title: Seasonal Variation of Rectal Foreign Bodies: Data from Nationwide Inpatient Sample.
abstract: BACKGROUND
  Seasonality is noted in various aspects of human behavior and functioning which have led to an increasing interest in their seasonality in the recent years.
  
  
  OBJECTIVE
  We aimed to examine the seasonal variation in the incidence of rectal foreign bodies in the US using a large inpatient database.
  
  
  METHODS
  We used the Nationwide Inpatient Sample database to identify patients aged ≥18 years admitted with a primary diagnosis of the rectal foreign body from 2009 to 2011. We used the Edward's recognition and estimation of cyclic trend method to study the seasonal variation of the incidence of rectal foreign body and Z-test to compare the seasonal incidences.
  
  
  RESULTS
  A total of 3359 hospitalizations with primary diagnosis of the rectal foreign body were reported from 2009 to 2011. The peak incidence of rectal foreign bodies was seen in October (peak/low ratio 1.20, 95% confidence interval [CI]: 1.10-1.32).
  
  
  CONCLUSIONS
  Data on seasonal variation of rectal foreign bodies are extremely limited. Further studies would be required to verify whether our findings of a higher incidence in the fall season are reflective of acute changes in the length of the days, climate, sleep-wake cycle, or decreased sexual intercourse at this time of the year. High suspicion at this time of the year may help promptly diagnose and avoid unnecessary investigations.
authors.affiliation: Department of Internal Medicine , Reading Health System , West Reading, Pennsylvania , USA.
authors.forename: Ranjan
authors.initials: R
authors.lastname: Pathak
authors.affiliation: Department of Internal Medicine , Reading Health System , West Reading, Pennsylvania , USA.
authors.forename: Paras
authors.initials: P
authors.lastname: Karmacharya
authors.affiliation: Department of Internal Medicine , Reading Health System , West Reading, Pennsylvania , USA.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Alweis
keywords: Nationwide Inpatient Sample; rectal foreign body; seasonal variation