1. North East Bowel Screening Cancer Study Doctorate of Medicine, University of Durham

2. Large scale epidemiological study of all colorectal cancers –In population eligible for screening as part of the National Bowel Cancer Screening Programme –Within the Northern Region

3. Approximately 1500 patients included –Aged 60-69 at time of diagnosis –Between April 2007- April 2010 Combination of data from: –NORCCAG Database –Regional Bowel Cancer Screening Database

4. Cases of Colorectal Cancer Screen Detected Cancer Interval Cancer Cancer after Negative FOBt Cancer after Negative Colonoscopy Cancer before Planned Surveillance Colonoscopy Non-Uptake Cancer Non-Uptake of FOBt Non-Uptake of Colonoscopy after Positive FOBt

5. Comparing the three patient groups described above, are there any differences in the epidemiology of the patients? Examples of data analysed will be: –Socioeconomic group and level of deprivation –Co-morbidities

6. What is the rate of interval cancer within the screening programme? –What type of interval cancer? –What are the reasons behind it? –How many positive FOB windows to these patients have – should we be performing more colonoscopies on those with weakly positive tests? –What groups of patients have an interval cancer?

7. Details of the cancers within each patient group –Are there any differences between the stages of cancers found in each group? –Is there a shift towards earlier cancers within the screen detected group and is there any difference in the interval group?

8. Errors & Missing Data Review Michael Gill NORCCAG Research Fellow

9. Sample of data from NBOCAP extract –Analysed for Missing data Data accuracy

10. Database analysed by NORCCAG research fellows Error and missing data queries created using Microsoft Access Results summarised using SPSS

11. 7020 Records 5971 (85.1%) Had Treatment Record 5449 (77.6%) Had Surgical Intervention 335 (4.8%) Documented as Having No Intervention 187 (2.7%) No Procedure Or No Reason Why No Procedure 1049 (14.9%) No Treatment Record Created All Empty Surgical And Why No Op Fields 1236 (17.6%) Missing Data

12. ASA Grade

14. Stomas

18. Of 1409 stomas recorded - total of 271 (19.2%) errors in recording of type of stoma –Includes those errors in the palliative procedure category

19. Urgency of Procedure

21. Surgical Access

23. Grade of Operating Surgeon

25. Tumour Location vs. Operation

28. Of 5449 recorded procedures –Total of 271 (5.0%) errors –Including those errors within palliative procedures

29. Conclusion

30. Significant errors seen throughout the database –Some human error –Some inbuilt errors within NBOCAP NORCCAG is able to identify these errors and missing data with ease, in order to aid correction

31. Any Questions?