EPIDEMIOLOGY V M

2009/10

Shane AllwrightDept. of Public Health & Primary Care

Lecture 1: Introduction

2 parts:

A. Course introduction

B. Definitions/uses of epidemiology

A. COURSE INTRODUCTION

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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 upevidence 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.305

230 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 BP2 Patient’s age ( age associated with Rx

decision)3 ?4 Target organ damage

Predictors of decision to treat:

1 Patient’s diastolic BP2 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 courseWHAT: 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

http://www.personal.dundee.ac.uk/~cdvflore/ 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.

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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 1 614.4 (SJH & Tallaght)

Clinical epidemiology, the essentials. Fletcher and Fletcher, 4th edition

Basic epidemiology. Beaglehole et al.

Epidemiology for the Uninitiatedhttp://www.bmj.com/epidem/epid.html

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