title: Opioid analgesic use among patients presenting with acute abdominal pain and factors associated with surgical diagnoses.
abstract: BACKGROUND
  The prevalence of chronic opioid use among non-cancer patients presenting with acute abdominal pain (AAP) is unknown. The aim was to characterize opioid use, constipation, diagnoses, and risk factors for surgical diagnoses among non-cancer patients presenting with AAP to an emergency department (ED).
  
  
  METHODS
  We performed a retrospective, observational cohort study of all (n=16,121) adult patients (88% from MN, IA and WI) presenting during 2014 with AAP. We used electronic medical records, and focused on 2352 adults with AAP who underwent abdominal CT scan within 24 hours of presentation. We determined odds ratios of association with constipation and features predicting conditions that may require surgery (surgical diagnosis).
  
  
  RESULTS
  There were 2352 eligible patients; 18.8% were opioid users. Constipation was more frequent in opioid (35.1%) compared to non-opioid users [OR 2.88 (95% CI 2.28, 3.62)]. Prevalence of surgical diagnosis in the opioid and non-opioid users was 35.3% and 41.7% respectively (P=.019). By univariate analysis, age and neutrophil count independently predicted increased risk, and chronic opioid use decreased risk of surgical diagnosis. Internal validation of logistic models using a randomly selected validation subset (25% of entire cohort, 587/2352) showed receiver operating characteristic (ROC) curves for the validation and full cohorts were similar.
  
  
  CONCLUSIONS
  Approximately 19% of adults presenting with AAP were opioid users; constipation is almost three times as likely in opioid users compared to non-opioid users presenting with AAP. Factors significantly associated with altered risk of surgical diagnoses were age, opioid use, and neutrophil count.
authors.affiliation: Clinical Enteric Neuroscience Translational and Epidemiological Research (CENTER), Mayo Clinic, Rochester, MN, USA.
authors.forename: D
authors.initials: D
authors.lastname: Khemani
authors.affiliation: Clinical Enteric Neuroscience Translational and Epidemiological Research (CENTER), Mayo Clinic, Rochester, MN, USA.
authors.forename: M
authors.initials: M
authors.lastname: Camilleri
authors.affiliation: Clinical Enteric Neuroscience Translational and Epidemiological Research (CENTER), Mayo Clinic, Rochester, MN, USA.
authors.forename: A
authors.initials: A
authors.lastname: Roldan
authors.affiliation: Clinical Enteric Neuroscience Translational and Epidemiological Research (CENTER), Mayo Clinic, Rochester, MN, USA.
authors.forename: A D
authors.initials: AD
authors.lastname: Nelson
authors.affiliation: Clinical Enteric Neuroscience Translational and Epidemiological Research (CENTER), Mayo Clinic, Rochester, MN, USA.
authors.forename: S-Y
authors.initials: SY
authors.lastname: Park
authors.affiliation: Clinical Enteric Neuroscience Translational and Epidemiological Research (CENTER), Mayo Clinic, Rochester, MN, USA.
authors.forename: A
authors.initials: A
authors.lastname: Acosta
authors.affiliation: Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA.
authors.forename: A R
authors.initials: AR
authors.lastname: Zinsmeister
mesh_terms: D000006:Abdomen, Acute / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology* / Q000601:surgery*; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D003248:Constipation / Q000453:epidemiology; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D000701:Analgesics, Opioid
keywords: 
  CT
  ; abdominal pain; constipation; emergency; opioids