Evaluation by Markov chain models of a non-randomised breast cancer screening programme in women aged under 50 years in Sweden. Issue 5 (May 1998)

• Record Type: Journal Article
• Authors: Chen, H H; Thurfjell, E; Duffy, S W; Tabar, L
• Is Part Of: Journal of epidemiology and community health. Volume 52:Issue 5(1998)
• Page Start: 329
• Page End: 335
• Publication Date: 1998-05
• Subjects: Public health -- Periodicals; Epidemiology -- Periodicals; 614.4
• DOI: 10.1136/jech.52.5.329
• Languages: English
• ISSNs: 0143-005X

Abstract

Abstract : STUDY OBJECTIVE: To apply Markov chain models that have previously been used on data in randomised trials of breast cancer screening to data from an uncontrolled service screening programme; to compare results with those from a randomised trial. DESIGN: A service screening programme in Uppsala county, Sweden, inviting 25, 660 women aged 39-49 to mammographic screening every 20 months, and the Swedish Two-County Trial inviting 19, 844 women aged 40-49 to two yearly screening, compared with 15, 604 women of the same age in an unscreened control group. Data were analysed using Markov chain models and quasi-likelihood estimation procedures. MAIN RESULTS: The results with respect to parameters of disease progression were very similar between the two studies. Use of estimated progression rates to predict the effect on mortality ranged from a 10% to a 17% reduction in breast cancer mortality in the Two-County Study and predicted a 15% reduction in the Uppsala programme. These compare well with the observed mortality reduction of 13% in the Two-County Trial. CONCLUSIONS: The screening in the Uppsala programme is likely to have a similar effect to that observed in the Two-County Trial. It is feasible to evaluate non-randomised service screening programmes using Markov chain models.