. Author manuscript; available in PMC: 2016 Jan 17.

Published in final edited form as: Ann Allergy Asthma Immunol. 2012 May 1;108(6):423–428.e2. doi: 10.1016/j.anai.2012.04.009

Table 4.

Predictors for 2 or more prednisone courses in the last 12 months among 104 asthmatic patients 65 years or older^a

Independent variable	Adjusted odds ratio (95% CI)	P value
High vs low ECAT concentration^b	3.24 (1.01–10.37)	.05
BMI (25th–75th percentile)^c	2.25 (1.02–4.95)	.04
Atopic (SPT positive)^d (yes vs no)	0.39 (0.12–1.26)	.12
Mixed rhinitis (yes vs no)	0.85 (0.26–2.76)	.79

Abbreviations: ACQ, Asthma Control Questionnaire; BMI, body mass index; CI, confidence interval; ECAT, elemental carbon attributable to traffic; SPT, skin prick test.

Multivariate logistic regression was used in this analysis; 99 patients had sufficient data for analysis. Two or more courses of prednisone were prescribed for 18 patients.

ECAT was analyzed as a dichotomous variable using the cut points from the spline for ACQ (high ECAT concentration defined as >0.39 µg/m³ and low ECAT concentration as <0.39 µg/m³).

BMI was analyzed as a continuous, log-transformed variable. The odds ratio presented is for a change in the log of BMI from the 25th to the 75th percentile.

At least 1 positive SPT result to a panel of 10 aeroallergens.