title: The RIPASA score is sensitive and specific for the diagnosis of acute appendicitis in a western population.
abstract: OBJECTIVE
  The definitive diagnosis of acute appendicitis (AA) requires histopathological examination. Various clinical diagnostic scoring systems attempt to reduce negative appendectomy rates. The most commonly used in Western Europe and the USA is the Alvarado score. The Raja Isteri Pengiran Anak Saleha appendicitis (RIPASA) score achieves better sensitivity and specificity in Asian and Middle Eastern populations. We aimed to determine the diagnostic accuracy of the RIPASA score in Irish patients with AA.
  
  
  METHODS
  All patients who presented to our institution with right iliac fossa pain and clinically suspected AA between January 1 and December 31, 2015, were indentified from our hospital inpatient enquiry database and retrospectively studied. Operating theatre records and histology reports confirmed those who underwent a non-elective operative procedure and the presence or absence of AA. SPSS version 22 was used for statistical analysis. Standard deviation is provided where appropriate.
  
  
  RESULTS
  Two hundred eight patients were included in the study (106/51% male, mean age 22.7 ± 9.2 years). One hundred thirty-five (64.9%) had histologically confirmed AA (mean symptom duration = 36.19 ± 15.90 h). At a score ≥7.5, the previously determined score most likely associated with AA in Eastern populations, the RIPASA scoring system demonstrated a sensitivity of 85.39%, specificity of 69.86%, positive predictive value of 84.06%, negative predictive value of 72.86% and diagnostic accuracy of 80% in our cohort.
  
  
  CONCLUSIONS
  The RIPASA score is a useful tool to aid in the diagnosis of acute appendicitis in the Irish population. A score of ≥7.5 provides sensitivity and specificity exceeding that previously documented for the Alvarado score in Western populations. WHAT DOES THIS PAPER ADD TO THE LITERATURE?: This is the first study evaluating the utility of the RIPASA score in predicting acute appendicitis in a Western population. At a value of 7.5, a cut-off score suggestive of appendicitis in the Eastern population, RIPASA demonstrated a high-sensitivity, specificity, positive predictive value and diagnostic accuracy in our cohort and was more accurate than the commonly used Alvarado score.
authors.affiliation: Department of Surgery, St. Luke's Hospital, Kilkenny, Ireland.
authors.forename: Muhammad Usman
authors.initials: MU
authors.lastname: Malik
authors.affiliation: Department of Surgery, University Hospital Waterford, Waterford, Ireland. tarconnelly@rcsi.ie.
authors.forename: Tara M
authors.initials: TM
authors.lastname: Connelly
authors.affiliation: Department of Surgery, St. Luke's Hospital, Kilkenny, Ireland.
authors.forename: Faisal
authors.initials: F
authors.lastname: Awan
authors.affiliation: Department of Surgery, St. Luke's Hospital, Kilkenny, Ireland.
authors.forename: Frederik
authors.initials: F
authors.lastname: Pretorius
authors.affiliation: Department of Surgery, St. Luke's Hospital, Kilkenny, Ireland.
authors.forename: Constantino
authors.initials: C
authors.lastname: Fiuza-Castineira
authors.affiliation: Department of Surgery, St. Luke's Hospital, Kilkenny, Ireland.
authors.forename: Osama
authors.initials: O
authors.lastname: El Faedy
authors.affiliation: Department of Surgery, St. Luke's Hospital, Kilkenny, Ireland.
authors.forename: Paul
authors.initials: P
authors.lastname: Balfe
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D001064:Appendicitis / Q000175:diagnosis*; D002648:Child; D015331:Cohort Studies; D005060:Europe; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: Acute appendicitis; Alvarado score; Histopathology; RIPASA score; Raja Isteri Pengiran Anak Saleha appendicitis score