***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: This review includes 11 published studies (172 participants); only one examined long-term oxygen therapy (28 participants). There was no statistically significant improvement in survival, lung, or cardiac health. There was an improvement in regular attendance at school or work in those receiving oxygen therapy at 6 and 12 months. Four studies examined the effect of oxygen supplementation during sleep by polysomnography. Although oxygenation improved, mild hypercapnia was noted. Participants fell asleep quicker and spent a reduced percentage of total sleep time in rapid eye movement sleep, but there were no demonstrable improvements in qualitative sleep parameters. Six studies evaluated oxygen supplementation during exercise. Again, oxygenation improved, but mild hypercapnia resulted. Participants receiving oxygen therapy were able to exercise for a significantly longer duration during exercise. Other exercise parameters were not altered by the use of oxygen. There are no published data to guide the prescription of chronic oxygen supplementation to people with advanced lung disease due to CF. Short-term oxygen therapy during sleep and exercise improves oxygenation but is associated with modest and probably clinically inconsequential hypercapnia. There are improvements in exercise duration, time to fall asleep and regular attendance at school or work. There is a need for larger, well-designed clinical trials to assess the benefits of long-term oxygen therapy in people with CF administered continuously or during exercise or sleep or both. However, we do not expect any new research to be undertaken in this area any time soon and do not plan to update this review again until any new evidence does become available.
Output:

We found eleven studies with 172 participants to include in the review. All studies compared low-flow oxygen to room air. Ten of the studies were short-term. Four of the studies looked at giving additional oxygen at night. At night, oxygen levels rose during both rapid eye movement (REM) sleep and non-REM sleep in those people breathing low-flow oxygen. Participants breathing oxygen at night also spent less time in REM sleep and took less time to fall asleep. Six of the studies looked at the effect of extra oxygen on exercise. The levels of oxygen and carbon dioxide in the blood of participants increased during or after exercise when they breathed in low-flow oxygen. People were able to exercise for longer if they breathed in low-flow oxygen. There was more regular attendance at school or work in those receiving long-term oxygen. There is little evidence to support or oppose the long-term use of oxygen therapy in people with advanced CF lung disease. In the short term, treatment has shown some improvement in blood oxygen levels in people with CF during sleep and exercise. This increase in oxygen also came with an increase in carbon dioxide levels, which is probably not clinically important. However, caution needs to be exercised in those with advanced lung disease where this may require further monitoring. There should be research into the effects of long-term oxygen treatment on sleep quality and exercise in people with CF. Unfortunately, we do not expect that any such research will be undertaken any time soon, so we do not plan to update this review again until we find any new trials.