Data selection flaw.
Loffeld
R J L F
RJ
D017668:Age of Onset; D015179:Colorectal Neoplasms / Q000473:pathology*; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000473:pathology*; D008403:Mass Screening / Q000458:organization & administration / Q000706:statistics & numerical data; D009426:Netherlands; D015983:Selection Bias