***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: Of 2313 participants without prior cerebral ischemia from five randomized trials, the mean age was 69 years. Participant features and study quality were similar between trials: the OAC in all five trials was warfarin. About half of participants (N = 1154) were randomized to adjusted-dose warfarin with mean achieved INRs ranging between 2.0 to 2.6. During 1.5 years mean follow up, warfarin was associated with large, highly statistically significant reductions in all strokes (odds ratio (OR) 0.39, 95% confidence interval (CI) 0.26 to 0.59), ischemic stroke (OR 0.34, 95% CI 0.23 to 0.52), all disabling or fatal stroke (OR 0.47, 95% CI 0.28 to 0.80), death (OR 0.69, 95% CI 0.50 to 0.94) and the combined endpoint of all stroke, myocardial infarction or vascular death (OR 0.56, 95% CI 0.42 to 0.76). The observed rates of intracranial and extracranial hemorrhage were not significantly increased by OAC therapy, but the confidence intervals were wide. Treatment with adjusted-dose warfarin to achieved INRs of 2 to 3 reduces stroke, disabling or fatal stroke, and death for patients with non-valvular AF. The benefits were not substantially offset by increased bleeding among these participants in randomized clinical trials. Limitations include relatively short follow up and imprecise estimates of bleeding risks from the selected participants enrolled in the trials. For primary prevention of stroke in AF patients, about 25 strokes and about 12 disabling or fatal strokes would be prevented yearly for every 1000 atrial fibrillation patients given OACs.
Output:

Oral anticoagulants prevent stroke and death in people with atrial fibrillation. Atrial fibrillation is an irregularity of the heartbeat that leads to blood clots forming in the upper chambers of the heart (the atria). These clots can break free and travel through the blood stream to the brain and cause a stroke. Anticoagulant drugs, such as warfarin, slow blood clotting. The degree of inhibition of blood clotting during warfarin treatment is measured by a blood test called the international normalized ratio (INR). Dosages of warfarin that lead to INRs of 2.0 to 2.6 reduce death and stroke when given to patients with atrial fibrillation. Oral anticoagulants can cause bleeding into the brain and elsewhere. However, provided that there is careful control of dosage (requiring INR measurements at least monthly with warfarin), the risk of serious bleeding is low. The decision about whether or not to use oral anticoagulants in patients with atrial fibrillation is guided by a number of factors, including the individual's risk of stroke, which varies widely among patients with atrial fibrillation. Most people with atrial fibrillation should be considered for treatment with oral anticoagulants based on their risk of stroke, ability to tolerate anticoagulation without bleeding, and access to adequate anticoagulation monitoring.