title: Age and Gender Variations in Cancer Diagnostic Intervals in 15 Cancers: Analysis of Data from the UK Clinical Practice Research Datalink.
abstract: BACKGROUND
  Time from symptomatic presentation to cancer diagnosis (diagnostic interval) is an important, and modifiable, part of the patient's cancer pathway, and can be affected by various factors such as age, gender and type of presenting symptoms. The aim of this study was to quantify the relationships of diagnostic interval with these variables in 15 cancers diagnosed between 2007 and 2010 using routinely collected data from the Clinical Practice Research Datalink (CPRD) in the UK.
  
  
  METHODS
  Symptom lists for each cancer were prepared from the literature and by consensus amongst the clinician researchers, which were then categorised into either NICE qualifying (NICE) or not (non-NICE) based on NICE Urgent Referral Guidelines for Suspected Cancer criteria. Multivariable linear regression models were fitted to examine the relationship between diagnostic interval (outcome) and the predictors: age, gender and symptom type.
  
  
  RESULTS
  18,618 newly diagnosed cancer patients aged ≥40 who had a recorded symptom in the preceding year were included in the analysis. Mean diagnostic interval was greater for older patients in four disease sites (difference in days per 10 year increase in age; 95% CI): bladder (10.3; 5.5 to 15.1; P<0.001), kidney (11.0; 3.4 to 18.6; P=0.004), leukaemia (18.5; 8.8 to 28.1; P<0.001) and lung (10.1; 6.7 to 13.4; P<0.001). There was also evidence of longer diagnostic interval in older patients with colorectal cancer (P<0.001). However, we found that mean diagnostic interval was shorter with increasing age in two cancers: gastric (-5.9; -11.7 to -0.2; P=0.04) and pancreatic (-6.0; -11.2 to -0.7; P=0.03). Diagnostic interval was longer for females in six of the gender non-specific cancers (mean difference in days; 95% CI): bladder (12.2; 0.8 to 23.6; P=0.04), colorectal (10.4; 4.3 to 16.5; P=0.001), gastric (14.3; 1.1 to 27.6; P=0.03), head and neck (31.3; 6.2 to 56.5; P=0.02), lung (8.0; 1.2 to 14.9; P=0.02), and lymphoma (19.2; 3.8 to 34.7; P=0.01). Evidence of longer diagnostic interval was found for patients presenting with non-NICE symptoms in 10 of 15 cancers (mean difference in days; 95% CI): bladder (62.9; 48.7 to 77.2; P<0.001), breast (115.1; 105.9 to 124.3; P<0.001), cervical (60.3; 31.6 to 89.0; P<0.001), colorectal (25.8; 19.6 to 31.9; P<0.001), gastric (24.1; 3.4 to 44.8; P=0.02), kidney (22.1; 4.5 to 39.7; P=0.01), oesophageal (67.0; 42.1 to 92.0; P<0.001), pancreatic (48.6; 28.1 to 69.1; P<0.001), testicular (36.7; 17.0 to 56.4; P< 0.001), and endometrial (73.8; 60.3 to 87.3; P<0.001). Pooled analysis across all cancers demonstrated highly significant evidence of differences overall showing longer diagnostic intervals with increasing age (7.8 days; 6.4 to 9.1; P<0.001); for females (8.9 days; 5.5 to 12.2; P<0.001); and in non-NICE symptoms (27.7 days; 23.9 to 31.5; P<0.001).
  
  
  CONCLUSIONS
  We found age and gender-specific inequalities in time to diagnosis for some but not all cancer sites studied. Whilst these need further explanation, these findings can inform the development and evaluation of interventions intended to achieve timely diagnosis and improved cancer outcomes, such as to provide equity across all age and gender groupings.
authors.affiliation: North Wales Centre for Primary Care Research, College of Health and Behavioural Sciences, Bangor University, Wrexham, United Kingdom.
authors.forename: Nafees U
authors.initials: NU
authors.lastname: Din
authors.affiliation: NIHR CLAHRC South West Peninsula, University of Exeter Medical School, Exeter, United Kingdom.
authors.forename: Obioha C
authors.initials: OC
authors.lastname: Ukoumunne
authors.affiliation: School of Medicine, Pharmacy and Health, Wolfson Research Institute, Durham University, Durham, United Kingdom.
authors.forename: Greg
authors.initials: G
authors.lastname: Rubin
authors.affiliation: University of Exeter Medical School, Exeter, United Kingdom.
authors.forename: William
authors.initials: W
authors.lastname: Hamilton
authors.affiliation: Institute of Primary Care & Public Health, Cardiff School of Medicine, Cardiff University, Cardiff, United Kingdom.
authors.forename: Ben
authors.initials: B
authors.lastname: Carter
authors.affiliation: University of Exeter Medical School, Exeter, United Kingdom.
authors.forename: Sal
authors.initials: S
authors.lastname: Stapley
authors.affiliation: North Wales Centre for Primary Care Research, College of Health and Behavioural Sciences, Bangor University, Wrexham, United Kingdom.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Neal
mesh_terms: D000367:Age Factors; D000368:Aged; D035843:Biomedical Research; D016208:Databases, Factual; D055088:Early Detection of Cancer / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D012737:Sex Factors; D013997:Time Factors; D006113:United Kingdom