Associations of Ambient Air Pollutant Concentrations With Respiratory Symptoms and Perceived Health Status in Japanese Adults With and Without Chronic Respiratory Diseases: A Panel Study.

OBJECTIVES: In recent years, transboundary air pollution from mainland East Asia has led to growing concerns about air pollution in Japan. Air pollution is reportedly associated with the exacerbation of respiratory diseases. In this study, we assessed the effects of air pollution on respiratory symptoms and the health status of participants with and without chronic respiratory diseases. METHODS: Participants (n=2753) with and without chronic respiratory diseases who visited healthcare facilities in Japan during February from 2010 to 2015 filled out a self-report questionnaire regarding their symptoms and perceived health status. Participants were followed up during April-May and June-July. RESULTS: Oxidant concentrations were associated with respiratory symptoms, overall health, and quality of life (QoL). Suspended particulate matter (SPM) and particulate matter <2.5 µm levels were associated with physical fitness; SPM was also associated with QoL. Recent experience of an Asian sand dust event had a significant effect on allergic symptoms, change in health, and QoL. CONCLUSIONS: Respiratory symptoms were more strongly affected by oxidants than by other pollutants. Significant associations of air pollutants were found with a comprehensive range of items related to perceived health status, including overall health and QoL. Although the effects of air pollutants on respiratory symptoms and health status were more apparent among patients with respiratory diseases, the adverse effects of air pollutants were significant even among participants without such conditions.

How different are COPD-specific patient reported outcomes, health status, dyspnoea and respiratory symptoms? An observational study in a working population.

OBJECTIVES: We hypothesised that chronic obstructive pulmonary disease (COPD)-specific health status measured by the COPD assessment test (CAT), respiratory symptoms by the evaluating respiratory symptoms in COPD (E-RS) and dyspnoea by Dyspnoea-12 (D-12) are independently based on specific conceptual frameworks and are not interchangeable. We aimed to discover whether health status, dyspnoea or respiratory symptoms could be related to smoking status and airflow limitation in a working population. DESIGN: This is an observational, cross-sectional study. PARTICIPANTS: 1566 healthy industrial workers were analysed. RESULTS: Relationships between D-12, CAT and E-RS total were statistically significant but weak (Spearman's correlation coefficient=0.274 to 0.446). In 646 healthy non-smoking subjects, as the reference scores for healthy non-smoking subjects, that is, upper threshold, the bootstrap 95th percentile values were 1.00 for D-12, 9.88 for CAT and 4.44 for E-RS. Of the 1566 workers, 85 (5.4%) were diagnosed with COPD using the fixed ratio of the forced expiratory volume in one second/forced vital capacity <0.7, and 34 (2.2%) using the lower limit of normal. The CAT and E-RS total were significantly worse in non-COPD smokers and subjects with COPD than non-COPD never smokers, although the D-12 was not as sensitive. There were no significant differences between non-COPD smokers and subjects with COPD on any of the measures. CONCLUSIONS: Assessment of health status and respiratory symptoms would be preferable to dyspnoea in view of smoking status and airflow limitation in a working population. However, these patient-reported measures were inadequate in differentiating between smokers and subjects with COPD identified by spirometry.

Relationships between perceived health status and ambient air quality parameters in healthy Japanese: a panel study.

BACKGROUND: There has been growing global concern about air pollution due to its great risk to public health. In Japan, although industrial- and traffic-related air pollution has been decreasing, concerns about particulate matter air pollution has been growing in recent years. In this study, we examined the effects of air pollution on symptoms and the health status of healthy subjects in Japan. METHODS: Participants (n = 2887) who visited healthcare centers in Kumamoto or Niigata prefectures in February from 2010 to 2015 were asked to fill out a questionnaire, which was a self-completed booklet containing questions on the characteristics of participants, their respiratory symptoms, and questionnaires on their health status in February, May, and July. Generalized estimating equation analyses were performed to predict the factors associated with the symptoms and health status using two-week averages of air quality parameters obtained from 49 monitoring stations as independent variables. RESULTS: Only allergy was associated with air quality in both areas. Prevalence of the other respiratory symptoms were correlated with air quality only in Kumamoto. The health statuses including the 'physical fitness', 'daily activities', and 'social activities' domains were related only to time spent outdoors. The 'overall health' was associated with time spent outdoors and concentrations of nitrogen dioxide and suspended particulate matters (SPM) in Kumamoto, and with temperatures and SPM in Niigata. The 'pain' score was correlated with temperature and carbon monoxide concentration only in Kumamoto. In Kumamoto, the 'quality of life (QoL)' was worse in those who spent shorter hours outdoors, were exposed to lower humidity, higher concentrations of oxidants, SPM, and PM2.5, and who experienced more Asian sand dust (ASD) events. In Niigata, a worsened 'QoL' was associated with time spent outdoors, temperature, and SPM. CONCLUSIONS: The associations between air quality and the health status was found mainly in the comprehensive domain of the health status such as 'overall health' and 'QoL'. The effect of short-term exposure to larger particles, such as SPM, on health status was observed when compared to smaller particles such as PM2.5 and gaseous pollutants.

COPD and disease-specific health status in a working population.

BACKGROUND: It has been debated whether treatment should be started early in subjects with mild to moderate COPD. An impaired health status score was associated with a higher probability of being diagnosed with COPD as compared with undiagnosed COPD. PURPOSE: To investigate the health status in a healthy working population, to determine reference scores for healthy non-smoking subjects, and to investigate the relationship between their health status and airflow limitation. METHODS: A total of 1333 healthy industrial workers aged ≥40 years performed spirometry and completed the St. George's Respiratory Questionnaire (SGRQ) and the COPD Assessment Test (CAT). RESULTS: The prevalence of COPD defined by the fixed ratio of the forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) was 10.9%, and the prevalence defined by the Lower Limit of Normal was 5.0%. All SGRQ and CAT scores were skewed to the milder end. In 512 non-smoking subjects with normal spirometry, the mean SGRQ score was 5.7, and the mean CAT score was 5.8. In 145 people with COPD defined by the fixed ratio, the mean SGRQ score was 7.9, with a zero score in 6.9% of the subjects. Using the CAT, the mean score was 7.3, with 7.6% of the scores being zero. The scores in patients identified using the Lower Limit of Normal approach were: SGRQ 8.4 (13.4% had a score of zero) and CAT 7.4 (13.4% had a score of zero). Although the 95th percentiles of the Total, Symptoms, Activity, and Impact scores of the SGRQ and CAT sores were 13.8, 34.0, 23.4, 7.2 and 13.6 in the 512 healthy non-smoking subjects, respectively, they were also distributed under their upper limits in over 80% of the COPD subjects. CONCLUSION: The COPD-specific health status scores in a working population were good, even in those with spirometrically diagnosed COPD. All scores were widely distributed in both healthy non-smoking subjects and in subjects with COPD, and the score distribution overlapped remarkably between these two groups. This suggests that symptom-based methods are not suitable screening tools in a healthy general population.

Case identification of subjects with airflow limitations using the handheld spirometer "Hi-Checker™" : comparison against an electronic desktop spirometer.

BACKGROUND: Systematic case identification has been proposed as a strategy to improve diagnosis rates and to enable the early detection of subjects with COPD. We hypothesized that case identification could be possible using the handheld spirometer Hi-Checker™. AIM: To determine how to modify the FEV(1)/FEV(6) values obtained using the Hi-Checker™ to screen for cases with airflow limitation. METHODS: Spirometry was performed with both an electronic desktop spirometer and with the Hi-Checker™ in 312 male subjects. RESULTS: The average FEV(1) (mean ± SD) measured using a conventional spirometer and the Hi-Checker™ was 2.99 ± 0.56L and 3.07 ± 0.57L, respectively. These results were significantly different (P<0.001, paired t-test for both). This difference of -0.08 ± 0.13L (95% confidence interval: -0.094-0.066L) was normally distributed, and thought to be random. Statistically significant correlations were found for all measurements between the spirometer and the Hi-Checker™ ; the Pearson's correlation coefficient (R) between the FEV(1)/FVC and FEV(1)/FEV(6) values was 0.881. If one defines a FEV(1/)FVC smaller than 0.7 measured by the spirometer as airflow limitation, then a FEV(1)/FEV(6) smaller than 0.746 measured by the Hi-Checker™ best matches this definition, and Cohen's kappa coefficient was 0.672. CONCLUSION: Although the Hi-Checker™ estimates resembled those from conventional spirometry, it should be emphasized that the two methods did not produce identical results due to random measurement error. Although one must be careful about overinterpreting these results, since the Hi-Checker™ is small and inexpensive, it could make a significant contribution in facilitating the case selection of patients with airflow limitation.