About OMICS Group OMICS Group International is an amalgamation of Open Access publications and worldwide international science conferences and events. Established in the year 2007 with the sole aim of making the information on Sciences and technology ‘Open Access’, OMICS Group publishes 400 online open access scholarly journals in all aspects of Science, Engineering, Management and Technology journals. OMICS Group has been instrumental in taking the knowledge on Science & technology to the doorsteps of ordinary men and women. Research Scholars, Students, Libraries, Educational Institutions, Research centers and the industry are main stakeholders that benefitted greatly from this knowledge dissemination. OMICS Group also organizes 300 International conferences annually across the globe, where knowledge transfer takes place through debates, round table discussions, poster presentations, workshops, symposia and exhibitions.Open Access publicationsscholarly journalsInternational conferences

About OMICS Group Conferences OMICS Group International is a pioneer and leading science event organizer, which publishes around 400 open access journals and conducts over 300 Medical, Clinical, Engineering, Life Sciences, Pharma scientific conferences all over the globe annually with the support of more than 1000 scientific associations and 30,000 editorial board members and 3.5 million followers to its credit. OMICS Group has organized 500 conferences, workshops and national symposiums across the major cities including San Francisco, Las Vegas, San Antonio, Omaha, Orlando, Raleigh, Santa Clara, Chicago, Philadelphia, Baltimore, United Kingdom, Valencia, Dubai, Beijing, Hyderabad, Bengaluru and Mumbai.

A Practical Guide To The Statistical Considerations Of Bio-medical Research. Dr.Bhagyajyothi C.S., Reader, Department of Public Health Dentistry, Bapuji Dental College and Hospital, Davangere, Karnataka, India.

4/23/2015 Statistical considerations of bio- medical research 1

4/23/2015 Statistical considerations of bio- medical research 2 “There are three kinds of lies: lies, damned lies and statistics” - Benjamin Disraeli.

4/23/2015 Statistical considerations of bio- medical research 3

1. Ignorance towards the type of analysis at the planning stage of the study. Scale of measurement of data Continuous scale (Interval or ratio) imparts high power and also smaller sample size. Selection of statistical tests Parametric tests – most powerful and robust. Influences sample size calculation. Generalizability One must decide upon the statistical approach to analyzing the data even before the data collection and sample size determination. 4/23/2015 Statistical considerations of bio- medical research 4

2. Failure to determine the sample size scientifically. ‘Larger the sample size the better the study’ is not always true. 4/23/2015 Statistical considerations of bio- medical research 5

3. Selective or self-selection of samples. Selective or self -selection of samples. Careless sampling is much more of a problem than an inappropriate analysis. 4/23/2015 Statistical considerations of bio- medical research 6

4/23/2015 Statistical considerations of bio- medical research 7 4. Not paying adequate attention to the assumptions underlying the statistical tests. “Never replace parametric tests for non-parametric tests”.

5. Chasing the ‘P’ value 4/23/2015 Statistical considerations of bio- medical research 8

5. Chasing the ‘P’ value 4/23/2015 Statistical considerations of bio- medical research 9

6. Multiple group comparisons without paying due importance to inflation of type I error. 4/23/2015 Statistical considerations of bio- medical research 10

4/23/2015 Statistical considerations of bio- medical research 11 Number of comparisons Probability of Type I error 5% 10% 14% 19% 23% 27% 30% 34% 37%40%

7. Concealment of neutral and negative results. Neutral and Negative results. Manipulation of the study findings – unethical. Wastage of resources in replicating the same findings. Likely to face rejection by the editors or reviewers- Publication bias. Failing to report the findings -“File -drawer effect” Use of medical Rx that is ineffective, unpleasant, costly or even dangerous. 4/23/ Major threat to the validity of systematic reviews and meta- analyses. it may be equally outraged by silence. Truth is not only violated by falsehood; Henri Frederic Amiel, Statistical considerations of bio- medical research

Statistical implications to bio-medical research. 4/23/2015 Statistical considerations of bio- medical research 13

Recommendations for improving the quality of statistical aspects of bio-medical research. 4/23/2015 Statistical considerations of bio- medical research 14

Conclusion………. 4/23/2015 Statistical considerations of bio- medical research 15 No research is perfect in itself. Focus should be on curtailing the statistical inadequacies in any research to the best possible level within practical limits. Besides, Nothing can be a substitute for the knowledgeable interpretation of data. Hence using computing power should go hand in hand; not replace statistical reasoning.

Dr. K. Sadashiva shetty, Principal, Bapuji Dental College and Hospital. Karnataka, India. Dr. L. Nagesh., Head of the Department, Department of Public Health Dentistry, Institute of Dental Sciences, Bareilly, Uttar Pradesh, India.