Results for an example trial of β blockers in chronic obstructive pulmonary disease (COPD)

Outcomeβ blocker (n=775)*Control (n=775)*Relative risk/rate† (95% CI)P value
No of patients/eventsRisk/rate†No of patients/eventsRisk/rate†
Hospital admission
Any cause2720.353020.40.90 (0.79 to 1.02)<0.12
COPD related1210.161510.20.80 (0.65 to 0.99)<0.045
Adverse events
Any shortness of breath39 7460.144239 4440.14311.01 (0.99 to 1.02)<0.29
Severe bronchospasm3780.0014760.00034.96 (3.91 to 6.40)<0.0001

*275 575 patient days of follow-up.

†Hospital admissions are described as risks and adverse events as rates.