Caveats: While most asthma patients use their inhaler medications for months and years, the benefits of the combination inhaler were tested in predominantly 12-week trials, thus there may be less or more benefit when their use is extended.
The symptom reductions in these trials that were found with combination therapy were very small. Typically the therapy led to pumps/day fewer uses of the rescue (beta-agonist) inhaler, and about 10% more 'symptom-free days' during the 12-week study periods. Despite these findings there was no 'Quality of Life' advantage. However, these advantages may be greater if the asthma is more severe. This may be a consideration for patients with severe relapsing asthma that leads to multiple hospital admissions. On the other hand, these patients may also be at highest risk for a fatal or severe attack, which would make LABA medicines potentially dangerous. This difficult balance will have to be struck by physicians and patients in concert based on symptoms, risk thresholds, and patient values.
Of the 48 trials represented in this review, 44 were sponsored by the pharmaceutical maker of the combination therapy. A long history of misrepresentation of data and occasionally fraudulent reporting of data suggests that industry sponsored results are often more optimistic than subsequent data produced by researchers and parties that do not have a financial stake in the results.
We have chosen to designate this therapy RED (no benefits) rather then BLACK (harms> benefits) because of the small benefit and the possibility of a trade-off of harms and benefits that may be worthwhile based on individual circumstances. In addition, while asthma-related deaths increase, all-cause mortality was unchanged in the reviewed studies, making the overall harm impact less definitive in terms of fatalities.