From 2007–2008 to 2012–2013, the participation rate decreased from 44.0% to 36.1%, but has since increased to reach 40.9% in 2015–2016. Similar trends were observed for males and females. Reasons for the recent increase in the participation rate include the increasing proportion of participants who have previously been invited to participate in the NBCSP in earlier years (re-invitees are known to participate at a higher rate), and higher participation rates among persons aged 70–74 years.1
Since 2007–2008, participation rates have generally decreased for most age groups. However, those decreases have plateaued or reversed since 2012–2013, which as previously noted is mostly due to the increasing proportion of re-invitees.
Remoteness and socioeconomic status (SES)
Trend data for participation by remoteness and by socioeconomic status are available for the 2-year periods 2013–2014, 2014−2015 and 2015–2016. The participation rate for each remoteness area and socioeconomic status area has increased in each rolling 2-year period since 2013–2014.1,4,5
Colorectal cancer control in Australia
Over the period since the initial trialling of national cancer control screening through the pilot program and the subsequent implementation of the NBCSP, improvements have been observed in the age-standardised colorectal cancer mortality rate (decreasing from 22.9 deaths per 100,000 in 2002 to 15.6 per 100,000 in 2015) and in the increased 5-year survival rate (62.0% in 2000–2004 to 70.2% in 2010–2014).1,6 The AIHW has analysed outcomes from the NBSCP for persons who were aged 50-74 years during Phases 1 and 2 of the NBSCP, and were diagnosed with colorectal cancer in the period 2006−2010. During these Phases, invitations to screen were sent to persons turning 50, 55 or 65 years old. For persons who did not receive an invitation to screen, the risk of colorectal cancer death was 13% higher than for those that did receive an invitation to screen.7
The NCCI measures Capture of stage data and Distribution of cancer stage present national data for Registry-Derived stage (RD-Stage) at diagnosis for the top 5 cancers by incidence in 2011. These data show that people aged 50 years and over had a higher proportion of early stage colorectal cancers at diagnosis (stage 1 and stage 2) than those aged less than 50 years. RD-stage data collection in subsequent years will provide us with more detailed evidence regarding the impact of the NBSCP on early detection of colorectal cancer in the target age range.