1. / 271 Zekeriya Aktürk, Prof. Atatürk University Medical Faculty, Class 1 25.10.2010, Erzurum BiostatisticsIntroduction http://aile.atauni.edu.tr zekeriya.akturk@gmail.com

2. / 272

3. 3 Aims – Objectives At the end of this lecture, the participants should defend the importance of research and have basic information about research and biostatistics. –Name the steps of research –Formulate an answerable clinical question –Classify types of data –Mention features of a data –Classify different types of studies –Explain cohort, case control, and randomized controlled studies

4. / 274 Lets do a study together AU Medical Faculty Students and Research Aktürk Z. Erzurum. October 25, 2009

5. / 275 Bir literatür Askew, DA. et al. GPs involvement in and attitudes to research. Med J Aust 2002;177(2):74-77

6. / 276 Stages of a study 1.Ask a question 2.Is the question already answered? 3.Formulate hypothesis 4.Design the method 5.Apply 6.Perform analysis 7.Discussion 8.Report Tyler CW, Epidemyology

7. / 277 Most important: idea My research panel IdeaMethodApplicationReport 1.Knowledge and use of the public on herbal remedies 2.Effect of constipation on cognitive functions 3.. 1.Medical specialty training in Turkey 2.. 1.Effect of structured exercise on weight loss 2.. 1.Osteoporosis prevalence among women in Edirne 2..

8. / 278 How to gather ideas? Clinical practice Work environment Ideas from patients Colleagues Unexpected health outcomes …

9. / 279 Answerable clinical question Patient/problemHasta/problem InterventionGirişim ComparisonKarşılaştırma OutcomesSonuç/Çıktı Is there any difference among a calorie diet and a glycemic diet in decreasing body mass index of obese women? Centre for EBM http:www.cebm.net/

10. / 2710 Is your question answered? Literature search Teachers Colleagues Books Internet …

11. / 2711 Formulating a hypothesis H 0 –There is no difference between a calorie diet and a glycemic diet in decreasing body mass index of obese women? H 1 –There is a difference between a calorie diet and a glycemic diet in decreasing body mass index of obese women?

12. / 2712 Types of studies (How to answer the question?) Observation –Case report –Prevalance –Case control –Cohost studies –Qualitative studies Intervention –Randomized controlled studies Methodologic –Validity –Reliability

13. / 2713 Case control study CasesControls Exposed Not exposedExposed Not exposed TIME

14. / 2714 Cohort study DiseasesHealthy Exposed Not exposed T I M E DiseasedHealthy Population

15. / 2715 Randomized controlled study SickImproved A therapy B therapy T I M E SickImproved Population Randomization

16. / 2716 Statistical analysis Features of data –Current –Reliable –Correct –Complete –Appropriate to use –Appropriate for aim

17. / 2717 Statistical analysis Frequency distribution Importance tests (hypothesis tests) –Student t-test –ANOVA –Chi square –Mann-Whitney U test –McNemar test –Wilcoxon –Fisher exact test –…–…

18. / 2718

19. / 2719 Lets do an example Stages of a study 1.Ask a question 2.Is the question already answered? 3.Formulate hypothesis 4.Design the method 5.Apply 6.Perform analysis 7.Discussion 8.Report

20. / 2720

21. / 2721 Ask a question Is there any difference in recognizing “thyme” between class 1 and class 6 medical students?

22. / 2722 Was the question answered? Aktürk Z ve ark. –Medical students have problems in recognizing herbs. Class six students are better in recognizing. Genel Tıp Derg 2003;16(3):101-106

23. / 2723 Hypothesis H 0 : There is no difference in recognizing “thyme” between class 1 and class 6 medical students? H 1 : There is a difference in recognizing “thyme” between class 1 and class 6 medical students?

24. / 2724 Method The following picture was shown to students from class 1 and 6 by a data projector

25. Statistics – Frequency distribution / 2725

26. Statistics – hypothesis testing / 2726

27. / 2727 Conclusion While 12% of class 1 students correctly recognized thyme, this was 78% in class 6. Although class 6 students are better in recognizing thyme, still 22% are not successfull in recognizing. There is a significant difference between class 1 and 6 students in recognizing thyme (p<0,001).