Role of meteorological factors in duodenal ulcer seasonality: a nation-wide, population-based study.
BACKGROUND
Understanding disease seasonality can provide guidance for future biomedical research.


OBJECTIVE
To examine whether meteorological factors and calendar months impact duodenal ulcer (DU) exacerbations.


METHODS
We conducted a retrospective time series analysis of population-based claims data.


METHODS
DU inpatients (1997-2003; all endoscopy confirmed) from Taiwan, a small island nation, n = 160,510. Inpatient admission was used as a proxy for exacerbation because 98.5% of cases had hemorrhage or perforation or both.


METHODS
We used multivariate autoregressive integrated moving average (ARIMA) modeling to examine if DU admissions/100,000 was associated with calendar month, ambient temperature, relative humidity, rainfall, atmospheric pressure, and sunshine hours, controlling for available DU-relevant comorbidities.


RESULTS
DU admissions increased with age. ARIMA modeling showed a February (Chinese New Year-related) trough in all age groups (all p < 0.001; adjusted for meteorological variables and comorbidities), consistent with a February dip in all-cause admissions. Among 35-49 and 50+ age groups, DU admissions were negatively associated with temperature (both p < 0.05; model R2 = 0.875 and 0.920, respectively), representing a winter peak and summer trough. Among the < or = 19 age group, sunshine hours and rainfall are positively associated with DU admissions (both p < 0.001; R2 = 0.565), representing a summer peak.


CONCLUSIONS
Meteorological variables are associated with DU exacerbations, although the potential role of nonsteroidal anti-inflammatory drug (NSAID) use because of seasonal acute respiratory illness cannot be ruled out. We recommend in-depth studies using chart reviews of DU patients admitted during peak and trough (incidence) months to clarify whether meteorological factors or the associated seasonal peaks of respiratory and other illnesses involving NSAID use are responsible for the observed seasonality.
Xirasagar
Sudha
S
Department of Health Services Policy and Management, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA.
Lin
Herng-Ching
HC
Chen
Chin-Shyan
CS
D000328:Adult; D017677:Age Distribution; D000368:Aged; D015331:Cohort Studies; D004381:Duodenal Ulcer / Q000453:epidemiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008685:Meteorological Concepts; D008875:Middle Aged; D015999:Multivariate Analysis; D011336:Probability; D012189:Retrospective Studies; D018570:Risk Assessment; D012621:Seasons; D017678:Sex Distribution; D013624:Taiwan / Q000453:epidemiology