Wong Chit Ming, Yang Lin, Thach Thuan Quoc, Chau Patsy Yuen Kwan, Chan King Pan, Thomas G Neil, Lam Tai Hing, Wong Tze Wai, Hedley Anthony J, Peiris J S Malik
Department of Community Medicine and School of Public Health, University of Hong Kong, Hong Kong Special Administration Region, People's Republic of China.
Environ Health Perspect. 2009 Feb;117(2):248-53. doi: 10.1289/ehp.11605. Epub 2008 Oct 3.
Both influenza viruses and air pollutants have been well documented as major hazards to human health, but few epidemiologic studies have assessed effect modification of influenza on health effects of ambient air pollutants.
We aimed to assess modifying effects of influenza on health effects of ambient air pollutants.
We applied Poisson regression to daily numbers of hospitalizations and mortality to develop core models after adjustment for potential time-varying confounding variables. We assessed modification of influenza by adding variables for concentrations of single ambient air pollutants and proportions of influenza-positive specimens (influenza intensity) and their cross-product terms.
We found significant effect modification of influenza (p < 0.05) for effects of ozone. When influenza intensity is assumed to increase from 0% to 10%, the excess risks per 10-microg/m(3) increase in concentration of O(3) increased 0.24% and 0.40% for hospitalization of respiratory disease in the all-ages group and >or= 65 year age group, respectively; 0.46% for hospitalization of acute respiratory disease in the all-ages group; and 0.40% for hospitalization of chronic obstructive pulmonary disease in the >or= 65 group. The estimated increases in the excess risks for mortality of respiratory disease and chronic obstructive pulmonary disease in the all-ages group were 0.59% and 1.05%, respectively. We found no significant modification of influenza on effects of other pollutants in most disease outcomes under study.
Influenza activity could be an effect modifier for the health effects of air pollutants particularly for O(3) and should be considered in the studies for short-term effects of air pollutants on health.
流感病毒和空气污染物均已被充分证明是对人类健康的主要危害，但很少有流行病学研究评估流感对环境空气污染物健康影响的效应修正作用。
我们旨在评估流感对环境空气污染物健康影响的修正作用。
我们将泊松回归应用于每日住院人数和死亡人数，在对潜在的随时间变化的混杂变量进行调整后建立核心模型。我们通过添加单一环境空气污染物浓度变量、流感阳性标本比例（流感强度）及其交叉项来评估流感的修正作用。
我们发现流感对臭氧的影响有显著的效应修正作用（p < 0.05）。当假设流感强度从0%增加到10%时，在全年龄组和≥65岁年龄组中，每10微克/立方米的臭氧浓度增加，呼吸系统疾病住院的额外风险分别增加0.24%和0.40%；在全年龄组中，急性呼吸系统疾病住院的额外风险增加0.46%；在≥65岁组中，慢性阻塞性肺疾病住院的额外风险增加0.40%。在全年龄组中，呼吸系统疾病和慢性阻塞性肺疾病死亡的额外风险估计增加分别为0.59%和1.05%。在大多数研究的疾病结局中，我们未发现流感对其他污染物的影响有显著的修正作用。
流感活动可能是空气污染物健康影响的效应修正因素，特别是对臭氧而言，在研究空气污染物对健康的短期影响时应予以考虑。
