Table 1

Study characteristics

Study ID	Country	Setting	Severity scales assessed	Time of outcome ascertainment	No of patients	Age (years)	% Male
Aujesky14	USA	32 hospital emergency departments	PSI, CURB, CURB-65	30 days	3181	63 (mean)	48
Barlow15	UK	University teaching hospital	CURB-65, CRB-65	30 days	419	74 (median)	47
Bauer16	Germany	10 hospitals and outpatient clinics	CRB-65, CURB	14, 30 and 180 days	2184	62.6 (mean)	56.6
Capelastegui17	Spain	Teaching hospital	CURB-65, CRB-65	30 days	1776	62 (mean)	63
Charles18	Australian	6 university teaching hospitals	PSI, CURB-65	30 days	882	76% >50 years	61
Etizion19	Israel	University hospital-based medical centre	PSI	30 days	591	63.5 (mean)	44.5
Ewig8	Spain	University hospital	PSI, CURB	30 days	592 for CURB, 489 for PSI	67.8 (mean)	66
Gutierrez20	Spain	University teaching hospital	PSI	30 days	493	56.6 (mean)	62.5
Huang21	USA	Community, teaching hospital and ED	PSI, CURB-65	30 days	1651	65 (mean)	52
Johnstone22	Canada	6 hospitals	PSI	30 days	3284	69 (mean)	53
Kruger23	Germany	10 clinical centres	CRB-65	14, 30 & 180 days	1671	61 (mean)	55
Lim5	UK, New Zealand, Netherlands	University teaching hospital	PSI, CURB, CURB-65, CRB-65	30 days	1068	64 (mean)	51
Man24	Hong Kong	Emergency department	PSI, CURB-65, CRB-65	30 days	1016	72 (mean)	57
Menendez25	Spain	University teaching hospital	PSI, CURB-65, CRB-65	30 days	453	67 (mean)	62
Myint4	UK	University teaching hospital	CURB-65, CRB-65, CURB	42 days	195	75 (median)	57
Myint26	UK	3 UK hospitals	CURB-65	42 days	190	76 (median)	53
Pilotto27	Italy	Hospital	PSI	30 days	134	78.7 (mean)	66
Renaud28	France	16 emergency departments	PSI	28 days	925	71 (median)	64
Renaud29	France, Spain, USA	University teaching hospital	PSI	30 days	853	65% >51 years	56
Reyes Calzada30	Spain	4 public hospitals	PSI	30 days	425	69 (mean)	64.5
Schuetz31	Switzerland	University teaching hospital	PSI, CURB-65, CRB-65	30 days	373	73 (median)	60
van der Eerden32	Netherlands	Teaching hospital	PSI	30 days	260	64 (mean)	53.8
Zuberi33	Pakistan	University teaching hospital	CURB-65, CRB-65	30 days	137	60.4 (mean)	74

CRB-65, confusion, respiratory rate, blood pressure, age ≥65 years; CURB, confusion, urea nitrogen, respiratory rate, blood pressure; CRB-65, confusion, respiratory rate, blood pressure, age ≥65 years; CURB, confusion, urea nitrogen, respiratory rate, blood pressure; CURB-65, confusion, urea nitrogen, respiratory rate, blood pressure, age ≥65 years; PSI, Pneumonia Severity Index.