| Title |
The effect of COPD severity and study duration on exacerbation outcome in randomized controlled trials
|
|---|---|
| Published in |
International Journal of Chronic Obstructive Pulmonary Disease, May 2017
|
| DOI | 10.2147/copd.s130713 |
| Pubmed ID | |
| Authors |
Göran Eriksson, Peter M Calverley, Christine R Jenkins, Antonio R Anzueto, Barry J Make, Magnus Lindberg, Malin Fagerås, Dirkje S Postma |
| Abstract |
When discontinuation in COPD randomized controlled trials (RCTs) is unevenly distributed between treatments (differential dropout), the capacity to demonstrate treatment effects may be reduced. We investigated the impact of the time of differential dropout on exacerbation outcomes in RCTs, in relation to study duration and COPD severity. A post hoc analysis of 2,345 patients from three RCTs of 6- and 12-month duration was performed to compare budesonide/formoterol and formoterol in moderate, severe, and very severe COPD. Outcomes were exacerbation rate, time-to-first exacerbation, or discontinuation; patients were stratified by disease severity. Outcomes were studied by censoring data monthly from 1 to 12 months. In patients treated with budesonide/formoterol, annualized exacerbation rates (AERs) were comparable for each study duration (rate ratio [RR] =0.6). With formoterol, the AER decreased with study duration (RR =1.20 at 1 month to RR =0.86 at 12 months). There was a treatment-related difference in exacerbation rates of 45%-48% for shorter study durations (≤4 months) and 27% for 12-month duration. This treatment-related difference in exacerbation rates was comparable for the three disease severities in studies ≤4 months (range: 39%-51%), but this difference decreased with longer study durations, especially in more severe groups (22% and 29% at 12 months). There were fewer discontinuations with budesonide/formoterol; the treatment-related difference in time-to-first discontinuation decreased by study duration (35%, 30%, 26%, and 22% at 3, 6, 9, and 12 months, respectively). Numbers of differential dropouts increased with increasing disease severity, being greatest during second, third, and fourth months. COPD severity and study duration impact exacerbation as an outcome in double-blind RCTs. This effect is most obvious in patients with severe/very severe COPD and in studies that are longer than 4 months. Early differential dropout particularly impacts study outcome, producing a "healthy survivor effect," which reduces estimations of treatment impact on exacerbations. |
Mendeley readers
The data shown below were compiled from readership statistics for 33 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 33 | 100% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Researcher | 9 | 27% |
| Student > Master | 5 | 15% |
| Student > Bachelor | 4 | 12% |
| Student > Ph. D. Student | 3 | 9% |
| Professor > Associate Professor | 2 | 6% |
| Other | 4 | 12% |
| Unknown | 6 | 18% |
| Readers by discipline | Count | As % |
|---|---|---|
| Medicine and Dentistry | 13 | 39% |
| Nursing and Health Professions | 6 | 18% |
| Pharmacology, Toxicology and Pharmaceutical Science | 3 | 9% |
| Social Sciences | 2 | 6% |
| Sports and Recreations | 1 | 3% |
| Other | 0 | 0% |
| Unknown | 8 | 24% |
Attention Score in Context
This research output has an Altmetric Attention Score of 14. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 13 June 2017.
All research outputs
#2,486,488
of 25,382,440 outputs
Outputs from International Journal of Chronic Obstructive Pulmonary Disease
#242
of 2,578 outputs
Outputs of similar age
#44,885
of 324,557 outputs
Outputs of similar age from International Journal of Chronic Obstructive Pulmonary Disease
#7
of 75 outputs
Altmetric has tracked 25,382,440 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 90th percentile: it's in the top 10% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 2,578 research outputs from this source. They typically receive a little more attention than average, with a mean Attention Score of 6.5. This one has done particularly well, scoring higher than 90% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 324,557 tracked outputs that were published within six weeks on either side of this one in any source. This one has done well, scoring higher than 86% of its contemporaries.
We're also able to compare this research output to 75 others from the same source and published within six weeks on either side of this one. This one has done particularly well, scoring higher than 90% of its contemporaries.