Prevalence of Bronchial Hyperresponsiveness and Asthma in the Adult Population in Thailand

• Published in: Chest Vol. 129; no. 3; pp. 602 - 609
• Main Authors: Dejsomritrutai, Wanchai, Nana, Arth, Chierakul, Nitipatana, Tscheikuna, Jamsak, Sompradeekul, Suree, Ruttanaumpawan, Pimon, Charoenratanakul, Suchai
• Format: Journal Article
• Language: English
• Published: Northbrook, IL Elsevier Inc 01.03.2006; American College of Chest Physicians; Elsevier B.V
• Subjects: Adult; Adults; Age groups; Airway management; Asthma; Asthma - diagnosis; Asthma - epidemiology; Asthma - physiopathology; ATS = American Thoracic Society; BHR = bronchial hyperresponsiveness; Biological and medical sciences; Bronchial diseases; Bronchial Hyperreactivity - epidemiology; bronchial hyperresponsiveness; Bronchial Provocation Tests; Cardiology. Vascular system; Chronic obstructive pulmonary disease, asthma; CI = confidence interval; Confidence intervals; Cross-Sectional Studies; Development and progression; Diseases; Dyspnea; ECRHS = European Community Respiratory Health Survey; epidemiology prevalence; Female; Humans; Male; Medical sciences; Pneumology; Prevalence; Prevalence studies (Epidemiology); Questionnaires; Respiratory Sounds; Spirometry; Thailand; Thailand - epidemiology; Thailand; Asia; epidemiology prevalence; ECRHS = European Community Respiratory Health Survey; asthma; ATS = American Thoracic Society; BHR = bronchial hyperresponsiveness; adult; bronchial hyperresponsiveness; Thailand; CI = confidence interval; Human; Lung disease; Prevalence; Respiratory disease; Cardiovascular disease; Epidemiology; Asthma; Bronchus disease; Adult; Population; Obstructive pulmonary disease
• ISSN: 0012-3692; 1931-3543
• DOI: 10.1378/chest.129.3.602

We conducted a nationwide cross-sectional survey of respiratory health in adults aged 20 to 44 years during 2001 to 2002 to determine the prevalence of bronchial hyperresponsiveness (BHR) and asthma in the adult Thai population. Subjects were selected by a multistage stratified random sampling. The stratification was done on geographic area, age group, and sex. Subjects were interviewed with questionnaires and underwent spirometric testing. Methacholine challenge tests were performed on all subjects without contraindication to determine BHR defined as the provocative concentration of methacholine producing a 20% fall in FEV1 ≤ 8 mg/mL. Definite asthma was defined as BHR present with any asthma symptom within the past 12 months or demonstrated reversible airflow obstruction. Current diagnosed asthma was defined as previous physician-diagnosed asthma and any asthma symptom within the past 12 months or currently receiving asthma medication. The study population was from 20 provinces of five geographic regions of Thailand and included 1,882 women and 1,572 men. The prevalence of BHR was 3.31% (95% confidence interval [CI], 2.68 to 3.94). However, if subjects with positive reversibility test results were included, the prevalence increased to 3.98% (95% CI, 3.30 to 4.67). The prevalence of definite asthma was 2.91% (95% CI, 2.32 to 3.50), whereas the prevalence of current diagnosed asthma by the questionnaire interview was 2.15% (95% CI, 1.66 to 2.63). The κ index of the agreement between both definitions of asthma was 0.40, indicating poor to fair agreement. The prevalence of BHR and asthma in the adult Thai population is relatively low as compared with western countries.