Association between air pollution and general outpatient clinic consultations for upper respiratory tract infections in Hong Kong.
OBJECTIVE
Many studies have shown the adverse effects of air pollution on respiratory health, but few have examined the effects of air pollution on service utilisation in the primary care setting. The aim of this study was to examine the association between air pollution and the daily number of consultations due to upper respiratory tract infections (URTIs) in general outpatient clinics (GOPCs) in Hong Kong.


METHODS
Daily data on the numbers of consultations due to URTIs in GOPCs, the concentrations of major air pollutants, and the mean values of metrological variables were retrospectively collected over a 3-year period (2008-2010, inclusive). Generalised additive models were constructed to examine the association between air pollution and the daily number of consultations, and to derive the relative risks and 95% confidence intervals (95% CI) of GOPC consultations for a unit increase in the concentrations of air pollutants.


RESULTS
The mean daily consultations due to URTIs in GOPCs ranged from 68.4 to 253.0 over the study period. The summary relative risks (and 95% CI) of daily consultations in all GOPCs for the air pollutants PM10, NO2, O3, and SO2 were 1.005 (1.002, 1.009), 1.010 (1.006, 1.013), 1.009 (1.006, 1.012), and 1.004 (1.000, 1.008) respectively, per 10 µg/m(3) increase in the concentration of each pollutant.


CONCLUSIONS
Significant associations were found between the daily number of consultations due to URTIs in GOPCs and the concentrations of air pollutants, implying that air pollution incurs a substantial morbidity and increases the burden of primary health care services.
Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Sha Tin, Hong Kong ; Shenzhen Municipal Key Laboratory for Health Risk Analysis, Shenzhen Research Institute of The Chinese University of Hong Kong, Shenzhen, Guangdong Province, China.
Wilson W S
WW
Tam
Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Sha Tin, Hong Kong.
Tze Wai
TW
Wong
General Outpatient Clinics, Kwong Wah Hospital, Yaumatei, Hong Kong.
Lorna
L
Ng
Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Sha Tin, Hong Kong.
Samuel Y S
SY
Wong
Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Sha Tin, Hong Kong.
Kenny K L
KK
Kung
Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Sha Tin, Hong Kong.
Andromeda H S
AH
Wong
D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000009:adverse effects*; D000554:Ambulatory Care Facilities / Q000706:statistics & numerical data*; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012017:Referral and Consultation; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000209:etiology*; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors
D000393:Air Pollutants