Surveillance of the risk factors for non-communicable diseases (NCDs)

1
Surveillance of the risk factors for
non-communicable diseases (NCDs)

• IDSP training module for state and district
  surveillance officers
• Module 14

2
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

3
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

4
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

5
Projected proportional increase in population gt
65 years age, 2000-2030
Italy
Japan
UK
USA
China
India
Chile
Mexico
0
50
100
150
200
250
Proportion ()
Social Determinants of Health Inequalities,
Marmot M, Lancet 2005
6
Projected population pyramid of India
7
Estimated and projected proportion of deaths due
to non-communicable diseases, India, 1990-2010
100
90
80
70
Injuries
60
Communicable diseases
Proportion ()
50
40
Non communicable diseases
30
20
10
0
1990
2000
2010
Year
8
Estimated and projected specific mortality rate
per 100,000, by sex, India
Epidemiological transition The concept of
evolution from a communicable diseases burden of
disease profile to a predominance of non
communicable disease
Source World Bank Health Sectorial Priorities
Review
9
Burden of major non-communicable diseases, India,
2004
Stroke
Ischemic heart diseases
Diabetes
10
Non communicable disease programmes in India

1. National cancer control programme
2. National mental health programme
3. National blindness control programme
4. Cardiovascular diseases, stroke and diabetes
   programme
5. Trauma and accident programme
6. Oral health programme
7. Rehabilitation programme
8. Geriatric care programme

11
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

12
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)

13
Implementation of non communicable diseases
programmes in countries of the WHO South East
Asia region
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

SourceNon-Communicable Diseases in South-East
Asia Region, A Profile, WHO, 2002
14
Prioritizing surveillance for non communicable
diseases

• Mortality?
• Morbidity?
• Disability?
• Risk factors
• The risk factors of today are the diseases of
  tomorrow

15
Life course approach for the prevention of non
communicable diseases
Foetallife
Infancy andchildhood
Adolescence
Adult Life

• Established adult risk factors
• (behavioural/biological)

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

Development of non communicable diseases

• SES
• Nutrition
• Diseases
• Linear growth
• Obesity

Range of individual risk

• SES
• Maternal nutritional status obesity,
• Fetal growth

Accumulated risk
Accumulated risk
Age
16
The causal chain explains the risk factor
approach for surveillance of non communicable
diseases

• Behavioral risk factors
• Tobacco
• Alcohol
• Physical inactivity
• Nutrition

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

• Physiological risk factors
• Body mass index
• Blood pressure
• Blood glucose
• Cholesterol

17
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

18
The WHO STEPwise approach to surveillance of
non-communicable disease risk factors
Step 3(Biological)
Complexity
Step 2(Physical)
At each step
Core Expanded Optional
Step 1(Verbal)
Comprehensiveness
Sequential approach, step by step
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Heterogeneity of non-communicable risk factors
in India
Kerala
High literacy rate, developed
Different dietary patterns
Delhi
Metropolitan city, highly urbanized,
heterogeneous population
Different body composition
Nested population Terrain, relatively
underdeveloped
Jammu Kashmir
Different habits
Nested population Underdeveloped, Tribes
and Terrain
Nagaland
Bihar
Illiterate, Poor population Rural, Agricultural,
Tribals
20
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

21
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

22
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

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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

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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

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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

26
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

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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

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Information collection

• Questionnaire
• Measurement
• Height
• Weight
• Blood pressure
• Biochemical results
• Fasting blood glucose
• Serum cholesterol

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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

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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

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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

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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

33
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

34
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

35
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

36
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

37
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

38
Timing of the survey

• Physiological and cultural considerations
• Overnight fasting needed
• Start early in the morning (600 am)
• Finish early in the afternoon (100 pm)
• Rest of the day
• Coding forms
• Dealing with the laboratory specimens and other
  documentation
• Preparations for the next day

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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

40
High risk and population approaches to prevention
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
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
41
Intervention strategies

• Population based strategy
• Prevent non-communicable diseases in the whole
  population
• High-risk strategy
• Target people with identified risk factors

42
Public health interventions
Educational interventions
Policy interventions
Health beliefs and behaviours (Community
Individual)
Enabling environment (Financial, Social, Physical)
Desired change
43
Challenges and opportunities

• 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

44
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

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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

46
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

47
Additional slides

• (Methodology)

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Urban sampling
49
Stratification for sampling in urban areas
50
Clusters in urban sampling
51
Choosing the city or the town

• Choose the city by simple random sampling method
• Choose towns by probability proportional to size
  and then by random sampling method

52
Choosing household clusters

• Obtain map areas of the town /city
• Divide city or town into zones by ethnicity,
  caste/ religion and income grade
• Cluster allotted as per share in population where
  as taking into consideration above divisions

53
Choosing household in cluster

• Map the area specific to households
• Number households
• Obtain population and demographic data pertaining
  to households
• Select households by random sampling on the list
  and mark them on the map

54
Design of the sample in rural areas
55
Number of villages
56
Sampling frame
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Selecting the village

• Divide the district into 2 / 3 geographical zones
• Decide the number of villages in each zone as per
  the proportion of rural population
• Make a list of all the villages in the zone with
  maps
• Choose the number of villages needed using random
  numbers among the list from each zone

58
Selecting the house cluster

• Make a list of households, also a map with
  numbers depicted.
• Choose from the list by random numbers the exact
  households.
• No substitution allowed.
• Repeat survey once / twice to cover the
  temporarily uninhabited households.