Cold air inhalation and exercise-induced bronchoconstriction in relationship to metacholine bronchial responsiveness: different patterns in asthmatic children and children with other chronic lung diseases.
Cold air inhalation and exercise-induced bronchoconstriction (EIB) have both been used as measures of bronchial responsiveness. Both stimuli are often combined in the Nordic climate. The main objective of the present study was to investigate the climatic influence of cold temperatures upon exercise-induced asthma. The secondary aims were: (a) to assess metacholine bronchial hyper-responsiveness and EIB in children with bronchial asthma (n = 32; mean age 10.8 years) compared to children with other chronic lung diseases (CLD) (n = 26, mean age 10.1 years); and (b) to assess the influence of cold air inhalation upon EIB in the two groups of children. Methods used were: (a) the metacholine concentration causing a reduction in FEV1 of 20% (PC20-M), (b) maximum FEV1 fall (delta FEV1) after submaximal treadmill run (EIB test); and (c) delta FEV1 after submaximal treadmill run while inhaling cold (-20 degrees C) dry air (CA-EIB test). Geometric mean PC20-M did not differ significantly between the asthma children (1.28 mg ml-1) and the CLD children (2.90 mg ml-1). In the asthma children, mean delta FEV1 after EIB test was 12.8% vs 21.8% after adding cold air (P
OBJECTIVE: To study the effect of an educational intervention on general practitioners' (GPs') ability to diagnose bronchial obstruction after clinical examination. DESIGN: Based on physical chest examination 11 GPs assessed the degree of bronchial obstruction by estimating the patient's predicted forced expiratory volume in one second (FEV1%). Half way in the study the GPs were taught new knowledge on associations between lung sounds and bronchial airflow. The agreements between estimated and measured FEV1% predicted before and after this educational intervention were compared. SETTING: 11 GPs in five health centres in northern Norway took part. PATIENTS: 351 adult patients were included in phase 1, and 341 in phase 2. MAIN OUTCOME MEASURES: Estimated and measured FEV1% predicted were compared in subgroups of patients according to clinical findings in phase 1 and 2. The effect of the intervention on the doctors' weighting of various chest signs could thus be evaluated. Kappa agreement and correlation between estimated and measured FEV1% predicted in both phases were determined. RESULTS: The agreement between estimated and measured FEV1% predicted increased from Kw (weighted Kappa) = 0.33 in phase 1 to Kw = 0.43 in phase 2 (95% confidence interval 0.35-0.52). The GPs laid more relevant emphasis on rhonchi in their estimates after the educational intervention, while too much weight was laid on uncertain chest findings in phase 2. CONCLUSION: The study shows a potential for better use of physical chest examination in the diagnosis of bronchial obstruction.
The objective of the study was to evaluate the reliability, validity and responsiveness of two generic multiattribute methods for measuring utility for health states: a 15-dimensional (15D) and a five-dimensional method (EuroQol and EQ-TTO). A self-administered questionnaire with both measures was used in 59 outpatients with chronic obstructive pulmonary disease and the findings compared with standard gamble (SG) and time trade-off (TTO) utilities, spirometry and arterial blood gases. Quality of life scores were smallest for EQ-TTO (median 0.73) and highest for SG and TTO (median 0.91 and 0.95 respectively), while 15D gave intermediate values (median 0.80). The test-retest reliability over 14 days was: 15D (p = 0.90) and EQ-TTO (p = 0.73), using Spearman's rank correlation. 15D was better than EQ-TTO at discriminating between groups of patients after reported global rating of change over 12 months (P = 0.004 versus P = 0.09), indicating that 15D was more responsive. The 15D instrument has many attractive properties when compared to the EQ-TTO method, including a better reliability and responsiveness. Validity depends on validation method. The findings in this study indicate that the different utility measures measure different aspects of health-related quality of life (HRQoL). Caution should be taken when choosing utility instruments in cost-utility studies, as this can strongly influence the results.