Monitoring indicators
Understanding the monitoring indicators for the bowel screening pilot.
Pātiki and Waharua Kōpito patterns
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Results
The information collected in the Bowel Screening Pilot has been compared with international bowel screening standards.
- Round 1: Final results for people invited from 1 January 2012 to 31 December 2013
- Round 2: Final results for people invited from 1 January 2014 to 31 December 2015
- Round 3: Final results for people invited from 1 January 2016 to 31 December 2017 for analyses relating to participation and coverage, and from 1 January 2016 to 30 June 2017 (excluding any participant who had their kit tested after 30 June 2017) for all other analyses.
Although the Pilot ran to the end of December 2017, the data on which this report is based covers people who returned their kits before 1 July 2017. On this date the National Bowel Screening Programme commenced and the threshold that triggered a positive result was changed[1].
To ensure the results from the Bowel Screening Pilot are consistent between the three rounds, any participant who returned a kit after the threshold change has been excluded from this report with regards to all analyses except participation and coverage. This means that for the purposes of this report, Rounds 1 and 2 are reported for a standard two year period whereas Round 3 covers a period of eighteen months.
The results presented in this report can all be considered final. Results relating to participants who returned a test kit between 1 July and 31 December 2017 in the Waitemata population will be included in the National Bowel Screening Programme Annual Monitoring Report for 2017/18.
Note: Unless otherwise stated, these figures do not include people who have exited the programme and had private colonoscopies, or adenomas and cancers detected through them. However, where reliable data for colonoscopies undertaken privately was made available, this information has been included to show a more complete view of the effects of the Bowel Screening Pilot.
[1] Read an explanation of why the threshold was altered (Word, 245 KB).
Indicator 1
| Description | Overall participation | |||
|---|---|---|---|---|
| Evidence | This is the % of people with a final FIT1 result (+ve or –ve) out of all those eligible invited by the programme, for the first and subsequent screening rounds. | |||
| Target | 60% for first screen (Round 1) | |||
| Value | Round 1: 57.4% |
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| Round 2: Average: 58.1% | Where Round 2 was first screen
|
Where Round 2 was subsequent screen: 86.4% | ||
| Round 3: Average: 56.8% | Where Round 3 was first screen
|
Where Round 3 was subsequent screen: 83.3% | ||
Indicator 2
| Description | Coverage2 |
|---|---|
| Evidence | This is the % of eligible people in Waitemata DHB region who were invited to participate during the first and subsequent screening rounds. |
| Target | >95% |
| Value | Round 1: 95.2%* Round 2: 97.1%# Round 3: 107.4%# |
* For Round 1, the number of eligible people in Waitemata is defined as all those people residing in Waitemata DHB region, aged 50–74 based on census 2013 data (Statistics NZ).
#For Round 2 and Round 3, the number of eligible people in Waitemata is defined as all those people residing in Waitemata DHB region, aged 50-74 based on the population estimate as at 31 Dec 2014 and 31 Dec 2015, respectively (Statistics NZ). This number excludes those who had a positive FIT result in a previous round and proceeded to have a colonoscopy.
Indicator 3
| Description | Time to colonoscopy for Round 3 |
|---|---|
| Evidence | This is the % of people whose time between the laboratory receiving a positive FIT to having a colonoscopy carried out was within a specified target (excludes persons who decline colonoscopy or those having a colonoscopy performed privately). |
| Target | 95% ≤ 11 weeks |
| Value | Round 1: 88.0% Round 2: 95.3% Round 3: 97.4% |
Indicator 4
| Description | Proportion of individuals with a positive screening test undergoing colonoscopy or CT colonography |
|---|---|
| Evidence | This is the % of screened people with a positive FIT result who have had a colonoscopy or CT colonography through the programme, or have a date booked for a colonoscopy. |
| Target | > 90% undergo colonoscopy or CT colonography |
| Value |
** This includes those that chose to receive a colonoscopy through a private provider
Indicator 5
| Description | Colonoscopy completion rate |
|---|---|
| Evidence | This is the % of completed colonoscopies (reaching the caecum). |
| Target |
|
| Value |
|
Indicator 6
| Description | Colonoscopy complication rate for perforation or bleeding |
|---|---|
| Evidence | This is the number of people requiring admission to hospital for an intermediate or serious adverse event related to perforation or bleeding occurring within 30 days of colonoscopy, per 1000 of those who had a colonoscopy during the first and subsequent screening rounds. |
| Target | <10 per 1000 colonoscopies*** |
| Value | 4.0 per 1000*** |
*** The target was calculated on the expected adverse event rates reported in the UK Bowel Cancer Screening Programme Quality Assurance Guidelines for Colonoscopy and based on the fact that 7 out of 10 pilot participants proceeding to colonoscopy are identified to have had a lesion.
Indicator 7
| Description | Colonoscopy complication rate for events other than perforation or bleeding |
|---|---|
| Evidence | This is the number of people requiring admission to hospital for other intermediate or serious adverse events not related to perforation or bleeding occurring within 30 days of colonoscopy, per 1000 of those who had a colonoscopy during the first and subsequent screening rounds. |
| Target | No agreed international standard |
| Value | 0.3 per 1000 |
Indicator 8
| Description | Positivity rate | |||
|---|---|---|---|---|
| Evidence | This is the % of people with a positive FIT during the first and subsequent screening rounds. | |||
| Target | 6–8% for first screen (Round 1) | No agreed target for subsequent screens | ||
| Value | Round 1: 7.5% |
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| Round 2: Average: 5.9% |
Where Round 2 was first screen
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Where Round 2 was subsequent screen: 5.4% | ||
| Round 3: Average: 5.5% |
Where Round 3 was first screen
|
Where Round 3 was subsequent screen: 5.1% | ||
Indicator 9
| Description | Colorectal Cancer (CRC) detection rate |
|---|---|
| Evidence | This is the number of people diagnosed with any CRC per 1000 screened with a FIT result available for the first and subsequent screening rounds. |
| Target | 1.8–9.5 For first screen (Round 1) per 1000 |
| (Range from population screening programmes with FIT) | |
| Value |
****This figure includes those who had cancer found through a colonoscopy undertaken privately.
Indicator 10
| Description | Colorectal Cancer (CRC) Stage at diagnosis (including polyp cancers) | ||
|---|---|---|---|
| Evidence | This is the TNM staging for CRC detected at the first and subsequent screening rounds. In cases where more than one staging was given for an individual only the most serious staging result is included. For cancers found through public colonoscopy. | ||
| Target | No agreed international standard | ||
| Value | % of staged cancers by TNM stage | ||
Round 1
No Stage: 6 (out of 193) |
Round 2
No Stage: 8 (out of 109) |
Round 3
No Stage: 9 (out of 88) |
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Indicator 11
| Description | Advanced Adenoma detection rate |
|---|---|
| Evidence | This is the number of people diagnosed with any advanced adenoma (villous or tubulovillous or, high grade dysplasia or, greater than or equal to 10 mm in size) per 1000 screened with a FIT result available for the first and subsequent screening rounds. |
| Target | No agreed international standard |
| Value |
|
Indicator 12
| Description | Adenoma detection rate |
|---|---|
| Evidence | This is the number of people diagnosed with any adenoma per 1000 screened with a FIT result available for the first and subsequent screening rounds. |
| Target | 13.3–22.3 per 1000 (Range from population screening programmes with FIT) |
| Value |
|
Indicator 13
| Description | Positive predictive value of FIT for cancer |
|---|---|
| Evidence | This is the % of people with a malignant outcome in those having a colonoscopy for the first and subsequent screening rounds. |
| Target | PPV Cancer first screen 4.5%–8.6% |
| Value |
*****This figure includes those who had cancer found through a colonoscopy undertaken privately.
Indicator 14
| Description | Positive predictive value of FIT for advanced adenoma |
|---|---|
| Evidence | This is the % of people with any advanced adenoma in those having a colonoscopy for the first and subsequent screening rounds. |
| Target | No agreed international standard |
| Value |
|
Indicator 15
| Description | Positive predictive value of FIT for adenoma |
|---|---|
| Evidence | This is the % of people with any adenoma in those having a colonoscopy for the first and subsequent screening rounds. |
| Target | PPV adenoma first screen 9.6 – 40.3% |
| Value |
|
Footnotes
- Although previous Ministry of Health publications have referred to ‘iFOBT’, FIT is now used to ensure alignment with international literature.
- These figures differ from coverage rates reported previously due to population estimates being updated by StatsNZ. Until NHI data is matched to immigration data, it is not possible to produce an accurate register of all eligible people. The coverage rate of 107.4% in Round 3 shows that the population register has invited more people than StatsNZ estimates were living in Waitemata and who were in the correct age range.