Prevalence and Risks for Chronic Pulmonary Diseases in Taiwan

• Main Authors: Yu-Chun Wang, 王玉純
• Other Authors: Fung-Chang Sung
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/47049322414950709141

博士 === 國立臺灣大學 === 環境衛生研究所 === 95 === Chronic pulmonary diseases (CPDs) are slowly progressive heterogeneous disorders of the airways with associated etiological factors remain nebulous and debatable. This study aimed to analyze the prevalence and risks of the diseases for the three metros, and Hualien/Taitung area in Taiwan. We used universal health insurance claims, measurements of air pollutants and weather, and virological surveillance data to clarify the relative importance of potential risk factors. We first used the reimbursement claims file of an established cohort from the National Health Insurance programe to estimate the chronological prevalence of CPDs and pneumonia and influenza (P&I) and comorbidity associated with severity of these diseases by multiple polytomous regression analyses between 1996 and 2003. The Poisson regression model was used to estimate the risk for these two diseases associated with weather conditions and air pollution, etc. We also conducted survival analyses for patients to compare the difference between patients with and without pneumonia and influenza. The chronological analysis for the population-based cohort demonstrated a dramatic pattern of declining prevalence of CPDs and P&I for the population in Taiwan two to three years after the launch of the nationwide health insurance. CPDs were the most common in the elderly but P&I were most prevalent in population aged 14 years and less that both with the highest rate in Kaohsiung, Taitung and Hualien and the lowest in Taipei. Pneumonia and influenza (P&I) were founded as the most important co-morbidities associated with the hospitalization for CPDs with an odds ratio of 2.16 (95% confidence interval (CI): 2.00-2.34, p < 0.0001). The risk for CPDs was the highest when ambient average temperature was at extreme cold (less than 5 percentile in 3 metros) with an overall relative risk (RR) of 1.18 (95% CI: 1.13-1.23, p < 0.0001). This association was significant in Taipei and Taichung, but not in Kaohsiung. This atmospheric environment association was significant for both bronchitis/emphysema/asthma (BEA) and severity of the disease (7-28 clinic vists), but not the chronic obstructive pulmonary disease (COPD). NOx had a greater health impacts in Taipei and Kaohsiung, but PM10 and SO2 in Taichung. Low wind speed and high sunshine rate in summer and autumn, and low relative humidity in spring and autumn were also significant weather conditions associated with the occurrence of CPDs. In all association models, P&I was consistently a significant risk factor for CPDs. The risk for P&I associated with extreme cold was greater in Taipei with a RR of 1.31 (95% CI: 1.20-1.42, p<0.0001) than in Kaohsiung with a RR of 1.19 (95% CI: 1.09-1.31, p<0.0001). Low relative humidity was also an important risk factor for P&I. Nitrogen oxides (NOx) was a significant air pollutant associated with P&I morbidity, with a RR of 1.004 (95% CI: 1.001-1.007, p= 0.0175) for per 1 ppb NOx increase in Taipei, 1.005 (95% CI: 1.002-1.008) in Taichung, and 1.011 (95% CI: 1.007-1.015) in Kaohsiung. The risk for P&I morbidity associated with PM10 of 1 microgram per cubic meter increase was also significant (RR=1.003, 95% CI: 1.002-1.004) in Taipei. In the survival analysis for the association between clinic visits of P&I and CPDs, the results showed that a lower cumulative survival rate occurred in cold season, male, and period before the influenza vaccination program. Lower cumulative survival rates for CPDs also appeared in the Kaohsiung population and those aged 0-14 and 50-69 years old before vaccination. But, there was a significant increase in survival in cases aged 60-69 years old, rose from 0.42 to 0.54. There was a greater impact from P&I for COPD with a hazard ratio (HR) of 11.7 (95% CI: 8.64-15.7, p <0.0001) than for BEA (HR= 4.82, 95% CI: 4.60-5.05, p <0.0001). The effect was reduced for those diagnosed with both BEA and COPD (HR= 2.59, 95% CI: 2.42-2.78, p <0.0001). Overall, the HR associated with pneumonia and influenza for CPDs was 3.91 (95% CI: 3.76-4.07, p <0.0001) after controlling for age, sex, area, vaccination, disease category and season. In conclusion, the prevalence of reimbursement claims for the care of CPDs during 1996-2002 in Taiwan varied by area in association with P&I prevalence, regional weather conditions and air pollution. P&I had strongest association with the risk for CPDs in the 3 study metros. Among the 3 areas, the ambient temperature was also a significant risk factor for CPDs in Taipei and Taichung and air pollution in Kaohsiung.