Biostatistics - Concepts Tudor Calinici – JPEMS 2014.

Slides:



Advertisements
Similar presentations
How would you explain the smoking paradox. Smokers fair better after an infarction in hospital than non-smokers. This apparently disagrees with the view.
Advertisements

Chapter 2 Notes Psychological Research Methods and Statistics
Designing Clinical Research Studies An overview S.F. O’Brien.
Observational Studies and RCT Libby Brewin. What are the 3 types of observational studies? Cross-sectional studies Case-control Cohort.
Study Designs in Epidemiologic
Section 1.3 Experimental Design © 2012 Pearson Education, Inc. All rights reserved. 1 of 61.
Section 1.3 Experimental Design.
Basic Design Consideration. Previous Lecture Definition of a clinical trial The drug development process How different aspects of the effects of a drug.
 Try to determine causes and risk factors for disease by drawing connections between behaviors or exposures and diseases through observation alone.
Biostatistics ~ Types of Studies. Research classifications Observational vs. Experimental Observational – researcher collects info on attributes or measurements.
Evaluating Whether Interventions on the Use of Antibiotics Work to Decrease Resistance Chris Ford Regina Joice 1/18/08.
Chapter 13 Analyzing Quantitative data. LEVELS OF MEASUREMENT Nominal Measurement Ordinal Measurement Interval Measurement Ratio Measurement.
Thomas Songer, PhD with acknowledgment to several slides provided by M Rahbar and Moataza Mahmoud Abdel Wahab Introduction to Research Methods In the Internet.
Cohort Studies Hanna E. Bloomfield, MD, MPH Professor of Medicine Associate Chief of Staff, Research Minneapolis VA Medical Center.
Quantitative Research
Study Designs Manish Chaudhary BPH( IOM),MPH( BPKIHS)
Psychological Research Method and Stats
Medical Statistics (full English class) Ji-Qian Fang School of Public Health Sun Yat-Sen University.
Statistical Analysis Statistical Analysis
Intervention Studies Principles of Epidemiology Lecture 10 Dona Schneider, PhD, MPH, FACE.
Epidemiology The Basics Only… Adapted with permission from a class presentation developed by Dr. Charles Lynch – University of Iowa, Iowa City.
Experimental Design 1 Section 1.3. Section 1.3 Objectives 2 Discuss how to design a statistical study Discuss data collection techniques Discuss how to.
Investigational Drugs in the hospital. + What is Investigational Drug? Investigational or experimental drugs are new drugs that have not yet been approved.
Applied Epidemiology Sharla Smith. Discussion Assignments How to complete a discussion assignment –Read the chapters –Evaluate the question –Be very specific.
Research Study Design. Objective- To devise a study method that will clearly answer the study question with the least amount of time, energy, cost, and.
Placebo-Controls in Short-Term Clinical Trials of Hypertension Sana Al-Khatib, MD, MHS Assistant Professor of Medicine Division of Cardiology Duke University.
Understanding real research 4. Randomised controlled trials.
EXPERIMENTAL EPIDEMIOLOGY
Medical Statistics as a science
Overview of Study Designs. Study Designs Experimental Randomized Controlled Trial Group Randomized Trial Observational Descriptive Analytical Cross-sectional.
Study designs. Kate O’Donnell General Practice & Primary Care.
Chapter Eight: Using Statistics to Answer Questions.
Organization of statistical research. The role of Biostatisticians Biostatisticians play essential roles in designing studies, analyzing data and.
Section 1.3 Experimental Design.
Postgraduate books recommended by Degree Management and Postgraduate Education Bureau, Ministry of Education Medical Statistics (the 2nd edition) 孙振球 主.
1 UNIT 13: DATA ANALYSIS. 2 A. Editing, Coding and Computer Entry Editing in field i.e after completion of each interview/questionnaire. Editing again.
Unit 2: Research & Statistics n Psychology deals with many experiments and studies n WHO? Every experimenter must decide on a SAMPLE, which is a group.
BIOSTATISTICS Lecture 2. The role of Biostatisticians Biostatisticians play essential roles in designing studies, analyzing data and creating methods.
Types of Studies. Aim of epidemiological studies To determine distribution of disease To examine determinants of a disease To judge whether a given exposure.
Headlines Introduction General concepts
Levels of Review of Research and Quality Improvement Walter Kraft, MD Associate Director, Office of Human Subjects Protection Department of Pharmacology.
Section 1.3 Objectives Discuss how to design a statistical study Discuss data collection techniques Discuss how to design an experiment Discuss sampling.
The JUPITER Trial Reference Ridker PM. Rosuvastatin to prevent vascular events in men and women with elevated C-reactive protein. N Engl J Med. 2008;359:2195–2207.
Introduction to General Epidemiology (2) By: Dr. Khalid El Tohami.
Angela Aziz Donnelly April 5, 2016
Research Methods. Define the Milgram experiment An experiment in which Milgram wanted to determine whether participants would administer painful shocks.
Epidemiological Study Designs And Measures Of Risks (1)
BIOSTATISTICS Qualitative variable (Categorical) DESCRIPTIVE
Data Analysis.
Epidemiological Studies
Biostatistics Case Studies 2016
INTRODUCTION TO BIOMEDICAL AND CLINICAL RESEARCH
REVEAL: Randomized placebo-controlled trial of anacetrapib in 30,449 patients with atherosclerotic vascular disease Louise Bowman on behalf of the HPS.
Effects of Anacetrapib on the Incidence of New-Onset Diabetes Mellitus and on Vascular Events in People With Diabetes Louise Bowman & Martin Landray on.
Design of Clinical Trials
Basic Statistics Overview
ASPIRE Workshop 5: Application of Biostatistics
Statistical Reasoning in Everyday Life
CHAPTER 2: PSYCHOLOGICAL RESEARCH METHODS AND STATISTICS
ASPIRE Workshop 5: Application of Biostatistics
Dr. John P. Abraham Professor University of Texas Pan American
NURS 790: Methods for Research and Evidence Based Practice
The Hypertension in the Very Elderly Trial (HYVET)
Review for Exam 1 Ch 1-5 Ch 1-3 Descriptive Statistics
Psychological Research Methods and Statistics
ASPIRE Workshop 5: Application of Biostatistics
HEC508 Applied Epidemiology
2. Sociological Research Methods
Introduction to epidemiology
Presentation transcript:

Biostatistics - Concepts Tudor Calinici – JPEMS 2014

 Based on the researchers role  Observational  Experimental Study types

Description of a health phenomenon Evaluation of a diagnostic test Evaluation of a therapeutic approach Evaluation of prognostic (risk or protective) factors Main domains of medical research

 Based on study objectives  Descriptive  Analytical Types of studies

 Descriptive  Inferential Statistics

Based on the studied population  Exhaustive  Sampling Study types

 Population  Sample / representative sample Statistical objects

Population vs. Sample  Use sample because  size  accessibility  Economical reasons  Financial reasons

Studies Source:

Representative sample  A good sample must provide an image about the population  Representative sample  quantitative condition  qualitative condition

 Representative sample  Exposed – non-exposed  Case - control Types of samples - groups

Based on the duration of data collection  Cross-sectional longitudinal - retrospective or prospective Study types

 Collecting data Descriptive statistics  Characteristics – Variables  Quantitative; Qualitative

 To present data  Tables  Charts  Numeric characteristics Descriptive statistics

Tables

Frequency tables Count of Gender TreatmentTotal Metistatin584 Placebo614 Grand Total1198

Gender TreatmentfmGrand Total Metistatin Placebo Grand Total Contingency tables

 The representation of the data  Distribution  For frequency tables  For contingency tables Charts

 A randomized clinical trial (RCT) has been performed in order to test the efficacy of Metistatin (a statin - drug intended to lower blood cholesterol levels) versus Placebo for preventing major vascular events (nonfatal myocardial infarction, cardiac death, stroke) in diabetic patients.   A number of 1198 patients with diabetes from several hospitals in England were included in the study sample.   The study was conducted after the approval for marketing of this preparation.  . Problem

 Of interest for the study was whether Metistatin is superior to placebo (placebo - identical in appearance, size, taste to Metistatin, but lacking the active substance) in preventing major vascular events. A secondary objective has been to follow if Metistatin lowers cholesterol more than Placebo. Another question was “Is gender related to major cardiovascular events?”  Every patient who entered the study was randomly allocated to one of two preparations: Metistatin 80 mg daily administered as a single dose, or placebo. The allocation of the two interventions was masked – the investigator was allocating for each eligible patient a code corresponding to one of the two interventions, found in opaque numbered sealed envelopes. The pharmacy of the hospital was making sure each patient would receive the correct intervention based on the codes.

 Neither the patients nor the physicians were aware about which intervention the patients were receiving.  Subjects were followed under similar care circumstances for all diabetic patients from the respective hospitals.  The study excluded subjects receiving other medications that alter cholesterol levels (prednisone, estrogen, progesterone, anabolic drugs, and cyclosporine), subjects allergic to Metistatin, obese subjects and subjects for whom transportation for follow- up would be difficult or impossible. Also, all subjects who entered the study signed an informed consent (the act by which the patient consents to enter the study, acknowledging their rights, all the risks and benefits posed by his/her participation in the study).  Patients were followed for 10 years. Blood cholesterol levels were measured at the beginning and at the end of the study and the occurrence of major vascular events has been recorded

 Describe the data collected in BD_Ten.xls file according to:  Gender  Treatment  Major vascular event  Treatment by gender  Major vascular event by gender Exercise 1

 Central Measures  Mean, median, mode  Spread Measures  Range, Standard Deviation, Coefficient of variation Quantitative characteristics

 Sqew  Kurt Normal distribution

 Prevalence  Incidence  Ratios  Odd Ratio  Risk Ratio Qualitative characteristics

 For qualitative variables compute the central measures, spread measures and decide if the data are normal distributed Exercise 2

Qualitative variables Chi Square test Quantitative variables T test for means Inference

 Define research questions in terms of statistical hypothesis?  Respond to the research questions! Exercise