Table 7.

General linear models for listed dependent variables: dependent variables were entered as the square root of the index variable to ensure residuals in the model were normally distributed

Dependent variable	Factors/co-variates	Regression coefficients (95% CI)	p Value
Hospital admission in 12 months prior to clinical assessment	Unscheduled visits in prior 12 months	0.051 (0.033 to 0.071)	p<0.001
	Total number of prior intensive care admissions	0.086 (0.012 to 0.16)	p<0.05
	Hospital centre	Belfast −0.108 (−0.341 to 0.126)	p<0.001
		Brompton 0.418 (0.187 to 0.650)
		Leicester 0.077 (−0.160 to 0.314)
		Manchester 0
	On theophylline at initial assessment	0.192 (0.017 to 0.366)	p<0.05
Rescue steroids in 12 months prior to clinical assessment	Hospital centre	Belfast 0.588 (0.295 to 0.881)	p<0.001
		Brompton 0.784 (0.490 to 1.078)
		Leicester 0.757 (0.458 to 1.055)
		Manchester 0
	Blood eosinophils at first assessment	0.238 (0.105 to 0.372)	p<0.001
	Age at first assessment at Difficult Asthma Service	−0.001 (−0.019 to −0.003)	p<0.01
	Nebuliser usage at initial assessment	0.223 (0.004 to 0.443)	p<0.05
Unscheduled visits in 12 months prior to clinical assessment	Age at first assessment at difficult asthma service	−0.011 (−0.019 to −0.003)	p<0.01
	Hospital centre	Belfast 0.500 (0.188 to 0.813)	p<0.01
		Brompton 0.148 (−0.159 to 0.454)
		Leicester 0.418 (−0.090 to 0.746)
		Manchester 0
	Gender	0.284 (0.051 to 0.518)	p<0.05
	Blood eosinophils at first assessment	0.147 (0.003 to 0.290)	p<0.05