Surveillance of the risk factors for non-communicable diseases

(NCDs)

IDSP training module for state and district surveillance officers

Module 14

Learning objectives (1/2)

• Describe the importance and the need for surveillance of risk factors for non communicable diseases

• Enumerate the differences between surveillance for communicable diseases and risk factors for non communicable diseases

• List non communicable disease risk factors under surveillance

Learning objectives (1/2)

• List steps involved in organization and conduct of surveillance of risk factors for non communicable diseases

• Describe the role of the district surveillance officer in surveillance of risk factors for non communicable diseases

Communicable versus non-communicable diseases

Communicable diseases• Sudden onset• Single cause• Short natural history• Short treatment schedule• Cure is achieved• Single discipline• Short follow up• Back to normalcy

Non-communicable diseases

• Gradual onset• Multiple causes• Long natural history• Prolonged treatment• Care predominates• Multidisciplinary• Prolonged follow up• Quality of life after

treatment

Social Determinants of Health Inequalities, Marmot M, Lancet 2005

Projected proportional increase in population > 65 years age, 2000-

2030

0% 50% 100% 150% 200% 250%

Mexico

Chile

India

China

USA

UK

Japan

Italy

Proportion (%)

Projected population pyramid of India

Estimated and projected proportion of deaths due to non-communicable

diseases, India, 1990-2010

0%10%20%30%40%50%60%70%80%90%

100%

1990 2000 2010

Year

Pro

port

ion (

%)

Injuries

Communicable diseases

Non communicable diseases

Source : World Bank Health Sectorial Priorities Review

Estimated and projected specific mortality rate per 100,000, by sex,

India1985 2000 2015

M F M F M FAll causes 1158 1165 879 790 846 745Infectious 478 476 215 239 152 175Neoplasms 43 51 88 74 108 91Circulatory 145 126 253 204 295 239Pregnancy 0 22 0 12 0 10Perinatal 168 132 60 48 40 30Injury 85 65 82 28 84 29Other 239 293 280 285 167 171

Epidemiological transition: The concept of evolution from a communicable diseases burden of disease profile to a predominance of non communicable disease

39.40

16.00

4.950.55

05

1015202530354045

No. of cases No.of DALY No. of YLL No. ofdeaths

No. in millions

1.64

6.36

5.28

0.63

0

1

2

3

4

5

6

7

No. ofcases

No.of DALY No. of YLL No. ofdeaths

No. in millions

2.26 1.15 0.11

66.58

0

10

20

30

40

50

60

70

No. of cases No.of DALY No. of YLL No. of deaths

No. in millions

Ischemic heart diseases Stroke

Diabetes

Burden of major non-communicable diseases, India, 2004

Non communicable disease programmes in India

A. National cancer control programmeB. National mental health programme C. National blindness control programmeD. Cardiovascular diseases, stroke and diabetes

programme E. Trauma and accident programme F. Oral health programme G. Rehabilitation programme H. Geriatric care programme

Existing reporting systems for non communicable diseases in India

• Sentinel surveillance systems National Cancer Registry Programme

• Periodic surveys/studies Census of India Sample registration systems National sample surveys National family health survey National nutrition monitoring programme

Sources of data collection for non communicable diseases in India

• Mortality data Medical certificates for death Cause of death surveys Hospital records

• Morbidity data Registry (Cancer) Special surveys Hospital reports

• Risk factors Special surveys

• Registries Cancer (Shift from hospital to community based) RF/RHD (Jai Vigyan Mission) Thalasemia (Jai Vigyan Mission)

Countries Tobacco control Cardio vascular diseases

Cancer Diabetes Integrated control

Bangladesh 1982 1978

Bhutan

DPR Korea 2000 2000

India 2000 1975

Indonesia 1989 1995

Maldives 2001

Myanmar 1982 1982 1996 1993

Nepal 1999 1998

Sri Lanka 1999 2000 2000

Thailand 1988 1988 1988 1988 1993

Source:Non-Communicable Diseases in South-East Asia Region, A Profile, WHO, 2002

Implementation of non communicable diseases

programmes in countries of the WHO South East Asia region

Prioritizing surveillance for non communicable diseases

? Mortality? ? Morbidity? ? Disability?Risk factors

The risk factors of today are the diseases of tomorrow

Age

Develo

pm

en

t of

non

com

mu

nic

ab

le

dis

ease

s

Foetallife

Adult Life Adolescence Infancy andchildhood

•SES•Nutrition•Diseases•Linear growth•Obesity

•Obesity•Lack of activity•Diet•Alcohol,•Smoking•SE potential

•Established adult risk factors(behavioural/biological)

•SES•Maternal nutritional status & obesity,•Fetal growth

Accumulated risk

Range of individual risk

Accumulated risk

Life course approach for the prevention of non communicable

diseases

Disease outcomes

• Heart disease • Stroke• Diabetes• Cancer• Respiratory diseases

Disease outcomes

• Heart disease • Stroke• Diabetes• Cancer• Respiratory diseases

Physiological risk factors

• Body mass index• Blood pressure• Blood glucose• Cholesterol

Physiological risk factors

• Body mass index• Blood pressure• Blood glucose• Cholesterol

Behavioral risk factors

• Tobacco• Alcohol• Physical

inactivity• Nutrition

Behavioral risk factors

• Tobacco• Alcohol• Physical

inactivity• Nutrition

The causal chain explains the risk factor approach for surveillance of

non communicable diseases

Rationale of the risk factor approach for non communicable diseases

• Non communicable diseases are slowly evolving Early recognition difficult

• A number of risk factors influence one or more non communicable diseases

• Risk factors have the greatest impact on non communicable diseases mortality and morbidity

• Effective modification of risk factors is possible through primary prevention

• Projections may be used to estimate burden • Simple surveillance systems can be used• Measurements standardized and validated and

obtainable within ethical limits

Step 3(Biological

)

Comprehensiveness

Com

ple

xit

y

Step 2(Physical)

Step 1(Verbal)

Core

Expanded

Optional

At each step

The WHO STEPwise approach to surveillance of non-communicable

disease risk factors

Sequential approach, step by step

Kerala

Delhi

Jammu & Kashmir

Nagaland

Bihar

High literacy rate, developed

Metropolitan city, highly urbanized, heterogeneous population

Nested populationTerrain, relatively underdeveloped

Nested populationUnderdeveloped, Tribes andTerrain

Illiterate, Poor populationRural, Agricultural, Tribals

Differentdietary patterns

Differentbody

composition

Differenthabits

Heterogeneity of non-communicable risk factors in India

Risk factors under surveillance

• Tobacco use• Alcohol consumption• Raised blood pressure

Systolic and diastolic

• Obesity Height, weight, body mass index, waist circumference

• Diet Low fruit, high fat, added salt to served food

• Physical inactivity• Diabetes mellitus

Fasting plasma glucose

• High serum cholesterol

How surveillance for non-communicable diseases differs

• Surveillance methods: Estimating the prevalence of risk factors Periodic sample surveys in each state every

five years

• Data generated: Prevalence of risk factors and unhealthy life

style Time trends Geographical distribution Distribution among various populations

Type and frequency of surveys

• Periodic sample surveys conducted in states once in five years

• 20% of districts surveyed each year• Whole population covered in 5 years • Survey conducted every year in

randomly selected districts in a five-year cycle

Organization of the surveys

• Practical implementation Institution with sufficient epidemiological

capacity Best bidders

• Coordination and supervision State directorate of public health State surveillance unit District surveillance unit

Target population for survey

• Population of 15 years to 64 years. • 10-year age groups

15-24 25-34 35-44 45-54 55-64

• Sampling technique National Family Health Survey

• Cluster sample survey

Sample size

• 2500 persons across the 15-64 years age range 250 participants in each 10-years age group

• Two strata 2500 individuals in urban area 2500 individuals from rural area

Proposed survey design

• Primary sampling unit Village in case of rural area Ward (Census Enumeration Block) in case of urban

area

• Stratification of primary sampling units based on selected variables

• House-listing in primary sampling units • Within each selected household, all male and

female members aged between 15-64 years are surveyed

Survey instrument

• A pre-tested simple questionnaire • Developed on the basis of the WHO

(STEPS) • Modified for the Indian context• Already in use for sentinel surveillance

for cardiovascular risk factors in 10 selected industrial populations all over India

Information collection

• Questionnaire • Measurement

Height Weight Blood pressure

• Biochemical results Fasting blood glucose Serum cholesterol

Step 1: Individual questionnaire (1/2)

• Baseline demography Identification, age, sex, education,

occupation

• Alcohol consumption Current drinkers, frequency, quantity

• Tobacco (Smoking and smokeless) Age at initiation, usage, cessation

Step 1: Individual questionnaire (2/2)

• Diet, fruits and vegetables In a typical week, frequency and quantity

• Physical activity At work, transportation and leisure

• History of diagnosis and treatment Hypertension and diabetes

Data collection instrument and analysis

• Computer friendly data collection instrument

• Easy data entry• Automated data analysis through

programme • Generation of information on trends and

patterns of non communicable disease risk factors

Findings and their uses

• Information generated on non communicable disease risk factors: Trends Prevalence in various areas Distribution in the populations

• Uses: Document the need for prevention and

control programmes in the community Influence policy makers Guide financial allocation

Ensuring validity

• Maximize response fraction• Use valid and reliable instruments • Calibrate instruments • Train staff• Ensure participation of individuals selected

Reduces the probability that those who do attend are unrepresentative of the sample

• Engage district surveillance officer and other health personnel

• Use existing local public health infrastructure

Role of the district public health laboratories

• Conduct tests: Blood sugar Cholesterol

• Co-ordinate collection, transport and receipt of the samples from the periphery

• Plan capacity to carry out analyses quickly • Ensure quality control of biochemical assays

Key factor to ensure useful results

Quality assurance

• Common protocol• Standardized training• Standardized survey methods• Monitoring and coordinating set ups• Advisory group and resources• Site visits• Common data management mechanisms• Critical appraisal

Ethical considerations

• Questionnaires dealing with lifestyle issues and simple non-invasive measurements Verbal consent

• Blood pressure Need to clarify whether persons with elevated readings

would be followed up and treatment provided Written consent needed

• Collection of blood Requires prior ethical clearance Built-in plans for treatment of those with raised levels

• Built-in consent form in the questionnaire

Promise to care

• Referral, diagnostic and treatment support to persons identified with non communicable disease risk factor will be built into the system

• Patients identified with hypertension, diabetes will be referred to the next level for treatment

Timing of the survey

• Physiological and cultural considerations • Overnight fasting needed

Start early in the morning (6:00 am) Finish early in the afternoon (1:00 pm)

• Rest of the day Coding forms Dealing with the laboratory specimens and

other documentation Preparations for the next day

Follow up action

• Coordinated approach for community level interventions

• Partnerships Medical colleges, state health departments,

primary health care services and non-governmental organisations

• Dissemination of health education material on causes, prevention and incentives to enhance public awareness

Truncate high risk end of exposure distribution (e.g., organize an obesity clinic). Clinical approach to disease

prevention

Reduce a small amount of risk in a large number of people (e.g., reduce fat a little in fast-food outlets). Lifestyle change plus

environmental approach

High risk and population approaches to prevention

More burden from a large proportion of the population exposed to moderate risk factors than from a small segment exposed to a high risk factor

Intervention strategies

• Population based strategy Prevent non-communicable diseases in the

whole population

• High-risk strategy Target people with identified risk factors

Public health interventions

Policy interventions Educational interventions

Health beliefs and behaviours

(Community; Individual)

Desired change

Enabling environment(Financial, Social, Physical)

Challenges• Huge population• Many programmes• Rural population• Emerging epidemics• Unemployed youth• Burden of non

communicable diseases

Opportunity• Good sample size• Different strategies• Complex exposures• Interventions• Trained workforce• Feasible intervention

Challenges and opportunities

Points to remember (1/3)

• The burden of diseases due to non communicable diseases in India became almost equal to that due to communicable diseases in 1990

• The burden of non communicable diseases is increasing while it is declining in developed countries because of surveillance and interventions

• The life style related modifiable risk factors for non communicable diseases have been identified and the magnitude of their impact is documented

Points to remember (2/3)

• The major non communicable diseases share common, preventable life style risk factors

• There is sound evidence that non communicable diseases can be reduced through a package of simple, effective and feasible life style changes

• The treatment of non communicable diseases is expensive and therefore the key to control is in its primary prevention

Points to remember (3/3)

• Non communicable diseases surveillance is therefore considered an important component of the integrated disease surveillance project

• Non communicable diseases surveillance will be done by periodic surveys of selected risk factors and will be independent of regular surveillance for other conditions

• The Non communicable disease risk factors to be measured in include: tobacco use, alcohol consumption, high blood pressure, obesity, diet, physical inactivity, fasting plasma glucose and serum cholesterol