Epidemiology of asthma and associated factors in an urban Pakistani population: adult asthma study-Karachi

BMC Pulmonary Medicine

Table 4 Multivariate logistic regression analysis for factors associated with asthma among adults ≥18 years, Karachi, Pakistan (n = 930)

Characteristics	Reversibility ≥200 ml in FEV₁^k	Respiratory symptoms and reversibility in FEV₁^k
	AOR (95% CI)	AOR (95% CI)
Age
18 to 27 years	1	1
28 to 37 years	0.9 (0.5–1.7)	0.7 (0.3–1.8)
≥ 38 years	1.9 (1.2–3.3)	2.1 (1.1–4.2)
Socio-economic status^a
High income	1	–
Middle income	1.7 (0.9–2.8)	–
Low income	1.9 (1.2–3.4)	–
History of any allergy
No	1	1
Yes	1.9 (1.2–2.9)	2.8 (1.7–4.8)
Pack years of smoking^b
Non smoker	–	1
< 5 years	–	0.6 (0.2–1.9)
≥ 5 years	–	2.3 (1.1–4.7)
Exposure to environmental tobacco smoke^c
No	1	1
Yes	1.6 (1.1–2.5)	1.9 (1.1–3.3)

^aSocio-economic status was defined using the proxy indicator of monthly household income which included income of all members living in the same house as well as additional earnings based on any business or other investment
^bPack years of smoking was defined as the number of cigarettes smoked per day divided by 20 and multiplied by the number of years that the person smoked
^cExposure to environmental tobacco smoke was defined as anyone who smoked cigarettes anywhere inside the house
^kDefinitions used for asthma:
Spirometry-based asthma assessed on presence of post-bronchodilator reversibility ≥200 ml in FEV₁
Asthma based on post-bronchodilator reversibility ≥200 ml in FEV₁ and one or more respiratory symptoms, or self-reported asthma

ISSN: 1471-2466