Colorectal Cancers Prevented in Czech National Screening Programme: Use of Markov Model for Synthesis of Clinical and Administrative Data
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| Year of publication | 2012 |
| Type | Conference abstract |
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| Description | Czech National Colorectal Cancer Screening Programme was initiated in year 2000 with biennial faecal occult blood test (FOBT) for individuals aged over 50. Since 2009, patients can opt for annual (individuals aged 50-54 years) or biennial (individuals over 55) FOBT or primary screening colonoscopy every 10 years. Our objective was to estimate number of colorectal cancers (CRCs) prevented by FOBT screening through removal of advanced adenomas. Since 2006, results of FOBT+ follow-up colonoscopy examinations in collaborating programme centres have been recorded in an electronic registry. This registry allows us to estimate proportion of advanced adenomas detected in followed-up subjects. Administrative data of all Czech healthcare payers were made available through the Czech National Reference Centre and provided information about population coverage by FOBT and its positivity. As the electronic registry does not provide complete coverage of follow-up colonoscopy examinations, decision tree was constructed to estimate annual numbers of patients with removed advanced adenoma utilising previously estimated compliance of FOBT+ subjects with follow-up colonoscopy. Potential progression of removed advanced adenomas to preclinical and clinically manifest CRCs was modelled using two consecutive Markov models, using previously published rates of progression. Czech National Cancer Registry was used for estimation and projection of CRC rates for reference. The annual number of patients undergoing screening FOBT gradually increased from 12,000 in 2000 to over 400,000 in 2009; however, the estimated biennial coverage of the Czech target population by FOBT remains pretty low (20.2% in 2009). Over years 2000-2009, the estimated number of FOBT+ patients with detected and removed advanced adenomas was 11,344. Clinically manifest CRC was prevented in 417 patients till 2009. Assuming participation and adenoma detection rates estimated in 2009 continuing in following years, 388 CRCs will be prevented in 2015, yielding cumulative number of 2,011 prevented cases during years 2000-2015. Expected reduction of CRC incidence in 2015 is 4.1% in comparison with projected colorectal cancer rates. Although primary objective of FOBT screening is CRC early detection, prevention of CRCs through detection and removal of advanced adenomas may also provide substantial public health benefit in long-term. Efforts to increase participation of individuals from Czech target population are nevertheless needed to achieve greater effectiveness as regards both prevention and early detection of CRCs. |
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