Analysis of interval XXXX in a randomized screening trial in Stockholm.

@entity1 @entity5 @entity0
In the interval between screening examinations, some cases of @entity0 are invariably detected clinically in @entity1 whose mammogram was considered to be normal at the earlier screening. During the first interval in the Stockholm study, 60 @entity5 were detected, giving a rate of 1.8 cases/1000 examinations/24 months. About half of these interval cases (31/60) were @entity5 in that no sign of them could be found on the first mammogram; the other half, non-true, were possible to trace on the first mammogram. It is mainly @entity1 under 50 who feature in the interval group, above all in the sub-group of true @entity5 (p less than 0.05). The incidence of @entity5 rises, as expected, with the length of the interval (Fig. 1). In the final six months of the 2-year interval the incidence of @entity5 had risen to 88 per cent of the @entity5 detected in the control group in the same period of time. The cumulative incidence of @entity5 supports the hypothesis that the distribution of sojourn time in the interval 0-2 years is approximately rectangular. This means that shortening the interval by one-half would halve the number of interval cases. If mammography becomes a wide spread screening method for early detection of @entity0 , the number of @entity5 could be a feed back on the effectiveness of the screening.(ABSTRACT TRUNCATED AT 250 WORDS)
