***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: Introduction Emergency calls to ambulance services are frequent for older people who have fallen , but ambulance crews often leave patients at the scene without ongoing care . Evidence shows that when left at home with no further support older people often experience subsequent falls which result in injury and emergency-department attendances . SAFER 2 is an evaluation of a new clinical protocol which allows paramedics to assess and refer older people who have fallen , and do not need hospital care , to community-based falls services . In this protocol paper , we report methods and progress during trial implementation . SAFER 2 is recruiting patients through three ambulance services . A successful trial will provide robust evidence about the value of this new model of care , and enable ambulance services to use re sources efficiently . Design Pragmatic cluster r and omised trial . Methods and analysis We r and omly allocated 25 participating ambulance stations ( clusters ) in three services to intervention or control group . Intervention paramedics received training and clinical protocol s for assessing and referring  older people who have fallen to community-based falls services when appropriate , while control paramedics deliver care as usual .  Patients are eligible for the trial if they are aged 65 or over ; resident in a participating falls service catchment area ; and attended by a trial paramedic following an emergency call coded as a fall without priority symptoms . The principal outcome is the rate of further emergency contacts ( or death ) , for any cause and for falls . Secondary outcomes include further falls , health-related quality of life , ‘ fear of falling ’ , patient satisfaction reported by participants through postal question naires at 1 and 6 months , and quality and pathways of care at the index incident . We shall compare National Health Service ( NHS ) and patient/carer costs between intervention and control groups and estimate quality -adjusted life years ( QALYs ) gained from the intervention and thus incremental cost per QALY . We shall estimate wider system effects on key-performance indicators . We shall interview 60 intervention patients , and conduct focus groups with contributing NHS staff to explore their experiences of the assessment and referral service . We shall analyse quantitative trial data by ‘ treatment allocated ’ ; and qualitative data using content analysis . Ethics and dissemination The Research Ethics Committee for Wales gave ethical approval and each participating centre gave NHS Research and Development approval . We shall disseminate study findings through peer- review ed publications and conference presentations . Trial Registration : IS RCT N AIMS To investigate the feasibility of delivering titrated oxygen therapy to adults with return of spontaneous circulation ( ROSC ) following out-of-hospital cardiac arrest ( OHCA ) caused by ventricular fibrillation ( VF ) or ventricular tachycardia ( VT ) . METHODS We used a multicentre , r and omised , single blind , parallel groups design to compare titrated and st and ard oxygen therapy in adults resuscitated from VF/VT OHCA . The intervention commenced in the community following ROSC and was maintained in the emergency department and the Intensive Care Unit . The primary end point was the median oxygen saturation by pulse oximetry ( SpO2 ) in the pre-hospital period . RESULTS 159 OHCA patients were screened and 18 were r and omised . 17 participants were analysed : nine in the st and ard care group and eight in the titrated oxygen group . In the pre-hospital period , SpO2 measurements were lower in the titrated oxygen therapy group than the st and ard care group ( difference in medians 11.3 % ; 95 % CI 1.0 - 20.5 % ) . Low measured oxygen saturation ( SpO2<88 % ) occurred in 7/8 of patients in the titrated oxygen group and 3/9 of patients in the st and ard care group ( P=0.05 ) . Following hospital admission , good separation of oxygen exposure between the groups was achieved without a significant increase in hypoxia events . The trial was terminated because accumulated data led the Data Safety Monitoring Board and Management Committee to conclude that safe delivery of titrated oxygen therapy in the pre-hospital period was not feasible . CONCLUSIONS Titration of oxygen in the pre-hospital period following OHCA was not feasible ; it may be feasible to titrate oxygen safely after arrival in hospital AIM To determine whether in patients with an ambulance response time of > 5min who were in VF cardiac arrest , 3min of CPR before the first defibrillation was more effective than immediate defibrillation in improving survival to hospital discharge . METHODS This r and omised control trial was run by the South Australian Ambulance Service between 1 July , 2005 , and 31 July , 2007 . Patients in VF arrest were eligible for r and omisation . Exclusion criteria were : ( i ) < 18 years of age , ( ii ) traumatic arrest , ( iii ) paramedic witnessed arrest , ( iv ) advanced life support performed before arrival of paramedics and ( v ) not for resuscitation order or similar directive . The primary outcome was survival to hospital discharge with secondary outcomes being neurological status at discharge , the rate of return of spontaneous circulation ( ROSC ) and the time from first defibrillation to ROSC . RESULTS For all response times , no differences were observed between the immediate defibrillation group and the CPR first group in survival to hospital discharge ( 17.1 % [ 18/105 ] vs. 10.3 % [ 10/97 ] ; P=0.16 ) , the rate of ROSC ( 53.3 % [ 56/105 ] vs. 50.5 % [ 49/97 ] ; P=0.69 ) or the time from the first defibrillation to ROSC ( 12:37 vs. 11:19 ; P=0.49 ) . There were also no differences between the immediate defibrillation group and the CPR first group , for response times of < or = or > 5min : survival to hospital discharge ( 50.0 % [ 7/14 ] vs. 25.0 % [ 4/16 ] ; P=0.16 or 12.1 % [ 11/91 ] vs.7.4 % [ 6/81 ] ; P=0.31 , respectively ) and the rate of ROSC ( 71.4 % [ 10/14 ] vs. 75.0 % [ 12/16 ] ; P=0.83 or 50.5 % [ 46/91 ] vs. 45.7 % [ 37/81 ] ; P=0.54 , respectively ) . No differences were observed in the neurological status of those surviving to hospital discharge . CONCLUSION For patient in out-of-hospital VF cardiac arrest we found no evidence to support the use of 3min of CPR before the first defibrillation over the accepted practice of immediate defibrillation Background The utility of advanced prehospital interventions for severe blunt traumatic brain injury ( BTI ) remains controversial . Of all trauma patient subgroups it has been anticipated that this patient group would most benefit from advanced prehospital interventions as hypoxia and hypotension have been demonstrated to be associated with poor outcomes and these factors may be amenable to prehospital intervention . Supporting evidence is largely lacking however . In particular the efficacy of early anaesthesia/muscle relaxant assisted intubation has proved difficult to substantiate . Methods This article describes the design and protocol of the Head Injury Retrieval Trial ( HIRT ) which is a r and omised controlled single centre trial of physician prehospital care ( delivering advanced interventions such as rapid sequence intubation and blood transfusion ) in addition to paramedic care for severe blunt TBI  compared with paramedic care alone . Results Primary endpoint is Glasgow Outcome Scale score at six months post injury . Issues with trial integrity result ing from drop ins from st and ard care to the treatment arm as the result of policy changes by the local ambulance system are discussed . Conclusion This r and omised controlled trial will contribute to the evaluation of the efficacy of advance prehospital interventions in severe blunt TBI.Trial Registration Clinical Trials.gov : Background Advanced prehospital interventions for severe brain injury remains controversial . No previous r and omised trial has been conducted to evaluate additional physician intervention compared with paramedic only care . Methods Participants in this prospect i ve , r and omised controlled trial were adult patients with blunt trauma with either a scene GCS score < 9 ( original definition ) , or GCS<13 and an Abbreviated Injury Scale score for the head region ≥3 ( modified definition ) . Patients were r and omised to either st and ard ground paramedic treatment or st and ard treatment plus a physician arriving by helicopter .  Patients were evaluated by 30-day mortality and 6-month Glasgow Outcome Scale ( GOS ) scores . Due to high non-compliance rates , both intention-to-treat and as-treated analyses were preplanned . Results 375 patients met the original definition , of which 197 was allocated to physician care . Differences in the 6-month GOS scores were not significant on intention-to-treat analysis ( OR 1.11 , 95 % CI 0.74 to 1.66 , p=0.62 ) nor was the 30-day mortality ( OR 0.91 , 95 % CI 0.60 to 1.38 , p=0.66 ) . As-treated analysis showed a 16 % reduction in 30-day mortality in those receiving additional physician care ; 60/195 ( 29 % ) versus 81/180 ( 45 % ) , p<0.01 , Number needed to treat = 6 . 338 patients met the modified definition , of which 182 were allocated to physician care . The 6-month GOS scores were not significantly different on intention-to-treat analysis ( OR 1.14 , 95 % CI 0.73 to 1.75 , p=0.56 ) nor was the 30-day mortality ( OR 1.05 , 95 % CI 0.66 to 1.66 , p=0.84 ) . As-treated analyses were also not significantly different . Conclusions This trial suggests a potential mortality reduction in patients with blunt trauma with GCS<9 receiving additional physician care ( original definition only ) . Confirmatory studies which also address non-compliance issues are needed . Trial registration number NCT00112398 IMPORTANCE A strategy using mechanical chest compressions might improve the poor outcome in out-of-hospital cardiac arrest , but such a strategy has not been tested in large clinical trials . OBJECTIVE To determine whether administering mechanical chest compressions with defibrillation during ongoing compressions ( mechanical CPR ) , compared with manual cardiopulmonary resuscitation ( manual CPR ) , according to guidelines , would improve 4-hour survival . DESIGN , SETTING , AND PARTICIPANTS Multicenter r and omized clinical trial of 2589 patients with out-of-hospital cardiac arrest conducted between January 2008 and February 2013 in 4 Swedish , 1 British , and 1 Dutch ambulance services and their referring hospitals . Duration of follow-up was 6 months . INTERVENTIONS Patients were r and omized to receive either mechanical chest compressions ( LUCAS Chest Compression System , Physio-Control/Jolife AB ) combined with defibrillation during ongoing compressions ( n = 1300 ) or to manual CPR according to guidelines ( n = 1289 ) . MAIN OUTCOMES AND MEASURES Four-hour survival , with secondary end points of survival up to 6 months with good neurological outcome using the Cerebral Performance Category ( CPC ) score . A CPC score of 1 or 2 was classified as a good outcome . RESULTS Four-hour survival was achieved in 307 patients ( 23.6 % ) with mechanical CPR and 305 ( 23.7 % ) with manual CPR ( risk difference , -0.05 % ; 95 % CI , -3.3 % to 3.2 % ; P > .99 ) . Survival with a CPC score of 1 or 2 occurred in 98 ( 7.5 % ) vs 82 ( 6.4 % ) ( risk difference , 1.18 % ; 95 % CI , -0.78 % to 3.1 % ) at intensive care unit discharge , in 108 ( 8.3 % ) vs 100 ( 7.8 % ) ( risk difference , 0.55 % ; 95 % CI , -1.5 % to 2.6 % ) at hospital discharge , in 105 ( 8.1 % ) vs 94 ( 7.3 % ) ( risk difference , 0.78 % ; 95 % CI , -1.3 % to 2.8 % ) at 1 month , and in 110 ( 8.5 % ) vs 98 ( 7.6 % ) ( risk difference , 0.86 % ; 95 % CI , -1.2 % to 3.0 % ) at 6 months with mechanical CPR and manual CPR , respectively . Among patients surviving at 6 months , 99 % in the mechanical CPR group and 94 % in the manual CPR group had CPC scores of 1 or 2 . CONCLUSIONS AND RELEVANCE Among adults with out-of-hospital cardiac arrest , there was no significant difference in 4-hour survival between patients treated with the mechanical CPR algorithm or those treated with guideline -adherent manual CPR . The vast majority of survivors in both groups had good neurological outcomes by 6 months . In clinical practice , mechanical CPR using the presented algorithm did not result in improved effectiveness compared with manual CPR . TRIAL REGISTRATION clinical trials.gov Identifier : NCT00609778 Background There is little in-depth research into how patients feel about  emergency medical trials  , and what influences these feelings . Objectives To investigate patients ’ feelings on taking part in  emergency medical research , particularly tri 
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Issues relating to consent were the most significant theme identified .
Type of consent differed depending on the condition or intervention being studied .
The country in which the research took place did not appear to influence the type of consent , apart from the USA where exception from consent appeared to be most commonly used .
A wide range of terms were used to describe consent .
Conclusions Consent was the main ethical consideration in published ambulance based research .
A range of consent models were used ranging from informed consent to exception from consent ( waiver of consent ) .