EPIDEMIOLOGY V M 2009/10 Shane Allwright Dept. of Public Health & Primary Care

Lecture 1: Introduction 2 parts: A. Course introduction B. Definitions/uses of epidemiology

A. COURSE INTRODUCTION Some slides have an optional voice recording which provides additional explanatory material. The voice clips look like this and are accessed by double clicking on the icon. Go ahead and try!

Epidemiology course goals: understanding of concepts and methods of epidemiology & their application to clinical and preventive medicine knowledge and skills to critically evaluate research findings (Course Handbook p17)

Epidemiology course objectives To know: principles of experimental design, including RCT most commonly used rates main sources of data in Republic of Ireland main observational research designs  appropriate analyses  strengths and weaknesses  appropriate interpretations (bias) criteria for causality principles of screening definitions and relevance of sensitivity, specificity and predictive values

Epidemiology course objectives To appreciate: need for evaluation of literature problems with assessment of causality problems of diagnosis

Clinical decision making (Dr Smith (Course Handbook p26)) EBM Ask questions Specific and focused Search literature Electronic and paper Appraise evidence (‘critical appraisal’) Implement findings

Critical appraisal is the process of weighing up evidence to see how useful it is in decision making Critical Appraisal Skills Programme (CASP)

Why epidemiology for medical students? Critical review of literature /EBM Keep up to date Research design e.g. Paeds projects

Sackett et al. Am Heart J 296: 297, 1977 / Clinical Epid p hyptertensives – identical work-ups All referred to 1 of 80 GPs Work – up results sent to GP Only 2/3 started on anti-hypertensive drugs Predictors of decision to treat? Jot down 2 or 3 before turning to next slide

Predictors of decision to treat: 1 Patient ’ s diastolic BP 2 Patient ’ s age (  age associated with  Rx decision) 3 ? 4 Target organ damage

Predictors of decision to treat: 1 Patient ’ s diastolic BP 2 Patient ’ s age (  age associated with  Rx decision) 3 Referring physician ’ s year of graduation (more recent graduates more likely to treat) 4 Target organ damage

Epidemiology course WHAT: Based around main components of clinical practice: Treatment Prognosis Aetiology Diagnosis and screening Systematic reviews HOW: Computer assisted learning (CAL) introductory seminar (‘Studying Populations’) Lectures (slides) on web Epidemiology small group seminar (1) Epidemiology course assessment (see Course Handbook p18-19)

Computer assisted learning (CAL) “Studying populations” software Available in Tallaght PAC Room Seminar (in Tallaght PAC Room) to introduce software Register for personal copy Replaces lectures / aids revision

Lectures Lectures (slides) on web: Treatment* Prognosis Aetiology Diagnosis and screening Systematic reviews* *These topics inadequately covered in ‘Studying Populations’ and in most textbooks so I recommend using lecture slides to cover these topics. Voice commentary to amplify bullet points Double click on icon to hear voice commentary

Epidemiology small group seminar 1 small group seminar each month. N.B. Please bring a calculator and any epidemiology lecture notes and / or text books Aim: To illustrate, in a participatory manner, applications of epidemiology To give student practice in interpreting journal articles. (Course handbook p19)

Epidemiology small group seminar Excerpts from 2 or 3 published journal articles will be presented. Series of questions - comment on design, analysis, generalisability and ethics issues relevant to each study. Specific objectives pertinent to each excerpt will be provided. Different seminar topics may be used for different groups.

Epidemiology course assessment MCQs Within MEQ(s) Excerpts from published journal article(s) Series of questions - on design, analysis, generalisability and ethics issues relevant to each study As per small group seminar!

p, CI RCT Intention-to-treat \ explanatory Effectiveness \ efficacy Incidence RR, OR Rate difference, risk reduction, NNT Systematic review Cohort study, case control study, ecological (correlation) study Sensitivity, specificity, predictive values Must know terms:

Epidemiology texts See course handbook, Appendix (SJH & Tallaght) Clinical epidemiology, the essentials. Fletcher and Fletcher, 4 th edition Basic epidemiology. Beaglehole et al. Epidemiology for the Uninitiated Epidemiology and Public Health Medicine Vetter & Matthews, Churchill Livingstone

Epidemiology texts ( cont.) How to read a paper. The basics of evidence based medicine. T. Greenhalgh, BMJ Publishing Group Clinical epidemiology Sackett, Haynes and Tugwell, Little Brown ( not on Course Handbook list)

B. DEFINITIONS / USES OF EPIDEMIOLOGY Epidemiology : "The study of the distribution and determinants of health-related states or events in specified human populations and the application of this study to the control of health problems (Last 1988)  Counting…..

Clinical epidemiology: The practice of epidemiology that begins in a clinical setting The study of the variation in outcomes of illness and the reasons for that variation

Clinical epidemiology Concerned with patient populations and: diagnosis definitions of normality/abnormality accuracy of diagnostic tests natural history and prognosis of disease evaluation of treatments aetiology prevention

Uses of epidemiology PREVENTION causation especially primary prevention natural history (secondary and tertiary prevention) Description of health status of populations service planning e.g.Tallaght Evaluation of interventions