surveillance of the risk factors for non-communicable diseases (ncds) idsp training module for state...
TRANSCRIPT
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