epidemiological studies/ introduction

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Epidemiological Studies/ Introduction

• Define research in a scientific way

• Identify the root causes of carrying out researches

• Define clinical epidemiology and its uses

• Determine different steps of research process

• Formulate a proper research question

• Formulate a proper research objective

• Set a well-structured research hypothesis

By the end of this section, you will be able to:

DefinitionResearch is an ORGANIZED and SYSTEMATIC way of

FINDING ANSWERS to QUESTIONS.

Research

ORGANIZED

SYSTEMATIC

FINDING ANSWERS

QUESTIONS

Definition

ORGANIZED: in that there is a structure in going about doing research. It is a planned process, not a spontaneous one. It is focused and limited to a specific scope.

• Research is an ORGANIZED and SYSTEMATIC way of FINDING ANSWERS to QUESTIONS.

Research

ORGANIZED

SYSTEMATIC

FINDING ANSWERS

QUESTIONS

Definition

SYSTEMATIC:because there is a definite set of

procedures and steps which youwill follow.


Research

ORGANIZED

SYSTEMATIC

FINDING ANSWERS

QUESTIONS

Definition

FINDING ANSWERS:is the end of all research. Whetherit is the answer to a hypothesis oreven a simple question, research issuccessful when we find answers.Sometimes the answer is no, but itis still an answer.


Research

ORGANIZED

SYSTEMATIC

FINDING ANSWERS

QUESTIONS

Definition

QUESTIONS:are central to research. If there is noquestion, then the answer is of nouse. Research is focused on relevant,useful, and important questions.Without a question, research has nofocus, drive, or purpose.


Research

ORGANIZED

SYSTEMATIC

FINDING ANSWERS

QUESTIONS

• The word epidemiology comes from the Greek word epi, meaning on or

upon, demos, meaning people, and logos, meaning the study of.

• Epidemiology is the study of

the distribution and determinants of health-related states or

events in specified populations, and the application of this study to

the control of health problems

Distribution Determinants

Epidemiology

1) to describe the distribution and size of disease problems in

human population.

2) to identify aetiological factors in the pathogenesis of disease.

3) to provide the date essential for the planning, implementation,

and evaluation of health services.

Aims of Epidemiological Research

The Research Spiral

Identify theResearch Problem

Review theLiterature

Evaluate Dataand

Write Report

Specify a Research Purpose

Collect Data

Analyze andInterpret

Data

A series of actions or steps necessary to effectively carry out research

Research Process

Define research problem

LiteratureReview

Formulate research question &/or hypothesis

Design research

Collect dataAnalyze data

Interpret and report

Research Problem / Question

•A research problem is an area of concern where there is a gap in the knowledge needed for professional practices.

•Examples:•What do this patient have? (Diagnosis); •How bad is it? (Prognosis); •What are the physiological and biochemical changes that ended up with this disease? (Mechanism/Natural History/Pathogenesis);

•How did he get it? and can he spread it to his family members? (Transmission); •Will this stuff help him? (Treatment or Prevention). •Change pattern of malignancy in Egypt in the last 30 years (Classic Epidemiology)

•Quality of life of breast cancer patients with total mastectomy (Health Service Research)

First Things First

•Research problem/question•Hypothesis•Aim/Goal(s) and Objectives

Conceiving the research question

The research question is a statement reflecting the uncertainty about something

in the population that the investigator wants to resolve by making measurements

on his study participants.

Characteristics of a Good Research Question :FINER” Criteria

Feasible• Adequate Number of Participants• Adequate technical expertise• Affordable in time and money• Manageable in scope Interesting

To the investigator

Novel• Confirms or refuse previous

findings• Extends previous findings• Provides new findings

Ethical Relevant• To Scientific knowledge• To Clinical and Health policy• To future research directions

1. Novelty & avoidance of

unnecessary duplications

2. Importance for field represented

3. Interest, intellectual curiosity &

drive

4. Training & personal

qualifications

5. Availability of data & method

Criteria of selection of a Problem

6. Special equipment & working

conditions

7. Approachability of the sample

8. Sponsorship & administrative

cooperation

9. Hazards, penalties & handicaps

10. Cost & returns

11. Time factor

1. Brainstorm with a mentor or colleagues about:

• potential areas

• topics of interest

• particular research questions that one might ask

How to Get a Research Question?

2. Review the literaturesearch of a study related to a specific research question.Find out if your budding question has already been answered

No need to reinvent the wheelConsider repeating a published study in a new population – thatwould be a different question.


2. Review the literature

Is there a need for your study?

Suggestions about how to approach your question, find

subjects, measure variables, and report results



Data Sources

paper chartselectronic medical records

registration databases clinical logs

3. Investigate data sources that exist in your institution as possible

foundations for research


What fields are actually captured in the database?

How are the data entered?

What is the accuracy of the data?

3. Investigate data sources that exist in your institution as possible foundations for research


SO WHAT !!!

5. Is this question relevant?

A reasonable test of this factor, is to explicitly write down why you

believe the results will make a difference.


6. Can I study this ethically and legally?

In any study, the risk to human subjects, however slight, must be

justified by a reasonable potential for positive impact on these or

future patients.

7. Conduct a pilot study

To understand the feasibility of your data collection process

To gain a small sense of the actual results that you can expect.

To help you decide to abandon or seriously revise your study

proposal before you have gone too far in the wrong direction.

Do not use your pilot data in the real study


The research question should specify

Components of a Research Question

1. Description of the target population (subjects)

2. Identification of one or more variables of interest

3. Description of the hypothesized relationships between these variables of

interest

Formulating a research question


Gender• two possible

states

Marital Status• multiple

possible states

Serum glucose• infinite number of

potential values

Components of a Research QuestionWhat is a VARIABLE• What we typically assess when we do research. • An attribute that can change, or vary, across subjects• An element for which more than one value or state is possible.

For example:


Dependent • the variable(s) that is possibly affected by the others (Outcome)

IndependentThe variable(s) that affect the outcome (Risk Factor, Exposure or experimental intervention)

Components of a Research Question

VARIABLES

Examples of Research Questions“Is there a relation between exposure to Environmental Tobacco Smoke

(ETS) and deterioration of lung function among school children ?”


Components of Research QuestionTarget population School Children Variables

Dependent Independent

Deterioration of Lung Function ETS

Hypothesized relationship Relation

Examples of Research Questions“Is there an association between NSAIDs use and the occurrence of peptic

ulcer among adolescence?”


Components of Research QuestionTarget population Adolescence

Variables Dependent Independent

Peptic ulcer NSAIDs use

Hypothesized relationship Association

Goals and Objectives

• Goals are long term objectives and could not be attained by the end of the research study.

• Before conducting any research work, we should have Clearobjectives.

The OBJECTIVES of a research project summarize what is to be achieved by the study.

• Objectives should be closely related to the statement of the problem.

• For example, if the problem identified is “low adherence to treatment among hypertensive patients”, the general objective of the study could be to identify the reasons for this low adherence, in order to solve this problem.

How to develop your objectives?

Your objectives should be SMART. The word SMART refers to: 1- S Specific2- M Measurable 3- A Achievable or Attainable4- R Relevant 5- T Time bound

Why should research objectives be developed?

The formulation of objectives will help you to:• Focus the study (narrowing it down to essentials); • Avoid the collection of data which are not strictly necessary for understanding and solving the problem you have identified; and

• Organize the study in clearly defined parts or phases.

How should you state your objectives?Take care that the objectives of your study:

• Are clearly phrased in operational terms, specifying exactly what you are going to do, where, and for what purpose;

• Are realistic considering local conditions; and • Use action verbs that are specific enough to be evaluated.

Examples of action verbs: to measure, to determine, to compare, to verify, to calculate, to describe, and to establish.

Avoid the use of vague non-action verbs such as: to appreciate, to understand, or to study.

HYPOTHESIS

• Based on your experience with the study problem, it might be possible to develop explanations for the problem, which can then be tested. If so, you can formulate hypotheses in addition to the study objectives.

• A HYPOTHESIS is a prediction of a relationship between one or more factors and the problem under study that can be tested.

If the research question is concerned with relationships between

observations or variables, a research hypothesis will need to be

developed.

The research hypothesis is a tentative statement that can be tested by a

scientific research design.

Generating a research hypothesis

• Post-menopausal women who received hormone replacement

therapy, of a specified type and duration, are more likely to

develop endometrial cancer than post-menopausal women who

did not receive such therapy.

• Children born to women whose husbands smoke more than 20

cigarettes a day are of lower birth weight than children born to

women whose husbands do not smoke.

Generating a research hypothesis (Examples)

Types of Epidemiological Studies

Observational

Analytic

Cross Sectional (Prevalence Study)

Case‐Control or Case Reference Study

Cohort or Follow up Study

Descriptive(Case Report – Case Series ‐

Ecological Studies)

Interventional

Clinical Trial

Non Randomized CTQuazi‐ExperimentalCommunity Trial

Complete the exercise of the lecture “Introduction to Research Methodology”

epidemiological studies/ introduction

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