Approaches for classifying the indications for colonoscopy using detailed clinical data

BMC Cancer

Table 2 Association between screening colonoscopy and risk of incident late-stage CRC according to data source, SEARCH Study 2006–2008, n = 1,039

Data source according to screening definition used	Odds Ratio and 95% CI	% Difference in beta coefficients	P-value of difference*
Screening defined as ‘probable’ or ‘definite’
Progress note	0.31 (0.14-0.70)	−9.5	0.64
Referral note	0.46 (0.22-0.98)	28.0	0.41
Procedure report	0.50 (0.25-1.02)	31.2	0.26
All sources combined	0.30 (0.14-0.65)	−21.6	0.52
Adjudicated indication	0.36 (0.19-0.68)	Ref	Ref
Same definition as above plus ‘high-risk’ screening exposures
Progress note	0.32 (0.17-0.64)	2.4	0.98
Referral note	0.45 (0.23-0.85)	34.9	0.12
Procedure report	0.43 (0.23-0.79)	27.4	0.23
All sources combined	0.31 (0.16-0.58)	−6.2	0.69
Adjudicated indication	0.33 (0.17-0.62)	Ref	Ref

Conditional logistic regression modelling was performed with separate indicator variables for colonoscopy and sigmoidoscopy and adjusted for receipt of ‘definite’ screening barium enema and FOBT, census block-group poverty levels (as a continuous variable), number of preventive health care visits, family history of colorectal cancer, and comorbidity index at baseline. Missing values of poverty level were imputed using predictive mean matching.
*Two-sided Wald Chi-square (χ ²) P-values of the difference between effect sizes.

ISSN: 1471-2407