***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Perioperative anemia leads to increased morbidity and mortality and potentially inhibits rehabilitation after hip fracture surgery . As such , the optimum transfusion threshold after hip fracture surgery is unknown . PATIENTS AND METHODS A total of 120 elderly , cognitively intact hip fracture patients admitted from their own home were r and omly assigned to receive transfusion at a hemoglobin threshold of 10.0 g per dL ( liberal ) versus 8.0 g per dL ( restrictive ) in the entire perioperative period . Patients were treated according to a well-defined multimodal rehabilitation program . Primary outcome was postoperative functional mobility measured with the cumulated ambulation score ( CAS ) . RESULTS Patients in the liberal group received transfusions more frequently than those in the restrictive group ( 44 patients vs. 22 patients ; p < 0.01 ) and received more transfusions during hospitalization ( median , 2 units [ interquartile range , 1 - 2 ] vs. 1 [ 1 - 2 ] ; p < 0.0001 ) . There were no significant differences in postoperative rehabilitation scores ( CAS : median , 9 [ 9 - 15 ] vs. 9 [ 9 - 13.5 ] ; p = 0.46 ) or in length of stay ( median , 18 days vs. 16 days , respectively ; p = 0.46 ) . There were fewer patients in the liberal transfusion group with cardiovascular complications ( 2 % vs. 10 % ; p = 0.05 ) and a lower mortality ( 0 % vs. 8 % ; p = 0.02 ) . CONCLUSION Although a liberal transfusion trigger did not result in increased ambulation scores , restrictive transfusion thresholds should be treated with caution in elderly high-risk hip fracture patients , until their safety has been proved in larger r and omized studies Objective : To determine the effect of admission hemoglobin level on patient outcome after hip fracture . Study Design : Prospect i ve , consecutive . Patients : From July 1991 to June 1997 , 395 communitydwelling patients sixty‐five years of age or older who had sustained an operatively treated femoral neck or intertrochanteric fracture were prospect ively followed up . Main Outcome Measurements : Postoperative complications , in‐hospital mortality rate , hospital length of stay , hospital discharge status , place of residence at one year , and mortality and recovery of ambulatory ability and activities of daily living status at three , six , and twelve months . Results : Women with admission hemoglobin levels below 12.0 grams per deciliter and men with admission hemoglobin levels below 13.0 grams per deciliter were classified as anemic . One hundred eighty patients ( 45.6 percent ) were considered anemic on admission . Patients who were anemic were more likely to have an American Society of Anesthesiologists rating of III or IV and have sustained an intertrochanteric fracture . Hospital length of stay and mortality rate at six and twelve months were significantly higher for patients who were anemic on admission . There were no differences in the incidence of postoperative complications , hospital discharge status , place of residence at one year , in‐hospital mortality rate , and three‐month mortality rate between patients who were and were not anemic on admission . In addition , there were no differences in the recovery of ambulatory ability and of basic and instrumental activities of daily living status at three , six , and twelve months between the two patient groups . Conclusions : Patients at risk for poor outcomes after hip fracture can be identified by assessing hemoglobin levels at hospital admission Background Anemia is more often seen in older patients . As the mean age of hip fracture patients is rising , anemia is common in this population . Allogeneic blood transfusion ( ABT ) and anemia have been pointed out as possible risk factors for poorer outcome in hip fracture patients . Methods In the timeframe 2005 - 2010 , 1262 admissions for surgical treatment of a hip fracture in patients aged 65 years and older were recorded . Registration was prospect i ve from 2008 on . Anemic and non-anemic patients ( based on hemoglobin level at admission ) were compared regarding clinical characteristics , mortality , delirium incidence , LOS , discharge to a nursing home and the 90-day readmission rate . Receiving an ABT , age , gender , ASA classification , type of fracture and anesthesia were used as possible confounders in multivariable regression analysis . Results The prevalence of anemia and the rate of ABT both were 42.5 % . Anemic patients were more likely to be older and men and had more often a trochanteric fracture , a higher ASA score and received more often an ABT . In univariate analysis , the 3- and 12-month mortality rate , delirium incidence and discharge to a nursing home rate were significantly worse in preoperatively anemic patients .In multivariable regression analysis , anemia at admission was a significant risk factor for discharge to a nursing home and readmission < 90 days , but not for mortality . Indication for ABT , age and ASA classification were independent risk factors for mortality at all moments , only the mortality rate for the 3 - 12 month interval was not influenced by ABT . An indication for an  ABT  was the largest negative contributor to a longer LOS ( OR 2.26 , 95 % CI 1.73 - 2.94 ) and the second largest for delirium ( OR 1.67 , 95 % CI 1.28 - 2.20 ) . Conclusions This study has demonstrated that anemia at admission and postoperative anemia needing an ABT ( PANT ) were independent risk factors for worse outcome in hip fracture patients . In multivariable regression analysis , anemia as such had no effect on mortality , due to a rescue effect of PANT . In-hospital , 3- and 12-month mortality was negatively affected by PANT , with the main effect in the first 3 months postoperatively BACKGROUND Patients undergoing pertrochanteric hip fracture ( PHF ) repair surgery often receive perioperative allogeneic blood transfusions ( ABTs ) to avoid the deleterious effects of anemia . Nevertheless , concerns about adverse effects of ABTs have prompted the review of transfusion practice and the search for a safer treatment of perioperative anemia . MATERIAL AND METHODS The effect of preoperative 200 to 300 mg of intravenous ( IV ; Group 2 ; n = 55 ) iron sucrose administration on transfusion requirements and postoperative morbidity-mortality in patients with PHF has been prospect ively investigated . A previous series of 102 PHF patients served as the control group ( Group 1 ) . All patients were older than 65 years and were operated on at the third day after admission to the hospital , by the same medical team and with the same implant . RESULTS Iron sucrose was well tolerated and reduced the transfusion rate in patients with admission hemoglobin levels of greater than 120 g per L ( p < 0.05 ) who also received fewer units of red blood cells ( p < 0.05 ) . In addition , iron sucrose reduced postoperative infection rate ( p < 0.05 ) , but not 30-day mortality rate or mean length of hospital stay . CONCLUSION The administration of IV iron sucrose seems to reduce ABT requirements in patients with PHF and is associated to lower postoperative morbidity . The possible mechanisms involved in these effects are discussed BACKGROUND Retrospective studies suggest that preoperative anaemia is associated with poor outcomes after surgery . The objective of this study was to describe mortality rates and patterns of intensive care re source use for patients with anaemia undergoing non-cardiac and non-neurological in-patient surgery . METHODS We performed a secondary analysis of a large prospect i ve study describing perioperative care and survival in 28 European nations . Patients at least 16 yr old undergoing in-patient surgery during a 7 day period were included in the study . Data were collected for in-hospital mortality , duration of hospital stay , admission to intensive care , and intensive care re source use .  Multivariable logistic regression analysis was performed to underst and the effects of preoperative haemoglobin ( Hb ) levels on in-hospital mortality . RESULTS We included 39 309 patients in the analysis . Preoperative anaemia had a high prevalence in both men and women ( 31.1 % and 26.5 % , respectively ) . Multivariate analysis showed that patients with severe [ odds ratio 2.82 ( 95 % confidence interval 2.06 - 3.85 ) ] or moderate [ 1.99 ( 1.67 - 2.37 ) ] anaemia had higher in-hospital mortality than those with normal preoperative Hb concentrations . Furthermore , hospital length of stay ( P<0.001 ) and postoperative admission to intensive care ( P<0.001 ) were greater in patients with anaemia than in those with normal Hb concentrations . CONCLUSIONS Anaemia is common among non-cardiac and non-neurological surgical patients , and is associated with poor clinical outcome and increased healthcare re source use . CLINICAL TRIAL REGISTRATION NCT01203605 ( Clinical Trials.gov ) Context : Pharmacological agents are used to reduce postoperative blood loss . Aims : To assess the effects of tranexamic acid on prevention of bleeding and requirement of blood transfusion after major hip and femoral surgeries . Setting s and Design : A prospect i ve , r and omized , double blinded study was conducted in the tertiary care teaching hospital . Methods : Ninety ASA grade I-II patients undergoing hip fracture surgery were included in this prospect i ve study . Forty-five patients received tranexamic acid ( TA ) given in a bolus dose of 500 mg 15 min before surgical incision followed by continuous infusion . The remaining , 45 patients were allocated as a control group . Postoperative bleeding ( volume of blood in the drain ) , percentage fall of hemoglobin , transfusions and complications were recorded . Results : Mean volume of blood in the drain was 39.33±10.09 ml ( mean±SD ) as compared to 91.11±17.61 ml in placebo group showing a P<0.001 . Mean percentage fall in Hb at day 0 was 2.99±3.45 in the study group as compared to 7.70±6.05 in the placebo group ( P<0.001 ) , and fall at day 2 in the study group was 0.35±0.74 , compared to 2.72±2.70 in the placebo group ( P<0.001 ) . The number of patients required blood transfusions were lower in the study group than in the placebo group ( P=0.01 ) . Conclusions : We conclude that tranexamic acid significantly reduces postoperative blood loss and transfusion requirements during major hip and femoral surgeries BACKGROUND The hemoglobin threshold at which postoperative red-cell transfusion is warranted is controversial . We conducted a r and omized trial to determine whether a higher threshold for blood transfusion would improve recovery in patients who had undergone surgery for hip fracture . METHODS We enrolled 2016 patients who were 50 years of age or older , who had either a history of or risk factors for cardiovascular disease , and whose hemoglobin level was below 10 g per deciliter after hip-fracture surgery . We r and omly assigned patients to a liberal transfusion strategy ( a hemoglobin threshold of 10 g per deciliter ) or a restrictive transfusion strategy ( symptoms of anemia or at physician discretion for a hemoglobin level of < 8 g per deciliter ) . The primary outcome was death or an inability to walk across a room without human assistance on 60-day follow-up . RESULTS A median of 2 units of red cells were transfused in the liberal- strategy group and none in the restrictive- strategy group . The rates of the primary outcome were 35.2 % in the liberal- strategy group and 34.7 % in the restrictive- strategy group ( odds ratio in the liberal- strategy group , 1.01 ; 95 % confidence interval [ CI ] , 0.84 to 1.22 ) , for an absolute risk difference of 0.5 percentage points ( 95 % CI , -3.7 to 4.7 ) . The rates of in-hospital acute coronary syndrome or death were 4.3 % and 5.2 % , respectively ( absolute risk difference , -0.9 % ; 99 % CI , -3.3 to 1.6 ) , and rates of death on 60-day follow-up were 7.6 % and 6.6 % , respectively ( absolute risk difference , 1.0 % ; 99 % CI , -1.9 to 4.0 ) . The rates of other complications were similar in the two groups . CONCLUSIONS A liberal transfusion strategy , as compared with a restrictive strategy , did not reduce rates of death or inability to walk independently on 60-day follow-up or reduce in-hospital morbidity in elderly patients at high cardiovascular risk . ( Funded by the National Heart , Lung , and Blood Institute ; FOCUS Clinical Trials.gov number , NCT00071032 . ) Background Around one third to one half of patients with hip fractures require red-cell pack transfusion . The increasing incidence of hip fracture has also raised the need for this scarce re source . Additionally , red-cell pack transfusions are not without complications which may involve excessive morbidity and mortality . This makes it necessary to develop blood-saving strategies . Our objective was to assess safety , efficacy , and cost-effictveness of combined treatment of i. 
    Output:
    
Transfusion threshold was not associated with differences in other outcomes .
Studies for most interventions recruited too few participants to determine effects on infections , mortality or function