human
***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 Patients with the sleep apnoea/hypopnoea syndrome ( SAHS ) report improved sleepiness , cognitive function , and psychological well being after continuous positive airway pressure ( CPAP ) therapy , and it is for these daytime features that CPAP is usually given . However , few r and omised or controlled studies exist on the effects of CPAP on daytime function . METHODS A prospect i ve , r and omised , single blind , placebo controlled , crossover trial of daytime function after CPAP was conducted in 23 patients with SAHS , all with ⩾15 apnoeas+hypopnoeas/hour and ⩾2 symptoms of SAHS . All patients spent four weeks on CPAP therapy and four weeks on oral placebo treatment , following r and omisation to treatment order . With ethics committee approval , patients were told the placebo tablet might improve upper airway function . Average effective CPAP use was monitored using hidden time clocks . Assessment s of objective and subjective sleepiness , symptoms , cognitive performance , and psychological well being were performed on the last day of each treatment and compared . RESULTS Objective sleepiness measured by sleep onset latency on the multiple sleep latency test improved with CPAP ( mean difference from placebo + 2.4 min , 95 % CI 0.8 to 4.0 ; p<0.001 ) as did subjective sleepiness on the Epworth scale ( mean difference –6 , 95 % CI –3 to –9 ; p = 0.001 ) . Symptom total score also fell with CPAP ( mean difference –1.6 , 95 % CI –2.2 to –1.0 ; p<0.001 ) . No determinants of these changes with active treatment were identified , and no significant enhancements to cognitive function or psychosocial well being were found in this small sample . CONCLUSIONS These findings provide further evidence for clinical ly significant benefits to daytime function  from CPAP BACKGROUND Limited data have suggested that sleep-disordered breathing , a condition of repeated episodes of apnea and hypopnea during sleep , is prevalent among adults . Data from the Wisconsin Sleep Cohort Study , a longitudinal study of the natural history of cardiopulmonary disorders of sleep , were used to estimate the prevalence of undiagnosed sleep-disordered breathing among adults and address its importance to the public health . METHODS A r and om sample of 602 employed men and women 30 to 60 years old were studied by overnight polysomnography to determine the frequency of episodes of apnea and hypopnea per hour of sleep ( the apnea-hypopnea score ) . We measured the age- and sex-specific prevalence of sleep-disordered breathing in this group using three cutoff points for the apnea-hypopnea score ( > or = 5 , > or = 10 , and > or = 15 ) ; we used logistic regression to investigate risk factors . RESULTS The estimated prevalence of sleep-disordered breathing , defined as an apnea-hypopnea score of 5 or higher , was 9 percent for women and 24 percent for men . We estimated that 2 percent of women and 4 percent of men in the middle-aged work force meet the minimal diagnostic criteria for the sleep apnea syndrome ( an apnea-hypopnea score of 5 or higher and daytime hypersomnolence ) . Male sex and obesity were strongly associated with the presence of sleep-disordered breathing . Habitual snorers , both men and women , tended to have a higher prevalence of apnea-hypopnea scores of 15 or higher . CONCLUSIONS The prevalence of undiagnosed sleep-disordered breathing is high among men and is much higher than previously suspected among women . Undiagnosed sleep-disordered breathing is associated with daytime hypersomnolence A comparison is made between the end-tidal fractional concentration of carbon dioxide ( FETCO2 ) obtained during application of varying levels of continuous positive airway pressure ( CPAP ) with a prototype mask ( from Carburos Metálicos ) and FETCO2 obtained with 2 commonly used nasal masks ( Profile Lite and ComfortClassic from Respironics ) . The nasal FETCO2 was measured on 3 consecutive days in 11 healthy volunteers , 12 patients with severe obstructive sleep apnea-hypopnea syndrome , and 12 hypercapnic patients . A different mask was r and omly assigned on each day and the FETCO2 was measured after 3 minutes of CPAP at 4 , 5 , 6 , 8 , 10 , 15 , and 20 cm H2O . Although in all cases a progressive reduction in FETCO2 was observed with increasing CPAP , the effect was greatest with the prototype mask at all pressures . In the 3 different study groups the pressures obtained with the prototype mask were similar to those generated by the CPAP machine . In conclusion , the lower concentration of nasal CO2 obtained using the prototype mask suggests that it causes less rebreathing BACKGROUND Nasal continuous positive airway pressure ( NCPAP ) is widely used as a treatment for obstructive sleep apnoea . However , to date there are no r and omised controlled trials of this therapy against a well-matched control . We undertook a r and omised prospect i ve parallel trial of therapeutic NCPAP for obstructive sleep apnoea compared with a control group on subtherapeutic NCPAP . METHODS Men with obstructive sleep apnoea , defined as an Epworth sleepiness score of 10 or more and ten or more dips per h of more than 4 % SaO2 caused by obstructive sleep apnoea on overnight sleep study , were r and omly assigned therapeutic NCPAP or subtherapeutic NCPAP ( about 1 cm H2O ) for 1 month . Primary outcomes were subjective sleepiness ( Epworth sleepiness score ) , objective sleepiness ( maintenance of wakefulness test ) , and SF-36 question naire measurements of self-reported functioning and well-being . FINDINGS 107 men entered the study : 53 received subtherapeutic NCPAP and 54 therapeutic NCPAP . Use of NCPAP by the two treatment groups was similar : 5.4 h ( therapeutic ) and 4.6 h ( subtherapeutic ) per night . Subtherapeutic NCPAP did not alter the overnight number of SaO2 dips per h compared with baseline , and thus acted as a control . Therapeutic NCPAP was superior to subtherapeutic NCPAP in all primary outcome measures . The Epworth score was decreased from a median of 15.5 to 7.0 on therapeutic NCPAP , and from 15.0 to 13.0 on subtherapeutic NCPAP ( between treatments , p<0.0001 ) . Mean maintenance-of-wakefulness time increased from 22.5 to 32.9 min on therapeutic NCPAP and , not significantly , from 20.0 to 23.5 min on subtherapeutic NCPAP ( between treatments p<0.005 ) . Effect sizes for SF-36 measures of energy and vitality were 1.68 ( therapeutic ) and 0.97 ( subtherapeutic ) NCPAP ( between treatments p<0.0001 ) . For mental summary score , the corresponding values were 1.02 and 0.4 ( between treatments p=0.002 ) . INTERPRETATION Therapeutic NCPAP reduces excessive daytime sleepiness and improves self-reported health status compared with a subtherapeutic control . Compared with controls , the effects of therapeutic NCPAP are large and confirm previous uncontrolled clinical observations and the results of controlled trials that used an oral placebo This study was undertaken to determine the efficacy of nasal mask ( NM ) versus full face mask ( FFM ) for the delivery of noninvasive ventilation ( NIV ) in subjects with nocturnal hypoventilation . A total of 16 patients ( 11 males ) were enrolled , all with nocturnal hypoventilation currently treated at home with NIV via pressure preset devices . Subjects underwent full polysomnography on three occasions ; on the first night current therapy on NM was review ed , followed by two experimental studies in r and omised order using either NM or FFM . NIV setting s and oxygen flow rate were the same under both conditions . Notably , 14 of the 16 subjects required the use of a chinstrap to minimise oral leak . Apnoea-hypopnoea indices were within normal limits under both conditions ( 1.7±3.4 NM versus 1.6±2.4 h FFM ) . The type of interface did not significantly affect gas exchange during sleep ( minimum average arterial oxyhaemoglobin saturation total sleep time 93.4±2.1 NM versus 92.8±2.5 % FFM , Delta transcutaneous carbon dioxide nonrapid eye movement sleep to rapid eye movement sleep ( 0.58±0.36 NM versus 0.50±0.40 kPa FFM ) . Sleep efficiency was significantly reduced on the FFM ( 78±9 NM versus 70±14 % FFM ) , although arousal indices were comparable under both conditions ( 15.6±9.8 NM versus 15.8±8.8 h FFM ) . Full face masks appear to be as effective as nasal masks in the delivery of noninvasive ventilation to patients with nocturnal hypoventilation . However , a chinstrap was required to reduce oral leak in the majority of subjects using the nasal mask To investigate the association between sleep apnea syndrome ( SAS ) and automobile accidents , and to evaluate potential underlying mechanisms , we prospect ively recruited 60 consecutive patients with SAS ( apnea-hypopnea index , 58 + /- 3 h-1 ) and 60 healthy control subjects , matched for sex and age . The number of automobile accidents during the past 3 yr was obtained from participants and insurance companies . We quantified the degree of daytime sleepiness ( Epworth scale ) , anxiety and depression ( Beck tests ) , and we assessed the level of vigilance ( PVT 192 ) and driving performance ( Steer-Clear ) . Patients had more accidents than control subjects ( OR : 2.3 ; 95 % CI : 0.97 to 5.33 ) and were more likely to have had more than one accident ( OR : 5.2 ; 95 % CI : 1.07 to 25.29 , p < 0.05 ) . These differences persisted after stratification for km/yr , age , and alcohol consumption . Patients were more somnolent , anxious , and depressed than control subjects ( p < 0.01 ) , and they had a lower level of vigilance and poorer driving performance ( p < 0.01 ) . Yet , we did not find any correlation between the degree of daytime sleepiness , anxiety , depression , the number of respiratory events , nocturnal hypoxemia , level of vigilance , or driving simulator performance and the risk of automobile accidents among SAS patients . In conclusion , patients with SAS have an increased risk of automobile accidents . None of the clinical or physiological markers commonly used to define disease severity appear able to discriminate those patients at higher risk of having an automobile accident OBJECTIVE To compare efficacy , compliance rates , and side effects of a new strapless oral interface , the Oracle , with available nasal masks over 8 weeks of use for the treatment of obstructive sleep apnea hypopnea syndrome ( OSAHS ) . METHODS A total of 38 patients with OSAHS ( respiratory disturbance index ( RDI ) > /=15/h ) were enrolled after the diagnostic polysomnogram for subsequent continuous positive airway pressure ( CPAP ) therapy .  After r and omization , therapeutic pressures during a titration study were determined for 21 patients in the oral group and 17 patients in the nasal group . Comparisons for nasal and oral interfaces were made for baseline patient characteristics , average hours of CPAP use , side effects from therapy , and among question naires evaluating patients ' subjective responses to therapy at months 1 and 2 . RESULTS No significant difference was observed in the average hours of CPAP use between the oral ( 4.5+/-2.1 ; 5.5+/-2.6 ) and nasal groups ( 4.0+/-2.6 ; 4.8+/-2.5 ) for either month 1 or 2 ( P>0.05 ) . The dropout rates were similar for both groups after 8 weeks of therapy . However , patients in the nasal group had higher occurrences of side effects such as nasal congestion , dryness , and air leaks , whereas patients in the oral group experienced more oral dryness and gum pain . CONCLUSION Oral delivery of CPAP with the Oracle is an effective and suitable alternative for patients with OSAHS The minimal disease severity at which patients with the sleep apnea/hypopnea syndrome ( SAHS ) gain benefit from treatment is not well characterized , although a pilot study of continuous positive airway pressure ( CPAP ) therapy showed daytime improvements in patients with 5 to 15 apneas + hypopneas per hour slept ( AHI ) . We have thus performed a second , larger , r and omized , placebo- controlled study in a prospect i ve series of 34 patients ( 13 female ) with mild SAHS ( AHI 5 to 15 ) and daytime sleepiness . Patients spent 4 wk on CPAP treatment and 4 wk on an oral placebo , with r and omization of treatment order , and daytime assessment s on the last day of each treatment . Effective  CPAP  use averaged 2.8 + /- 2.1 h ( mean + /- SD ) per night . Compared with placebo , CPAP improved symptom score ( p < 0.01 ) , subjective ( Epworth ; p < 0.01 ) but not objective ( maintenance of wakefulness test ; p > 0.2 ) sleepiness , performances on 2 of 7 cognitive tasks ( p < 0.02 ) , depression score ( p < 0.01 ) , and five subscales of the SF-36 
    Output:
    
agent
***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 Patients with the sleep apnoea/hypopnoea syndrome ( SAHS ) report improved sleepiness , cognitive function , and psychological well being after continuous positive airway pressure ( CPAP ) therapy , and it is for these daytime features that CPAP is usually given . However , few r and omised or controlled studies exist on the effects of CPAP on daytime function . METHODS A prospect i ve , r and omised , single blind , placebo controlled , crossover trial of daytime function after CPAP was conducted in 23 patients with SAHS , all with ⩾15 apnoeas+hypopnoeas/hour and ⩾2 symptoms of SAHS . All patients spent four weeks on CPAP therapy and four weeks on oral placebo treatment , following r and omisation to treatment order . With ethics committee approval , patients were told the placebo tablet might improve upper airway function . Average effective CPAP use was monitored using hidden time clocks . Assessment s of objective and subjective sleepiness , symptoms , cognitive performance , and psychological well being were performed on the last day of each treatment and compared . RESULTS Objective sleepiness measured by sleep onset latency on the multiple sleep latency test improved with CPAP ( mean difference from placebo + 2.4 min , 95 % CI 0.8 to 4.0 ; p<0.001 ) as did subjective sleepiness on the Epworth scale ( mean difference –6 , 95 % CI –3 to –9 ; p = 0.001 ) . Symptom total score also fell with CPAP ( mean difference –1.6 , 95 % CI –2.2 to –1.0 ; p<0.001 ) . No determinants of these changes with active treatment were identified , and no significant enhancements to cognitive function or psychosocial well being were found in this small sample . CONCLUSIONS These findings provide further evidence for clinical ly significant benefits to daytime function  from CPAP BACKGROUND Limited data have suggested that sleep-disordered breathing , a condition of repeated episodes of apnea and hypopnea during sleep , is prevalent among adults . Data from the Wisconsin Sleep Cohort Study , a longitudinal study of the natural history of cardiopulmonary disorders of sleep , were used to estimate the prevalence of undiagnosed sleep-disordered breathing among adults and address its importance to the public health . METHODS A r and om sample of 602 employed men and women 30 to 60 years old were studied by overnight polysomnography to determine the frequency of episodes of apnea and hypopnea per hour of sleep ( the apnea-hypopnea score ) . We measured the age- and sex-specific prevalence of sleep-disordered breathing in this group using three cutoff points for the apnea-hypopnea score ( > or = 5 , > or = 10 , and > or = 15 ) ; we used logistic regression to investigate risk factors . RESULTS The estimated prevalence of sleep-disordered breathing , defined as an apnea-hypopnea score of 5 or higher , was 9 percent for women and 24 percent for men . We estimated that 2 percent of women and 4 percent of men in the middle-aged work force meet the minimal diagnostic criteria for the sleep apnea syndrome ( an apnea-hypopnea score of 5 or higher and daytime hypersomnolence ) . Male sex and obesity were strongly associated with the presence of sleep-disordered breathing . Habitual snorers , both men and women , tended to have a higher prevalence of apnea-hypopnea scores of 15 or higher . CONCLUSIONS The prevalence of undiagnosed sleep-disordered breathing is high among men and is much higher than previously suspected among women . Undiagnosed sleep-disordered breathing is associated with daytime hypersomnolence A comparison is made between the end-tidal fractional concentration of carbon dioxide ( FETCO2 ) obtained during application of varying levels of continuous positive airway pressure ( CPAP ) with a prototype mask ( from Carburos Metálicos ) and FETCO2 obtained with 2 commonly used nasal masks ( Profile Lite and ComfortClassic from Respironics ) . The nasal FETCO2 was measured on 3 consecutive days in 11 healthy volunteers , 12 patients with severe obstructive sleep apnea-hypopnea syndrome , and 12 hypercapnic patients . A different mask was r and omly assigned on each day and the FETCO2 was measured after 3 minutes of CPAP at 4 , 5 , 6 , 8 , 10 , 15 , and 20 cm H2O . Although in all cases a progressive reduction in FETCO2 was observed with increasing CPAP , the effect was greatest with the prototype mask at all pressures . In the 3 different study groups the pressures obtained with the prototype mask were similar to those generated by the CPAP machine . In conclusion , the lower concentration of nasal CO2 obtained using the prototype mask suggests that it causes less rebreathing BACKGROUND Nasal continuous positive airway pressure ( NCPAP ) is widely used as a treatment for obstructive sleep apnoea . However , to date there are no r and omised controlled trials of this therapy against a well-matched control . We undertook a r and omised prospect i ve parallel trial of therapeutic NCPAP for obstructive sleep apnoea compared with a control group on subtherapeutic NCPAP . METHODS Men with obstructive sleep apnoea , defined as an Epworth sleepiness score of 10 or more and ten or more dips per h of more than 4 % SaO2 caused by obstructive sleep apnoea on overnight sleep study , were r and omly assigned therapeutic NCPAP or subtherapeutic NCPAP ( about 1 cm H2O ) for 1 month . Primary outcomes were subjective sleepiness ( Epworth sleepiness score ) , objective sleepiness ( maintenance of wakefulness test ) , and SF-36 question naire measurements of self-reported functioning and well-being . FINDINGS 107 men entered the study : 53 received subtherapeutic NCPAP and 54 therapeutic NCPAP . Use of NCPAP by the two treatment groups was similar : 5.4 h ( therapeutic ) and 4.6 h ( subtherapeutic ) per night . Subtherapeutic NCPAP did not alter the overnight number of SaO2 dips per h compared with baseline , and thus acted as a control . Therapeutic NCPAP was superior to subtherapeutic NCPAP in all primary outcome measures . The Epworth score was decreased from a median of 15.5 to 7.0 on therapeutic NCPAP , and from 15.0 to 13.0 on subtherapeutic NCPAP ( between treatments , p<0.0001 ) . Mean maintenance-of-wakefulness time increased from 22.5 to 32.9 min on therapeutic NCPAP and , not significantly , from 20.0 to 23.5 min on subtherapeutic NCPAP ( between treatments p<0.005 ) . Effect sizes for SF-36 measures of energy and vitality were 1.68 ( therapeutic ) and 0.97 ( subtherapeutic ) NCPAP ( between treatments p<0.0001 ) . For mental summary score , the corresponding values were 1.02 and 0.4 ( between treatments p=0.002 ) . INTERPRETATION Therapeutic NCPAP reduces excessive daytime sleepiness and improves self-reported health status compared with a subtherapeutic control . Compared with controls , the effects of therapeutic NCPAP are large and confirm previous uncontrolled clinical observations and the results of controlled trials that used an oral placebo This study was undertaken to determine the efficacy of nasal mask ( NM ) versus full face mask ( FFM ) for the delivery of noninvasive ventilation ( NIV ) in subjects with nocturnal hypoventilation . A total of 16 patients ( 11 males ) were enrolled , all with nocturnal hypoventilation currently treated at home with NIV via pressure preset devices . Subjects underwent full polysomnography on three occasions ; on the first night current therapy on NM was review ed , followed by two experimental studies in r and omised order using either NM or FFM . NIV setting s and oxygen flow rate were the same under both conditions . Notably , 14 of the 16 subjects required the use of a chinstrap to minimise oral leak . Apnoea-hypopnoea indices were within normal limits under both conditions ( 1.7±3.4 NM versus 1.6±2.4 h FFM ) . The type of interface did not significantly affect gas exchange during sleep ( minimum average arterial oxyhaemoglobin saturation total sleep time 93.4±2.1 NM versus 92.8±2.5 % FFM , Delta transcutaneous carbon dioxide nonrapid eye movement sleep to rapid eye movement sleep ( 0.58±0.36 NM versus 0.50±0.40 kPa FFM ) . Sleep efficiency was significantly reduced on the FFM ( 78±9 NM versus 70±14 % FFM ) , although arousal indices were comparable under both conditions ( 15.6±9.8 NM versus 15.8±8.8 h FFM ) . Full face masks appear to be as effective as nasal masks in the delivery of noninvasive ventilation to patients with nocturnal hypoventilation . However , a chinstrap was required to reduce oral leak in the majority of subjects using the nasal mask To investigate the association between sleep apnea syndrome ( SAS ) and automobile accidents , and to evaluate potential underlying mechanisms , we prospect ively recruited 60 consecutive patients with SAS ( apnea-hypopnea index , 58 + /- 3 h-1 ) and 60 healthy control subjects , matched for sex and age . The number of automobile accidents during the past 3 yr was obtained from participants and insurance companies . We quantified the degree of daytime sleepiness ( Epworth scale ) , anxiety and depression ( Beck tests ) , and we assessed the level of vigilance ( PVT 192 ) and driving performance ( Steer-Clear ) . Patients had more accidents than control subjects ( OR : 2.3 ; 95 % CI : 0.97 to 5.33 ) and were more likely to have had more than one accident ( OR : 5.2 ; 95 % CI : 1.07 to 25.29 , p < 0.05 ) . These differences persisted after stratification for km/yr , age , and alcohol consumption . Patients were more somnolent , anxious , and depressed than control subjects ( p < 0.01 ) , and they had a lower level of vigilance and poorer driving performance ( p < 0.01 ) . Yet , we did not find any correlation between the degree of daytime sleepiness , anxiety , depression , the number of respiratory events , nocturnal hypoxemia , level of vigilance , or driving simulator performance and the risk of automobile accidents among SAS patients . In conclusion , patients with SAS have an increased risk of automobile accidents . None of the clinical or physiological markers commonly used to define disease severity appear able to discriminate those patients at higher risk of having an automobile accident OBJECTIVE To compare efficacy , compliance rates , and side effects of a new strapless oral interface , the Oracle , with available nasal masks over 8 weeks of use for the treatment of obstructive sleep apnea hypopnea syndrome ( OSAHS ) . METHODS A total of 38 patients with OSAHS ( respiratory disturbance index ( RDI ) > /=15/h ) were enrolled after the diagnostic polysomnogram for subsequent continuous positive airway pressure ( CPAP ) therapy .  After r and omization , therapeutic pressures during a titration study were determined for 21 patients in the oral group and 17 patients in the nasal group . Comparisons for nasal and oral interfaces were made for baseline patient characteristics , average hours of CPAP use , side effects from therapy , and among question naires evaluating patients ' subjective responses to therapy at months 1 and 2 . RESULTS No significant difference was observed in the average hours of CPAP use between the oral ( 4.5+/-2.1 ; 5.5+/-2.6 ) and nasal groups ( 4.0+/-2.6 ; 4.8+/-2.5 ) for either month 1 or 2 ( P>0.05 ) . The dropout rates were similar for both groups after 8 weeks of therapy . However , patients in the nasal group had higher occurrences of side effects such as nasal congestion , dryness , and air leaks , whereas patients in the oral group experienced more oral dryness and gum pain . CONCLUSION Oral delivery of CPAP with the Oracle is an effective and suitable alternative for patients with OSAHS The minimal disease severity at which patients with the sleep apnea/hypopnea syndrome ( SAHS ) gain benefit from treatment is not well characterized , although a pilot study of continuous positive airway pressure ( CPAP ) therapy showed daytime improvements in patients with 5 to 15 apneas + hypopneas per hour slept ( AHI ) . We have thus performed a second , larger , r and omized , placebo- controlled study in a prospect i ve series of 34 patients ( 13 female ) with mild SAHS ( AHI 5 to 15 ) and daytime sleepiness . Patients spent 4 wk on CPAP treatment and 4 wk on an oral placebo , with r and omization of treatment order , and daytime assessment s on the last day of each treatment . Effective  CPAP  use averaged 2.8 + /- 2.1 h ( mean + /- SD ) per night . Compared with placebo , CPAP improved symptom score ( p < 0.01 ) , subjective ( Epworth ; p < 0.01 ) but not objective ( maintenance of wakefulness test ; p > 0.2 ) sleepiness , performances on 2 of 7 cognitive tasks ( p < 0.02 ) , depression score ( p < 0.01 ) , and five subscales of the SF-36 
    Output:
    