Overdiagnosis in organised mammography screening in Denmark. A comparative study

<p>Abstract</p> <p>Background</p> <p>Overdiagnosis in cancer screening is the detection of cancer lesions that would otherwise not have been detected. It is arguably the most important harm. We quantified overdiagnosis in the Danish mammography screening programme, which is uniquely suited for this purpose, as only 20% of the Danish population has been offered organised mammography screening over a long time-period.</p> <p>Methods</p> <p>We collected incidence rates of carcinoma in situ and invasive breast cancer in areas with and without screening over 13 years with screening (1991-2003), and 20 years before its introduction (1971-1990). We explored the incidence increase comparing unadjusted incidence rates and used Poisson regression analysis to compensate for the background incidence trend, variation in age distribution and geographical variation in incidence.</p> <p>Results</p> <p>For the screened age group, 50 to 69 years, we found an overdiagnosis of 35% when we compared unadjusted incidence rates for the screened and non-screened areas, but after compensating for a small decline in incidence in older, previously screened women. Our adjusted Poisson regression analysis indicated a relative risk of 1.40 (95% CI: 1.35-1.45) for the whole screening period, and a potential compensatory drop in older women of 0.90 (95% CI: 0.88-0.96), yielding an overdiagnosis of 33%, which we consider the most reliable estimate. The drop in previously screened women was only present in one of the two screened regions and was small in absolute numbers.</p> <p>Discussion</p> <p>One in four breast cancers diagnosed in the screened age group in the Danish screening programme is overdiagnosed. Our estimate for Denmark is lower than that for comparable countries, likely because of lower uptake, lower recall rates and lower detection rates of carcinoma in situ.</p

Anticipated regret to increase uptake of colorectal cancer screening in Scotland (ARTICS): Study protocol for a randomised controlled trial

Background: Colorectal cancer is the second leading cause of cancer deaths in the UK. Screening is key to early detection. The Scottish programme of colorectal cancer screening is running successfully, and involves all adults aged between 50 and 74 years being invited to post back a faecal sample for testing every 2 years. However, screening uptake is sub-optimal: for example rates for the period November 2009 to October 2011 ranged from just 39% for males living in the most deprived areas to 67% for least deprived females. Recent research has shown that asking people to consider the emotional consequences of not participating in screening (anticipated regret) can lead to a significant increase in screening uptake. Methods/Design: We will test a simple anticipated regret manipulation, in a large randomised controlled trial with 60,000 members of the general public. They will be randomly allocated to one of 3 arms, no questionnaire, control questionnaire or anticipated regret questionnaire. The primary outcome will be screening test kit return. Results will also be examined by demographic variables (age, gender, deprivation) as these are currently related to screening kit return. Discussion: If this anticipated regret intervention leads to a significant increase in colorectal cancer screening kit returns, this would represent a rare example of a theoretically-driven, simple intervention that could result in earlier detection of colorectal cancer and many more lives saved. Trial registration: Current Controlled trials: ISRCTN7498645

Breast and cervical cancer screening in Great Britain: Dynamic interrelated processes.

No previous analysis has investigated the determinants of screening uptake for breast and cervical cancer screening for possible spillover effects from one type of screening examination to the other type of screening examination with a dynamic bivariate panel probit model. For our analysis, we used a dynamic random effects bivariate panel probit model with initial conditions (Wooldridge-type estimator) and dependent variables were the participation of breast and cervical cancer screening in the recent year. The balanced panel sample consisted of 844 women from the British Household Panel Survey (BHPS) from the time period 1992 to 2008. Our analysis showed the high relevance of past screening behaviour and the importance of state dependency for the same and the other type of cancer screening examinations even after controlling for covariates and unobserved heterogeneity. The uptake for breast and cervical cancer screening was higher when the same screening examination was done one or three years earlier. This result is in accordance with the medical screening programmes in Great Britain. With regard to breast and cervical cancer screening positive spillover effects existed between screening examinations in the third order lags. Women with a previous visit to a general practitioner and individuals in the recommended age groups had a higher uptake for breast and cervical cancer screening. Other socioeconomic and health related variables had non-uniform results in both screening examinations. Promoting the uptake of one female prevention activity could also enhance the uptake of the other prevention activity