Table 1—

Number of participants and prevalence(%) of asthma, respiratory symptoms, airway hyperresponsiveness (AHR), smoking, atopy and obesity in Busselton surveys 1981, 1990 and 2005–2007 by age group and sex

	Year	Males		Females
	Year	18–54 yrs	55–79 yrs	18–54 yrs	55–79 yrs
Participants n	1981	1015	739	1227	858
	1990	528		626
	2005–2007	634	658	805	625
DDA	1981	8.7***	7.7**	10.1***	6.8***
	1990	16.1*		14.7***
	2005–2007	21.0	12.1	23.0	17.3
Wheeze (ever)	1981	24.5***	33.4	26.0***	26.0**
	1990	38.1*		35.6
	2005–2007	44.2	33.3	38.7	32.7
Wheeze (recent)	1981	17.4**	22.8	17.5*	22.3
	1990	29.4		28.6
	2005–2007	25.7	24.4	24.3	20.1
DDA plus wheeze (recent)	1981	6.0*	4.7	6.2***	5.0
	1990	12.3		11.8
	2005–2007	10.5	8.3	13.1	9.7
AHR	1981	7.8	15.7	12.4	13.4
	1990	8.3		7.7***
	2005–2007	10.5	11.2	13.4	13.9
AHR plus wheeze (recent)	1981	4.3	8.4*	5.6	4.7
	1990	7.9*		6.4
	2005–2007	4.6	4.4	5.6	4.4
Shortness of breath	1981	6.2	16.7	10.5*	18.8
	1990	4.9		10.3
	2005–2007	6.5	15.1	13.6	18.5
Cough/phlegm (recent)	1981	11.5***	18.7*	7.7***	13.5***
	1990	15.4***		12.1*
	2005–2007	25.9	30.6	16.7	22.1
Doctor-diagnosed bronchitis	1981	12.3*	23.4	20.8	20.3
	1990	20.0*		30.1***
	2005–2007	15.7	20.4	20.8	27.5
Smoking (current)	1981	28.3**	16.1***	19.0**	12.7***
	1990	18.4		12.9
	2005–2007	21.7	7.7	14.0	4.1
Atopy	1981	46.6***	41.3	42.3**	34.9
	1990	52.7***		50.2
	2005–2007	63.2	46.0	52.2	37.4
Obese (BMI >30 kg·m⁻²)	1981	9.0***	11.9***	8.2***	15.3***
	1990	9.2***		12.3***
	2005–2007	20.1	28.7	19.8	24.3

Data are presented as %, unless otherwise stated. DDA: doctor-diagnosed asthma; BMI: body mass index. *: p<0.05 compared with 2005–2007; **: p<0.01 compared with 2005–2007; ***: p<0.001 compared with 2005–2007.