Review of the National Bowel Cancer Screening Program (Phase 2) - Final report, part one

5.1 Interpreting current participation rates

Page last updated: 20 June 2019 (this page is generated automatically and reflects updates to other content within the website)

The overall participation rate during the pilot phase was 45.4 per cent. Participation was higher amongst women (47.4 per cent) than men (43.4 per cent) – the NBCSP was the first organised cancer screening program in Australia targeting men. Nine per cent of participants returned a positive FOBT result. During Phase One the overall participation rate was 38.7 per cent, and in Phase Two it was 38.4 per cent.66

By way of comparison, uptake in the first round of the English bowel cancer screening pilot was 61.8 per cent. It reduced to 57 per cent in the second round, and then increased to 58.7 per cent in the third and final pilot round – although as previously noted, the recruitment method in the English pilots differed from the Australian approach in that it involved participants’ registered NHS general practitioners (and recommendation from a trusted health provider is a key predictor of participation). In the English pilots, people from culturally and linguistically diverse and low SES backgrounds were less likely to participate – and this was consistent across the three rounds67. Uptake was lower in men, but this difference decreased over time.68 Of those diagnosed with cancer, the majority (70 per cent) were early stage cancers.69

There was considerable variation in the way stakeholders interpreted the participation rates. A number of stakeholders consider 38 per cent to be a positive participation rate, especially given that rates have increased from Phase One for the older (and at higher risk) cohorts, and also given lack of promotion for the program and generally low levels of bowel cancer awareness in the community. Others feel that participation rates are disappointing and should be closer to 50 or 60 per cent, based on the English experience and the Australian BreastScreen and cervical cancer screening rates. However, others maintained that NBCSP participation was excellent given its level of maturity, and they noted that, by comparison, Australian breast and cervical cancer screening rates at the same level of maturity were lower than that achieved by the NBCSP.

The review has concluded that, although comparisons to other screening programs can provide a useful (if qualified) guide to interpreting participation rates, it is very difficult to interpret the ‘success’ of participation rates in the absence of agreed, published program target participation rates.

It is also noted again that the level of screening occurring in the community outside of the NBCSP, is not currently well-known. This information is highly relevant to understanding NBCSP participation rates.

66 It should be noted that participants in the pilot phase were older (aged 55-75), which is likely to be one of the reasons for the significantly higher overall participation in the pilot compared to subsequent rounds; in the subsequent rounds, the older age cohorts have continued to have the highest participation rates.
67 Von Wagner, C et al (2011) ‘Inequalities in participation in an organized national colorectal cancer screening programme: Results from the first 2.6 million invitations in England’, International Journal of Epidemiology, 40 (3), 712:718.
68 Moss, SM et al (2011) ‘Performance measures in three rounds of the English bowel cancer screening pilot’, Gut, published online 10 May at www.gut.bmj.com/content/early/2011/05/10/gut.2010.236430.full.html#ref-list-1
69 Logan, RL et al (2011) ‘Outcomes of the Bowel Cancer Screening Program (BCSP) in England after the first 1 million tests’, Gut, published online 7 December at www.gut.bmj.com/content/early/201111/22gutjnl-2011- 300843.full.html#ref-lisr-1