Table 5. Odds ratios of recording a serious error (vs. not) for categorical variables – multivariable analyses (including interaction).

	Reference category	Category	Odds ratio (95% CI)	p value
Sex		Male	Female	1.50 (1.07, 2.11)	0.018
BMI by Inhaler check	Inhaler check = YES	Underweight/Normal weight	Overweight	0.75 (0.43, 1.32)	0.090
			Obese	1.26 (0.70, 2.27)
	Inhaler check = NO		Overweight	1.77 (1.03, 3.03)
			Obese	2.26 (1.28, 3.99)
Inhaler check by BMI	Underweight/Normal	Inhaler check = Yes	No	0.91 (0.53, 1.57)	0.090
	Overweight		No	2.14 (1.22, 3.76)
	Obese		No	1.63 (0.88, 3.01)
ATAQ	Good control/Partial control	Poor control	1.60 (1.06, 2.41)	0.026
Inpatient admission or ED attendance	0	1+	2.00 (1.22, 3.29)	0.006

Abbreviations: ATAQ, Asthma Therapy Assessment Questionnaire; BMI, body mass index; ED, emergency department.