
Dunlop 2005 Australia	CR	Article	Fever	No	260 52%	35 NR	6 months to 6 years 25.7 months††	1	suR	High
Easter 2012 USA	CR	Article	All	Yes	97 374 NR	1091** 52%	0–21 years 52% <5 years‡	4	suR	Low
Florin 2013 USA	CR	Article	Pneumonia	Yes	100 615 54%	6439 NR	2 months to 18 years 3 years (1–6)	3	suR	Low
Freedman 2013 Canada	CR	Article	GE	Yes	3346 55%	526 57%	<18 years 3.4 years ±3.5	7	uR	Low
Gallagher 2013 USA	CR	Article	All	Yes	119 792 53%	1499** NR	All 7.6 years¶	3	uR	Low
Gaucher 2012 Canada	CR	Article	All	No	49 146 51%	2534 NR	<19 years 62% <5 years	2	uR	Low
Goldman 2006 Canada	CR	Article	All	Yes	37 725 NR	1990 NR	<19 years 18% <1 year	3	uR	Low
Goldman 2011 Canada	CR	Article	All	Yes	2062 55%	353** 59%	<19 years 57 months (0–215)	3	suR	High
Gregor 2009 USA	CP	Article	RTI/GE	No	455 59%	49 NR	6 weeks to 8 years 1.9 years ±1.9	60	suR	High
Hacking 2012 UK	CR	Abstract	All	Yes	2453 NR	130 NR	NR 4 years††	NR	uR	High
Jacobstein 2005 USA	CC	Article	Fever	Yes	15 384 54%	165 54%	All 38 months ±43	3	uR	Low
Jain 2010 USA	CR	Article	All	No	452 868 54%	17 335 NR	<19 years 22% <1 years	3	suR	Low
Klein-Kremer 2011 Canada	CR	Article	Fever	Yes	397 NR	92 67%	3–36 months 17 months ±8‡	3	suR	High
Lal et al 1999 UK	CP	Article	All	Yes	7328 NR	65 NR	NR	3	uR	High
LeDuc 2006 USA	CP	Article	All	Yes	932 NR	237 49%	All 4 years¶	2, 90	suR	High
Liberman 2012 USA	CR	Article	RTI	No	467 59%	189 NR	<19 years NR	7, 30	suR	Low
Logue 2013 Canada	CR	Article	All	Yes	1173 NR	261 61%	All 4.4 years¶	3	suR	High
Maguire‡‡ 2011 UK	CP	Article	Fever	No	220 56%	127 NR	<5 years 27% ≤1 years	NS	suR	High
Mansbach 2008 USA	CP	Article	Bronchiolitis	No	1456 58%	837 58%	<2 years 6.9 (4.2–11.3)§§	14	NS	Low
Michelson 2012 USA	CR	Article	All	No	198 778 NR	7281 NR	All 10% <1 years	2	suR	High
Mintegui 2000 Spain	CR	Abstract	All	Yes	3667 NR	495 NR	All NR	7	uR	High
Mistry 2007 USA	CP	Article	Fever	Yes	322 57%	76 NR	28 days to 17 years 31.5 months¶	10	uR	High
Mistry 2009 USA	CP	Article	Fever	No	97 56%	18 NR	2–18 years 58.7 months ±40.1	7–10	uR	High
Moineau‡‡ 2004 Canada	CR	Abstract	GE	Yes	1862 NR	108 NR	NR 2.6 years ±2.8	7	uR	High
O'Loughlin 2012 UK	CR	Article	All	Yes	10 573 NR	532 NR	<16 years 34% <2 years	7	uR	High
Roback 1997 USA	CC	Article	Bronchiolitis	Yes	181 NR	57 NR	<1 year NR	4	NS	High
Roggen 2012 Belgium	CR	Abstract	All§	Yes	46 386 NR	1864 NR	<16 years NR	3	suR	High
Samuels-Kalow 2013 Canada	CR	Abstract	Fever	Yes	202 NR	14 NR	2–24 months NR	3	suR	High
Sartain 2002 UK	RCT	Article	All	No	399	31 NS	All 25.7 months¶	90	suR	High
Seow 2007 Taiwan	CR	Article	Fever	No	345 47%	115 NR	3–36 months NR	3	uR	Low
Simmons 2012 UK	CR	Abstract	All	Yes	NR	51 NR	All 59% <2 years	7	uR	High
Small 2005 UK	CP	Article	GE	No	112 NR	56 NR	1–6 years 1.9 (1.3)**	7, 30	suR	Low
Zimmerman 1996 USA	CR	Article	All	Yes	5228 58%	242 NR	<18 years 13% <1 years	14	suR	Low

*Time until revisit.
†Minimum and maximum.
‡Of the number of children with revisits.
§Common illnesses, without children with traumatic complaints.
¶Mean (CI).
**Revisits requiring admission.
††Median (IQR).
‡‡Studies included for both study aims (Maguire et al12 and Moineau et al13).
§§Of the number of children sent home.
All, all emergency department diagnoses; CC, case–control study; CP, cohort study, prospective; CR, cohort study, retrospective; CS, cross-sectional study; GE, gastroenteritis; NR, not recorded; RCT, randomised controlled trial; RTI, respiratory tract illnesses; suR, scheduled and unscheduled revisit; uR, unscheduled revisit.