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| LETTER |
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| Year : 2014 | Volume
: 6
| Issue : 2 | Page : 134-136 |
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Negative animal studies published in Indian Medical Journal: Are they methodologically strong enough to conclude what they are concluding?
Jaykaran Charan1, Deepak Saxena2
1 Department of Pharmacology, GMERS Medical College, Dharpur (Patan), India
2 Department of Epidemiology, Indian Institute of Public Health, Ahmedabad, Gujarat, India
| Date of Web Publication | 20-Mar-2014 |
Correspondence Address:
Jaykaran Charan
Department of Pharmacology, GMERS Medical College, Dharpur (Patan)
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/0975-7406.129181
How to cite this article:
Charan J, Saxena D. Negative animal studies published in Indian Medical Journal: Are they methodologically strong enough to conclude what they are concluding?. J Pharm Bioall Sci 2014;6:134-6 |
How to cite this URL:
Charan J, Saxena D. Negative animal studies published in Indian Medical Journal: Are they methodologically strong enough to conclude what they are concluding?. J Pharm Bioall Sci [serial online] 2014 [cited 2020 Jul 16];6:134-6. Available from: http://www.jpbsonline.org/text.asp?2014/6/2/134/129181 |
Sir,
Negative studies refer to the studies where authors formally conclude that any statistical significant difference amongst the variables under study could not be found. Published negative study should be methodologically strong as it usually discourages other researcher to further research same topic. [1] Published negative study should also report all statistical and methodological parameters, which can help a reader to critically appraise the negative study for the results and conclusion. [2] It is observed that negative studies published in various peer reviewed journals do not report statistical and methodological parameters, which are in fact essential in critical appraisal of published study. [2] More so, studies concluding with "No significant difference" should have adequate power to detect the difference, for which appropriate methodology and statistics is required. There is a paucity of data regarding methodological and statistical reporting standard of negative animal studies published in Indian Medical Journals. The present study attempts to reflect on validity of such studies with primary objective of assessing negative animal studies published in medical journals from India in terms of reporting of various statistical and methodological parameters.
Study was conducted at Department of Pharmacology, Govt. Medical College, Surat (Gujarat), India in collaboration of Indian Institute of Public Health Gandhinagar. Study was initiated in July 2012 and ended in February 2013. It was a cross sectional study based on animal negative studies published in Indian medical journals from Science Citation Index (SCI). A two stage Delphi technique was utilized to develop consensus on tool to be used for data collection. The members participated in the Delphi process included selected journal editors, peer reviewers, member of academia and researchers from Gujarat state and other part of India. A roundtable was done with journal editors, researchers and academicians after the Delphi process to decide the final tool and inclusion criteria for journals and studies to be included in the present work. Original articles published during 2000-2011, dealing with negative animal studies and published in 15 SCI indexed Indian journals were downloaded and included in the present study. Studies dealing with two or three groups (drug with placebo or with active comparator) were included in the final analysis. The Journals which were finally included as per the eligible criteria included Indian Pediatrics (IP), Annals of Indian Academy of Neurology (AIAN), Indian Journal of Dermatology, Venereology and Leprology (IJDVL), Indian Journal of Medical Microbiology (IJMM), Indian Journal of Ophthalmology (IJO), Indian Journal of Pharmacology (IJP), Journal of Postgraduate Medicine (JPGM), Neurology India (NI), Indian Journal of Orthopedics (IJO), Journal of Anatomical Society of India (JASI), Indian Journal of Medical Research (IJMR), Indian Journal of Otolaryngology and Head and Neck Surgery, Indian Journal of Pathology and Microbiology (IJPM), Indian Journal of Pediatrics (IJP) and International Journal of Diabetes in Developing Countries (IJDD).
Operational definition to suffice any study as negative included studies which reported
- Difference between primary endpoint as non-significant.
- If there was no primary endpoint reported in reference to the difference in endpoint which was considered for sample size calculation and was reported to be non-significant.
- Sample size was not calculated and no primary endpoint reported with reference to the difference in first endpoint reported in abstract and was reported to be non-significant.
Out of total 300 negative studies published in selected 15 SCI indexed Indian Journals only 19 studies (6.3%) had animal as study units rest all were found to have human subjects [Flow Chart 1]. [Additional file 1] Information related to power, confidence interval, sample size calculation, type of sampling, process of sampling, adjustment of multiple endpoints and post hoc power were not reported in any of the studies. However, names of statistical test for negative endpoint were reported in 11 (57.8%) studies. It was observed that P values were reported in 14 (73.6%) studies. Out of these 14 exact P value was mentioned in 3 studies. Limitation of small sample size was also mentioned in 2 studies (10.5%) studies. 9 studies (47.3%) concluded that both groups include in respective studies were equal or similar as no significant difference was obtained. 5 studies (26.3%) mentioned that intervention has no effect based on non-significant results.
Observations from the present study narrate that majority of the animal negative studies reported as negative studies doesn't include calculation of power and sample size. It was also observed that there is an under reporting of various parameters that might assist the readers to critically appraise the published study. Observations from present study stresses that there is an urgent need for generating awareness related to methodological issues involve in designing and reporting negative animal studies. [3] Already available guidelines like ARRIVE can very well be used for reporting of animal research also. [4] It is observed that Ethics Committee restricts the number of animals for the study but that restriction should be based on sound scientific reason like sample size calculation etc., Serious issues were raised about the scientific outputs generated from animal studies and it is the duty of Ethics Committee members to allow use of enough number of animals (based on sample size calculation) so that valid and reliable results can be obtained. [5] Our aim was to analyze all published negative animal studies in SCI indexed Indian Journals and it was observed that only 19 negative animal studies were published in these 12 years hence the sample size was less [Flow Chart 1].
 References | |  |
| 1. | Sexton SA, Ferguson N, Pearce C, Ricketts DM. The misuse of 'no significant difference' in British orthopaedic literature. Ann R Coll Surg Engl 2008;90:58-61. 
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| 2. | Hebert RS, Wright SM, Dittus RS, Elasy TA. Prominent medical journals often provide insufficient information to assess the validity of studies with negative results. J Negat Results Biomed 2002;1:1.
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| 3. | Kilkenny C, Parsons N, Kadyszewski E, Festing MF, Cuthill IC, Fry D, et al. Survey of the quality of experimental design, statistical analysis and reporting of research using animals. PLoS One 2009;4:e7824.
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| 4. | Kilkenny C, Browne WJ, Cuthill IC, Emerson M, Altman DG. Improving bioscience research reporting: The ARRIVE guidelines for reporting animal research. J Pharmacol Pharmacother 2010;1:94-9.
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| 5. | Pound P, Ebrahim S, Sandercock P, Bracken MB, Roberts I, Reviewing Animal Trials Systematically (RATS) Group. Where is the evidence that animal research benefits humans? BMJ 2004;328:514-7.
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