A snapshot of pneumonia research activity and collaboration patterns (2001–2015): a global bibliometric analysis

Table 2 Geographical regions and income brackets by total number of publications and quinquennium 2001–2005, 2006–2010, and 2010–2015

	Total			2001–2005		2006–2010		2011–2015
	N of docs	%	^a PPD	N of docs	%	N of docs	%	N of docs	%
Geographic area
North America	9549	42.08	−5,46	2469	45.18	3187	42.91	3893	39.72
Europe & Central Asia	9256	40.79	−4,54	2359	43.17	3110	41.87	3787	38.63
East Asia & Pacific	4742	20.90	13,18	743	13.60	1374	18.50	2625	26.78
Latin America & Caribbean	1099	4.84	2,52	174	3.18	366	4.93	559	5.70
Middle East & North Africa	590	2.60	0,93	115	2.10	178	2.40	297	3.03
Sub-Saharan Africa	523	2.30	0,35	121	2.21	151	2.03	251	2.56
South Asia	461	2.03	1,48	56	1.02	160	2.15	245	2.50
Income bracket			0
HI	20,102	88.58	−7,76	5092	93.17	6638	89.38	8372	85.41
UMI	3094	13.63	10	434	7.94	902	12.14	1758	17.94
LMI	803	3.54	2,43	109	1.99	261	3.51	433	4.42
LI	222	0.98	0,74	32	0.59	60	0.81	130	1.33

N of docs = numbers of documents
^a PPD = Percentage point difference from 2001 to 2005 to 2011–2015
HI high-income, UMI upper-middle-income, LMI = lower-middle-income, LI = low-income

ISSN: 1471-2288