***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: Nineteen randomised trials on banding ligation versus non-selective beta-blockers for primary prevention in oesophageal varices were included. Most trials specified that only patients with large or high-risk oesophageal varices were included. Bias control was unclear in most trials. In total, 176 of 731 (24%) of the patients randomised to banding ligation and 177 of 773 (23%) of patients randomised to non-selective beta-blockers died. The difference was not statistically significant in a random-effects meta-analysis (RR 1.09; 95% CI 0.92 to 1.30; I2 = 0%). There was no evidence of bias or small study effects in regression analysis (Egger's test P = 0.997). Trial sequential analysis showed that the heterogeneity-adjusted low-bias trial relative risk estimate required an information size of 3211 patients, that none of the interventions showed superiority, and that the limits of futility have not been reached. When all trials were included, banding ligation reduced upper gastrointestinal bleeding and variceal bleeding compared with non-selective beta-blockers (RR 0.69; 95% CI 0.52 to 0.91; I2 = 19% and RR 0.67; 95% CI 0.46 to 0.98; I2 = 31% respectively). The beneficial effect of banding ligation on bleeding was not confirmed in subgroup analyses of trials with adequate randomisation or full paper articles. Bleeding-related mortality was not different in the two intervention arms (29/567 (5.1%) versus 37/585 (6.3%); RR 0.85; 95% CI 0.53 to 1.39; I2 = 0%). Both interventions were associated with adverse events. This review found a beneficial effect of banding ligation on primary prevention of upper gastrointestinal bleeding in patient with oesophageal varices. The effect on bleeding did not reduce mortality. Additional evidence is needed to determine whether our results reflect that non-selective beta-blockers have other beneficial effects than on bleeding.
Output:

This review includes 19 randomised trials on banding ligation versus beta-blockers for patients with high-risk oesophageal varices and no history of bleeding. Bias control was unclear in most trials. There was no difference in mortality among the patients randomised to banding ligation compared with beta-blockers. The trials with adequate bias control based on the assessment of randomisation methods found no difference in bleeding rates. The trials with unclear randomisation methods found that banding ligation reduced bleeding. The effect of banding ligation was associated with the duration of follow-up and publication status of the trials. The results of trials with less than 20 months of follow-up found a better effect of banding ligation compared to trials with longer follow-up. Trials published in abstract form were more positive towards the effect of banding ligation than trials published as full paper articles. The combined evidence suggests that banding ligation and beta-blockers may be used as primary prophylaxis in oesophageal varices in adult patients. Additional evidence from trials with adequate bias control and sufficient follow-up is still needed to determine long-term effects.