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Discovery related publications:
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Discovery related publications - 2015

These are publications derived from Discovery research data and databases and/ or research collaborations with other research staff outside the Discovery programme.

9th June 2015

Age and Gender Variations in Cancer Diagnostic Intervals in 15 Cancers: Analysis of Data from the UK Clinical Practice Research Datalink. Din NU, Ukoumunne OC, Rubin G, Hamilton W, Carter B, Stapley S, Neal RD. PLoS One. 2015 May 15;10(5):e0127717. doi: 10.1371/journal.pone.0127717. eCollection 2015.


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.


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.


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).


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.

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1st May 2015

Patient-doctor continuity and diagnosis of cancer: electronic medical records study in general practice. Matthew J Ridd, Diana L Santos Ferreira, Alan A Montgomery, Chris Salisbury, William Hamilton. British Journal of General Practice. 2015 May;65(634):e305-11. doi: 10.3399/bjgp15X684829.


Continuity of care may affect the diagnostic process in cancer but there is little research.


To estimate associations between patient-doctor continuity and time to diagnosis and referral of three common cancers.

Design and setting

Retrospective cohort study in general practices in England.


This study used data from the General Practice Research Database for patients aged ≥40 years with a diagnosis of breast, colorectal, or lung cancer. Relevant cancer symptoms or signs were identified up to 12 months before diagnosis. Patient-doctor continuity (fraction-of-care index adjusted for number of consultations) was calculated up to 24 months before diagnosis. Time ratios (TRs) were estimated using accelerated failure time regression models.


Patient-doctor continuity in the 24 months before diagnosis was associated with a slightly later diagnosis of colorectal (time ratio [TR] 1.01, 95% confidence interval [CI] =1.01 to 1.02) but not breast (TR = 1.00, 0.99 to 1.01) or lung cancer (TR = 1.00, 0.99 to 1.00). Secondary analyses suggested that for colorectal and lung cancer, continuity of doctor before the index consultation was associated with a later diagnosis but continuity after the index consultation was associated with an earlier diagnosis, with no such effects for breast cancer. For all three cancers, most of the delay to diagnosis occurred after referral.


Any effect for patient-doctor continuity appears to be small. Future studies should compare investigations, referrals, and diagnoses in patients with and without cancer who present with possible cancer symptoms or signs; and focus on 'difficult to diagnose' types of cancer.

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10th February 2016

New Discovery Research publication

The SYMPTOM Study team's research into symptom appraisal for colorectal cancer has been published in BMJ Open. This is a unique piece of research which compares the appraisal and help seeking experiences of patients with colorectal cancer symptoms who go on to have cancer and those who turn out to have non-cancer conditions. The research did not identify any clear differences between the two groups but did identify important barriers to presentation around the ‘private nature’ of colorectal symptoms which will prove useful to policy makers and the design of awareness campaigns. To read more about the research paper see the results section here.

9th June 2015

Discovery conference slides available & new research publications

The Discovery Programme held its research conference at the Royal College of General Practitioners on June 2nd 2015. The team presented their research findings and outlined the impact of the programme to a wide range of patient groups, clinicians, policy makers, researchers and journalists. The PowerPoint slides used during the presentation have been uploaded to this website and can be viewed here.

There are also 2 new research papers to report. Chantal Balasooriya-Smeekens has published the literature review of her PhD in Psycho-Oncology, "The role of emotions in time to presentation for symptoms suggestive of cancer: a systematic review of quantitative studies". Abstract and publication details are here and further papers from Chantal's PhD will be published soon.

Nafees Din has published a new paper under the Discovery related research umbrella. The paper uses Discovery data drawn from the CAPER (theme 2) studies and considers "Age and Gender Variations in Cancer Diagnostic Intervals in 15 Cancers". Full publication details and abstract can be found here.