Asthma, chronic bronchitis and respiratory symptoms among adults in Estonia according to a postal questionnaire

Epidemiological studies indicate a lower prevalence of asthma in Eastern than Western Europe. This study of the prevalence of asthma, chronic bronchitis, and respiratory symptoms was performed in three different regions of Estonia, a state incorporated in the Soviet Union until 1991. A postal questionnaire was sent to a random sample of 24,307 of the population aged 15-64 years. The response rate was 77.6%. The prevalence of physician-diagnosed asthma was 2.0% or considerably lower than in Northern and Western European countries. The prevalence of wheezing last 12 months, 21.7%, recurrent wheeze, 13.3%, and attacks of shortness of breath, 12.5%, were similar or even higher compared with prevalence rates found in the Nordic countries. The prevalence of physician-diagnosed chronic bronchitis was 10.7%, and was higher among women than in men, although the proportion of current smokers among men, 57%, was considerably greater than in women, 28%. A possible explanation to the high prevalence of respiratory symptoms also among non-smoking women may be exposure to environmental tobacco smoke in small, crowded Estonian homes. Diagnostic criteria based on the Soviet-time definitions is discussed as a possible explanation to the low prevalence of physician-diagnosed asthma and high prevalence of chronic bronchitis in Estonia compared with other Northern European countries.     

Usefulness of bronchial reactivity analysis in the diagnosis of bronchial asthma in patients with bronchial hyperresponsiveness

We examined the usefulness of some bronchial reactivity indices to identify bronchial asthma in patients with airway hyperresponsiveness. Eighty-eight consecutive patients with positive response to histamine bronchial challenge (> or = 20% fall in FEV1) were included in the study. Dose-response curves were characterised by their sensitivity (PD20) and reactivity. Dose-response slope, continuous index of responsiveness (CIR) and bronchial reactivity index (BRI) with respect to baseline and post-diluent baseline values were determined as reactivity indices. The clinical diagnosis remaining in the case history 2 years after the bronchial challenge was considered the definitive diagnosis. Asthmatic patients had higher baseline BRI (12.121+/-0.412 vs. 11.615+/-0.201; P<0.001) and post-diluent baseline BRI (12.054+/-0.368 vs. 11.563+/-0.531; P = 0.003) than other subjects. Area beneath their receiver operating characteristic (ROC) curve was 82.68% (standard error: 0.77) for the baseline BRI and 81.73 (standard error: 0.76). By multiple logistic regression analysis, baseline BRI was the only independent variable identified as a predictor for diagnosis of bronchial asthma (r = 0.387, P = 0.0007). A cut-off of 11.76 for baseline BRI reached an 87.2% sensitivity and an 80% specificity for bronchial asthma diagnosis. In conclusion, BRI calculated with respect to baseline FEV1 should be useful in identifying asthmatic patients among subjects with airway hyperresponsiveness.     

脉冲振荡技术在COPD与支气管哮喘鉴别诊断中的价值

目的探讨脉冲振荡法(IOS)对COPD、支气管哮喘(哮喘)的鉴别诊断价值。方法 102例受试者(其中AECOPD40例,哮喘急性发作期36例,以及健康者26例)完成脉冲振荡法检查、肺通气功能(PFT)。比较三组间肺通气功能参数、脉冲振荡的全呼吸相阻抗以及吸气-呼气相阻抗的差别。结果 (1)肺通气功能结果:COPD组、哮喘组均表现为阻塞性通气功能障碍,FEV1%pred、FEV1/FVC、PEF%pred差异无统计学意义。(2)哮喘组代表中心气道阻力的指标R20高于COPD组(P<0.01)。(3)COPD组、哮喘组、健康组吸气-呼气相阻抗比较:仅COPD组的呼气相R5-20大于吸气相R5-20、呼气相X5小于吸气相X5(P值分别为0.041、0.017)。另外COPD组的吸气-呼气相的R5-20变化值(ΔR5-20)、X5变化值(ΔX5)大于哮喘组(均P<0.01)。结论脉冲振荡法有助于支气管哮喘与AECOPD的鉴别诊断。     

The assessment of a computer administered questionnaire in the differential diagnosis of asthma and chronic airflow limitation

We have tested a computer administered respiratory symptom questionnaire in patients with asthma, chronic airflow limitation, and subjects with no evidence of respiratory disease. The questionnaire was highly effective at distinguishing patients with respiratory disease from those without. However, the responses of asthmatic patients and patients with CAL to the majority of questions were similar though the responses to four out of 11 questions were significantly different. We conclude that such a computer administered questionnaire is of limited value in distinguishing patients with asthma and CAL, underlining the importance of objective tests in this differential diagnosis.     

The interrelationship among bronchial hyperresponsiveness, the diagnosis of asthma, and asthma symptoms

Bronchial hyperresponsiveness (BHR) to inhaled histamine has often been cited as the gold standard in asthma diagnosis, but recently this has been questioned. This report assesses the relationship of BHR to asthma symptoms and asthma diagnosis in a large community-based sample of children. A total of 2,053 children 7 to 10 yr of age were randomly sampled from Auckland primary schools and assessed by a questionnaire and histamine inhalation challenge. In all, 14.3% had had asthma diagnosed, 29.6% reported having had one of the four respiratory symptoms in in the previous 12 months, and 15.9% had BHR (PD20 less than or equal to 7.8 mumol histamine). After a cumulative dose of 3.9 mumol histamine, the percent change in FEV1 from postsaline FEV1 was unimodally distributed, with those in whom asthma had been diagnosed dominating the severe end of the spectrum. However, 53% of those with BHR had no asthma diagnosis, and 41% had no current asthma symptoms. On the other hand, 48% of all subjects with diagnosed asthma and 42% of children with diagnosed asthma and current symptoms did not have BHR. Although severity of BHR tended to increase with wheezing frequency, all grades of severity (including no BHR) were found for any given frequency of wheeze. An existing diagnosis of asthma identified symptomatic children more accurately than did BHR, regardless of the criteria used for BHR or for "symptomatic" and irrespective of ethnic group. In conclusion, BHR is related to, but not identical to, clinical asthma. Bronchial challenge testing is an important tool of respiratory research, but cannot reliably or precisely separate asthmatics from nonasthmatics in the general community.     

The differential diagnosis of bronchial asthma in children.

Bronchial asthma in children is not uncommon in the tropics. Conditions simulating this disease in the tropics have been discussed with a view to arriving at a diagnosis without sophisticated investigations.     

The diagnosis of emphysema, chronic bronchitis, and asthma

Although of some value for understanding etiologic mechanisms, the classic diagnostic categories of asthma and emphysema and especially chronic bronchitis have not served clinicians well for defining prognosis and therapeutic options. Until more useful diagnostic categories are available, the choice of diagnostic tests should be guided more by their clinical usefulness than by their sensitivity and specificity for identifying classic diagnostic categories of obstructive lung disease. A history consistent with asthma is as good evidence of asthma as that provided by most tests, especially if combined with spirometric evidence of complete reversibility of episodes of obstruction. Positive bronchial challenge studies and partial responses to bronchodilators are common in asthma but of limited diagnostic specificity. Tests of allergic function are of limited specificity for asthma, although a low IgE level is rare. Findings of reduced expiratory flows, high TLC, and low DLCO, or radiologic signs of hyperinflation, bullae, and pulmonary vascular deficiency pattern are useful for diagnosing cases of severe emphysema, but they are of limited sensitivity for the detection of mild to moderate disease. Advances in high resolution CT offer promise of earlier diagnosis of emphysema. Making a diagnosis of chronic bronchitis based on defined criteria for chronic sputum production is easy but of limited clinical value. Prospective longitudinal studies and advances in technology promise more clinically useful diagnoses in the future.     

Ipratropium bromide, salbutamol and prednisolone in bronchial asthma and chronic bronchitis.

Eleven patients with bronchial asthma and 10 with chronic bronchitis were treated over four consecutive 3-day periods, firstly with aerosols either of ipratropium bromide (40 microgram four times a day) or of salbutamol (200 microgram four times daily) by random allocation, then the alternate drug, next by both drugs together, and finally with prednisolone (10 mg three times daily) in addition to both drugs. The effects of these four treatment periods were assessed both clinically and by measuring ventilatory capacity, nitrogen slope and progressive exercise testing. Ipratropium bromide and salbutamol produced approximately equal improvements in both diseases, with salbutamol showing a marginal advantage in patients with asthma. The combination of both drugs together more than doubled the FEV1 change in both groups of patients. The addition of prednisolone to both drugs produced a marginal advantage only in those with asthma.     

The x-ray diagnosis of the functional disorder of bronchial patency in chronic bronchitis

The aim of the study was to investigate functional impairments of bronchial patency in chronic bronchitis. Various up-to-date roentgenological procedures were used. Data on complex clinicoroentgenological examination of 94 patients with chronic bronchitis are presented. Bronchograms and bronchial zonograms reflecting various respiration phases, video recording on magnetic tape with using broncholytics and a new procedure of bronchogram digital processing developed by the authors were used to solve the problems. Classification, frequency, localization and nature of functional impairments of bronchial patency in chronic bronchitis are described. The role of x-ray examination in diagnosis of functional impairment of bronchial patency was shown.     

Prevalence of asthma and chronic respiratory symptoms among Alaska Native children

STUDY OBJECTIVES: To quantify the prevalence and impact of chronic respiratory symptoms among predominantly Alaska Native (AN)/American Indian (AI) middle school students. DESIGN: School-based prevalence assessment using the International Study of Asthma and Allergy in Children survey, with supplemental video material and added questions about productive cough, exposure to tobacco smoke, and the functional impact of symptoms. SETTING: The Yukon-Kuskokwim delta region of western Alaska. PARTICIPANTS: A total of 466 children in the sixth to ninth grades, 81% of whom are AN/AI (377 children). INTERVENTIONS: No study intervention. RESULTS: Among the 377 AN/AI children, 40% reported one of the following three categories of chronic respiratory disease: physician-diagnosed asthma, 7.4%; asthma-like symptoms (ALS) without an asthma diagnosis, 11.4%; and chronic productive cough (CPC) without asthma diagnosis or symptoms, 21.5%. Symptom prevalence differed substantially between the largest town in the region and rural villages. After an adjustment for demographic factors, exposure to environmental tobacco smoke, active tobacco smoking, and self-report of atopy, village residents were 63% less likely to have ALS (p = 0.009), and had a twofold greater risk of CPC (p < 0.001) compared to children living in the town. Children with respiratory symptoms experienced sleep disturbances and accessed clinic visits for respiratory problems more often than did asymptomatic children. CONCLUSIONS: Chronic respiratory symptoms are very common among AN children. CPC is an important nonasthmatic respiratory condition in this population. The differing patterns of respiratory illness within this region may help to elucidate the specific risk factors for asthma and chronic bronchitis in children.     

Predictive value of respiratory symptoms and bronchial hyperresponsiveness to diagnose asthma in New Zealand

Respiratory symptoms are often used as the only diagnostic criteria for asthma in epidemiological surveys and the clinical diagnosis of asthma relies primarily on a detailed history. The aim of this study is to predict the diagnostic value of 11 different respiratory symptoms to diagnose asthma, and to determine if bronchial hyperresponsiveness (BHR) improves the predictive value of these respiratory symptoms. A random sample of 1257 subjects aged 20-44 years old in 3 different areas of New Zealand were selected between March 1991 and December 1992 to answer the European Community Respiratory Health Survey questionnaire on respiratory symptoms. Of these, 784 underwent bronchial challenge with methacholine. The prevalence of current doctor diagnosed asthma (DDA) defined as asthma confirmed by a physician and an asthma attack in the last 12 months was 8.3%. Wheezing with dyspnoea is the single best predictor of diagnosed asthma with a sensitivity of 82%, a specificity of 90% and a Youden's index of 0.72. Wheezing alone is more sensitive (94%) but less specific (76%), with a Youden's index of 0.70. The addition of BHR to asthma symptoms decreases sensitivity and increases specificity with a small increase in Youden's index to 0.75. In New Zealand adults, a history of wheezing with BHR best predicts a diagnosis of asthma but wheezing alone or with dyspnoea are the two best symptoms for predicting asthma.     

儿童支气管哮喘误诊的新特点及鉴别诊断探讨

目的 探讨儿童支气管哮喘(简称哮喘)的误诊现状及鉴别诊断新特点.方法 回顾性分析作者所在单位1998年11月至2008年10月收治外院转来"哮喘"患儿共810例的最后确诊情况.结果 810例中误诊105例(12.96%).被误诊为哮喘的疾病达19种.其中Tourette综合征和心因性咳嗽共50例(47.62%),均见于5岁以上的大龄患儿;而诊断为大、中气管阻塞性疾病32例(30.48%)均为5岁以下小龄患儿.结论 儿童哮喘的误诊发生率仍较高,常见的大、中气管阻塞性疾病除外,大龄儿童的Tourette综合征、心因性咳嗽被误诊的情况值得重视.     

Convenience and utility of the easy asthma program questionnaire for long-term management of bronchial asthma]

The Asthma Prevention and Management Guidelines suggest that physicians should monitor peak expiratory flow (PEF) for long-term management of bronchial asthma. However, PEF monitoring is not widespread throughout Japan, except for specialists in respirology and allergology clinics. In 2002, a convenient new questionnaire, the Easy Asthma Program (EAP), was developed to allow precise management of asthma patients even outside specialized institutions. We examined whether this questionnaire was useful for the evaluation of the severity and management of asthmatic patients. The EAP questionnaire consists of four questions about asthmatic events during the interval between visits to the hospital. Before the medical interview, we distributed the EAP questionnaire to patients to complete by themselves. We received 595 effective answers from 105 asthmatic patients and assessed the disease severity based on the EAP questionnaire, which we called the EAP step. The result of the EAP step correlated strongly with the severity of asthma, as determined by doctors following physical examinations (p<0.0001, r= 0.7). Our study also revealed that the EAP step tended to correlate negatively with the predicted PEF values. Thus, the accurate evaluation of the disease severity of asthma based on the Asthma Prevention and Management Guidelines could be provided by the EAP questionnaire, which could be performed in only a few minutes. The EAP questionnaire could be a useful tool for the management of asthma by non-specialists especially in primary care facilities.     

Asthma, asthmalike symptoms, chronic bronchitis, and the degree of bronchial hyperresponsiveness in epidemiologic surveys

Measurement of bronchial hyperresponsiveness has been suggested to be a useful test in identifying subjects with asthma in epidemiologic groups. We explored the association between the degree of bronchial hyperresponsiveness, respiratory symptoms suggestive of asthma, chronic bronchitis, and various definitions of asthma based upon information obtained from a questionnaire. We determined bronchial hyperresponsiveness by methacholine inhalation test, administered a standardized respiratory questionnaire, and performed spirometry on 1,392 male workers in various industries: 229 (16.5%) had PC20 less than 8 mg/ml, 66 (4.7%) had PC20 less than 2 mg/ml, and 8 (0.6%) had PC20 less than 0.5 mg/ml. Only 760 workers had no respiratory symptoms; no workers with PC20 less than or equal to 0.5 mg/ml, 31.0% of workers with PC20 greater than 0.5 but less than or equal to 2 mg/ml, and 38.0% of workers with PC20 greater than 2 but less than or equal to 8 mg/ml had no chest symptoms. Those reporting wheeze or breathlessness, and especially those with both symptoms, were significantly more likely to have bronchial hyperresponsiveness with a low PC20. The reporting of chest tightness did not influence this relationship, and there was no difference between the occurrence of "wheeze without a cold" and "persistent wheeze." Although there was a stronger association of PC20 less than or equal to 2 mg/ml with asthma than with chronic bronchitis, the association of PC20 greater than 2 and less than or equal to 8 mg/ml was not different with asthma than with chronic bronchitis. Bronchial hyperresponsiveness was more closely associated with asthma than with any asthmalike symptoms ascertained by a questionnaire developed for the study of chronic bronchitis.(ABSTRACT TRUNCATED AT 250 WORDS)