Publication details
Estimation Of The Mean Sojourn Time And Sensitivity In Mammographic Screening Programme Using Bayesian Methods
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| Year of publication | 2009 |
| Type | Conference abstract |
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| Citation | |
| Description | Background: Organized breast cancer screening programme in the Czech Republic was initiated in September 2002. Free biennial preventive mammography examinations are offered to women aged 45-69. Important parameters in assessing the quality of the screening process and natural history of breast cancer are: mean duration of the preclinical screen-detectable phase (the carcinoma is without clinical signs but it could be found by the screening test - mammography), which is called mean sojourn time (MST), and sensitivity of mammography (capability of the test to detect cancer). These parameters are not directly observable; however, they can be estimated using mathematical models. Objective: To estimate the MST and sensitivity of mammography in women aged 50-59 and 60-69 years. Methods: Using the numbers of examinations and numbers of tumours detected by screening in the first three rounds, three state Markov models with states: disease free – preclinical screendetectable – clinical disease were constructed. In the first model, we assumed a constant interval between screens, in the second model, there was different time interval between screens. Analysis was performed using WinBUGS software. Results: In 2002-2007, there were 741,655 examinations performed in women aged 50-59 and 434,165 in women aged 60-69 in the first three screening rounds. According to the first model, the estimated MST was 2.73 years for women aged 50-59 and 3.30 for women aged 60-69. The estimated sensitivity of mammography was 73% for women aged 50-59 and 93% for women aged 60-69. As regards the second model, the estimated MST was 2.31 years for women aged 50- 59 and 3.12 for women aged 60-69. The estimated sensitivity of mammography was 84% for women aged 50-59 and 95% for women aged 60-69. Conclusion: Two year screening interval for mammography examinations is appropriate for programme in the Czech Republic. Sensitivity of mammography is adequate in age groups covered by the programme. |