WEO CRC SC Meeting Vienna, Austria October 14, 216
Possibleconflictsofinterest The Bowel Health Service receives material support from Eiken Chemical Company. Erin Symonds
FIT positivity rate is highest in the people who participate in the first week after receiving the kit Observations from a South Australian screening program Erin Symonds Graeme Young Bowel Health Service, Repatriation General Hospital Flinders Centre for Innovation in Cancer AUSTRALIA
FOBT participation rates around the world Higher participation found with: Females Older age Subsequent screening rounds Blom J et al J Med Screen 214 Higher socioeconomic status Von Wagner et al Int J Epidemiol 211 Higher level of education Frederiksen BL et al Br J Cancer 21 No effect of family history of CRC Perencevich M, et al Gastroenterol 213 % 1% 2% 3% 4% % 6% 7% 8% Klabunde, et al J Med Screen 21 Most <% participation
Aim To establish FIT participation and positivity profiles and predictors. Population A hospital based screening and surveillance program for people at higher risk for CRC. 2 sample FITs (OC Sensor) have been used since Aug 28. Total of 36,331 FITs sent. Positive FIT = one sample 2μg Hb/g faeces. All samples are analysed within two weeks of sample collection Erin Symonds
FIT participation in a higher risk population 3 2 FIT participation (%) 2 1 1 Reminder letter wk 1 (n=3421) wk 2 (n=698) wk 3 (n=328) wk 4 (n=244) wk (n=147) wk 6 (n=183) wk 7 (n=1491) wk 8 (n=1) wk 9 (n=94) Participation in the hospital program is 6.% (higher than National program participation of 37%) 9% of the people who are going to participate do so in the first 9 weeks
FIT participation PREDICTORS FOR PARTICIPATION IN A HIGHER RISK POPULATION Female Older age Higher SES Previous FIT rounds (same as average risk population) Factor OR (9% CI) P value Female (compared to male) 1.23 (1.18-1.29) <.1 Age (compared to <y) -6y 1.76 (1.6-1.88) <.1 6-7y 3.4 (2.8-3.2) <.1 7+ 3.44 (3.19-3.73) <.1 Socioeconomic status (compared to highest quintile) 2 nd highest.99 (.92-1.6).69 Middle.93 (.87-.998).44 2 nd lowest.91 (.86-.97).4 lowest.8 (.79-.92) <.1 Subsequent FIT offer (compared to 1 st offer) 1.9 (.8-.67) <.1
FIT participation (%) 3 2 2 1 1 FIT positivity rate Participation Reminder letter wk 1 wk 2 wk 3 wk 4 wk wk 6 wk 7 wk 8 wk 9 FIT positivity (%) 9 8 7 6 4 3 2 1 % of samples with Hb 2µg/g faeces Reminder letter wk 1 wk 2 wk 3 wk 4 wk wk 6 wk 7 wk 8 wk 9 Greatest FIT positivity with samples returned week 1 in the higher risk population
Positivity rate: average risk population 4 Participation 12 % of samples with Hb 2µg/g faeces % particiaptino 3 3 2 2 1 1 Reminder letter FIT positivity (%) 1 8 6 4 2 Reminder letter Same observations in an average risk population, with greatest positivity in the first week of returns.
Risk factors for positivity Variables associated with positivity High Hb levels Rectal bleeding Cancer and adenomas Male Socioeconomic status Older age
Early positives due to symptoms? Are these samples associated with people noticing bleeding? (multivariate OR.36 (9%CI.1-1.24)) Will there be a higher Hb level? NO 7 Median Hb of positive samples 2 Proportion of samples with Hb 2µg/g faeces Median Hb (ug/ug) 6 4 3 2 1 wk 1 wk 2 wk 3 wk 4 wk wk 6 wk 7 wk 8 wk 9 % of positive samples with a high Hb (>2ug/g) 2 1 1 wk 1 wk 2 wk 3 wk 4 wk wk 6 wk 7 wk 8 wk 9
Early positives due to symptoms? Will these samples have a higher positive predictive value for neoplasia? 2 OR 1.13 (9% CI:.87-1.46) Positive predictive value (%) 2 1 1 significant adenoma Cancer wk 1 (n=249) wk 2 (n=369) wk 3 (n=22) wk 4 (n=118) wk (n=86) wk 6 (n=66) wk 7 (n=14) wk 8 (n=1) wk 9 (n=41)
Early positives due to demographic differences with participation? Male gender Lower socioeconomic status Older age All linked to increased positivity risk FIT participation (%) 3 2 2 1 1 No significant differences male female FIT participation (%) 3 2 2 1 1 No significant differences highest SES 2nd highest middle 2nd lowest lowest SES wk 1 wk 2 wk 3 wk 4 wk wk 6 wk 7 wk 8 wk 9 wk 1 wk 2 wk 3 wk 4 wk wk 6 wk 7 wk 8 wk 9
Early positives due to demographic differences with participation? Male gender Lower socioeconomic status Older age 3 3 Odds ratio of having an early positive FIT result Factor OR (9% CI) P value Age (compared to <y) -6y.69 (.32-1.) >. 6-7y 1.4 (.71-2.99) >. 7+ y 2.46 (1.16-.2).19 participation (%) 2 2 1 1 wk 1 wk 2 wk 3 wk 4 wk wk 6 wk 7 wk 8 wk 9 <y -9y 6-69y >=7y Earliest participation in the 7+ age group
Conclusions Participation Predictors for FIT participation are the same in a higher risk population compared to average risk populations. Positivity Highest returns of positive FITs week 1 and again after reminder letters. This is most likely due to the older age group participating early and being at higher risk for a positive result An early returned positive FIT does not indicate increased risk for neoplasia and can not be used to triage for colonoscopy.
ACKNOWLEDGEMENTS Repatriation General Hospital Steve Cole Graeme Young Robert Fraser Charles Cock Gretchen Jean Kalindra Simpson Michelle Coats Susan Wick Jo Osborne Dawn Bastin Flinders Medical Centre Peter Bampton Karen Saxty Jayne Sandford Angela Chaplin Tennyson Centre Lyn Williams Noarlunga Centre Dawn Cotterill