title: Time to diagnosis and stage of symptomatic colorectal cancer determined by three different sources of information: A population based retrospective study.
abstract: Survival rates from colorectal cancer (CRC) are highly variable in Europe. This variability could potentially be explained by differences in healthcare system delays in diagnosis. However, even when such delays are reduced, the relationship of the diagnostic interval (time from presentation with symptoms to diagnosis) with outcome is uncertain.
  
  
  
  A total of 795 patients with CRC from 5 regions of Spain were retrospectively examined in this population-based multicenter study. Consecutive incident cases of CRC were identified from pathology services. The total diagnostic interval (TDI) was defined as the time from the first presentation with symptoms to diagnosis based on 3 different sources of information: (i) patient-recorded data (PR-TDI) by interview, (ii) hospital-recorded data (HR-TDI), and (iii) general practitioner-recorded data (GPR-TDI). Concordance correlation coefficients (CCCs) were used to estimate the agreement of 3 different TDIs. The TDIs of patients with different stages of CRC were also compared using the Kruskal-Wallis test.
  
  
  
  The median TDI was 131days based on patient interview data, 91days based on HR data, and 111days based on GPR data. Overall, the agreement of these TDIs was poor (CCCPRvsHR=0.399, CCCPRvsGPR=0.518, CCCHRvsGPR=0.383). Univariate analysis indicated that the TDI was greater in those with less advanced CRC for all 3 methods of calculation, but this association was only statistically significant for the HR-TDI (p=0.021).
  
  
  
  There is no evidence that patients with more advanced CRC have longer TDIs. In fact, we found an inverse relationship between the TDI and CRC stage, an example of the "waiting time paradox". This association may likely be due to the presence of unmeasured confounders as the stage when symptoms appear or the tumour aggressiveness.
authors.affiliation: Primary Care Research Unit of Mallorca, Baleares Health Services-IbSalut, 07005 Palma, España, Instituto de Investigación Sanitaria de Palma, 07010 Palma, Spain. Electronic address: aleiva@ibsalut.caib.es.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Leiva
authors.affiliation: Primary Care Research Unit of Mallorca, Baleares Health Services-IbSalut, 07005 Palma, España, Instituto de Investigación Sanitaria de Palma, 07010 Palma, Spain. Electronic address: mesteva@ibsalut.caib.es.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Esteva
authors.affiliation: Primary Care Research Unit of Mallorca, Baleares Health Services-IbSalut, 07005 Palma, España, Instituto de Investigación Sanitaria de Palma, 07010 Palma, Spain. Electronic address: jllobera@ibsalut.caib.es.
authors.forename: Joan
authors.initials: J
authors.lastname: Llobera
authors.affiliation: Evaluation and Clinical Epidemiology Department, Hospital del Mar, Passeig Marítim 25-29, 08003, Barcelona, Spain. Electronic address: 91932@hospitaldelmar.es.
authors.forename: Francesc
authors.initials: F
authors.lastname: Macià
authors.affiliation: Clinical Epidemiology and Biostatistics Unit, A Coruña University, Complexo Hospitalario Universitario A Coruña, Xubias de Arriba, 84, Hotel de los pacientes 7ª planta, 15006, A Coruña, Spain. Electronic address: salvador.pita.fernandez@sergas.es.
authors.forename: Salvador
authors.initials: S
authors.lastname: Pita-Fernández
authors.affiliation: Serreria II Primary Care Centre, Valencia Institute of Health, C/Pedro de Valencia 28, 46022, Valencia, Spain. Electronic address: gonzalez_lluiluj@gva.es.
authors.forename: Luis
authors.initials: L
authors.lastname: González-Luján
authors.affiliation: Canal Imperial Primary Care Centre, Paseo Colon 4, Zaragoza, 50006, Spain. Electronic address: mascalavera62@hotmail.com.
authors.forename: María A
authors.initials: MA
authors.lastname: Sánchez-Calavera
authors.affiliation: Department of Public Health, Balearic Department of Health, C/Jesus n 33, 07001, Instituto de Investigación Sanitaria de Palma, 07010 Palma, Spain, Spain. Electronic address: mramos@dgsanita.caib.es.
authors.forename: María
authors.initials: M
authors.lastname: Ramos
mesh_terms: D000368:Aged; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000401:mortality*; D057210:Delayed Diagnosis; D003695:Delivery of Health Care; D005260:Female; D006296:Health Services; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D013030:Spain / Q000453:epidemiology; D015996:Survival Rate; D013997:Time Factors
keywords: Colorectal neoplasms/mortality; Colorectal neoplasms/pathology; Colorectal neoplasms/therapy; Delayed diagnosis; Middle aged; Neoplasm staging; Retrospective studies