community diagnosis and epidemiology in community medicine

Community Diagnosis and Epidemiology in Community

Medicine

By Ricky H Hipolito, MD

Part 1 Community Diagnosis

• A Scientific inquiry

• Determining

– The collective health status of the members of a community

– Factors affecting health present in the community

– Health problems present in the community

– Health problem/s that can be dealt with most efficiently using the present resources, and under present circumstances.


A. Dimensions Secondarily Related to Health

1. Background/ Setting

1.1 Local history

1.2 Geography

– Part of which Region, Municipality/ City

– Boundaries whether land locked, coastal or both

– Land area

– Subdivisions, political, economic or social

1.3 Climate


2. Demography

2.1 Geographic distribution

Age – sex structure (Population pyramid)

2.2 Factors such as: Migration; Age dependency (18-49 yr); Birth/death rate; Ethnic dist; Density

3. Economic life

3.1 Sources of income

3.2 Indications of economic status: Employment; Income per capita; Poverty level; Economic organizations


4. Social Indicators

Education

Housing, Communication, Transportation

Recreation

Sources of health care and health informationPublic assistance

Leadership pattern


B. Community Dimensions Directly Related to Health

1. Health Status of the Community

• Top Mortality

• Top Morbidity

2. Environmental Indices

• Water Supply

• Excreta Disposal

• Vermin/ Insect Control

• Sanitation, Garbage Collection


3. Food / Nutrition

• Sources of food: Backyard gardens/ Markets/ Public eating establishments

• Prevalence of Malnutrition

4. Health Resources

• Manpower / Health officer: Brgy health worker, Brgynutritionist, Midwife, Nurse, Doctor

• Health facilities

• Health financing: Public funds versus private funding

• Health related legislations: National; Local


5. Organized Community health programs

• Expanded program on Immunization

• Maternal and Child health

• Reproductive health

• Nutrition programs


C. Situational Analysis

• Involves organizing the data presented in the preceding parts in order to decide on the health problem to be addressed and the type of interventions to be employed.

• The following concepts are helpful guide in the conduct of situational analysis.

Factors affecting health and well being

Protective factors

Psychosocial

factors

Effective health

services

Healthy lifestyles

Participation in

civic activities

and social

engagement

Strong social

networks

Supportive

family structure

Provision of

preventive

services

Access to

culturally

appropriate

health services

Community

participation in

the planning

and delivery of

health services

Decreased use

of tobacco and

drugs

Regular

physical activity

Balanced

nutritional

intake

Positive mental

health

Safe sexual

activity

Factors affecting health

and well being

Protective factors

Healthy Conditions and

Environments

Safe physical

environments

Supportive economic

and social conditions

Regular supply of

nutritious food and

water

Restricted access to

tobacco and drugs

Healthy public policy

and organizational

practice

Provision of meaningful

paid employment

Affordable housing

Risk factors

Risk Conditions Psychosocial risk

factors

Behavioral risk

factors

Physiological risk

factors

Poverty

Low social

status

Dangerous work

Polluted

environment

Natural resource

depletion

Discrimination

(age, sex race,

disability)

Isolation

Lack of social

support

Poor social

networks

Low self esteem

Abuse

Smoking

Poor nutritional

intake

Substance

abuse

Poor hygiene

Overweight

Unsafe sexual

activity

High blood

pressure

High Cholesterol

Adapted from: Labonte R (1998), A community development approach to health

promotion: a background paper on practice, tensions, strategic models and

accountability requirements for health authority work on the broad determinants of

health, Health Education Board of Scotland, Research Unit on Health and Behavior

Change, University of Edinburgh, Edinburgh.

Part 1 Community DiagnosisC. Situational Analysis

1. Selection of a Target Area

• Usually for pilot programs: Brgy subunit; Brgy; Municipality

• Criteria: Feasibility; Need

2. Selection of problem to be addressed

• Top causes of mortality or morbidity

• Factors to consider

• Magnitude: How many affected

• Feasibility and Sustainability: probability of developing a sustainable health program

• Impact to community: Potential of disease to cause long term disability or mortality

• Concern of the community: Perception of the community of the seriousness of the health problem.


Decision Matrix

Scores (Weight) Highest = 3

Total

Factors

Magnitude

(30%)

Feasibility/

Sustainabili

ty (30%)

Impact to

Community

(20%)

Concern of

the

Community

(20%)

High Blood

Pressure

2 (0.6) 1 (0.3) 2 (0.4) 3 (0.6) 1.7

Parasitism 3 (0.9) 3 (0.9) 3 (0.6) 2 (0.4) 2.8

Overweight 1 (0.3) 2 (0.6) 1 (0.3) 1 (0.2) 1.5


3. SWOT Analysis

A strategic planning tool that enables you to refine a certain health program. It allows you to focus your resources on activities with higher probability of success.

• Strength: Advantages present in the community; Resources that the community have;

• Weakness: Areas that need improvement

• Opportunities: Changes in technology and policy that makes it easier to carry out programs; Changes in social patterns and trends;

• Threats: Potential obstacles to your health project


4. Formulating the Problem Tree and the Objective tree

• There are no specific rules in the creation of these conceptual frameworks

• The following pointers are helpful


Problem Tree

1. The center is the health problem identified

2. Downward are the causes. Arrange the causes with the more immediate causes in the proximal areas and the underlying causes more downward

3. Upward are the effects. Arrange the effects with the more immediate in the proximal and the long-term in the distal areas


Objective Tree

1. The Center is the General Objective

2. Downward are the activities in order to meet the G.O. Arrange the concepts with the more immediate activities in the proximal and the preparatory activities in the more distal

3. Upward are the effects of the intervention. Arrange the concepts with the more immediate at the proximal and the long term effects at the more distal


5. General objectives

The SMART principle is used in the formulation of the General objectives

»S - Specific

»M - Measurable

»A - Attainable

»R - Relevant

»T - Time-bound


Examples of General objectives:

• To decrease by 20% the consults for URTI in Brgy Sampiro within 10 months

• By the end of 2010, there would be a reduction in infant mortality rates in Pagsanjan by 75-80%


Workshop 1: Formulation of Health Program Objectives

• Objective: At the end of the allotted time, the participants will be able to formulate and present health program objectives using the SMART framework.


Mechanics:

• Participants will be grouped into 10.

• Each of the ten groups will be given 20 min to formulate Health program objectives which include:

General objective

Specific objectives

• After 20 min the groups will be given 5 min each to present their work and another 5 min for critiquing.


• Workshop 2: Creation of the Problem Tree

• Objective: At the end of the alloted time, the participants will be able to present a problem tree based on the guidelines and example previously given.


• Mechanics:

– Participants will use the previous grouping (10 groups)

– They will use the health problem, gen objectives and specific objectives they used in the previous presentation

– They will be given 20 min to formulate their problem tree

– After 20 min, they will be given 5 min to present and another 5 min for critiquing

Part 1 Community Diagnosis• 6. Health project plan

Specific

Objective

Strategy Activity Time Frame Persons

Involved

To collect

information

on the health

situation of

the

community

Survey Conduct of

survey in all

households

Feb 13-15

2003

Students

Barangay

council

Resources Budget Evaluation:

Method

Evaluation:

Indicator

Survey forms

Pens

200 Comparison with

the census of

2000

Covering 85% of

the households

Part 2 Data Gathering

1. Primary sources of data

• Data collected by the researcher specifically for his purpose.

• Interviews, focus group discussions, surveys conducted by the researchers


2. Secondary sources of data

• Data collected for purposes other than the researchers

• Sources:

– Vital statistics – Birth and Death certificates

– Disease registries

– National Surveys

– Hospital data


• Sources

– Hospital data

– Previous or ongoing research studies

– Data bases

• Uses

– Disease surveillance, estimating incidence and prevalence

– Cross sectional studies

– Retrospective studies

– Determining the natural history of disease


• Advantages of Primary vs Secondary Data

Primary Secondary

Exact data elements are collected

Interventions can be tested using

an RCT

The Collection process is

controlled to ensure internal

validity

The sample maybe selected to

what the researcher requires

Less expensive

Less time consuming

Pooled data from secondary

sources are more practical if the

effect size sought is small

Less ethical considerations

Part 3 Top Mortality and Morbidity Causes

Part 2 Top Mortality and Morbidity Causes

Part 4 Epidemiology in Community Medicine

1. Introduction

Epidemiology

• A Basic Medical Science dealing with patterns of disease occurrence.

• Aims to determine the distribution and determinants of disease occurrence in a given population.

• Disease distribution is characterized as to Person, Place, Time

• These data is used for:

– Disease surveillance


1. Introduction

• These data is used for:

– Determining causes and/or risk factors

– Evaluating diagnostics and screening methods

– Observing the natural history of disease

– Designing population based interventions including preventive measures

– Evaluating current treatment options

– Determining prognosis of disease


2. Relevance and purposes

• Primary Health Care (PHC)– Tailored to the unique needs and resources of the

community and entails their full participation in the planning and implementation.

– With some modifications, the concepts of PHC is still an important guiding principle in how we serve the health needs of our people.

– National Objectives for Health 2005 – 2010: Health services delivery are intended to improve the accessibility and availability of basic and essential health care for all.


3. Primary care epidemiology

– Epidemiological principles applied in health problems encountered in primary health care (PHC).

– Aims to improve management by studying disease etiology, prevention and diagnosis

– Old concept with increasing scope in terms of information sought and personnel involved.

– Integrates the knowledge of different professions


• 3. Primary care epidemiology

– Studying the determinants and outcomes of consultations in primary care

– Studying the nature of symptom, signs or illnesses occurring in the community and the factors influencing decisions to consult or not to consult.

– Outcomes considered include the duration, severity and impact of signs and symptoms or illnesses.

– The perspective in studying disease should be attuned to

that of the community.


• Primary Care Epidemiology Purposes

– 1. Improving understanding of patterns and clinical significance of common symptoms and conditions seen in primary care.

– 2. Providing information that can optimise the efficient use of primary care services.

– 3. Providing a framework for the design and targeting of feasible and acceptable interventions.

• From: Hannaford PC, et al. Primary care epidemiology: its scope and purpose. Fam Practice 2006


• Some questions that primary care epidemiology can answer through studies at different health care levels

Health care level

A. Community

Patterns of

illness

What are the frequency, severity, and impact of illnesses in the

community?

What is the natural history (duration and recurrence if untreated) of

different illnesses?

Does the occurrence and characteristics of illness vary with time,

person, place?

How are different symptoms and signs related to each other?

What are the factors that influence the occurrence and

characteristics of illness?

Patterns of

response

How do people manage their illnesses?

What factors influence people in their response to their illnesses?

Does it matter that some people have illnesses, for which they do

not seek health care?



Health care level

B. Primary care

Patterns of

illness

What is the range of illnesses seen by different primary care

professionals?

Is this range changing?

What is the predictive value of symptoms, seen by different

primary care professionals?

Patterns of

response

Is primary care meeting the health care needs of the population

served?

What is the effectiveness of health care services given?

Are investigations and referrals to secondary care optimal?

How do management decisions now affect patients' future patterns

of response?



Health care level

C. Secondary care

Patterns of

illness

What is the proportion of patients with a particular condition

referred to secondary care?

Does the proportion of referred patients vary according to the

age, gender, ethnicity or other characteristic of the patient or

referrer?

Pattern of

response

Is secondary care meeting the health care needs of the

population served?

Could primary care be taking over some of the work of secondary

care?


• 4. Rates

– Rate

• Compares number of actual cases with potential cases

Actual cases (Numerator) X Factor (usually 100,000)

Potential cases

(Denominator)


• Denominator defines who is at risk.

• Rates are generally multiplied by a factor such as 1,000

– Crude rate – Rates computed with number of whole population as denominator

– Specific – Rates computed with number specific population as denominator

• Example: When computing for rate of breast cancer it is more logical to include only females, the same is true for prostate cancer


• Crude Birth Rate (CBR)

• Philippine CBR: 23.1 per 1,000 pop (2000)

# Births in 1 year X 1,000 40 X 1000 = 1.6 births per

1000

populationMid year population 25,000


• Crude Death Rate (CDR):

• Philippine CDR: 4.8 per 1,000 pop (2000)

# Deaths in 1 year X 1,000 7 X 1000 = 0.28 deaths

per 1000

population

Mid year population 25,000


• Morbidity rates

# Diseases cases in 1 year X 1,000

Mid year population


5. Incidence and Prevalence

5.1 Incidence

• New events in a population

• The denominator includes only individuals at risk

• At the start of observation period, only those without the event of interest is included as the population to be studied (denominator)

• Only individuals that developed the event during the study period are included in the numerator


• Incidence

# NEW Cases in the period of observation

# of People at risk during observation


5.2 Prevalence

• All persons that have the event in a population

• The numerator includes all persons with the event whether old or new cases

• The denominator includes all individuals observed (the dead at the beginning of the period are excluded)

# Cases in the period of observation

# Total number observed


• Practice Excercises

What are the prevalence, incidence and point prevalence


• A. Prevalence

(All cases) 6/ 9 (Pop observed)


• B. Incidence

(New cases) 3/ 6 (Pop at risk)


• C. Point Prevalence

(All cases seen on June 2004) 1/ 9 (Pop observed)

Part 4 Epidemiology in Community Medicine• 6. Common Measures Used in Community Health

Assessment

Name Formula Significance

Crude Birth Rate # Births in 1 year/ Mid

year population

Measure of population growth

Effectiveness of population

intervention programs

Crude Death Rate # Deaths in 1 year/ Mid

year population

General index of the delivery of

preventive and curative health

care

Infant Mortality Rate # of death under 1 year

of age registered in the

population/ # Registered

live births in the same

year

High IMR is associated with the

following

Poor antenatal and delivery care

Low maternal education

Mothers aged below 20 yr and

above 40 yr

Short interval between births

(less than 2 years)


Name Formula Significance

Maternal Mortality

Rate

# of Deaths from

Maternal causes for a

given year/ # Live births

in the same year

Measure of the delivery of

maternal health care

Index of the delivery of antenatal

and delivery care

Total fertility rate Greater spacing between births

improves health of mother and

child

Reduction in the number of births

leads to reduction in resource

allocation for obstetric care,

immunization, and maternal and

child interventions

Life expectancy at

birth

Given as a National data Number of people expected to

reach old age

General index of the delivery of

preventive and curative health

care

Part 5. Data presentation and Interpretation

1. Text

• Used if there is 1 to 2 results to be presented.

• Must be clear and concise. It should have a clear explanation of what was measured, where the data was collected and when.

• When whole numbers are written in text, numbers less than or equal to 9 should be written as words and numbers from 10 upwards should be written as digits.


1. Text

Example:

• “In Britain in 1948, when surveys of smoking began, smoking was extremely prevalent among men: 82% smoked some form of tobacco and 65% were cigarette smokers.”

• From: Smoking-statistics. News and resources. Cancer research UK. Available online through: http://info.cancerresearchuk.org/cancerstats/types/lung/smoking/

http://info.cancerresearchuk.org/cancerstats/types/lung/smoking/



2. Tables

• Structured numeric information. Most commonly used for presenting counts or frequencies resulting from surveys.

• Should be self-explanatory. Includes a concise text description of the data being presented.

• Must have an informative title, the rows and columns should be labeled.

• May also be used to make comparisons between groups. In such cases, the groups should define the rows and measured variables define the columns. Reduce the number of significant decimal places.


Table 2b: Mean growth rate and intakes of supplement, milk and water for 4 diets.

Supplement

Growth

rate

Supplement

intake

Milk

intake

Water

intake

(g/day) (g/day) (ml/kg0.75) (ml/kg0.75)

145 450 10.5 144

Sesbania 132 476 9.2 128

Leucaena 128 364 8.9 121

None 89 0 9.8 108

From: Informative presentation of tables, graphs and statistics. Statistical Good Practice Guidelines. University of Reading. Last

updated on 24 April 2003

Available online through: http://www.reading.ac.uk/ssc/publications/guides/toptgs.html


3. Graphs

• Useful for presenting trends, broad comparisons and relationships. Includes a concise text description of the data being presented.

• Must have an informative title, the axes should be labeled.

• Use line graphs if the horizontal (or one of the axes) axis presents a continuous variable such as time or quantity

• Use bar graphs if the horizontal (or one of the axes) axis is a qualitative factor such as gender or ethnic group


From: Smoking-statistics. News and resources. Cancer research UK. Available online

through: http://info.cancerresearchuk.org/cancerstats/types/lung/smoking/


From: Smoking-statistics. News and resources. Cancer research UK. Available online through:


Part 6. Research in Community Medicine

Study type Design Measures/ example

Case-control With or without disease in the beginning Looking retrospectively for the risk factors

Odds ratio“Patients with lung cancer have a higher odds of a history of smoking”

Cohort With or with risk factors in the beginning Looking prospectively if disease will develop

Relative risk“Smokers have a higher risk of developing lung cancer than non-smokers”

Cross-sectional study Random sample (or whole population) Looking for the risk factors and disease at the same time

Disease prevalence ratesRisk factor association only

Research Title

• Subjects (Population)

• Key Variables: Dependent and Independent

• Suggests a relationship between the key variables

• 15-20 words

Research Objectives• Think of a research topic first

• Action words: To Determine; To Compare; To Evaluate; To Describe

• Coherent and Logical

• General Specific

Research in Community Medicine• Workshop 3: Formulation of Research Title;

General and Specific Objectives

• Mechanics:

– Same groupings

– Same Disease problems

– Each group is Given 20 min to come up with

• Research Title

• Gen Objectives

• Specific objectives (2)

– Groups will be given 5 min to present and 5 min for critiquing

Part 6. Research in Community Medicine

Disease (+) (-)

Test (+) A B

(-) C D

Sensitivitya/(a+c)1 – False Neg

Specificityd/(d+b)1 – False Pos

NPVd/(c+d)

PPVa/(a+b)

Community Diagnosis and Epidemiology in Community Medicine

References:

• 1. Medical Epidemiology. Greenberg ,et al. 2003

• 2. Field Work Report for Public Health 195. R Hipolito et al, Faculty preceptor: Prof R R Quizon. College of Public Health, University of the Philippines Manila. 2003


References:

• 3. Using Secondary Data. Romano PS. 2005

• 4. National Objectives for Health. Health Status of the Filipinos. Available online through: http://www2.doh.gov.ph/noh2007/NOHWeb32/NOHperSubj/Chap1/HealthStat.pdf

http://www2.doh.gov.ph/noh2007/NOHWeb32/NOHperSubj/Chap1/HealthStat.pdf

http://www2.doh.gov.ph/noh2007/NOHWeb32/NOHperSubj/Chap1/HealthStat.pdf


References:

• 5. Hannaford PC, Smith BH, Elliott AM. Primary care epidemiology: its scope and purpose. Family Practice 2006 23(1):1-7; doi:10.1093/fampra/cmi102

• 6. Handbook of Reproductive Health Indicators. Economic and Social Commission for Asia and the Pacific, United Nations. 2003. Available online through: http://www.unescap.org/esid/psis/publications/handbookhealth/handbook.pdf


• 7. Informative presentation of tables, graphs and statistics. Statistical Good Practice Guidelines. University of Reading. Last updated on 24 April 2003. Cited on 16 March 2010. Available online through: http://www.reading.ac.uk/ssc/publications/guides/toptgs.html

• 8. Smoking-statistics. News and resources. Cancer research UK. Last updated on 9 December 2009. Cited on 16 March 2010. Available online through: http://info.cancerresearchuk.org/cancerstats/types/lung/smoking/

community diagnosis and epidemiology in community medicine

Documents