/ 401 Prof. Dr. Hamit ACEMOĞLU Atatürk University School of Medicine Biostatistics Department INTRODUCTION TO BIOSTATISTICS

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Lectures Introduction to Biostatistics Data types Data collection and recording Introductionto SPSS Hypothesis tests and their usage Errorchecking and outliers Presenting data using graphics Presenting data using tables The average The spread Theory distributions (normal distribution) Other theory distributions Data conversion Sampling and sampling distribution Confidence intervals / 404

Lectures Study design 1 Study design 2 Clinical studies Cohort studies Case control studies Numerical data one group Numerical data two related groups Hypothesistests Errors in hypothesistests Numerical data two independent groups Numerical data more than two independentgroups Categorical data two relatedgroups Categorical data two independen tgroups Correlationan dregression analysis Reinforcement / 405

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● Statistics is the study of the collection, analaysis, interpretation, presentation, and organization of data. -INPUT -ANALYSIS -OUTPUT ● Biostatistics is the application of statistics to a wide range of topics in biology. / 408

9 Let’s do a quick research The participants of reasearch course and the reascarch

/ 4010 A literature Askew, DA. et al. GPs involvement in and attitudes to research. Med J Aust 2002;177(2):74-77

/ 4011 Steps of a clinical reasearch 1.Ask an answerable question 2.Is your question has been asked before? 3.Hipothesise 4.Define method 5.Aplication 6.Statistics 7.Interpretation 8.Reporting Tyler CW, Epidemiyoloji

/ 4012 The most valuable thing is the opinion An example of a reasearch board OpinionMethodsAplicationReport 1.The usage of herbal drugs among puplic. 2.The affect of constipation on entellectual functions 3.The affecet of counselling on adolescent risky behewior Medical spetiality educatin in Turkey The affect of Established exersize on loosing weight 2.Developing a national registration software for primarıy health care Prevalance of osteoporosis among womans of Edirne sitizans 2.Herbs recognising condition of medical students 3.-

/ 4013 We should be aware of catching idea! Clinical practices Study condition Ideas originated from patients Corridors of hospital Friends Unexpected medical outputs …

An answerable clinical question In obesity treatment, is there any difference between calory diet and dietary glycemic index, in regard to reduction in terms of improving the quality of life and body mass index? / 4014

/ 4015 An answerable clinical question Patient/problemHasta/problem InterventionGirişim ComparisonKarşılaştırma OutcomesSonuç/Çıktı Örn.: Şişmanlığın tedavisinde kalori diyeti ile glisemik endekse bağlı bir diyet arasında vücut kitle endeksini düşürme ve yaşam kalitesini artırma açısından fark var mıdır?

An answerable clinical question In obesity treatment, is there any difference between calory diet and dietary glycemic index, in regard to reduction in terms of improving the quality of life and body mass index? / 4016

/ 4017 Is your question answered? Literature search Teachers Other colleagues Friends Books Internet …

/ 4018 Hypothesise H 0 –In obesity treatment, there is NO difference between calory diet and dietary glycemic index, in regard to reduction in terms of improving the quality of life and body mass index. H 1 –In obesity treatment, there is a difference between calory diet and dietary glycemic index, in regard to reduction in terms of improving the quality of life and body mass index.

/ 4019 Researsh Methods (How we answer the question?) Observational Experimantal Methodological

/ 4020 Research Methods (How we answer the question?) Observational –Vaka sunumu (case report) –Prevalans-yaygınlık (prevalence) –Vaka kontrol (case control) –Kalitatif araştırmalar (qualitative) –Kohort çalışmaları (cohort) Experimantal –Randomize kontrollü çalışmalar (randomized controlled trial) –Saha deneyleri (field experiments) Methodological –Geçerlilik, güvenilirlik çalışması (validity and reliability studies)

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Cross-sectional study / 4022

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Case-control study / 4024

/ 4025 Case-control study Cases Controls Exposed to factor Unexposed to factor Exposed to factor Unexposed to factor TİME

/ 4026 Cohort study PatientHealthy Exposed to factor Unexposed to factor TIME PatientHealthy Population

/ 4027 Randomized controlled studies PatientHealed A treatment B treatment TIME PatientHeald Population Randomisation

/ 4028 Statistical Analysis The porperties which should be in data –Popular –Reliable –Correct –Complete –Apropriate for usage –Apropriate for aim

/ 4029 Statistical Analysis Frequency distribution Tests of hypotehesis –Student t-test –ANOVA –Chi square –Mann-Whitney U test –McNemar test –Wilcoxon –Fisher exact test –…–…

/ 4030 Let’s do an example Steps for a study –Ask an answerable question –Is your question has been asked before –Hypotesise –Difine a method –Aplication –Statistics –Interpretation –Reporting

Which herb is this? / 4031

/ 4032 An answerable question Is there any differance between medical studens phase-1 and phase-2, in regard to identify thyme hearb.

/ 4033 Is this question answered before? Aktürk Z and colleagues. –Medical students do not identify herb enough. The knowledge level of phase-6 students is higher than phase-1 students. Genel Tıp Derg 2003;16(3):

/ 4034 Hypothesis H 0 : Ther is no differance between phase-1 and phase-6 students in regard to identify herbs. H 1 : Ther is a differance between phase-1 and phase-6 students in regard to identify herbs.

/ 4035 Method The picture at the bottom showen to phase-1 and phase-6 students.

Statistical frequency distribution / 4036

Statistics: Hypothesis tests / 4037

/ 4038 Hypothesis H 0 : Ther is no differance between phase-1 and phase-6 students in regard to identify herbs. H 1 : Ther is a differance between phase-1 and phase-6 students in regard to identify herbs.

/ 4039 Interpretation Wile 12% of phase-1 students identifying thyme herb, the ratio is 78% for phase-6 students. Although the identification thyme herb ratio is higher for phase-6 students, 22% of phase-6 students do not identify this herb. There is a significant differance between phase-1 and phase-6 patient in regard of identifying thyme herb. (p<0,001)

Summary –Steps for a study ? –Answerable question ? –The properties which should be looked for a data ? –Reasearch types? / 4040