1. Epidemiology of Airway Diseases-Asthma and COPD in India
S. K. Jindal
Department of Pulmonary Medicine
Postgraduate Institute of Medical Education and Research
Chandigarh, India

2. Prevalence of C.R.D. Global Estimates
Ch Resp Dis
Year
Prevalence (Million)
Asthma
2004
300
COPD
2000 80
Allergic rhinitis
2006
400
Others
> 50
S.A.S.
> 100
Bousquet et al, ERJ 2007

3. 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.

4. Global Initiatives in Epidemiology
Asthma: ISAAC (International study on Asthma and Allergies in Children) ECRHS (European Community Respiratory Health Survey) COPD: BOLD (Burden of Obstructive Lung Disease) PLATINO (COPD Prevalence in five Latin American Cities)

5. Global Adult Asthma Prevalence (%)
Country
Australia
N.Zealand
Belgium
England
Germany
Spain
France
U.S.
Italy
Greece
Switzerland
Tristan da Cunha
Current 25 - 4
Ever 12 10 7 3 56
Recent
Wheeze 28 30 17 22 14 9 16
AHR 36 27 18 47
Atopy 44 35 34 42 26 24

6. Adult* Asthma in Asia Prevalence Rate**(%) China 0.67 – 1.39
Hong Kong – 8.0
Japan
Singapore – 9.0
South Korea 10 – 12.1
Taiwan – 6.0
Thailand – 10.1
Range – 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

7. All cause Ranking of Burden of COPD Global Burden of Disease Study
Cause of death 6th 3rd
DALYs
Worldwide 12th 5th
Developed regions 9th
Developing regions 4th
Murray & Lopez, Lancet 1997

8. Prevalence studies on asthma from India
Study Population
Age (yrs)
Definition / Methodology
Prevalence (%)
Region
Group
No. 1.
Viswanathan (1966)
North (P)
Urban
15805
All ages
Symptoms on interview
1.8
Children 2.
Shah (2000)
Multicentric
Schools
37171
31697
13-14
6-7
Self reported, (ISAAC)
3.7
4.5 3.
Awasthi (2004)
North (L)
3000 do
3.3
2.3 4.
Mistry (2004)
North ( C)
575
Q. wheezing
12.5 5.
Chakravarthy (2002)
South (TN)
Field
855
< 12
Q.Diagnosed asthma 5 6.
Chhabra (1998)
North (D)
2609
4-17
Q; Current
11.6 7.
Paramesh (2002)
South (B)
6550
6-15
16.6 8.
Gupta (2001)
North (C )
9090
9-20
IUATLD based validated Q
Adults 9.
Chowgule (1998)
West (M)
2313
20-44
ECRHS Q
3.5
10.
Jindal (2000)
2016
18 - > 70
Validated Q
2.8
11.
Aggarwal (2006)
73605
> 15
2.4
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

9. Validated questionnaire
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
Questionnaire 2
Bhattacharya et al (1975)
U.P.(R)
30-70+
629
511 3
Thiruvengadam et al (1977)
Madras city (U)
5-60+
408
409
Interview 4
Vishwanathan & Singh (1977)
Delhi (U)
5-94
552
441 5
Radha et al (1977)
New Delhi (U)
3-60+
1087
1011
Questionnaire & PEF 6
Nigam et al (1982)
U.P. (R)
20-70+
775
649 7
Malik SK (1986)
Chandigarh (U)
15-65+
2121
2251 8
Jindal SK (1993)
Punjab (U)
15-70+
1475
1329 9
Ray et al (1995)
Tamil Nadu (R )
30+
4857
5089 10
Jindal et al (2006)
Multicentric*
>=35
18217
17078
Validated questionnaire
PEF = Peak Expiratory Flow; U = Urban; R = Rural; * Bangalore, Chandigarh, Delhi, Kanpur

10. 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.

11. Shimla Chandigarh Bikaner Delhi Kanpur Guwahati Ahmedabad Kolkata
Mumbai
Bangalore
Chennai
Secunderabad
Nagpur
Kolkata
Kanpur
Chandigarh
Trivandrum
Guwahati
Delhi
Shimla
Berhampur
Mysore
2012

12. INSEARCH Study Population (Phase II)
Centre
Rural
Urban
Total
Male
Female
Ahmedabad
6068
5945
3074
3000
18087
Berhampur
6138
6039
1434
1414
15025
Bikaner
5475
4755
2690
2431
15351
Chennai
3472
5436
2320
3773
15001
Guwahati
5374
4823
2573
2232
15002
Kolkata
4515
4244
1828
1941
12528
Mumbai
3682
3843
3416
3001
13942
Mysore
4778
4347
2960
2932
15017
Nagpur
5209
4865
2555
2450
15079
Secunderabad
2339
2207
4546
Shimla
5725
5083
2138
2057
15003
Trivandrum
4447
4548
2895
3104
14994
54883
53928
30222
30542
169575

13. 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 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)

14. 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.

15. Statistical analyses Questionnaire pre-testing Group comparisons
Test-retest method
Split-half method
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
National burden estimates – based on age-
standardized prevalence estimates based on
Census 2011.

16. Results: I. Sample 1,69,575 individuals surveyed
Urban - 60, Rural - 1,08,811
Men – 85, Women – 84,470
% of surveyed individuals to the total eligible individuals in the households.
Urban – 98.6% Rural – 97.6%

17. II. National Prevalence (Adults)
Asthma %
Chronic bronchitis (CB) %
Smoking Men %
Women %
Any respiratory Symptom %
Total patient estimates
(as per 2011 census):
Asthma : million (>15 years)
CB : million (>35 years)

18. Asthma Prevalence in India (INSEARCH)
Urban
Rural

19. Chronic Bronchitis (INSEARCH)
Urban
Rural

20. Risk factors - Asthma

21. Risk Factors - CB

22. Smoking, ETS & Asthma (Insearch) Multiple Logistic Regression

23. ETS Exposure in Asthma No Yes ED visits 0.6 0.82*
Hospitalisation
Ac. episodes *
Parenteral BD *
Work absence (wks) *
Steroid use (wks) *
BD use (wks)
*p < 0.01
(Jindal et al, Chest 1994)

24. Environmental tobacco smoke exposure and asthma
Aggravation and occurrence of increased prevalence of respiratory symptoms
Bronchial hyper-responsiveness in adults
Aggravation of asthma symptoms
Precipitation of acute episodes
Risk factor for development of asthma (both children and adults)

25. Active smoking in asthma in adults
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 ?

26. Exposure to Solid-Fuel Combustion & Asthma (Insearch) Multiple Logistic Regression

27. 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)

28. Aspergillus hypersensitivity in asthma
Agarwal et al. Int J Tuberc Lung Dis 2009; 13: 936–944

29. ABPA in asthma
Agarwal et al. Int J Tuberc Lung Dis 2009; 13: 936–944

30. Economic burden of asthma (Rs in crores)
Year Chronic Acute Total
Murthy & Sastry NCMH Background Papers

31. Economic Burden of Asthma
Murthy & Sastry. NCMH Background Papers

32. Health costs on Smoking and COPD
Annual cost of management of COPD per patient*
Expenditure on smoking Rs. 1340
Direct costs: Patient Rs. 2259
work absence Rs. 410
Indirect losses Rs.11454
*Comprised ~ 1/3 of average income of patient
ICMR Report, Jindal et al )
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

33. 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.

34. Symptom-based diagnosis - Limitations
Lack of objective measurements like Spirometry
No specific terms for asthma (vs COPD/ CB) in Indian vernacular languages
GPs do not often differentiate between asthma and COPD
Inhalers and bronchodilators are commonly used/ abused for nonspecific cough/ breathlessness
The term “asthma” is interpreted differently in cross-cultural comparisons
(Sunyer et al, AJRCCM 2000)
5. Confounding (bronchiectasis, CB, TB)

35. THANKS