Table 2. Ratio of clinical to chest X-ray diagnoses in various samples of children.

N	Age	Location	Ratio of diagnoses: clinical/chest X-Ray	Comments	Reference
222	0-60Ma	Sevagram Wardha, central India	1.05	Chest X-ray criteria were more sensitive than the WHO-EPC introduced in 2001.	Gupta 1996 [34]
2,071	<21Yb	Boston MA, USA	1.2	1,501 < 5 years old. Ratio is for physician rated probability of pneumonia >75%. Study conducted at Children's Hospital of Boston.	Neuman 2010 [35]
155	≤19Y	Baltimore MD and Columbus OH, USA	1.4	62% < 2 years old.	Grossman 1988 [36]
314	<60M	Hong Kong	1.8	Hospitalized. Clinical diagnosis: bacterial, pneumonia; chest X-ray criterion: consolidation.	Chiu 2014 [37]
191	<60M	Orlando FL, USA	1.9		Rothrock 2001 [38]
420	2-59M	Gambia (rural)	1.9		Kuti 2014 [39]
651	<24M	Mozambique (rural)	2.3		Roca 2010 [40]
4,093	1-35M	Bogotá, Colombia	2.4		Benavides 2012 [41]
125,983c	<60M	Washington, USA	2.4		Nelson 2008 [9]
100	<16Y	Unugu, Nigeria	2.7	Clinical diagnostic criteria were not specified.	Njeze 2011 [42]
13,026	1-35M	Goiana, Brazil	2.8	Goiana, Brazil, children who presented at hospital, but were not necessarily hospitalized.	Andrade 2012 [43]
1,068	<36M	Northern California	2.8	“High suspicion” of pneumonia from clinical exam. (See Black [44] below for “low suspicion” pneumonia.)	Black 2002 [44]
570	12M-16Y	Ontario or Quebec, Canada	2.8	Study includes all who presented to hospital; 97% were not admitted.	Lynch 2004 [45]
30,397d30,444e	0-17M	Guatemala (rural)	2.8	Parents excluded some clinically diagnosed children from X-ray, so ratio may be artifactually large.	Smith 2011 [46]
525	1M-16Y	Tel Aviv, Israel	2.9	68% <6 years old.	Ayalon 2013 [47]
351	≤18M	Guatemala (rural)	3.0	Children with WHO criteria for pneumonia referred to MD by field health worker for diagnosis and X-ray read by same MD.	Bruce 2007 [48]
NRf	<24M	Refugee camp, Thailand	3.3	Cohort was 955 children. Incidence reported as cases/(child·year).	Turner 2013 [49]
1,608	1-36M	San Jose, Costa Rica	3.5	Prospective Surveillance of children presenting to health centers for invasive pneumococcal disease only.	Arguedas 2012 [50]
413	36-60M	Hong Kong	4.1		Ho 2007 [51]
1,698	<36M	Northern California	4.5	“Lower suspicion” pneumonia (See Black [44] above for “high suspicion” of pneumonia).	Black 2002 [44]
477	<24M	Hong Kong	4.9		Ho 2007 [51]
711	0-15Y	Northern England	5.0	80% < 5years old.	Clark 2007 [52]
1,519	<60M	Pakistan (urban)	5.8	Clinical impression was "suspicion" of pneumonia.	Hazir 2006 [53]
1,622	<60M	Boston MA, USA	5.9	Clinical diagnosis based on WHO tachnypea.	Shah 2010 [54]
200	<60M	Beer Shiva, Israel	6.1	Clinical impression was “suspicion” of pneumonia.	Ben Shimol 2012 [55]
1,918	4-23M	Ukraine (urban)	7.7		Pilishvili 2013 [56]

^a Months.

^b Years.

^c Child·years of observation.

^d Child weeks of observation, clinical diagnoses.

^e Child weeks of observation, chest X-ray diagnoses.

^f Not reported, but 488/955 (51.1%) had at least one episode.