Epidemiology of Airway DiseasesAsthma and COPD in India
S. K. Jindal
Department of Pulmonary Medicine
Postgraduate Institute of Medical Education and Research
Chandigarh, India
Prevalence of C.R.D.
Global Estimates
Ch Resp Dis
•Asthma
2004
Prevalence
(Million)
300
•COPD
2000
80
•Allergic rhinitis
2006
400
•Others
2006
> 50
•S.A.S.
Year
> 100
Bousquet et al, ERJ 2007
Global Burden of Asthma
• Currently: Around 300 m. patients
• Expected by 2025: 100 m. additional
• Loss of DALYs: About 15 m./year
(around 1% of all DALYs lost)
• Mortality: Accounts for in every 250 deaths
• Economic costs: Include direct treatment
expenditure and indirect losses due to
absenteeism, disability and health-care
management.
Global Initiatives in Epidemiology
Asthma:
COPD:
ISAAC (International study on
Asthma and Allergies in Children)
ECRHS (European Community
Respiratory Health Survey)
BOLD (Burden of Obstructive Lung
Disease)
PLATINO (COPD Prevalence in five
Latin American Cities)
Global Adult Asthma Prevalence (%)
Country
Australia
N.Zealand
Belgium
England
Germany
Spain
France
U.S.
Italy
Greece
Switzerland
Tristan da
Cunha
Current
Ever
Recent
Wheeze
AHR
Atopy
25
4
-
12
10
7
12
3
4
4
7
4
3
7
56
28
30
17
22
14
25
9
16
-
36
27
4
16
14
10
18
18
10
16
47
56
44
28
35
34
35
42
26
25
24
47
Adult* Asthma in Asia
China
Hong Kong
Japan
Singapore
South Korea
Taiwan
Thailand
Range
Prevalence Rate**(%)
0.67 – 1.39
3.9 – 8.0
3.6
0.9 – 9.0
10 – 12.1
2.4 – 6.0
2.91 – 10.1
0.67 – 12.1
* >15 year old
** Figures reported the collective range of period prevalence of asthma
ranging from 3 months to 1 year rates depending on the variation in
study methodology
Choi et al APSAR 2004
All cause Ranking of Burden of COPD
Global Burden of Disease Study
1990
• Cause of death
6th
• DALYs
Worldwide
12th
Developed regions
Developing regions
Murray & Lopez, Lancet 1997
2020
3rd
5th
9th
4th
Prevalence studies on asthma from India
Study Population
Region
Group
No.
1. Viswanathan (1966)
Age (yrs)
Definition /
Methodology
Prevalence
(%)
North (P)
Urban
15805
All ages
Symptoms on
interview
1.8
Multicentric
Schools
37171
31697
13-14
6-7
Self reported,
(ISAAC)
3.7
4.5
North (L)
Schools
3000
13-14
6-7
do
3.3
2.3
4. Mistry (2004)
5. Chakravarthy (2002)
North ( C)
South (TN)
Schools
Field
575
855
13-14
< 12
Q. wheezing
Q.Diagnosed
asthma
12.5
5
6. Chhabra (1998)
7. Paramesh (2002)
8. Gupta (2001)
North (D)
South (B)
North (C )
Schools
Schools
Schools
2609
6550
9090
4-17
6-15
9-20
Q; Current
11.6
16.6
2.3
Adults
9. Chowgule (1998)
10. Jindal (2000)
West (M)
North (C )
Field
Field
2313
2016
20-44
18 - > 70
ECRHS Q
Validated Q
3.5
2.8
11. Aggarwal (2006)
Multicentric
Field
73605
> 15
Validated Q
2.4
Children
2. Shah (2000)
3. Awasthi (2004)
IUATLD based
validated Q
B = Bangalore; C = Chandigarh; D = Delhi; IUATLD = International Union Against Tuberculosis & Lung Disease; ISAAC = International Study on
Allergies and Asthma in Children; L = Lucknow; M = Mumbai; P = Patna; Q = Questionnaire; ECRHS = European Community Respiratory Health
Survey; TN = Tamil Nadu
A summary of important field studies from India on
prevalence of CB/COPD published in last 30 years
Authors
Population
group
Age
(Yrs)
Subject No.
M
F
Method of
diagnosis
Prevalence
M
F
1
Joshi et al (1975)
Punjab (Ind)
17-64
427
0
Questionnaire
12.5
-
2
Bhattacharya et al
(1975)
U.P.(R)
30-70+
629
511
Questionnaire
6.7
4.5
3
Thiruvengadam et al
(1977)
Madras city (U)
5-60+
408
409
Interview
1.9
1.2
4
Vishwanathan &
Singh (1977)
Delhi (U)
5-94
552
441
Questionnaire
8.0
4.3
5
Radha et al (1977)
New Delhi (U)
3-60+
1087
1011
Questionnaire
& PEF
8.1
4.6
6
Nigam et al (1982)
U.P. (R)
20-70+
775
649
Interview
9.0
4.5
7
Malik SK (1986)
Chandigarh (U)
15-65+
2121
2251
Questionnaire
& PEF
5.5
2.9
8
Jindal SK (1993)
Punjab (U)
15-70+
1475
1329
Questionnaire
& PEF
5.0
2.7
9
Ray et al (1995)
Tamil Nadu (R )
30+
4857
5089
Questionnaire
4.1
2.5
10
Jindal et al (2006)
Multicentric*
>=35
18217
17078
Validated
questionnaire
5.0
3.2
PEF = Peak Expiratory Flow; U = Urban; R = Rural; * Bangalore, Chandigarh, Delhi, Kanpur
Variations in prevalence
Depend upon differences in:
•
•
•
•
•
•
•
•
Definition of disease used in the study
Study designs
Sampling methods
Use of study-instruments
Collection, recording and analysis of data
Interpretation of results
Extraneous factors: Expertise & errors
True differences: Ethnic, geographical, seasonal,
environmental etc.
2012
Chandigarh
Shimla
Bikaner
Delhi
Kanpur
Guwahati
Ahmedabad
Nagpur
Mumbai
Kolkata
Berhampur
Secunderabad
Bangalore
Mysore
Trivandrum
Chennai
INSEARCH Study Population (Phase II)
Centre
Ahmedabad
Berhampur
Bikaner
Chennai
Guwahati
Kolkata
Mumbai
Mysore
Nagpur
Secunderabad
Shimla
Trivandrum
Total
Rural
Male
Female
6068
5945
6138
6039
5475
4755
3472
5436
5374
4823
4515
4244
3682
3843
4778
4347
5209
4865
0
0
5725
5083
4447
4548
54883
53928
Urban
Male
Female
3074
3000
1434
1414
2690
2431
2320
3773
2573
2232
1828
1941
3416
3001
2960
2932
2555
2450
2339
2207
2138
2057
2895
3104
30222
30542
Total
18087
15025
15351
15001
15002
12528
13942
15017
15079
4546
15003
14994
169575
INSEARCH Sampling & Methodology
Two stage stratified sampling system
– First stage – Village/Urban area (30 clusters per centre)
– Second stage – Houses (100 Houses per cluster)
•
All residents of the selected houses aged ≥15 years were interviewed.
•
Two additional attempts were made to contact an individual in case of non availability at
the first visit.
•
A Sample size of 12421 subjects was calculated to be required to give a 95% C.I of ±0.3%
for a prevalence of 3 %.
Questionnaire Administration
The Questionnaire was administered by the field staff who were trained for the same.
•
Internal Quality assurance : 10% of the households visited by the study site supervisor
randomly.
•
External Quality assurance : Periodic monitoring visits by the officers from the controlling
centre ( Chandigarh)
Questionnaire & Definitions
• Bronchial Symptom Questionnaire (1984) developed by
International Union Against Tuberculosis and Lung Diseases
(IUALTD). Symptoms in the preceding 12 months were considered
• Asthma definition
Any 1 of: (a) whistling sound from the chest or
(b) Early morning chest tightness.
AND
Any 1 of: (a) attack of asthma .
(b) physician diagnosis of asthma in the past or
(c) Use of bronchodilators
• Chronic Bronchitis Definition
Cough with expectoration for ≥ 3 mths for 2 consecutive years.
• Objective measurements such as spirometry and bronchial hyper
reactivity were not measured.
• Diagnosis based only on questionnaire.
Statistical analyses
1. Questionnaire pre-testing
• Test-retest method
• Split-half method
2. Group comparisons
• Chi-square test (categorical variables)
• Student’s t-test (scalar variable)
• Univariate and multivariate logistic regression
analyses for Odds Ratios (OR) and 95% Confidence
Intervals
3. National burden estimates –
based on agestandardized prevalence estimates based on
Census 2011.
Results: I. Sample
• 1,69,575 individuals surveyed
Urban - 60,764
Men – 85,105
Rural - 1,08,811
Women – 84,470
• % of surveyed individuals to the total
eligible individuals in the households.
Urban – 98.6%
Rural – 97.6%
II. National Prevalence (Adults)
Asthma
- 2.04%
Chronic bronchitis (CB) - 3.58%
Smoking
Men
- 18.5%
Women - 0.5%
Any respiratory Symptom - 8.5%
•
Total patient estimates
(as per 2011 census):
Asthma : 17.23 million (>15 years)
CB
: 14.84 million (>35 years)
Asthma Prevalence in India
(INSEARCH)
Urban
6%
4%
2%
Ahmedabad
Berhampur
Bikaner
Chennai
Guwahati
Kolkata
Mumbai
Mysore
Nagpur
Secunderabad
Shimla
Trivandrum
Rural
0
2%
4%
Asthma prevalence (questionnaire definition)
6%
Men
Women
Chronic Bronchitis (INSEARCH)
Urban
Rural
Ahmedabad
Berhampur
Bikaner
Chennai
Guwahati
Kolkata
Mumbai
Mysore
Nagpur
Secunderabad
Shimla
Trivandrum
15%
10%
5%
0
5%
10%
15%
Cough and phlegm for last three years (age >40 years)
Men
Women
Risk factors - Asthma
Risk Factors - CB
Smoking, ETS & Asthma (Insearch)
Multiple Logistic Regression
1.084 (0.911-1.290)
Men
Women
7.324 (6.713-7.992)
No relative with asthma
Relative with asthma
1.720
2.834
1.599
4.801
Nonsmoker
Cigarette smoker
Bidi smoker
Hookah smoker
Other smoker
(1.453-2.037)
(2.532-3.173)
(1.191-2.145)
(3.628-6.353)
No exposure to ETS
Exposure to ETS
1.146 (1.053-1.248)
0.1
1
10
Adjusted odds ratio
ETS Exposure in Asthma
•
•
•
•
•
•
•
ED visits
Hospitalisation
Ac. episodes
Parenteral BD
Work absence (wks)
Steroid use (wks)
BD use (wks)
No
0.6
0.33
0.6
6.0
3.0
8.6
36.3
Yes
0.82*
0.34
1.32*
8.6*
3.6*
11.3*
38.3
*p < 0.01
(Jindal et al, Chest 1994)
Environmental tobacco smoke
exposure and asthma
1. Aggravation and occurrence of increased
prevalence of respiratory symptoms
2. Bronchial hyper-responsiveness in adults
3. Aggravation of asthma symptoms
4. Precipitation of acute episodes
5. Risk factor for development of asthma
(both children and adults)
Active smoking in asthma in adults
1.
2.
3.
4.
5.
6.
7.
8.
Increased bronchial responsiveness
Frequent bronchial irritation symptoms
Increased sensitization to occupational agents
Aggravation of acute episodes
Association with asthma severity
Risk factor for asthma ?
Exaggerated decline in lung functions
Role in development of fixed airway obstruction
and COPD ?
Exposure to Solid-Fuel Combustion & Asthma
(Insearch) Multiple Logistic Regression
1.096 (0.437-2.749)
1.232 (1.020-1.489)
1.410 (0.993-2.002)
2.441 (1.395-4.270)
1.275 (1.062-1.531)
1.678 (1.256-2.242)
1.274 (0.148-10.93)
0.000 (0.000-9999.)
Not regularly cooking
Cooking with electricity
Cooking with LPG
Cooking with kerosene
Cooking with coal
Cooking with wood
Cooking with dung cake
Cooking with crop residue
Cooking with other fuel
1.256 (1.154-1.367)
1.124 (0.940-1.343)
Middle social status
Low social status
High social status
0.1
1
10
Adjusted odds ratio
Aspergillin hypersensitivity and/or
ABPA in Bronchial Asthma
(Prospective studies)
Study
Hypersensitivity
ABPA
(n/N)
1.
Eaton (2000)
47/255
9/35
2.
Kumar (2000)
47/200
32/200
3.
Maurya (2005
30/105
8/105
4.
Agarwal (2007)
291/755
155/755
5.
Prasad (2008)
74/244
18/244
6.
Agarwal (2010)
87/242
54/242
Agarwal R, ABPA(Text Book PCCM, 2011)
Aspergillus hypersensitivity in asthma
Agarwal et al. Int J Tuberc Lung Dis 2009; 13: 936–944
ABPA in asthma
Agarwal et al. Int J Tuberc Lung Dis 2009; 13: 936–944
Economic burden of asthma (Rs in crores)
Year
1996
2001
2006
2011
2016
Chronic
960.05
1543.74
2294.73
3197.60
4180.35
Acute
167.07
267.63
388.84
528.84
672.52
Total
1127.12
1811.37
2683.57
3726.44
4852.86
Murthy & Sastry NCMH Background Papers
Economic Burden of Asthma
Murthy & Sastry. NCMH Background Papers
Health costs on Smoking and COPD
1. Annual cost of management of COPD per patient*
Expenditure on smoking
Direct costs:
Patient
work absence
Indirect losses
Rs. 1340
Rs. 2259
Rs. 410
Rs.11454
*Comprised ~ 1/3 of average income of patient
ICMR Report, Jindal et al 1993-98)
2. Families with one (or more) smoker members
had significantly higher health related expenditure, work
and school absenteeism and number of illnesses
Jindal et al, NMJI 2005
Conclusions
• The total population prevalence estimate of asthma
and CB in adults account for over 32 million patients
for the projected 2011 population of around 415
million. Cumulative prevalence increases with age.
• Smoking, Environmental Tobacco Smoke and
Biomass combustion exposures are important &
preventable risk factors for asthma as well as CB.
• Allergic Bronchopulmonary Aspergillosis is a
common problem seen in asthma.
• There is an enormous economic burden from both
disorders. Guideline-directed management is
significantly cheaper and cost-effective.
Symptom-based diagnosis - Limitations
1. Lack of objective measurements like Spirometry
2. No specific terms for asthma (vs COPD/ CB) in
Indian vernacular languages
3. GPs do not often differentiate between asthma and
COPD
4. Inhalers and bronchodilators are commonly used/
abused for nonspecific cough/ breathlessness
5. The term “asthma” is interpreted differently in crosscultural comparisons
(Sunyer et al, AJRCCM 2000)
5. Confounding (bronchiectasis, CB, TB)