***TASK***
the task is to simplify the input abstract of a biomedical literature

***INPUT***
the input is the abstract of a biomedical literature

***OUTPUT***
the output is the simplified abstract for the input abstract of a biomedical literature

***DOCUMENTATION***

***EXAMPLES***

Input: Four studies met the inclusion criteria (331 participants), with two studies producing a statistically and clinically significant benefit in favour of the intervention for dyspnoea post exercise.The quality of life domain for all four included studies produced a statistically significant benefit for the subcategories of dyspnoea and fatigue, in favour of the oxygen group (dyspnoea mean difference (MD) 0.28, 95% confidence interval (CI) 0.10 to 0.45; P value 0.002; fatigue MD 0.17, 95% CI 0.04 to 0.31; P value 0.009). No evidence of any effect was reported for survival, and limited benefits were observed for exercise capacity (as measured by step test and distance walk test), with one study showing a statistically significant improvement in the number of steps taken in the oxygen group for group N-of-1 studies only. No other statistically significant benefits were observed for exercise capacity among the other trials or individual N-of-1 studies. In patients with COPD with moderate hypoxia, current evidence on ambulatory oxygen therapy reveals improvements in dyspnoea post exercise and in the dyspnoea and fatigue domain of quality of life. However, evidence for the clinical utility and effectiveness of ambulatory oxygen in improving mortality and exercise capacity was not evident in this review. Methodologically rigorous RCTs with sufficient power to detect a difference are required to investigate the role of ambulatory oxygen in the management of COPD.
Output:

We looked at randomised controlled trials that compared ambulatory oxygen versus a placebo (normal air). We found four studies on 331 people with a mean age of 71 years. Two of the included studies were from Australia, one from New Zealand and one from Canada. The method of oxygen delivery and the dose of oxygen varied, although equipment in all instances consisted of light-weight or portable cylinders with flow ranging from 3 L/min to 6 L/min. Final follow-up was reported as 12 weeks for three studies and two weeks for the Nonoyama study. We found that ambulatory oxygen therapy reduced breathlessness and decreased the number of patients who felt tired. However, the distance that people could walk in five to six minutes and survival (death rate) did not change. The overall quality of evidence from the studies in this review was moderate. The way the studies were conducted (methods) was not fully reported in all cases. Most studies were lacking the pre-published study plan (protocol). From this review, it is not possible to know whether ambulatory oxygen therapy should be provided during exercise or for day-to-day activities for patients with COPD who are not severely hypoxaemic at rest. This Cochrane plain language summary is up-to-date as of November 2012.