1. Greg Rubin,1 Nafees Din,2 Richard Neal,2 William Hamilton3
Diagnostic Intervals in Colorectal Cancer and : Database Study
Greg Rubin,1 Nafees Din,2 Richard Neal,2 William Hamilton3
1-School of Medicine and Health, Durham University 2-North Wales Centre for Primary Care Research, North Wales Clinical School, Bangor University 3-Peninsula College of Medicine and Dentistry, University of Exeter
Background
Results
Results
Fig. 3: Overlaid histograms showing distribution of diagnostic intervals in Cohort 1 & 2 up to a year before the date of diagnosis. The arrow head shows the shift of diagnostic intervals from to
Shorter ‘Diagnostic Intervals’, the crucial period between the first presentation of potential cancer symptoms, usually to primary care, and diagnosis, may lead to earlier stage diagnoses and better cancer outcomes.
The General Practice Research Database (GPRD) in the UK is a well-validated dataset for research in primary care. As part of the National Awareness and Early Diagnosis Initiative (NAEDI), we undertook a GPRD study.
Fig. 1a & 1b: First presentation of any cancer symptom: There was a reduction of around 25% (21 days) in median diagnostic interval from to This difference was statistically significant (below left). Despite this, both cohorts had long diagnostic intervals towards the third and fourth quartiles as presented in the 90th centile graph (below right) and overlaid histograms of the two cohorts in Fig. 3 (opposite right).
Aims
To determine and compare diagnostic intervals in two time periods ( & ), before and after the introduction of the 2005 NICE Referral Guidelines for Suspected Cancer; and to create baselines for future comparisons.
Conclusions
Median diagnostic intervals significantly reduced between and The 90th centile diagnostic intervals also reduced but less so. Both remained relatively high in (median 75 days, 90th centile 279 days) suggesting that there remains considerable room and potential for improvement.
Patients with an initial non-NICE qualifying symptom, followed by a NICE qualifying symptom had the shortest diagnostic intervals, followed by those with an initial NICE symptom, followed by those with no NICE qualifying symptoms; the diagnostic intervals for all three groups fell between the two cohorts but they were significant for the NICE category.
The difference between the cohort and the cohort was that patients with a diagnostic interval of 3-8 months were ‘shifted’ to one of 1-4 months. There was little effect on the important tail of the distribution. The beneficial effect of this shift on stage at diagnosis remains unknown.
Between the two cohorts there was a major policy initiative; that of implementation of the 2005 Referral Guidelines for Suspected Cancer; whilst the study was not designed to be causal, we can hypothesise that the changes between the two cohorts were in part due to this.
Methods
Dataset: Newly diagnosed cancer patients aged ≥ 40 with at least one year of complete medical records before diagnosis.
Patient cohorts: Symptomatic patients diagnosed between:
01/01/ /12/2002 inclusive (Cohort 1 n= 1825)
01/01/ /12/2008 inclusive (Cohort 2 n= 2716)
Patients who did not present with symptoms were excluded.
Symptom identification: Symptoms included were anaemia, anorexia, fatigue, weight loss, abdominal pain, change in bowel habit, constipation, diarrhoea and rectal bleeding.
NICE qualifying symptoms: Symptoms were categorised into ‘NICE qualifying and non-qualifying’ based on the review of guidelines, literature and current practice.
Diagnostic interval: The duration in days from first presentation of cancer related symptom(s) in primary care to date of diagnosis.
Data analysis: Diagnostic intervals in the two cohorts were compared and are presented here for:
First symptomatic presentation (Fig. 1)
NICE qualifying symptoms, divided into three groups (Fig. 2):
Initial presentation of a NICE qualifying symptom (‘always NICE’)
Initial presentation of a NICE non-qualifying symptom, followed by a NICE qualifying symptom prior to diagnosis (‘became NICE’)
No NICE qualifying symptoms prior to diagnosis (‘never NICE’)
Fig. 2: Diagnostic intervals by NICE categories: There was a reduction in diagnostic intervals for all the categories of NICE symptoms but this was more pronounced and significant for NICE qualifying category.
Greg Rubin:
Nafees Din:
Richard Neal:
William Hamilton:
Contact
Conflicts of interest:
The authors declare that there are no conflicts of interest in this study.
Acknowledgements:
This research was funded by the National Cancer Action Team and the Department of Health Cancer Policy Team. The views contained are those of the authors and do not represent Department of Health Policy.
We thank Sally Stapley for her help in data manipulation.