Respiratory effect of beta-blockers in people with asthma and cardiovascular disease: population-based nested case control study

Table 3 Incidence rate ratios for the association between beta-blocker exposure and asthma exacerbations by dose and duration of exposure

	Cardioselective beta-blockers						Non-selective beta-blockers
	Exposed	Exposed	Crude	Adjusted			Exposed	Exposed	Crude	Adjusted
	cases^a	controls^a	IRR	IRR	95% CI	P value	cases^a	controls^a	IRR	IRR	95% CI	P value
Low to moderate dose
Acute
Severe exacerbation^b	4	28	1.41	1.47	0.44–4.97	0.532	0	2	–	–	–	–
Moderate exacerbation	19	255	1.02	1.04	0.64–1.70	0.865	6	12	5.19	5.16	1.83–14.54	0.002
Chronic
Severe exacerbation^b	19	360	0.63	0.81	0.48–1.35	0.409	8	42	1.11	1.22	0.32–4.67	0.773
Moderate exacerbation	264	3031	0.86	0.95	0.82–1.10	0.517	23	259	0.86	0.99	0.60–1.62	0.954
High dose
Acute
Severe exacerbation^b	1	6	1.67	2.76	0.32–23.78	0.347	0	0	–	–	–	–
Moderate exacerbation	2	51	0.49	0.55	0.13–2.31	0.416	0	0	–	–	–	–
Chronic
Severe exacerbation^b	7	63	0.73	0.82	0.24–2.82	0.754	1	7	5.00	12.04	1.01–143.48	0.049
Moderate exacerbation	77	682	1.03	1.11	0.84–1.47	0.339	6	39	2.50	2.68	1.08–6.64	0.033

^aExposed cases/controls, exposed within the 60 day risk window
^bSevere asthma exacerbations associated with acute non-selective beta-blocker exposure inestimable due to lack of exposure IRR Incidence Rate Ratios
Adjusted for asthma medication use in the 90 days prior to the index date; respiratory tract infection in the 90 days prior to the index date; prior hospitalization for asthma; type of CVD medicine use in the year prior to the index date; exact age; smoking status; body mass index; social deprivation; Charlson comorbidity index; and primary care asthma review in the year prior to the index date. Empty cells (–), inestimable due to lack of corresponding beta-blocker exposure among cases and controls

ISSN: 1741-7015