Table 3.

Linear regression model of determinates of the total number of emergency department attendances between July 2022 and July 2023 amongst individuals with antibody deficiency in the Birmingham cohort

Variable	Estimate	Standard error	95% CI (asymptotic)	P value
Age	0.00422	0.00256	-0.000823 to 0.00926	0.1006
Sex	0.0379	0.0798	-0.119 to 0.195	0.6348
Secondary antibody deficiency	0.196	0.0896	0.0195 to 0.372	0.0297
Treatment with IVIG	0.183	0.105	-0.0238 to 0.390	0.0826
Treatment with SCIG	0.0906	0.0968	-0.100 to 0.281	0.3503

Linear regression model uses sex and primary vs. secondary antibody deficiency as binary categorical variables (male sex and secondary antibody deficiency as reference levels), and immunological treatment as a three-level categorical variable with treatment with prophylactic antibiotics as a reference level