Lau, SL (Lau, S. L.); Samman, N (Samman, N.) Levels of evidence and journal impact factor in oral and maxillofacial surgery INTERNATIONAL JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY, 36 (1): 1-5 JAN 2007

[Eugene Garfield]

E-mail Address: nsamman at hku.hk 

Author(s): Lau, SL (Lau, S. L.); Samman, N (Samman, N.) 

Title: Levels of evidence and journal impact factor in oral and 
maxillofacial surgery 

Source: INTERNATIONAL JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY, 36 (1): 1-
5 JAN 2007 

Language: English 

Document Type: Article 

Author Keywords: journal impact factor; levels of evidence
 
Keywords Plus: RANDOMIZED CLINICAL-TRIALS; EVIDENCE-BASED MEDICINE; 
ANESTHESIA; QUALITY 

Abstract: The aim of this study was to identify the relationship between 
quality of research, in terms of levels of evidence, and journal impact 
factor (IF), and to describe the pattern of publications in oral and 
maxillofacial surgery. All four major journals in this subject area only, 
and with a published IF, were included in the study. Latest published IF 
dated 2004 was chosen, and all articles related to its calculation were 
accessed and classified into four levels of evidence. Correlation between 
levels of evidence and IF was investigated and the pattern of publications 
was described. All eligible 932 published articles were analysed. None 
(0%) were level I evidence, 20 (2%) were Level 11, 70 (8%) level III and 
337 (40%) level IV; 465 (50%) articles were classified as non-evidence. IF 
ranged from 0.689 to 1.154. There were statistically significant 
correlations between levels of evidence and IF (rho = 1.0, P < 0.01). 
Among the 465 non-evidence articles, there were 219 (47%) case reports, 91 
(20%) animal studies, 52 (11%) laboratory studies, 35 (8%) technical 
notes, 24 (5%) tutorial articles, and 16 (3%) reviews articles. 

Addresses: Univ Hong Kong, Prince Philip Dent Hosp, Sai Ying Pun, Hong 
Kong, Peoples R China 

Reprint Address: Samman, N, Univ Hong Kong, Prince Philip Dent Hosp, 2-
F,34 Hosp Rd, Sai Ying Pun, Hong Kong, Peoples R China. 

E-mail Address: nsamman at hku.hk 

Cited Reference Count: 33 

Times Cited: 3 

Publisher: CHURCHILL LIVINGSTONE 

Publisher Address: JOURNAL PRODUCTION DEPT, ROBERT STEVENSON HOUSE, 1-3 
BAXTERS PLACE, LEITH WALK, EDINBURGH EH1 3AF, MIDLOTHIAN, SCOTLAND 

ISSN: 0901-5027 

29-char Source Abbrev.: INT J ORAL MAXILLOFAC SURG 

ISO Source Abbrev.: Int. J. Oral Maxillofac. Surg. 

Source Item Page Count: 5 

Subject Category: Dentistry, Oral Surgery & Medicine; Surgery 

ISI Document Delivery No.: 127UQ 

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