This data supplement forms an addendum to the National Bowel Cancer Screening Program annual monitoring report 2009 (AIHW 2009). Based on data extracted from the National Bowel Cancer Screening Register on 31 January 2010 this supplement provides an extra 12 months of follow-up data for those participants invited into the National Bowel Cancer Screening Program (NBCSP) in 2008. Estimated participation and screening outcomes from the previous report are updated with final figures for those participants. It is important to note, however, that follow-up data remain incomplete due either to participants failing to follow-up a positive screening test, or follow-up outcome forms—particularly those relating to histopathology—not being returned to the NBCSP Register.
Of the 685,000 people invited into the NBCSP in 2008, 40.1% agreed to participate. Overall, participation was lower than previous years due to the inclusion of invitees aged 50 years, who had a lower participation rate (33.8%) than the other two target ages. Participation of those aged 55 (39.9%) and 65 years (48.6%) was similar to previous years. Participation in the NBCSP by males (36.7%) was significantly lower than females (43.5%).
Faecal occult blood test outcomes
The proportion of positive screening test results for those participants who correctly completed a faecal occult blood test (FOBT) was 6.6%. This was statistically significantly lower than 2007, possibly due to the inclusion of invitees aged 50 years from 1 July 2008 who generally had lower positivity rates than the older target ages.
Male participants had a higher FOBT positivity rate (7.7%) than females (5.7%), which correlated with known bowel cancer incidence patterns between the sexes.
Follow-up of positive faecal occult blood test results
Of the 17,991 people who returned a positive FOBT, 49.4% had a primary health care practitioner visit recorded by 31 January 2010, and 76.3% were recorded as having had a colonoscopy to investigate the positive FOBT result.
There were 11,598 people invited in 2008 who had outcome data for follow-up of a positive FOBT recorded by 31 January 2010. Of these, 120 had a confirmed cancer and 334 a suspected cancer. Potentially pre-cancerous adenomas were confirmed in a further 1,754 people.
Outcomes for a further 6,393 participants with a positive FOBT result were unknown as follow-up data were not available. This may be because they had not progressed to follow-up, or follow-up forms had not been returned to the NBCSP Register as at 31 January 2010. There were also no final histopathology diagnoses available for the 334 participants with suspected cancers or the 3,745 participants with polyps detected at colonoscopy.