Seasonal variation in the presentation of abdominal pain.
BACKGROUND
Anxiety and depression, conditions frequently associated with childhood chronic abdominal pain (AP), are characterized by seasonal exacerbations. A seasonal pattern characterized by a higher frequency of consultations for AP during winter has been suspected but has never, to our knowledge, been demonstrated. We hypothesize the presence of a seasonal variation in AP consultations with a winter predominance.


OBJECTIVE
To determine the seasonal distribution of AP consultations among centers across time and geographic latitude.


METHODS
This was a retrospective cohort study. The number of outpatient consultations from primary care clinics and every pediatric specialty clinic that resulted in a diagnosis of AP and the total number of outpatient consultations (2001-2004) from 6 tertiary care institutions (Chicago, Pittsburgh, Wilmington, Pensacola, Orlando, Jacksonville) was determined. Rates of consultations were compared across time and between cities. Four time periods of interest, with 2- and 3-month definitions, were arbitrarily selected. Seasonal rates across time were compared separately for each of the 2-month (January-February vs June-July) and 3-month periods (January-March vs June-August). Logistic regression models for each city were used to determine variations in the rate of outpatient AP cases by season or by year.


RESULTS
A total of 3,929,522 outpatient consultations and 73,591 AP consultations were analyzed. The rates of AP consultations were consistently higher in the winter months at all of the sites. The results differed between sites at northern and southern latitudes.


CONCLUSIONS
There seems to be a seasonal variation in consultation patterns for AP at the tertiary care level. A possible role of daylight hours, climate, latitude, and stress is proposed.
Saps
M
M
Division of Pediatric Gastroenterology, Hepatology and Nutrition, Children's Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL 60614, USA. msaps@childrensmemorial.org
Blank
C
C
Khan
S
S
Seshadri
R
R
Marshall
Bm
B
Bass
Lm
L
Di Lorenzo
C
C
D015746:Abdominal Pain / Q000453:epidemiology* / Q000523:psychology*; D002648:Child; D015331:Cohort Studies; D016001:Confidence Intervals; D003710:Demography; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D015995:Prevalence; D012189:Retrospective Studies; D012621:Seasons; D014481:United States / Q000453:epidemiology