Colonoscopy in a CRC Screening Program With FOBT
Colonoscopy in a CRC Screening Program With FOBT
The organised screening programme with FIT in Italy is performed at a regional level. Screening centres in each region are responsible for inviting eligible subjects. In 2010, overall 107 centres were active in Italy, with a target population of 9 493 250 50-year-old to 69-year-old persons. Programs invite people (mostly aged 50–69 years) to perform a single-sample FIT on a biennial basis; only in the Piedmont region and in the province of Verona, people aged 58 or 60 years (Verona) are offered screening with flexible sigmoidoscopy (FS) once in the lifetime, while biennial FIT is offered until age 69 years to those who are not screened with FS. Due to heterogeneity in resources, the screening programme has been mainly implemented in the North-Central Italian regions. Individuals with a positive FIT result (cut-off=100 ng HB/mL buffer) are offered colonoscopy. Persons attending colonoscopy are required to give preprocedure consent and are given explicit instructions on bowel preparation. Sedation and bowel preparation are performed in accordance with local guidelines, which vary among screening centres. All demographic, colonoscopic and histopathological data are recorded by the screening centre on a regional database. There is no established accreditation programme or examination and/or audit, for an endoscopist to practise in the organised screening programme.
All the organised CRC screening programmes in Italy were invited to participate in this study. Each participating programme was required to provide individual data about all colonoscopies carried out within the regional screening programmes during 2010. Depending on data availability, individual programmes, or regions, could provide additional data referring to other calendar years.
For each patient, demographic information, screening history and colonoscopic procedure and histology results were collected on a standard precoded electronic form. Information concerning the endoscopy centre (EC) and the endoscopists were collected based on a standard form (Table 1).
In order to reduce variation in the baseline prevalence of lesions and to avoid double-counting of adenomas, only first colonoscopies following a positive FIT were included in the analysis.
At the patient level, individual colonoscopy data routinely included the following information: (1) patient demographics, (2) number of previous FIT examinations, (3) quality of bowel preparation (endoscopist's judgement, aggregated as adequate/inadequate), (4) sedation (conscious/deep/none), (5) caecal intubation and (6) number and characteristics of diagnosed polyps/masses, including morphology, localisation, size and histology. In detail, due to the heterogeneity of bowel preparation scales adopted in the different programmes, participating centres were asked to record bowel cleansing, according to a 4-categories scale (excellent, good, fair, poor) that was subsequently aggregated as adequate (excellent/good) and inadequate (fair/poor).
At the endoscopist level, we collected (1) demographics, (2) specialty, (3) number of years of activity as endoscopist (≤5, 6–9, ≥10-year experience), (4) number of screening colonoscopies performed in 2010 (≤100, 101–180, >180) and (5) overall number of colonoscopies performed in 2010 (≤300, 301–600, >600).
At the centre level, we collected the following indicators: (1) use of screening-dedicated sessions for FIT-positive colonoscopies (ie, scheduled outside daily non-screening endoscopy), (2) use of sedation (<33%, 33%–66% and >66% of colonoscopies), (3) adoption of routine quality assurance procedures (ie, monitoring of postprocedural complications, documentation of caecal intubation, scale used to assess quality of bowel preparation). Based on the 2010 data, we also calculated the number of post-FIT-positive colonoscopies performed in 2010 (≤300, 301–600, 601–800 and >800).
In order to assess the variability in the detection rate among individual endoscopists, we aggregated the diagnosis of the following findings at a per-patient level: (1) polyp (polyp detection rate, PDR), (2) ADR, (3) advanced adenoma detection rate (an adenoma with villous component >20%, or high-grade dysplasia, or size ≥1 cm—AADR).
We used linear regression to assess correlation between ADR on one side and PDR/AADR on the other. In order to identify possible predictors of ADR, we evaluated the association between several variables and ADR. These variables were classified as characteristics of (1) patient, (2) EC and (3) endoscopist (Table 1). Sedation was considered as an organisation modality of the EC.
We initially explored the relationship between each group of variables and ADR by univariate analysis. The variables with a significant association with detection were included in a multivariate model with SE correction. Finally, the variables that remained associated with detection rates were included in a final multilevel model (with Laplace approximation), that accounted for the intralevel and interlevel variability at the following levels: region, EC and endoscopist. The Variance Partition Coefficient was used to quantify the proportion of the residual outcome variation attributable to unobserved characteristics of each level of the model.
We performed the same analysis for predictors of CIR, excluding colonoscopies with inadequate cleansing. Indeed, the examination might have been interrupted already during the insertion phase in these cases, if the endoscopist had judged the preparation inadequate, since the colonoscopy needed to be repeated in any case. However, we also added inadequate cleansing as a putative predictor of CIR in a secondary analysis.
All reported p values are two sided. A p value of <0.05 was considered significant. All analyses were performed using Stata V.10.0 statistical package.
Materials and Methods
CRC-organised Screening Programme in Italy
The organised screening programme with FIT in Italy is performed at a regional level. Screening centres in each region are responsible for inviting eligible subjects. In 2010, overall 107 centres were active in Italy, with a target population of 9 493 250 50-year-old to 69-year-old persons. Programs invite people (mostly aged 50–69 years) to perform a single-sample FIT on a biennial basis; only in the Piedmont region and in the province of Verona, people aged 58 or 60 years (Verona) are offered screening with flexible sigmoidoscopy (FS) once in the lifetime, while biennial FIT is offered until age 69 years to those who are not screened with FS. Due to heterogeneity in resources, the screening programme has been mainly implemented in the North-Central Italian regions. Individuals with a positive FIT result (cut-off=100 ng HB/mL buffer) are offered colonoscopy. Persons attending colonoscopy are required to give preprocedure consent and are given explicit instructions on bowel preparation. Sedation and bowel preparation are performed in accordance with local guidelines, which vary among screening centres. All demographic, colonoscopic and histopathological data are recorded by the screening centre on a regional database. There is no established accreditation programme or examination and/or audit, for an endoscopist to practise in the organised screening programme.
Study Population
All the organised CRC screening programmes in Italy were invited to participate in this study. Each participating programme was required to provide individual data about all colonoscopies carried out within the regional screening programmes during 2010. Depending on data availability, individual programmes, or regions, could provide additional data referring to other calendar years.
For each patient, demographic information, screening history and colonoscopic procedure and histology results were collected on a standard precoded electronic form. Information concerning the endoscopy centre (EC) and the endoscopists were collected based on a standard form (Table 1).
In order to reduce variation in the baseline prevalence of lesions and to avoid double-counting of adenomas, only first colonoscopies following a positive FIT were included in the analysis.
Study Variables
At the patient level, individual colonoscopy data routinely included the following information: (1) patient demographics, (2) number of previous FIT examinations, (3) quality of bowel preparation (endoscopist's judgement, aggregated as adequate/inadequate), (4) sedation (conscious/deep/none), (5) caecal intubation and (6) number and characteristics of diagnosed polyps/masses, including morphology, localisation, size and histology. In detail, due to the heterogeneity of bowel preparation scales adopted in the different programmes, participating centres were asked to record bowel cleansing, according to a 4-categories scale (excellent, good, fair, poor) that was subsequently aggregated as adequate (excellent/good) and inadequate (fair/poor).
At the endoscopist level, we collected (1) demographics, (2) specialty, (3) number of years of activity as endoscopist (≤5, 6–9, ≥10-year experience), (4) number of screening colonoscopies performed in 2010 (≤100, 101–180, >180) and (5) overall number of colonoscopies performed in 2010 (≤300, 301–600, >600).
At the centre level, we collected the following indicators: (1) use of screening-dedicated sessions for FIT-positive colonoscopies (ie, scheduled outside daily non-screening endoscopy), (2) use of sedation (<33%, 33%–66% and >66% of colonoscopies), (3) adoption of routine quality assurance procedures (ie, monitoring of postprocedural complications, documentation of caecal intubation, scale used to assess quality of bowel preparation). Based on the 2010 data, we also calculated the number of post-FIT-positive colonoscopies performed in 2010 (≤300, 301–600, 601–800 and >800).
Study End-points and Statistical Analysis
In order to assess the variability in the detection rate among individual endoscopists, we aggregated the diagnosis of the following findings at a per-patient level: (1) polyp (polyp detection rate, PDR), (2) ADR, (3) advanced adenoma detection rate (an adenoma with villous component >20%, or high-grade dysplasia, or size ≥1 cm—AADR).
We used linear regression to assess correlation between ADR on one side and PDR/AADR on the other. In order to identify possible predictors of ADR, we evaluated the association between several variables and ADR. These variables were classified as characteristics of (1) patient, (2) EC and (3) endoscopist (Table 1). Sedation was considered as an organisation modality of the EC.
We initially explored the relationship between each group of variables and ADR by univariate analysis. The variables with a significant association with detection were included in a multivariate model with SE correction. Finally, the variables that remained associated with detection rates were included in a final multilevel model (with Laplace approximation), that accounted for the intralevel and interlevel variability at the following levels: region, EC and endoscopist. The Variance Partition Coefficient was used to quantify the proportion of the residual outcome variation attributable to unobserved characteristics of each level of the model.
We performed the same analysis for predictors of CIR, excluding colonoscopies with inadequate cleansing. Indeed, the examination might have been interrupted already during the insertion phase in these cases, if the endoscopist had judged the preparation inadequate, since the colonoscopy needed to be repeated in any case. However, we also added inadequate cleansing as a putative predictor of CIR in a secondary analysis.
All reported p values are two sided. A p value of <0.05 was considered significant. All analyses were performed using Stata V.10.0 statistical package.