You will be presented with a collection of medical randomized controlled trial (RCT) reports addressing a shared clinical question -- for instance, the efficacy of a medical intervention on a disease or condition. Given the titles and abstracts of these reports, your task is to generate the conclusion of the systematic review article synthesizing the key findings. Your conclusion should be a few sentences long. In your response, include only the conclusion and no other text. The RCT reports are below.



Title 1:
Prevalences of symptoms of asthma and other allergic diseases in korean children: a nationwide questionnaire survey.
Abstract 1:
The purpose of this study was to estimate the national prevalence of childhood asthma and other allergic diseases in Korea , and to determine potential risk factors for the diseases . Stratified r and om sample s of 42,886 were selected from 34 elementary ( 6 - 12 yr olds ) and 34 middle schools ( 12 - 15 yr olds ) nationwide , and 38,955 were in the final analysis . The Korean-translated modified version of the International Study of Asthma and Allergies in Childhood question naire was used in this cross-sectional survey . Twelve-month prevalences of the symptoms of asthma , rhinoconjunctivitis , and flexural eczema were 8.7 % , 10.5 % , 7.3 % in 6 - 12 yr olds , and 8.2 % , 10.0 % , 3.9 % in 12 - 15 yr olds , respectively . For allergic conjunctivitis , food allergy , and drug allergy , the prevalences in 6 - 12 yr olds were 11.2 % , 6.5 % , and 1.5 % , respectively . Asthma and flexural eczema decreased significantly with age . Other significant risk factors were also noted . For 6 - 12 yr-old asthma , adjusted odds ratio ( aOR ) of body mass index was 1.21 with 95 % confidence interval ( CI ) 1.0 - 1.48 , aOR of passive smoking was 1.37 with 95%CI 1.24 - 1.51 , aOR of carpet use was 1.28 with 95%CI 1.10 - 1.49 . For 6 - 12 yr-old eczema , aOR of affluence was 1.22 with 95%CI 1.07 - 1.39 . The control of obesity and passive smoking would be the most important preventive measures of allergic diseases


Title 2:
CXCR3 polymorphisms associated with risk of asthma.
Abstract 2:
The chemokine ( C-X-C motif ) receptor 3 ( CXCR3 ) gene , on chromosome Xq13 , is known to have critical roles in inflammatory and immune responses . In an effort to discover polymorphisms have been implicated in asthma , we investigated the genetic polymorphisms in CXCR3 to evaluate it as a potential c and i date gene for a host genetic study of asthma . Statistical analysis revealed that one SNP in intron 1 , c.12 + 234 G > A , showed significant association with the risk of asthma development ( P = 0.007 , OR = 0.81 ) . By subgroup analyses stratified by gender and atopic status , the genetic effect of c.12 + 234 G > A on asthma was more apparent among male atopic subjects ( P = 0.0009 , OR = 0.61 ) . Our findings suggest that polymorphisms in CXCR3 might be one of the genetic factors for the risk of asthma development , especially in male atopic subjects . CXCR3 variation/haplotype information identified in this study will provide valuable information and insight into strategies for the control of asthma and its subgroup , atopy


Title 3:
Underdiagnosis of asthma: is the doctor or the patient to blame? The DIMCA project
Abstract 3:
BACKGROUND It is important to diagnose asthma at an early stage as early treatment may improve the prognosis in the long term . However , many patients do not present at an early stage of the condition so the physician may have difficulty with the diagnosis . A study was therefore undertaken to compare the proportion of patients who underpresented their respiratory symptoms with the proportion of underdiagnosed cases of asthma by the general practitioner ( GP ) . A secondary aim was to investigate whether bad perception of dyspnoea by the patient was a determining factor in the underpresentation of asthma symptoms to the GP . METHODS A r and om sample of 1155 adult subjects from the general population in the eastern part of the Netherl and s was screened for respiratory symptoms and lung function and the results were compared with the numbers of asthma related consultations registered in the medical files of the GP . In subjects with reduced lung function the ability to perceive dyspnoea was investigated during a histamine provocation test in subjects who did and did not report their symptoms to their GP . RESULTS Of the r and om sample of 1155 subjects 86 ( 7 % ) had objective airflow obstruction ( forced expiratory volume in one second ( FEV1 ) below the reference value corrected for age , length , and sex minus 1.64SD on two occasions ) and had symptoms suggestive of asthma . Of these 86 subjects only 29 ( 34 % ) consulted the GP , which indicates underpresentation by 66 % of patients . Of all subjects with objective airflow obstruction who presented to their GP with respiratory symptoms , 23 ( 79 % ) were recorded in the medical files as having asthma , indicating underdiagnosis by the GP in 21 % of cases . Of the subjects with objective airflow obstruction who visited the GP with respiratory symptoms 6 % had bad perception of dyspnoea compared with 26 % of those who did not present to the GP in spite of airflow obstruction ( χ2 = 3.02 , p = 0.08 ) . CONCLUSIONS Underpresentation to GPs of respiratory symptoms by asthmatic patients contributes significantly to the problem of underdiagnosis of asthma . Underdiagnosis by the GP seems to play a smaller role . Furthermore , there are indications that underpresentation of symptoms by the patient is at least partly explained by a worse perception of dyspnoea


Title 4:
Citrus red mite (Panonychus citri) may be an important allergen in the development of asthma among exposed children
Abstract 4:
Background Recent investigations have demonstrated that spider mites are important allergens in the development of asthma in fruit‐cultivating farmers
Disease severity , level of control , and symptom state were all found to negatively impact the quality of life of asthmatics .