title: Impact of delay in diagnosis on survival to head and neck carcinomas: a systematic review with meta-analysis.
abstract: OBJECTIVE
  To address the contradictory information on the role of delay in diagnosis on head and neck cancer survival.
  
  
  METHODS
  Systematic review and meta-analysis.
  
  
  METHODS
  Search on MEDLINE (1966 to March 2011), EMBASE (1980 to March 2011) and ISI proceedings (from inception to March 2011). The terms used were ('Head and neck cancers') AND ('delay'OR'prognostic'OR'survival') both in MeSH terms and free-text words. The reference lists of the retrieved articles were also revised manually to identify other potentially relevant papers. All searches were independently undertaken by two clinicians and one epidemiologist, and the results merged.
  
  
  METHODS
  Primary and specialised care levels.
  
  
  METHODS
  Meta-analysis of data from papers on the subject published from 1966 to 2011.
  
  
  METHODS
  Survival.
  
  
  METHODS
  After search in Medline and other databases, we computed pooled relative risks (RR) and 95% confidence interval (95%CI) from the 10 studies retrieved.
  
  
  RESULTS
  The estimate of the relative risk of mortality related to any diagnostic delay (either patient or professional delay) was 1.34 (95%CI 1.12-1.61). Referral delay was associated with a three-fold increase in mortality. Total delay was marginally related to mortality (RR: 1.04, 95%CI: 1.01-1.07). By anatomic location, pharynx cancer shows the highest association (RR: 1.68, 95%CI: 1.22-2.31).
  
  
  CONCLUSIONS
  Diagnostic delay is a moderate risk factor of mortality from head and neck cancer. However, part of the effect observed may be due to residual confounding (confounding from unknown variables that are not eliminated by adjustment).
authors.affiliation: Stomatology Department, School of Medicine and Dentistry, University of Santiago de Compostela, Spain. juanmanuel.seoane@usc.es
authors.forename: J
authors.initials: J
authors.lastname: Seoane
authors.forename: B
authors.initials: B
authors.lastname: Takkouche
authors.forename: P
authors.initials: P
authors.lastname: Varela-Centelles
authors.forename: I
authors.initials: I
authors.lastname: Tomás
authors.forename: J M
authors.initials: JM
authors.lastname: Seoane-Romero
mesh_terms: D002277:Carcinoma / Q000175:diagnosis* / Q000401:mortality*; D057210:Delayed Diagnosis; D014943:Global Health; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000401:mortality*; D006801:Humans; D015996:Survival Rate / Q000639:trends