The study involved government health data in Ontario on almost 12,000 people with COPD between 2003 and 2011, including 8,712 patients newly placed on combination therapy and 3,160 new users of long-acting beta agonists.

The records involved real-world situations, with doctors treating patients according to their best judgment, Edelman noted.
"It's one thing to perform a drug trial and select patients very carefully and see how your drugs perform, and another to look back and see how people have done in the real world with real doctors," he said.
Researchers found that about 37.3 percent of people died while using beta agonists alone, compared with 36.4 percent of people using the combination therapy.
Similar results occurred for hospitalizations caused by COPD -- about 30.1 percent for people on the single drug, versus 27.8 percent for people taking the combination.
Overall, the use of combination therapy reduced risk of death or hospitalization by 3.7 percent, compared with beta agonists alone, the study found.

The greatest difference was among COPD patients who had also been diagnosed with asthma. Overall, those on combination therapy had a 6.5 percent reduced risk of either death or hospitalization compared with those taking a single drug. ...