Mental disorders, participation, and trajectories in the Danish colorectal cancer programme: a population-based cohort study.

BACKGROUND: People with mental disorders exhibit increased mortality due to colorectal cancer, despite having a similar incidence to the general population. We aimed to evaluate the extent to which people with mental disorders participate in organised colorectal cancer screening. METHODS: We conducted a population-based cohort study of all Danish residents aged 50-74 years who were invited to undergo biennial faecal immunochemical testing between March 1, 2014, and Sept 30, 2018. We used national registry data from all first-time invitees. The primary endpoint was participation within 90 days of invitation. We calculated the proportion who participated and assessed their screening results and adherence to and completeness of follow-up colonoscopy according to their history of mental disorders, classified as none, mild or moderate, or severe. We computed crude and adjusted participation differences in percentage points and participation ratios using the pseudo-observations method. FINDINGS: Of 2 036 704 people who were invited, we included 2 036 352 in the final cohort, of whom 1 008 045 (49·5%) were men and 1 028 307 (50·5%) were women, with a mean age of 60·7 years (SD 8·3, range 49-78). Data on ethnicity were not collected. Compared with people with no mental disorders, the adjusted analysis showed lower participation among people with mild or moderate mental disorders (men: participation difference -4·4 percentage points [95% CI -4·7 to -4·1]; women: -3·8 percentage points [-4·1 to -3·6]) and severe mental disorders (men: participation difference -13·8 percentage points [-14·3 to -13·3]; women: -15·4 percentage points [-15·8 to -14·9]). People with mental disorders had a higher proportion of positive faecal immunochemical test results, lower adherence to colonoscopy, and more incomplete colonoscopies than people without mental disorders. INTERPRETATION: People with mental disorders were less likely to participate in colorectal cancer screening than those without these disorders. Patients with mental disorders could benefit from support or encouragement from their general practitioner or mental health-care facility to participate in cancer screening. Potential interventions should consider type of mental disorder, as needs might differ. FUNDING: Danish Cancer Society, Danish Health Foundation.

Risk-stratified selection to colonoscopy in FIT colorectal cancer screening: development and temporal validation of a prediction model.

BACKGROUND: Faecal immunochemical tests (FITs) yield many false positives and challenge colonoscopy capacity in colorectal cancer (CRC) screening programmes. We aimed to develop a risk-based selection of participants to undergo diagnostic colonoscopy. METHODS: The study was observational and used registry data from the Danish CRC screening programme. We included all participants invited 2014-2016 with a positive FIT (≥ 20 µg fHb/g) who underwent colonoscopy (n = 56,459). We predicted the risk of CRC or advanced neoplasia (AN) from age, gender and FIT value using logistic regression. We evaluated calibration and discrimination and conducted temporal validation. We compared the number of CRCs and adenomas identified by risk cut-offs and by a corresponding FIT cut-off. RESULTS: AUCs were 74.9% (95% CI: 73.6; 76.3) and 67.4% (95% CI: 66.8%; 68.0%) for the models predicting CRC and AN in the validation dataset. The cut-off of CRC risk calculated from age, gender and FIT value identified 1.03 times (95% CI: 1.02; 1.05) more CRCs and 1.01 times (95% CI: 1.01; 1.01) more medium/high-risk adenomas compared with the corresponding FIT cut-off. CONCLUSIONS: With existing data, risk-stratified FIT screening using a risk cut-off instead of a FIT cut-off can slightly improve the selection to colonoscopy of those at highest risk of cancer and adenomas.

Colonoscopy-related complications in a nationwide immunochemical fecal occult blood test-based colorectal cancer screening program.

BACKGROUND: The Danish national screening program for colorectal cancer (CRC) consists of an immunochemical fecal occult blood test (iFOBT) followed by colonoscopy. The Danish Colorectal Cancer Screening Database (DCCSD) records data on the incidence of hospital-registered complications after colonoscopy. However, the validity of these data is unknown, and the incidence of complications is potentially underreported. OBJECTIVE: To evaluate the validity of the colonoscopy complications registered in the DCCSD by using medical records as the reference. Further, to evaluate the incidence of complications leading to hospital contact. METHODS: Among 14,671 individuals with a positive iFOBT result and a colonoscopy procedure performed from March 3, 2014 to December 31, 2014, we selected 295 individuals for medical record review. We calculated sensitivity as the proportion of true complications registered in the DCCSD out of all complications found in the medical records, and the positive predictive value (PPV) as the number of true complications in the DCCSD out of all DCCSD-registered complications. On the basis of the medical record data, we calculated the incidence proportion of hospital-registered complications overall and by subtype. RESULTS: In total, we reviewed 286 records and found 102 individuals with at least one complication. The sensitivity of the DCCSD for any complication was 29.4% (95% CI: 20.8-39.3) and the PPV was 88.2% (95% CI: 72.6-96.7). On the basis of the medical record data, the incidence proportion of any complication after colonoscopy was 0.70% (95% CI: 0.57-0.84) and that of perforation or lesion was 0.10% (95% CI: 0.06-0.17); bleeding, 0.41% (95% CI: 0.31-0.53); post-polypectomy syndrome, 0.16% (95% CI: 0.10-0.24); and other medical complications, 0.04 (95% CI: 0.02-0.09). CONCLUSION: The DCCSD has low sensitivity for complications, and improvements in data registration are warranted. The incidence proportion of any hospital-treated post-colonoscopy complication was 0.70% in 2014, which was the first year of the Danish national CRC screening program. This is within the range of complications reported by other studies.

Demographic and comorbidity predictors of adherence to diagnostic colonoscopy in the Danish Colorectal Cancer Screening Program: a nationwide cross-sectional study.

BACKGROUND: Predictors of participation in colorectal cancer screening with a stool sample screening modality have been widely studied, but adherence to subsequent diagnostic colonoscopy after a positive screening test has received less attention. We aimed to determine predictors of adherence to diagnostic colonoscopy in the Danish Colorectal Cancer Screening Program. METHODS: We conducted a cross-sectional study using data from National Health Service registries. We included 8,112 individuals invited to screening between March 3, 2014, and August 31, 2014, who had a positive immunochemical fecal occult blood test. Potential predictors were gender, age, region of residence, Charlson Comorbidity Index (CCI) score, specific diseases (cardiovascular disease, chronic pulmonary disease, diabetes, and cancer), and number of prior hospital stays. We estimated prevalence proportion differences (PPDs) for the associations between potential predictors and adherence. RESULTS: Overall, adherence to diagnostic colonoscopy was 88.6%. Adherence was lower in individuals aged 75 years compared with those aged <70 years, PPD=-4.20 (95% confidence interval [CI]: -6.19; -2.20). Adherence decreased with a higher level of comorbidity: PPD=-2.30 (95% CI: -3.87; -0.74) for a CCI score of 1-2 and PPD=-9.24 (95% CI: -12.30; -6.19) for a CCI score of ≥3 compared to 0. For specific diseases, adherence was decreased in those with a diagnosis of cardiovascular disease, chronic pulmonary disease, or diabetes, but less for cancer. When comorbidity was measured as number of prior hospital stays, the adjusted PPDs were -2.41 (95% CI: -4.43;-0.39) for one to two stays and -14.50 (95% CI: -20.30; -8.74) for three or more stays compared with no in-hospital stays. CONCLUSION: Major predictors of nonadherence to diagnostic colonoscopy after a positive immunochemical fecal occult blood test were older age, a CCI score of 1 or more, cardiovascular disease, chronic pulmonary disease, diabetes, and one or more in-hospital stays within the last year.

Validity of data in the Danish Colorectal Cancer Screening Database.

BACKGROUND: In Denmark, a nationwide screening program for colorectal cancer was implemented in March 2014. Along with this, a clinical database for program monitoring and research purposes was established. OBJECTIVE: The aim of this study was to estimate the agreement and validity of diagnosis and procedure codes in the Danish Colorectal Cancer Screening Database (DCCSD). METHODS: All individuals with a positive immunochemical fecal occult blood test (iFOBT) result who were invited to screening in the first 3 months since program initiation were identified. From these, a sample of 150 individuals was selected using stratified random sampling by age, gender and region of residence. Data from the DCCSD were compared with data from hospital records, which were used as the reference. Agreement, sensitivity, specificity and positive and negative predictive values were estimated for categories of codes "clean colon", "colonoscopy performed", "overall completeness of colonoscopy", "incomplete colonoscopy", "polypectomy", "tumor tissue left behind", "number of polyps", "lost polyps", "risk group of polyps" and "colorectal cancer and polyps/benign tumor". RESULTS: Hospital records were available for 136 individuals. Agreement was highest for "colorectal cancer" (97.1%) and lowest for "lost polyps" (88.2%). Sensitivity varied between moderate and high, with 60.0% for "incomplete colonoscopy" and 98.5% for "colonoscopy performed". Specificity was 92.7% or above, except for the categories "colonoscopy performed" and "overall completeness of colonoscopy", where the specificity was low; however, the estimates were imprecise. CONCLUSION: A high level of agreement between categories of codes in DCCSD and hospital records indicates that DCCSD reflects the hospital records well. Further, the validity of the categories of codes varied from moderate to high. Thus, the DCCSD may be a valuable data source for future research on colorectal cancer screening.