title: Risk factors associated with pelvic inflammatory disease.
abstract: OBJECTIVE
  To investigate factors associated with pelvic inflammatory disease (PID).
  
  
  METHODS
  A case-control study was used to investigate demographic and behavioural factors, and causative agents associated with PID.
  
  
  RESULTS
  A total of 381 participants were recruited: 140 patients, and 105 and 136 controls in tubal ligation and general practice groups, respectively. When compared with a PID-free tubal ligation control group, increased risk of PID was associated with: age <25 years; age at first sexual intercourse <20 years; non-white ethnicity; not having had children; a self-reported history of a sexually transmitted disease; and exposure to Chlamydia trachomatis. When compared with a general practice control group, increased risk was associated with: age <25 years; age at first sexual intercourse <15 years; lower socioeconomic status; being single; adverse pregnancy outcome; a self-reported history of a sexually transmitted disease; and exposure to C trachomatis. Of the cases, 64% were not associated with any of the infectious agents measured in this study (idiopathic).
  
  
  CONCLUSIONS
  A high proportion of cases were idiopathic. PID control strategies, which currently focus on chlamydial screening, have to be reviewed so that they can prevent all cases of PID. Behavioural change is a key factor in the primary prevention of PID, and potential modifiable risk factors were associated with PID.
authors.affiliation: Health Protection Agency Centre for Infections, 61 Colindale Avenue, London NW9 5EQ, UK. ian.simms@hpa.org.uk
authors.forename: I
authors.initials: I
authors.lastname: Simms
authors.forename: J M
authors.initials: JM
authors.lastname: Stephenson
authors.forename: H
authors.initials: H
authors.lastname: Mallinson
authors.forename: R W
authors.initials: RW
authors.lastname: Peeling
authors.forename: K
authors.initials: K
authors.lastname: Thomas
authors.forename: R
authors.initials: R
authors.lastname: Gokhale
authors.forename: P A
authors.initials: PA
authors.lastname: Rogers
authors.forename: P
authors.initials: P
authors.lastname: Hay
authors.forename: P
authors.initials: P
authors.lastname: Oakeshott
authors.forename: J
authors.initials: J
authors.lastname: Hopwood
authors.forename: H
authors.initials: H
authors.lastname: Birley
authors.forename: M
authors.initials: M
authors.lastname: Hernon
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D000292:Pelvic Inflammatory Disease / Q000209:etiology*; D012307:Risk Factors; D012749:Sexually Transmitted Diseases / Q000209:etiology*