***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: This r and omised controlled trial used a manikin model of cardiac arrest to compare skill performance in untrained lay persons r and omised to receive either compression-only telephone CPR ( Compression-only tel . , n=29 ) or st and ard telephone CPR instructions ( St and ard tel . , n=30 ) . Performance was evaluated during st and ardised 10 min cardiac arrest simulations using a video recording and data from a laptop computer connected to the training manikin . A number of subjects in both groups did not open the airway . More than 75 % in the St and ard tel . group failed to deliver two effective initial rescue breaths , and only 17 % provided an adequate inflation volume for subsequent breaths , delivering a median of only five inflations during the entire scenario . Most subjects in both groups gave chest compressions that were too shallow and at an inappropriately rapid rate . H and position was also poor , but was worse in the group given simplified instructions . There was a significant delay to first compression in both groups , although this interval was shortened by over a minute when ventilations were eliminated from the telephone instruction algorithm ( 245 vs. 184 s , P<0.001 ) . Over two- and -a-half times as many chest compressions were delivered during an average ambulance response time with compression-only telephone directions compared with st and ard CPR ( 461 vs. 186 , P<0.001 ) . These variables may be critical in predicting survival from out-of-hospital cardiac arrest . Further research is necessary to establish if modifications to scripted telephone instructions can remedy the identified performance deficiencies . Eliminating instructions for rescue breaths from scripted telephone directions will have little impact on the ventilation of most patients . Research is required to determine if the consequent reduction in the delay to starting chest compressions and the significant increase in the number of compressions delivered can increase survival from out-of-hospital cardiac arrest AIM Outcomes from out-of-hospital cardiac arrest ( OHCA ) may improve if rescuers perform chest compressions ( CCs ) deeper than the previous recommendation of 38 - 51 mm and consistent with the 2010 AHA Guideline recommendation of at least 51 mm . The aim of this study was to assess the relationship between CC depth and OHCA survival . METHODS Prospect i ve analysis of CC depth and outcomes in consecutive adult OHCA of presumed cardiac etiology from two EMS agencies participating in comprehensive CPR quality improvement initiatives . ANALYSIS Multivariable logistic regression to calculate adjusted odds ratios ( aORs ) for survival to hospital discharge and favorable functional outcome . RESULTS Among 593 OHCAs , 136 patients ( 22.9 % ) achieved return of spontaneous circulation , 63 patients ( 10.6 % ) survived and 50 had favorable functional outcome ( 8.4 % ) . Mean CC depth was 49.8±11.0 mm and mean CC rate was 113.9±18.1CCmin(-1 ) . Mean depth was significantly deeper in survivors ( 53.6 mm , 95 % CI : 50.5 - 56.7 ) than non-survivors ( 48.8 mm , 95 % CI : 47.6 - 50.0 ) . Each 5 mm increase in mean CC depth significantly increased the odds of survival and survival with favorable functional outcome : aORs were 1.29 ( 95 % CI 1.00 - 1.65 ) and 1.30 ( 95 % CI 1.00 - 1.70 ) respectively . CONCLUSION Deeper chest compressions were associated with improved survival and functional outcome following OHCA . Our results suggest that adhering to the 2010 AHA Guideline -recommended depth of at least 51 mm could improve outcomes for victims of OHCA AIMS To compare quality of CPR during out-of-hospital cardiac arrest with and without automated feedback . MATERIAL S AND METHODS Consecutive adult , out-of-hospital cardiac arrests of all causes were studied . One hundred and seventy-six episodes ( March 2002-October 2003 ) without feedback  were compared to 108 episodes ( October 2003-September 2004 ) where automatic feedback on CPR was given . Automated verbal and visual feedback was based on measured quality with a prototype defibrillator . Quality of CPR was the main outcome measure and survival was reported as specified in the protocol . RESULTS Average compression depth increased from ( mean + /- S.D. ) 34 + /- 9 to 38 + /- 6 mm ( mean difference ( 95 % CI ) 4 ( 2 , 6 ) , P < 0.001 ) , and median percentage of compressions with adequate depth ( 38 - 51 mm ) increased from 24 % to 53 % ( P < 0.001 , Mann-Whitney U-test ) with feedback . Mean compression rate decreased from 121 + /- 18 to 109 + /- 12 min(-1 ) ( difference -12 ( -16 , -9 ) , P = 0.001 ) . There were no changes in the mean number of ventilations per minute ; 11 + /- 5 min(-1 ) versus 11 + /- 4 min(-1 ) ( difference 0 ( -1 , 1 ) , P = 0.8 ) or the fraction of time without chest compressions ; 0.48 + /- 0.18 versus 0.45 + /- 0.17 ( difference -0.03 ( -0.08 , 0.01 ) , P = 0.08 ) . With intention to treat analysis 7/241 control patients were discharged alive ( 2.9 % ) versus 5/117 with feedback ( 4.3 % ) ( OR 1.5 ( 95 % CI ; 0.8 , 3 ) , P = 0.2 ) . In a logistic regression analysis of all cases , witnessed arrest ( OR 4.2 ( 95 % CI ; 1.6 , 11 ) , P = 0.004 ) and average compression depth ( per mm increase ) ( OR 1.05 ( 95 % CI ; 1.01 , 1.09 ) , P = 0.02 ) were associated with rate of hospital admission . CONCLUSIONS Automatic feedback improved CPR quality in this prospect i ve non-r and omised study of out-of-hospital cardiac arrest . Increased compression depth was associated with increased short-term survival . TRIAL REGISTRATION Clinical Trials.gov ( NCT00138996 ) , http://www . clinical BACKGROUND Basic life support ( BLS ) performed by lay rescuers is poor . We developed software for mobile phones augmented with a metronome to improve BLS . STUDY OBJECTIVES To assess BLS in lay rescuers with or without software assistance . METHODS Medically untrained volunteers were r and omized to run through a cardiac arrest scenario with ( " assisted BLS " ) or without ( " non-assisted BLS " ) the aid of a BLS software program installed on a mobile phone . RESULTS Sixty-four lay rescuers were enrolled in the " assisted BLS " and 77 in the " non-assisted BLS " group . The " assisted BLS " when compared to the " non-assisted BLS " group , achieved a higher overall score ( 19.2 ± 7.5 vs. 12.9 ± 5.7 credits ; p < 0.001 ) . Moreover , the " assisted BLS " when compared to the " non-assisted " group checked ( 64 % vs. 27 % ) and protected themselves more often from environmental risks ( 70 % vs. 39 % ) ; this group also called more often for help ( 56 % vs. 27 % ) , opened the upper airway ( 78 % vs. 16 % ) , and had more correct chest compressions rates ( 44 % ± 38 % vs. 14 % ± 28 % ; all p < 0.001 ) . However , the " assisted BLS " when compared to the " non-assisted BLS " group , was slower in calling the dispatch center ( 113.6 ± 86.4 vs. 54.1 ± 45.1 s ; p < 0.001 ) and starting chest compressions ( 165.3 ± 93.3 vs. 87.1 ± 53.2 s ; p < 0.001 ) . CONCLUSIONS " Assisted BLS " augmented by a metronome result ed in a higher overall score and a better chest compression rate when compared to " non-assisted BLS . " However , in the " assisted BLS " group , time to call the dispatch center and to start chest compressions was longer . In both groups , lay persons did not ventilate satisfactorily during this cardiac arrest scenario Objective : Byst and er cardiopulmonary resuscitation ( CPR ) significantly improves survival of cardiac arrest victims . Dispatch assistance increases  byst and er CPR , but the quality of dispatcher-assisted CPR remains unsatisfactory . This study was conducted to assess the effect of adding interactive video communication to dispatch instruction on the quality of byst and er chest compressions  in simulated cardiac arrests . Design : A r and omized controlled study with a scenario developed to simulate cardiac arrest in a public place . Setting : The victim was simulated by a mannequin and the cell phone for dispatch assistance was a video cell phone with both voice and video modes . Chest compression-only CPR instruction was used in the dispatch protocol . Subjects : Ninety-six adults without CPR training within 5 years were recruited . Interventions : The subjects were r and omized to receive dispatch assistance on chest compression with either voice instruction alone ( voice group , n = 53 ) or interactive voice and video demonstration and feedback ( video group , n = 43 ) via a video cell phone . Measurements and Main Results : Performance of chest compression-only CPR throughout the scenario was videotaped . The quality of CPR was evaluated by review ing the videos and mannequin reports . Chest compressions among the video group were faster ( median rate 95.5 vs. 63.0 min−1 , p < 0.01 ) , deeper ( median depth 36.0 vs. 25.0 mm , p < 0.01 ) , and of more appropriate depth ( 20.0 % vs. 0 % , p < 0.01 ) . The video group had more “ h and s-off ” time ( 5.0 vs. 0 second , p < 0.01 ) , longer time to first chest compression ( 145.0 vs. 116.0 seconds , p < 0.01 ) and total instruction time ( 150.0 vs. 121.0 seconds , p < 0.01 ) . Conclusion : The addition of interactive video communication to dispatcher-assisted chest compression-only CPR initially delayed the commencement of chest compressions , but subsequently improved the depth and rate of compressions . The benefit was achieved mainly through real-time feedback Background Byst and er actions and skills determine among others the outcome of out-of-hospital cardiac arrest . However , the depth and rate of chest compressions ( CC ) are difficult to estimate for laypeople and poor CC quality may result . Our study aim ed to evaluate the impact of a new feedback device on CC performance by laypeople . The percentage of CC with both correct rate and correct depth of all CC served as primary endpoint . Methods Forty-eight subjects with no medical background performed 2 min of CC on a manikin with and without a novel feedback device ( TrueCPR ™ , Physio-Control , Redmond , Wash. ) . The device uses a novel , non-accelerometer-based technology . Participants were r and omized into two groups . Group 1 performed a 2-min CC trial first with audiovisual feedback followed by a trial with no feedback information , while group 2 performed the task in reverse order . Results The absolute percentage of CC with correct rate and depth was significantly higher with the use of the device ( 59 ± 34 % vs. 15 ± 21 % , p < 0.0001 ) . The longest interval without correct CC was significantly decreased ( 76.5 s vs. 27.5 s , p < 0.0001 ) . Conclusion The quality of CC carried out by laypeople is significantly improved with the use of a new feedback device . The device may be useful for cardiopulmonary resuscitation ( CPR ) by laypeople and for educational purpose s . ZusammenfassungHintergrundDie praktischen Fähigkeiten von Laienhelfern tragen entscheidend zum Ergebnis ( Outcome ) bei präklinischem Herzstillst and bei . Jedoch sind Kompressionstiefe und -frequenz bei der Herzdruckmassage ( HDM ) für Laien schwierig abzuschätzen , woraus eine unzureichende Qualität der Thoraxkompressionen result ieren kann . Die vorliegende Studie untersuchte den Einfluss eines neuen Feedbackgeräts auf die HDM von Laienhelfern . Primärer Endpunkt war hierbei der Anteil an Thoraxkompressionen mit korrekter Frequenz und Drucktiefe bezogen auf alle Thoraxkompressionen . Method eEs führten 48 Teilnehmer ohne medizinische Ausbildung Thoraxkompressionen an einer Reanimationspuppe mit und ohne Hilfe eines neuen Feedbackgeräts ( TrueCPR ™ , Fa . Physio-Control , Redmond/WA , USA ) durch . Das Gerät benutzt eine neue Technologie ohne Akzelerometer . Die Teilnehmer wurden in 2 Gruppen r and omisiert . Gruppe 1 führte zuerst Thoraxkompressionen über 2 min mit audiovisuellem Feedback durch , i m Anschluss erfolgte ein Durchgang ohne Feedbackinformationen . Gruppe 2 führte die Versuche in umgekehrter Reihenfolge durch . ErgebnisseDie absolute Prozentzahl an Thoraxkompressionen mit richtiger Frequenz und Tiefe war mithilfe des Feedbackgeräts signifikant höher ( 59 ± 34 % vs. 15 ± 21 % ; p < 0 
    Output:
    
Devices providing real-time feedback and mobile devices containing CPR applications or software were also found to be beneficial in improving the quality of byst and er CPR .
However , using mobile devices for improving CPR quality or for assisting DA-CPR might cause rescuers to delay starting CPR .