Abstract
INTRODUCTION: Asthma is a chronic respiratory disease characterized by chest tightness, coughing, shortness of breath, and wheezing. Results from the Global Burden of Diseases Study 2021 have shown that asthma poses a notable burden on patients in Malaysia and Singapore (age-standardized prevalence rates of 2461.83 and 3352.79 per 100,000 individuals, and age-standardized disability-adjusted life year rates of 189.06 and 139.99 per 100,000 individuals, respectively). The current study aimed to compare the patterns of asthma symptoms and exacerbations between participants from Malaysia and Singapore, using data from the Singapore/Malaysia Cross-Sectional Genetic Epidemiological Study (SMCGES). METHODS: The SMCGES has been ongoing since August 2005 at the National University of Singapore; Universiti Tunku Abdul Rahman; and Sunway University. Data on asthma status, symptoms, and exacerbations were obtained via a standardized and validated protocol established by the International Study of Asthma and Allergies in Childhood. Participants who indicated having ever had asthma were classified as recognized asthma cases. RESULTS: Participants recruited in Malaysia (henceforth referred to as "Malaysian subset", n = 4028) and Singapore (henceforth referred to as "Singaporean subset", n = 11,473) were analyzed. Compared to participants from Singapore, those from Malaysia were younger (mean age ± standard deviation: 21.1 ± 4.6 vs 22.8 ± 5.7, P < .001) and more likely to be female (65.0% vs 58.1%, P < .001). The prevalence of recognized asthma was higher among subjects recruited in Singapore than in Malaysia (22.7% vs 12.0%, P < .001). However, asthma symptoms were significantly more prevalent among respondents from Malaysia than from Singapore. These included ever-wheezing (20.8% vs 18.9%, P = .01), wheezing in the past 12 months (15.8% vs 9.2%, P < .001), experiencing a wheezy chest after exercise (11.6% vs 4.0%, P < .001), and experiencing a dry nocturnal cough (13.2% vs 11.4%, P = .004). Participants recruited in Malaysia experienced more daytime asthma attacks (fewer than once a month: 26.1% vs 13.3%, at least once monthly: 3.3% vs 2.6%, P < .001) and nighttime asthma attacks (fewer than once a month: 25.6% vs 10.5%, at least once monthly: 6.1% vs 2.3%, P < .001) than their Singaporean counterparts. As compared to the Singaporean subset, more individuals from the Malaysian subset missed school or work at least once in the past 12 months due to wheezing or asthma (8.0% vs 2.8%, P < .001), visited the general practitioner or specialist for asthma (1-3 visits: 14.2% vs 9.5%, at least 4 visits: 3.4% vs 1.2%, P = .002), visited the emergency department for asthma (at least once: 6.0% vs 1.6%, P < .001), or had been admitted to the hospital for asthma (at least once: 8.1% vs 1.1%, P < .001). CONCLUSION: The prevalence of recognized asthma was higher in the Singaporean subset than in the Malaysian subset. However, there was a greater proportion of the Malaysian subset than that of Singapore that exhibited higher frequencies of wheezing, wheezing after exercising, and dry nocturnal coughing. Additionally, asthma exacerbations were more frequent in Malaysia than in Singapore. These results suggest that asthma is under-recognized and undermanaged in Malaysia.