title: Inappropriate initial treatment of secondary intra-abdominal infections leads to increased risk of clinical failure and costs.
abstract: OBJECTIVE
  The objective of this population-based, retrospective cohort study was to investigate the incidence and initial antibiotic treatment of secondary intra-abdominal infections (sIAI) and to assess whether inappropriate initial antibiotic therapy affects patient outcomes.
  
  
  METHODS
  All patients hospitalized for sIAI (1995-1998) were identified in the PHARMO Record Linkage System, a patient-centric database including pharmacy dispensing records from community pharmacies linked to hospitalization records in the Netherlands. Complementary in-hospital antibiotic drug use was obtained from the computerized inpatient pharmacy files. The patient outcomes considered were switch to second-line antibiotic treatment, re-operation, and death. In addition, a composite variable clinical failure was constructed based on the above-mentioned outcomes. Furthermore, the effect of clinical failure on length of hospital stay and costs of hospitalization was assessed. Associations between appropriateness of initial antibiotic treatment and outcomes were estimated using multivariate logistic and linear regression models.
  
  
  RESULTS
  In the source population of 228,000 persons, 175 cases were classified as sIAI (mean age 49.3 +/- 24.5, 50.9% male) resulting in an incidence of 2.3/10,000 person-years [95% confidence interval (CI) 2.0, 2.7]. Initial antibiotic treatment was appropriate for 84% of the cases. The risk of clinical failure was 17.1%. Inappropriate initial antibiotic treatment increased the risk of clinical failure 3.4-fold (95% CI 1.3, 9.1). Length of hospital stay and costs of hospitalization were significantly increased for patients with clinical failure.
  
  
  CONCLUSIONS
  Inappropriate choice of initial antibiotic therapy in sIAI patients leads to more clinical failure resulting in a longer hospital stay and higher costs of hospitalization compared with appropriate initial antibiotic therapy.
authors.affiliation: International Pharmacoepidemiology and Pharmacoeconomics Research Centre, Desio, Italy.
authors.forename: Miriam C J M
authors.initials: MC
authors.lastname: Sturkenboom
authors.forename: Wim G
authors.initials: WG
authors.lastname: Goettsch
authors.forename: Gino
authors.initials: G
authors.lastname: Picelli
authors.forename: Bas
authors.initials: B
authors.lastname: in 't Veld
authors.forename: Don D
authors.initials: DD
authors.lastname: Yin
authors.forename: Romy B
authors.initials: RB
authors.lastname: de Jong
authors.forename: Peter M N Y H
authors.initials: PM
authors.lastname: Go
authors.forename: Ron M C
authors.initials: RM
authors.lastname: Herings
mesh_terms: D000006:Abdomen, Acute / Q000188:drug therapy* / Q000209:etiology; D000328:Adult; D000368:Aged; D001424:Bacterial Infections / Q000188:drug therapy* / Q000191:economics / Q000453:epidemiology; D003365:Costs and Cost Analysis; D005260:Female; D006300:Health Services Misuse; D006760:Hospitalization / Q000191:economics; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D010538:Peritonitis / Q000188:drug therapy* / Q000453:epidemiology; D011446:Prospective Studies; D012189:Retrospective Studies; D017211:Treatment Failure; D016896:Treatment Outcome