Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
IRRs, stratified by treatment step.
Notes: Adjustment for step 6 resulted in very wide CIs due to low sample size. This made the forest plot unreadable, so this adjustment is not displayed.
Abbreviations: BTS, British Thoracic Society; IRR, incidence rate ratio; med; medication; NOS, not otherwise specified.
