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 —There is increasing evidence that obstructive sleep apnea ( OSA ) is an independent risk factor for arterial hypertension . Because there are no controlled studies showing a substantial effect of nasal continuous positive airway pressure ( nCPAP ) therapy on hypertension in OSA , the impact of treatment on cardiovascular sequelae has been question ed altogether . Therefore , we studied the effect of nCPAP on arterial hypertension in patients with OSA . Methods and Results —Sixty consecutive patients with moderate to severe OSA were r and omly assigned to either effective or subtherapeutic nCPAP for 9 weeks on average . Nocturnal polysomnography and continuous noninvasive blood pressure recording  for 19 hours was performed before and with treatment . Thirty two patients , 16 in each group , completed the study . Apneas and hypopneas were reduced by ≈95 % and 50 % in the therapeutic and subtherapeutic groups , respectively . Mean arterial blood pressure decreased by 9.9±11.4 mm Hg with effective nCPAP treatment , whereas no relevant change occurred with subtherapeutic nCPAP ( P = 0.01 ) . Mean , diastolic , and systolic blood pressures all decreased significantly by ≈10 mm Hg , both at night and during the day . Conclusions —Effective nCPAP treatment in patients with moderate to severe OSA leads to a substantial reduction in both day and night arterial blood pressure . The fact that a 50 % reduction in the apnea-hypopnea index did not result in a decrease in blood pressure emphasizes the importance of highly effective treatment . The drop in mean blood pressure by 10 mm Hg would be predicted to reduce coronary heart disease event risk by 37 % and stroke risk by 56 % Objective It is unclear whether all snoring patients require polysomnography , and there are no highly sensitive clinical predictors of sleep apnea . Our objective was to develop a simple clinical screening test for OSA in snoring patients . Study Design Prospect i ve , IRB-approved study at a university sleep disorders center . Subjects and Methods In 211 patients undergoing polysomnography , snoring severity , Epworth sleepiness scale , body mass index , demographic , and sleep study data were collected . Receiver operating characteristic ( ROC ) analysis and Pearson correlation were used to develop a sensitive screening test for OSA . Results Snoring severity score ( SSS ) and BMI were the two most accurate predictors of OSA on the ROC curve . A bipartite threshold of SSS = 4 or BMI = 26 carried sensitivity of 97.4 % , specificity of 40 % , positive predictive value of 82.3 % , and negative predictive value of 84.2 % for moderate/severe OSA . Patients at high risk were those with BMI ≥32 ( 89 % PPV ) or SSS ≥7 ( 92 % PPV ) . Conclusions The statistic most predictive of OSA was snoring severity . Combining this with BMI yielded a highly sensitive screening test for moderate/severe OSA . This clinical assessment may be useful in risk-stratifying patients for polysomnography and therapy , facilitating deferred work-up in low-risk patients and expedited therapy in high-risk patients Purpose We aim ed to verify whether it is clinical ly useful to repeat the Epworth Sleepiness Scale ( ESS ) in individuals with suspected sleep-disordered breathing ( SDB ) . Methods In this cross-sectional , prospect i ve study , results of the repeated administration of the ESS were analyzed . In 929 consecutive patients ,  ESS  was obtained as usual in the laboratory routine , immediately before the sleep study ( ESS1 ) and was repeated in the morning , after the polysomnography ( ESS2 ) . ROC curve , classical psychometry , and item response theory ( IRT ) Rasch analysis were used to assess measurement properties of ESS . Results The ESS1 score was ( mean ± SD ) , 11 ± 5.1 , and the ESS2 , 13 ± 4.7 ( p < 0.001 ) . Change in ESS score is explained in multivariate analysis by age , but not by gender , educational level , change in Stanford Sleepiness Scale , symptoms of sleep disorder , or polysomnography results . Accuracy of an ESS score > 10 to predict apnea – hypopnea index ≥5 increased from 56 % ( ESS1 ) to 72 % ( ESS2 ) . IRT psychometric properties ( unidimensionality , invariance , local independence ) were maintained in ESS2 . Conclusions Repeating the administration of the Epworth Sleepiness Scale in a clinical setting increases its score and diagnostic accuracy and correlation with SDB variables , without changing the psychometric properties of the scale . This experiment indicates the clinical usefulness of repeating the ESS . The scale can be repeated at a negligible cost , before dismissing individual patients on the basis of a low ESS score , discontinuing a potentially lifesaving diagnostic and therapeutic process 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 Background : Clinical detection of structural narrowing of the upper airway may facilitate early recognition of obstructive sleep apnoea ( OSA ) . To determine whether the craniofacial profile predicts the presence of OSA , the upper airway and craniofacial structure of 239 consecutive patients ( 164 Asian and 75 white subjects ) referred to two sleep centres ( Hong Kong and Vancouver ) were prospect ively examined for suspected sleep disordered breathing . Methods : All subjects underwent a history and physical examination with measurements of anthropometric parameters and craniofacial structure including neck circumference , thyromental distance , thyromental angle , and Mallampati oropharyngeal score . OSA was defined as an apnoea-hypopnoea index ( AHI ) of ⩾5/hour on full overnight polysomnography . Results : Discriminant function analysis indicated that the Mallampati score ( F = 0.70 ) , thyromental angle ( F = 0.60 ) , neck circumference ( F = 0.54 ) , body mass index ( F = 0.53 ) , and age ( F = 0.53 ) were the best predictors of OSA . After controlling for ethnicity , body mass index and neck circumference , patients with OSA were older , had larger thyromental angles , and higher Mallampati scores than non-apnoeic subjects . These variables remained significantly different between OSA patients and controls across a range of cut-off values of AHI from 5 to 30/hour . Conclusions : A crowded posterior oropharynx and a steep thyromental plane predict OSA across two different ethnic groups and varying degrees of obesity Background The Berlin Question naire ( BQ ) is a useful tool to identify the high-risk group for obstructive sleep apnea ( OSA ) in the primary care sites or hospital , but the usefulness of the BQ to identify the high-risk group for OSA in the general population has not been evaluated . The purpose of our study was to develop the Korean version of the BQ ( KBQ ) and evaluate the usefulness of the BQ in identifying patients with OSA in the general population . Methods A total of 1,305 subjects were included in a population -based door-to-door cross-sectional study . For validation of the KBQ , an overnight polysomnography ( PSG ) was performed on 101 subjects who were r and omly selected considering their age , sex , and risk group classification at a controlled sleep laboratory . Results The KBQ showed a relatively good to excellent internal consistency ( Cronbach ’s α correlation 0.64–0.78 ) and test – retest reliability ( intraclass correlation 0.92 ) . The apnea – hypopnea index ( AHI ) was significantly correlated with the scores in each category and the total scores of the KBQ . In addition , high risk grouping based on the KBQ predicted an AHI ≥ 5 with a sensitivity of 0.69 and a specificity of 0.83 . According to the risk categorization based on the KBQ , 26.1 % subjects were in the high-risk group for OSA which was similar to the prevalence of OSA in a previous large epidemiological study using PSG in Korea . Conclusion This is the first study to confirm the usefulness of the BQ as a screening tool for OSA by prioritizing subjects at high risk for OSA in the general population STUDY OBJECTIVES Clinical prediction models for the diagnosis of  obstructive sleep apnea ( OSA ) have lacked the accuracy necessary to confidently replace polysomnography ( PSG ) . Artificial neural networks are computer programs that can be trained to predict outcomes based on experience . This study was conducted to test the hypothesis that a generalized regression neural network ( GRNN ) could accurately classify patients with OSA from clinical data . STUDY DESIGN Retrospective review . SETTING Regional sleep referral center . PATIENTS R and omly selected records of patients referred for possible OSA . MEASUREMENTS The neural network was trained using 23 clinical variables from 255 patients , and the predictive performance was evaluated using 150 other patients . RESULTS The prevalence of OSA  in this series of 405 patients ( 293 men and 112 women ) was 69 % . The trained GRNN had an accuracy of 91.3 % ( 95 % confidence interval [ CI ] , 86.8 to 95.8 ) . The sensitivity was 98.9 % for having OSA ( 95 % CI , 96.7 to 100 ) , and the specificity was 80 % ( 95 % CI , 70 to 90 ) . The positive predictive value that the patient would have OSA was 88.1 % ( 95 % CI , 81.8 to 94.4 ) , whereas the negative predictive value that the patient would not have OSA ( if so classified ) was 98 % ( 95 % CI , 94 to 100 ) . CONCLUSIONS Appropriately trained GRNN has the ability to accurately rule in OSA from clinical data , and GRNN did not misclassify patients with moderate to severe OSA . In this study , use of the neural network could have reduced the number of PSG studies performed . Prospect i ve validation of the neural network for the diagnosis of OSA is now required The aim of the study was to investigate psychosocial function before and after continuous positive airway pressure ( CPAP ) therapy  , and establish the determinants and consequences of objective CPAP use . In a prospect i ve , parallel-group study , changes in psychosocial scores were compared with conservative management or CPAP therapy for the sleep apnoea/hypopnoea syndrome ( SAHS ) . Patient/partner couples from the top ( CPAP treated , n=44 ) or bottom ( conservatively treated , n=25 ) of a CPAP waiting list rated marital satisfaction ( evaluation and nurturing relationship issues , communication and happiness ( ENRICH ) , behavioural question naire ) , health/functional status ( Short-Form-36 Health Survey , functional outcomes of sleep question naire ) and sleepiness ( Epworth sleepiness scale ) . Both groups ' ratings at baseline were completed while on conservative therapy . Baseline variables did not differ between groups . At follow-up , all seven summary psychosocial scores were statistically better in CPAP-treated patients , effect sizes ( ES ) ranging from moderate ( 0.5 sd : marital satisfaction ) to very large ( > 1.0 sd : patients health , functional status and sleepiness scores ) . Scores in conservatively-treated patients deteriorated to a small or moderate degree ( ES −0.2– −0.7 sd ) , while those in the CPAP-treated group improved to a larger degree ( 0.3–1.3 sd ) . Baseline polysomnographical and psychosocial scores , including marital satisfaction , did not predict objective CPAP use ( r<0.3 ) . CPAP use was modestly correlated ( r=0.3–0.6 ) with improvement in all psychosocial areas . Continuous positive airway pressure produced statistically and clinical ly significant psychosocial improvements , some of large magnitude , in psychosocial function . Determinants of usage were not identified , but benefits and usage were positively correlated Obstructive sleep apnea ( OSA ) is traditionally diagnosed using overnight polysomnography . Decision rules may provide an alternative to polysomnography . A consecutive series of patients referred to a tertiary sleep center underwent prospect i ve evaluation with the upper airway physical examination protocol 
    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 —There is increasing evidence that obstructive sleep apnea ( OSA ) is an independent risk factor for arterial hypertension . Because there are no controlled studies showing a substantial effect of nasal continuous positive airway pressure ( nCPAP ) therapy on hypertension in OSA , the impact of treatment on cardiovascular sequelae has been question ed altogether . Therefore , we studied the effect of nCPAP on arterial hypertension in patients with OSA . Methods and Results —Sixty consecutive patients with moderate to severe OSA were r and omly assigned to either effective or subtherapeutic nCPAP for 9 weeks on average . Nocturnal polysomnography and continuous noninvasive blood pressure recording  for 19 hours was performed before and with treatment . Thirty two patients , 16 in each group , completed the study . Apneas and hypopneas were reduced by ≈95 % and 50 % in the therapeutic and subtherapeutic groups , respectively . Mean arterial blood pressure decreased by 9.9±11.4 mm Hg with effective nCPAP treatment , whereas no relevant change occurred with subtherapeutic nCPAP ( P = 0.01 ) . Mean , diastolic , and systolic blood pressures all decreased significantly by ≈10 mm Hg , both at night and during the day . Conclusions —Effective nCPAP treatment in patients with moderate to severe OSA leads to a substantial reduction in both day and night arterial blood pressure . The fact that a 50 % reduction in the apnea-hypopnea index did not result in a decrease in blood pressure emphasizes the importance of highly effective treatment . The drop in mean blood pressure by 10 mm Hg would be predicted to reduce coronary heart disease event risk by 37 % and stroke risk by 56 % Objective It is unclear whether all snoring patients require polysomnography , and there are no highly sensitive clinical predictors of sleep apnea . Our objective was to develop a simple clinical screening test for OSA in snoring patients . Study Design Prospect i ve , IRB-approved study at a university sleep disorders center . Subjects and Methods In 211 patients undergoing polysomnography , snoring severity , Epworth sleepiness scale , body mass index , demographic , and sleep study data were collected . Receiver operating characteristic ( ROC ) analysis and Pearson correlation were used to develop a sensitive screening test for OSA . Results Snoring severity score ( SSS ) and BMI were the two most accurate predictors of OSA on the ROC curve . A bipartite threshold of SSS = 4 or BMI = 26 carried sensitivity of 97.4 % , specificity of 40 % , positive predictive value of 82.3 % , and negative predictive value of 84.2 % for moderate/severe OSA . Patients at high risk were those with BMI ≥32 ( 89 % PPV ) or SSS ≥7 ( 92 % PPV ) . Conclusions The statistic most predictive of OSA was snoring severity . Combining this with BMI yielded a highly sensitive screening test for moderate/severe OSA . This clinical assessment may be useful in risk-stratifying patients for polysomnography and therapy , facilitating deferred work-up in low-risk patients and expedited therapy in high-risk patients Purpose We aim ed to verify whether it is clinical ly useful to repeat the Epworth Sleepiness Scale ( ESS ) in individuals with suspected sleep-disordered breathing ( SDB ) . Methods In this cross-sectional , prospect i ve study , results of the repeated administration of the ESS were analyzed . In 929 consecutive patients ,  ESS  was obtained as usual in the laboratory routine , immediately before the sleep study ( ESS1 ) and was repeated in the morning , after the polysomnography ( ESS2 ) . ROC curve , classical psychometry , and item response theory ( IRT ) Rasch analysis were used to assess measurement properties of ESS . Results The ESS1 score was ( mean ± SD ) , 11 ± 5.1 , and the ESS2 , 13 ± 4.7 ( p < 0.001 ) . Change in ESS score is explained in multivariate analysis by age , but not by gender , educational level , change in Stanford Sleepiness Scale , symptoms of sleep disorder , or polysomnography results . Accuracy of an ESS score > 10 to predict apnea – hypopnea index ≥5 increased from 56 % ( ESS1 ) to 72 % ( ESS2 ) . IRT psychometric properties ( unidimensionality , invariance , local independence ) were maintained in ESS2 . Conclusions Repeating the administration of the Epworth Sleepiness Scale in a clinical setting increases its score and diagnostic accuracy and correlation with SDB variables , without changing the psychometric properties of the scale . This experiment indicates the clinical usefulness of repeating the ESS . The scale can be repeated at a negligible cost , before dismissing individual patients on the basis of a low ESS score , discontinuing a potentially lifesaving diagnostic and therapeutic process 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 Background : Clinical detection of structural narrowing of the upper airway may facilitate early recognition of obstructive sleep apnoea ( OSA ) . To determine whether the craniofacial profile predicts the presence of OSA , the upper airway and craniofacial structure of 239 consecutive patients ( 164 Asian and 75 white subjects ) referred to two sleep centres ( Hong Kong and Vancouver ) were prospect ively examined for suspected sleep disordered breathing . Methods : All subjects underwent a history and physical examination with measurements of anthropometric parameters and craniofacial structure including neck circumference , thyromental distance , thyromental angle , and Mallampati oropharyngeal score . OSA was defined as an apnoea-hypopnoea index ( AHI ) of ⩾5/hour on full overnight polysomnography . Results : Discriminant function analysis indicated that the Mallampati score ( F = 0.70 ) , thyromental angle ( F = 0.60 ) , neck circumference ( F = 0.54 ) , body mass index ( F = 0.53 ) , and age ( F = 0.53 ) were the best predictors of OSA . After controlling for ethnicity , body mass index and neck circumference , patients with OSA were older , had larger thyromental angles , and higher Mallampati scores than non-apnoeic subjects . These variables remained significantly different between OSA patients and controls across a range of cut-off values of AHI from 5 to 30/hour . Conclusions : A crowded posterior oropharynx and a steep thyromental plane predict OSA across two different ethnic groups and varying degrees of obesity Background The Berlin Question naire ( BQ ) is a useful tool to identify the high-risk group for obstructive sleep apnea ( OSA ) in the primary care sites or hospital , but the usefulness of the BQ to identify the high-risk group for OSA in the general population has not been evaluated . The purpose of our study was to develop the Korean version of the BQ ( KBQ ) and evaluate the usefulness of the BQ in identifying patients with OSA in the general population . Methods A total of 1,305 subjects were included in a population -based door-to-door cross-sectional study . For validation of the KBQ , an overnight polysomnography ( PSG ) was performed on 101 subjects who were r and omly selected considering their age , sex , and risk group classification at a controlled sleep laboratory . Results The KBQ showed a relatively good to excellent internal consistency ( Cronbach ’s α correlation 0.64–0.78 ) and test – retest reliability ( intraclass correlation 0.92 ) . The apnea – hypopnea index ( AHI ) was significantly correlated with the scores in each category and the total scores of the KBQ . In addition , high risk grouping based on the KBQ predicted an AHI ≥ 5 with a sensitivity of 0.69 and a specificity of 0.83 . According to the risk categorization based on the KBQ , 26.1 % subjects were in the high-risk group for OSA which was similar to the prevalence of OSA in a previous large epidemiological study using PSG in Korea . Conclusion This is the first study to confirm the usefulness of the BQ as a screening tool for OSA by prioritizing subjects at high risk for OSA in the general population STUDY OBJECTIVES Clinical prediction models for the diagnosis of  obstructive sleep apnea ( OSA ) have lacked the accuracy necessary to confidently replace polysomnography ( PSG ) . Artificial neural networks are computer programs that can be trained to predict outcomes based on experience . This study was conducted to test the hypothesis that a generalized regression neural network ( GRNN ) could accurately classify patients with OSA from clinical data . STUDY DESIGN Retrospective review . SETTING Regional sleep referral center . PATIENTS R and omly selected records of patients referred for possible OSA . MEASUREMENTS The neural network was trained using 23 clinical variables from 255 patients , and the predictive performance was evaluated using 150 other patients . RESULTS The prevalence of OSA  in this series of 405 patients ( 293 men and 112 women ) was 69 % . The trained GRNN had an accuracy of 91.3 % ( 95 % confidence interval [ CI ] , 86.8 to 95.8 ) . The sensitivity was 98.9 % for having OSA ( 95 % CI , 96.7 to 100 ) , and the specificity was 80 % ( 95 % CI , 70 to 90 ) . The positive predictive value that the patient would have OSA was 88.1 % ( 95 % CI , 81.8 to 94.4 ) , whereas the negative predictive value that the patient would not have OSA ( if so classified ) was 98 % ( 95 % CI , 94 to 100 ) . CONCLUSIONS Appropriately trained GRNN has the ability to accurately rule in OSA from clinical data , and GRNN did not misclassify patients with moderate to severe OSA . In this study , use of the neural network could have reduced the number of PSG studies performed . Prospect i ve validation of the neural network for the diagnosis of OSA is now required The aim of the study was to investigate psychosocial function before and after continuous positive airway pressure ( CPAP ) therapy  , and establish the determinants and consequences of objective CPAP use . In a prospect i ve , parallel-group study , changes in psychosocial scores were compared with conservative management or CPAP therapy for the sleep apnoea/hypopnoea syndrome ( SAHS ) . Patient/partner couples from the top ( CPAP treated , n=44 ) or bottom ( conservatively treated , n=25 ) of a CPAP waiting list rated marital satisfaction ( evaluation and nurturing relationship issues , communication and happiness ( ENRICH ) , behavioural question naire ) , health/functional status ( Short-Form-36 Health Survey , functional outcomes of sleep question naire ) and sleepiness ( Epworth sleepiness scale ) . Both groups ' ratings at baseline were completed while on conservative therapy . Baseline variables did not differ between groups . At follow-up , all seven summary psychosocial scores were statistically better in CPAP-treated patients , effect sizes ( ES ) ranging from moderate ( 0.5 sd : marital satisfaction ) to very large ( > 1.0 sd : patients health , functional status and sleepiness scores ) . Scores in conservatively-treated patients deteriorated to a small or moderate degree ( ES −0.2– −0.7 sd ) , while those in the CPAP-treated group improved to a larger degree ( 0.3–1.3 sd ) . Baseline polysomnographical and psychosocial scores , including marital satisfaction , did not predict objective CPAP use ( r<0.3 ) . CPAP use was modestly correlated ( r=0.3–0.6 ) with improvement in all psychosocial areas . Continuous positive airway pressure produced statistically and clinical ly significant psychosocial improvements , some of large magnitude , in psychosocial function . Determinants of usage were not identified , but benefits and usage were positively correlated Obstructive sleep apnea ( OSA ) is traditionally diagnosed using overnight polysomnography . Decision rules may provide an alternative to polysomnography . A consecutive series of patients referred to a tertiary sleep center underwent prospect i ve evaluation with the upper airway physical examination protocol 
    Output:
    