USES OF EPIDEMIOLOGY

BY DR. HEMANT GOLHARMODERATOR: DR. SUBODH GUPTA

FRAME WORK• INTRODUCTION OF EPIDEMIOLOGY• DEFINITIONS• AIMS OF EPIDEMIOLOGY• USES OF EPIDEMIOLOGY

Classically speaking

• Epi = upon• Demos = people• Ology = science• Epidemiology = the science which deals with what falls upon

people…..• Bridge between biomedical, social and behavioral sciences

What is Epidemiology?

Simple Old Definitions

Oxford English Dictionary

THE BRANCH OF MEDICAL SCIENCE WHICH TREATS EPIDEMICS

Kuller LH: American J of Epidemiology 1991;134:1051

EPIDEMIOLOGY IS THE STUDY OF "EPIDEMICS" AND THEIR PREVENTION

Anderson G. In: Rothman KJ: Modern Epidemiology

THE STUDY OF THE OCCURRENCE OF ILLNESS

A Modern Definition

Study of the occurrence and distribution of health-related diseases or events in specified populations, including the study of the determinants influencing such states, and the application of this knowledge to control the health problem (Porta M, Last J, Greenland S. A Dictionary of Epidemiology, 2008)

Purposes of Epidemiology

1. To investigate nature / extent of health-related phenomena in the community / identify priorities

2. To study natural history and prognosis of health-related problems

3. To identify causes and risk factors4. To recommend / assist in application of /

evaluate best interventions (preventive and therapeutic measures)

5. To provide foundation for public policy

AIM

EPIDEMIOLOGYOF

HEAL

TH

ACTION

DISEASE LOAD

EDUCATION AL & RESEARCH

CAUSE

AIM OF EPIDEMIOLOGY

FOR

TAKING

MORRIS’ SEVEN USES

1. TREND STUDY

2. COMMUNITY DIAGNOSIS

3. HEALTH SERVICES EVALUATION

4. TO KNOW THE INDIVIDUAL RISKS AND CHANCES

5. SYNDROME IDENTIFICATION

6. COMPLETING THE CLINICAL PICTURE

7. SEARCHING FOR CAUSES / RISK FACTORS FOR ESTABLISHING CAUSAL RELATIONSHIP

(1) TREND STUDY

1. Studying the past history for rise and fall

2. Studying its changing behaviour

3. Making future predictions

4. Giving early warnings or feed –back

5. Results are useful in planning for health services

and public health

SOCIAL ANATOMY

COMMUNITY DIAGNOSIS

SOCIAL PATHOLOGY

SOCIAL PHYSIOLOGY

QUANTIFICATIONQUALITATIVE ESTIMATION

(2) COMMUNITY DIAGNOSIS

COMMUNITY DIAGNOSIS

1. SOCIAL ANATOMY: Race, age and sex composition, socio economic status, population at risk, resources available.

2. SOCIAL PHYSIOLOGY: Positive &negative lifestyles, occupation, health services awareness and utilization.

3. SOCIAL PATHOLOGY: Morbidity, mortality, disability, alcoholism, smoking, crime & violence, risk prone behavior.

COMMUNITY DIAGNOSIS

• Must be dynamic

In a world of change, epidemiologist have a special duty to observe the impact “upon the people” and the way we live to diagnose where well -being is increasing and where losing out, to probe for unintended consequences , to identify trends and to think ahead.

(3) HEALTH SERVICES ASSESSMENTS, EVALUATION AND RESEARCH

• Translates knowledge of changing health scenario into needs for services.

• After that measures how they are met or unmet.• The success of met health demands are then appraised in

relation to available resources• Basically measures how well do public health services meet

the problems and needs of the population• This helps in wise allocation of resources in planning and

setting up health facilities and services

(4)ESTIMATE INDIVIDUAL RISK AND CHANCES

• Estimate individual risk of disease, accident or defect, it can be arrived using odds ratio and relative risk.

• Estimate the chances of avoiding them. It can be calculated using attributable risk.

• It is of huge public health importance.

(5) SYNDROME IDENTIFICATION

• Helps to establish and set criteria to define syndromes.

• This is done by describing the distribution and association of clinical phenomena in the population.

(6) COMPLETING THE CLINICAL PICTURE OF DISEASE • Going to the bottom, the deeper part of the iceberg to study the earlier part of disease, which is either stoppable or at least preventable by searching for

• Precursors of the disease• Dispositions due to disease• Asymptomatic disease• Subclinical cases• Latent cases• Carrier state

• Epidemiologist immensely contribute to physicians understanding of the clinical picture and natural history of disease.

• They identify gaps in natural history of the disease and take measures to fill this gap.

• Epidemiology plays an important role in outbreak investigation to establish the proper diagnosis of individual patients using case definition.

(7) EXAMINE CAUSATION

Several Causes Single Disease

Single Cause Several Diseases

Search for cause in interrelated diseases may yield clues for new causes / risk factors

SCOPE AND JURISDICTION Strictly speaking, there is no life science, where

epidemiological approach and principles cannot be applied

FROM WOMB TO TOMB EPIDEMIOLOGY IS APPLICABLE

PREVENTIVE PAEDIATRICSPREVENTIVE GERIATRICS

PREVENTIVE CARDIOLOGYCLINICAL EPIDEMIOLOGY

Reference

• 1) Basic Epidemiology by R. Beaglehole R. Bonita T. Kjellstrom

• 2) Epidemiology by Leon Gordis( Fifth Edition)

• 3) International Journal of Epidemiology 2001;30:1146-1155

• 4) Text book of Public Health and community medicine by Armed

Force Medical College

• 5)Morris J.N. uses of epidemiology third edition new York 1975

•Thank you…