***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: Objective Compare respiratory health in children born extremely preterm ( EP ) or with extremely low birthweight ( ELBW ) nearly one decade apart , hypothesizing that better perinatal management has led to better outcome . Design Fifty-seven ( 93 % ) of 61 eligible 11-year old children born in Western Norway in 1999–2000 with gestational age ( GA ) < 28 weeks or birthweight < 1000 gram ( EP1999–2000 ) and matched term-controls were assessed with comprehensive lung function tests and st and ardized question naires . Outcome was compared with data obtained at 10 years of age from all ( n = 35 ) subjects born at GA < 29 weeks or birthweight < 1001 gram within a part of the same region in 1991–92 ( EP1991–1992 ) and their matched term-controls . Results EP1999–2000 had significantly reduced forced expiratory flow in 1 second ( FEV1 ) , FEV1 to forced vital capacity ( FEV1/FVC ) and forced expiratory flow between 25–75 % of FVC ( FEF25–75 ) , with z-scores respectively -0.34 , -0.50 and -0.61 below those of the term-control group , and more bronchial hyperresponsiveness to methacholine ( dose-response-slope 13.2 vs. 3.5 ; p<0.001 ) , whereas other outcomes did not differ . Low birthweight z-scores , but not neonatal bronchopulmonary dysplasia ( BPD ) or low GA , predicted poor outcome . For children with neonatal BPD , important lung-function variables were better in EP1999–2000 compared to EP1991–1992 . In regression models , improvements were related to more use of antenatal corticosteroids and surfactant treatment in the EP1999–2000 . Conclusions Small airway obstruction and bronchial hyperresponsiveness were still present in children born preterm in 1999–2000 , but outcome was better than for children born similarly preterm in 1991–92 , particularly after neonatal BPD . The findings suggest that better neonatal management not only improves survival , but also long-term pulmonary outcome The purpose of this study was to determine the respiratory symptoms , pulmonary function , and airway reactivity in school-age survivors of very-low-birth-weight and to describe the influence of birth weight and perinatal illness on their pulmonary function . Thirty ( of 39 ) 10- to 11-year-old survivors of very-low-birth-weight ( VLBW ) recruited at birth into a prospect i ve longitudinal study of development ; 30 ( of 32 ) normal-birth-weight peers recruited from the same school or census tract as the VLBW group at age 5 ; and 15 normal-birth-weight siblings of the VLBW group participated in the study . Outcome measures were mother 's reports of respiratory health ; forced vital capacity ( FVC ) , forced expiratory volume in 1 second ( FEV1 ) ; FEV1/FVC ; forced expiratory flow , midexpiratory phase ( FEF25 75 ) ; peak expiratory flow rate ( PEFR ) ; and tolerance to methacholine . There were no differences between groups in mothers ' reports of current respiratory health . Pulmonary function values were lower for the VLBW survivors but significant only for FEF25 - 75 ( F=4.13 ; P=0.02 ) . Number of days in the intensive care nursery correlated significantly with decreased FEV1 ( r=-.40 , df=28 , P-0.03 ) , FEV1/FVC ( r=-.37 , df=28 , P=0.04 , and FEF25 - 75 ( r=-.39 , df=28 , P=0.03 ) . Only the relationship between length of nursery stay and FEV1/FVC was independent of birth weight . Number of days on mechanical ventilation was significantly correlated with decreased FEV1 ( -.44 , df=28 , P=0.01 ) , FEV1/FVC ( r=-.38 , df=28 , P=0.04 ) , FEF25 - 75 ( r=-.44 , df=28 , P=0.01 , and PEFR ( r=-.40 , df=28 , P=0.03 ) . All of these relationships were independent of birth weight . There were no significant associations between perinatal risk factors and methacholine responsiveness . Differences between VLBW children and normal-birth-weight children in pulmonary function are modest even when statistically significant . Severity of perinatal illness influences pulmonary function parameters into late childhood OBJECTIVE To determine whether measurement of airways responsiveness to methacholine can help physicians diagnose asthma in children . METHODS Children from the 1995 Manitoba birth cohort were assessed by asthma specialists , had skin testing and measurement of airways responsiveness to methacholine ( PC20 ) . We selected children with doctor-diagnosed asthma and healthy children as controls ( no asthma , no allergic rhinitis , negative skin tests ) . Sensitivities and specificities for asthma were calculated . Receiver operating curves were calculated to determine the best fit of the methacholine challenge as a diagnostic test . RESULTS 640 children were assessed . Two hundred fifteen children with doctor diagnosed asthma and 197 healthy controls successfully completed a methacholine challenge .  Airways hyperresponsiveness was a moderately sensitive and specific measure for the diagnosis of asthma in girls , whether atopic ( sensitivity of 71 % and specificity of 69 % at PC20 < or = 4.0 mg/ml ) or not ( sensitivity of 77 % and specificity of 53 % at PC20 < or = 8.0 mg/ml ) . Airways hyperresponsiveness was also helpful for the diagnosis of asthma in atopic boys ( sensitivity of 67 % and specificity of 75 % at PC20 < or = 2.0 mg/ml ) , but of absolutely no help in the diagnosis of asthma in nonatopic boys . CONCLUSION Measurement of airways hyperresponsiveness to methacholine can be useful in children who are atopic and of some value in nonatopic girls . The presence or absence of airways hyperresponsiveness to methacholine is of no help for the diagnosis of asthma in nonatopic boys . Laboratory tests must be placed in context of the clinical assessment of children for asthma We assessed the relationship between very low birth weight ( VLBW ) ( < or=1500 g ) and the development of asthma , lung function and atopy .  The study groups comprised 74 of all 86 ( 86 % ) VLBW and 64 of all 86 ( 74 % ) matched term children who were prospect ively followed for 12 years . A question naire on asthmatic and allergic symptoms was completed and skin prick tests , spirometry and hypertonic saline provocation tests were performed at 12 years of age . Cytokine secretion was analysed in stimulated blood leukocyte cultures in 28 VLBW and 23 term children . A history of asthma was more frequent among the VLBW children , as compared with the term children at age 12 ( 22 % vs. 9 % , p = 0.046 ) . Among the VLBW children , very preterm birth ( gestational age : week 25 to 29 ) ( RR 2.5 , 95%CI 1.1 - 5.8 ) , neonatal mechanical ventilation ( RR 2.8 , 95%CI 1.2 - 6.4 ) and neonatal oxygen supplementation ( RR 4.3 , 95%CI 1.3 - 14.0 ) were significantly associated with a history of asthma by the age of 12 years in univariate analyses . In multivariate logistic regression , neonatal oxygen supplementation > or= 9 days was the only remaining significant risk factor for a history of asthma ( adjusted OR 6.7 , 95%CI 1.0 - 44 ) . The VLBW children who required mechanical ventilation during the neonatal period were more likely to have bronchial hyperresponsiveness than those not requiring mechanical ventilation ( 60 % vs. 28 % , p = 0.050 ) . The spirometric values were similar among the VLBW and the term children at 12 years . Very low birth weight was not significantly related to allergic rhinoconjunctivitis , eczema or positive skin prick tests . Furthermore , the levels of IL-4 , IL-5 and IFN-gamma in stimulated cell cultures were similar in the VLBW and the term children . A history of asthma by 12 years of age was twice as common among the VLBW as the term children , and neonatal oxygen supplementation seemed to be associated with the increased risk . Furthermore , mechanical ventilation during the neonatal period was associated with bronchial hyperresponsiveness at age 12 . Very low birth weight per se was not , however , related to atopy 
    Output:
    
Preterm-born subjects especially those who had CLD had increased rates of BHR to direct ( methacholine ) and indirect ( exercise ) stimuli compared to term-born subjects suggesting subgroups might benefit from anti-inflammatory or bronchodilator therapies