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Sisse Helle Njor

Publications and source records attributed to Sisse Helle Njor.

4 recordsLinked to original sources

Do nonattenders in mammography screening programmes seek mammography elsewhere?

The objectives of our study were to analyse the use of diagnostic mammography among nonattenders and attenders in organised mammography screening in Denmark in 2000, to assess the contamination from organised screening of noninvited age groups and to measure the impact of local policy on opportunistic screening. Data on all diagnostic mammographies performed in Denmark in 2000 and data on women targeted by the 2 organised mammography screening programmes in Copenhagen and the county of Fyn were collected. All data were linked by the Danish personal identification number. Information on the official policy in 2000 with regard to opportunistic screening was collected from all counties. The proportion of women using diagnostic mammography was only 1-3% for both attenders and nonattenders in organised mammography screening, but it was significantly higher in Copenhagen than in Fyn, due to availability of mammography in private clinics. The proportion of women using diagnostic mammography varied from 1-4% across counties. The official policy on access to diagnostic mammography and contamination from organised mammography screening of adjacent age groups had no impact on the use. Instead, urbanisation was positively correlated with use of diagnostic mammography. In conclusion, our results clearly showed that nonattenders in organised mammography screening programmes do not seek mammography outside the programme. Since a positive policy toward opportunistic screening did not have any effect, our results add further evidence to existing knowledge that the only reasonable way to achieve high mammography coverage is through a well-organised screening programme.

Adult↗

A model for determining the effect of mammography service screening.

In an overview, Swedish mammography screening trials demonstrated a 29% reduction in breast cancer mortality in women aged 50-69 and no effect on total mortality. Three Danish regions introduced mammography screening in the 1990s. The authors developed a method to evaluate the effect of mammography service screening on breast cancer mortality and validated it applying it to total mortality, where no effect was expected. Study groups and historical and national control groups were analysed using Poisson regression. Total mortality in the screening regions and periods was close to that expected in the absence of screening. A small (3%) excess risk, also seen in a non-screening area, probably results from regional differences changing over time. The effect of this is inseparable from the screening effect. The design is adequate for analysing the effect of mammography service screening on breast cancer mortality.

Aged↗

Mammography screening in the county of Fyn. November 1993-December 1999.

This report covers the outcome of the first three invitation rounds of the organised mammography screening programme in the county of Fyn. The programme started in November 1993, and the third invitation round ended on 31 December 1999. The screening takes place either at a special clinic located at University Hospital Odense or in a mobile unit. Women living in and around the city of Odense are examined at the clinic (about 55%), while the rest are examined in the mobile unit. Two-view mammography is used at the first screening. Women with dense breast tissue will continue to have two-view mammography (about 60%), whereas the rest will have singleview mammography at the subsequent screens. All screening images are exposed at the mammography-screening clinic and evaluated with double reading in the clinic. The programme targets women aged 50-69, except those undergoing treatment for breast cancer or going for regular check-ups following breast cancer. Based on the updated population register, the IT-Centre of the county of Fyn issues the invitations. Invited are all women aged 50-69 and living in the county of Fyn when their general practitioners' patients are invited. During the first 3 invitation rounds, 136,079 screening tests were made. Of these, 129,375 tests were made in the women aged 50-69 targeted by the programme. In addition, 6682 screening tests were made in women aged 70 and above, and 22 screening tests were made in women below the age of 50. As a consequence of the mammography screening 2657 assessments were made, 1145 women had surgery, 782 women were diagnosed with invasive breast cancer, and 109 women were diagnosed with ductal carcinoma in situ. A participation rate for the first invitation round was calculated immediately after the end of the round based on the number of participants divided by the number of women invited. This percentage was 88%. Invitation data are, however, not stored. It is therefore not possible now to calculate the participation rates in previous invitation rounds based on the same method. We have therefore chosen to calculate the participation rate as the coverage, i.e. the number of participants divided by the average number of women in the county of Fyn during a given invitation round. Calculated in this way, 84% participated in the first round, 84% in the second round, and 82% in the third round. It should be remembered that these figures do not take into account that some women are not invited because they 1) were undergoing current treatment for breast cancer or going for regular check-ups following breast cancer, or 2) did not participate in the previous round (and never actively informed the programme that they wanted an invitation to the next invitation round), relevant only for the second and third invitation round. For the second and third invitation rounds, the programme only invited women who participated in the previous invitation round, asked the clinic for an invitation, or entered the target population since the last invitation round. Therefore the participation rate in the second invitation round among actually invited women will be close to 94%, as 94% of those participating in the first round came for the second round. For the third invitation round, the participation rate among actually invited women will be close to 96%, as 96% of those participating in the first and second rounds came for the third round. One per cent of the participants in the first invitation round were diagnosed with invasive breast cancer or ductal carcinoma in situ. The detection rate was 0.5% in both the second and third invitation rounds. Ductal carcinoma in situ cases constituted 14% of the detected cases in the first and second rounds, and 10% in the third round. The percentage of invasive breast cancer 10 mm of less was 38%, 31%, and 32%, respectively, and 68%, 74%, and 73%, respectively, were node-negative. The screening programme of the county of Fyn fulfilled all the quality assessment parameters specified by the European guidelines on breast cancer screening, except two. The proportionate interval cancer rate was higher than specified in the guidelines, probably mainly due to the fact that the Fyn programme operates without early recalls. The proportion of stage II+ cancers was higher than specified in the guidelines, which seems, however, to be due to inconsistency between some of the performance indicators in the European guidelines. This analysis of the outcome from the first three invitation rounds of the mammography screening programme in the county of Fyn thus showed that it is a programme of high quality with a favourable profile of the prognostic indicators. The screening programme is hopefully well on its way to reducing breast cancer mortality in the county of Fyn.

Aged↗