Colonoscopies in Australia - how much does the National Bowel Cancer Screening Program contribute to colonoscopy use?

Objectives and importance of study: Colorectal cancer (CRC) is Australia's fourth most commonly diagnosed cancer. CRC screening is an effective intervention to reduce this burden. The National Bowel Cancer Screening Program (NBCSP) provides 2-yearly immunochemical faecal occult blood tests (iFOBTs) to Australians aged 50-74 years; a diagnostic colonoscopy is conducted after a positive iFOBT. Clinical guidelines inform colonoscopy usage, and appropriate use of these guidelines is vital to investigate gastrointestinal symptoms, detect bowel abnormalities and CRC, and remove precancerous polyps. Colonoscopy services are under strain, with limited formal strategies to prioritise patients. There are concerns among practitioners and patient advocates that the NBCSP generates additional colonoscopy requests and increases wait times, worsening patient outcomes and prolonging distress. In this research study, we estimate and project colonoscopy use in Australia from 2001 to 2030 and determine the impact of the NBCSP by examining model-estimated NBCSP colonoscopy demand. METHODS: Colonoscopy use in Australia was compiled using Medicare Benefits Schedule (MBS) claims for colonoscopies from 2001 to 2019. From these data, projections were made from 2020 to 2030. Policy1-Bowel, a microsimulation model, was used to estimate NBCSP-related colonoscopy demand from screening follow-up and colonoscopic surveillance from 2006 to 2030. RESULTS: MBS-funded colonoscopy use increased from 284 676 in 2001 to 663 213 in 2019. Annual use is projected to be more than 780 000 by 2030. Of these, 10-14% are projected to be generated by the NBCSP. Per-capita MBS-funded colonoscopy utilisation increased 0.2% annually over 2015-2019, a slowing of growth compared to previous trends. CONCLUSION: The NBCSP accounts for a modest fraction of colonoscopy use in Australia, and a better understanding of colonoscopy use not associated with the NBCSP is needed. Promoting adherence to guideline-recommended iFOBT and colonoscopy use could ease pressure on services and improve outcomes.

The combined impact of implementing HPV immunisation and primary HPV screening in New Zealand: Transitional and long-term benefits, costs and resource utilisation implications.

BACKGROUND: In response to emergent evidence, many countries are transitioning from cytology-based to HPV screening. We evaluated the impact of an upcoming transition on health outcomes and resource utilisation in New Zealand. METHODS: An extensively validated model of HPV transmission, vaccination, natural history and cervical screening ('Policy1-Cervix') was utilised to simulate a transition from three-yearly cytology for women 20-69 years to five-yearly HPV screening with 16/18 genotyping for women 25-69 years, accounting for population growth and the impact of HPV immunisation. Cervical cancer rates, resources use (test volumes), costs, and test positivity rates from 2015 to 2035 were estimated. FINDINGS: By 2035, the transition to HPV screening will result in declines in cervical cancer incidence and mortality rates by 32% and 25%, respectively, compared to 2018. A potentially detectable 5% increase in cervical cancer incidence due to earlier detection is predicted for the year of transition. Annual numbers of women screened will fluctuate with the five-year screening interval. Cytology volumes will reduce by over 80% but colposcopy volumes will be similar to pre-transition rates, and program costs will be reduced by 16%. A 9% HPV test positivity rate is expected in the first round of HPV screening (2019-2023), with 2.7% of women referred for colposcopy. Transitioning from cytology to primary HPV cervical screening could avert 149 cancer cases and 45 deaths by 2035. CONCLUSION: Primary HPV screening and vaccination will reduce cervical cancer and resources use. A small transient apparent increase of invasive cancer rates due to earlier detection may be detectable at the population level, reflecting the introduction of a more sensitive screening test. These findings can be used to inform health services planning and public communications surrounding program implementation.