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  1. M Muir
  1. BMJ Journals; mmuir{at}

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    Bigger is better but medium is ok too

    There is a clear need to bolster public confidence in breast screening programmes after recent (media sensationalised) errors and the most transparent way of doing this is to identify problems in the process and eliminate them, therefore improving performance. Bearing this in mind, researchers evaluated the performance of the current 95 breast screening programmes in the UK and found that the smaller programmes are less effective then their medium and large counterparts (


    The annual standard statistical returns of all programmes were analysed alongside extra information taken from supplementary questionnaires and demonstrated that smaller programmes (defined as the smallest 25%) detected fewer cancers and also had a lower positive predictive value (9.97 PPV compared with 12.06 PPV at 95% confidence intervals). Although the performance of smaller programmes was only marginally poorer than that of the medium and large programmes (which performed to similar standards), the inherent statistical instability associated with small numbers means that problems are harder to identify in these programmes. The solution to the problem may have already been found through the decision to screen older (65 to 70 year old) women, effectively making many of the small programmes medium sized and therefore enabling easier problem detection.

    Inconsistency city

    Glasgow, UK, experienced an overall downward trend in the prevalence of congenital anomalies between 1980 and 1997. This pattern was inconsistent however, as there was a significant increase in chromosomal anomalies generally and Down’s syndrome particularly. (


    As the prevention and treatment of infectious disease and malnutrition improve, a proportionally higher amount of child health problems are caused by congenital anomalies. They are still a major cause of perinatal mortality and child disability throughout Europe, despite the fact that the continent as a whole has also experienced a drop in some types of the disorders. The authors examined the Glasgow Register of Congenital Anomalies for the period of 1980 to 1997, which included cases of congenital anomalies identified in live births, stillbirths, and induced abortions following prenatal diagnosis. Spontaneous abortions were not included and there was no formal time limit for the registration of newly diagnosed cases.

    They found that most categories of congenital anomaly dropped in prevalence, including those of the ear (−88%), heart (−69%), and nervous system (−61%). Chromosomal anomalies, however, experienced a significant rise (+50%) with the increase in prevalence of Down’s syndrome (+100%) making up most of that figure. The authors point to external demographic and environmental factors as possible reasons for the fluctuations, but as yet the contrasting risk of congenital anomaly in Glasgow compared with the rest of Europe and the declining prevalence of most types of anomaly remains largely unexplained.

    Mortality in non-diabetic female cataract sufferers

    Cataract, already associated with increased mortality in diabetes patients, has now been linked for the first time to higher mortality in non-diabetic people—but only in women.

    As a cause of visual impairment in the elderly population, cataract is a major problem worldwide and the need for modelling of its population dynamics is well recognised. A random sample was drawn from a defined population of people aged 65 and over in north London, UK. After following up the study cohort for four years, the age and sex specific mortality from various causes was estimated and compared in those with and without cataract.

    The results show a significant association between cataract and increased mortality in non-diabetic women, with an age standardised death rate per 1000 of 39.8 compared with 24.8 in women without cataract. The opposite was true for men, with death rates per 1000 of 57.8 with cataract and 63.0 without cataract. Possible explanations for the observed differential risk in women revolve around sex specific risk factors such as pregnancy and childbirth, while the fact that men have higher exposure to factors that increase mortality but not cataract may also have a bearing on the data. (


    Paediatric tuberculosis on the rise in London

    The incidence of paediatric tuberculosis (TB) in London, UK, increased by 130% between 1988 and 1998 and is showing no signs of stopping. (


    Data were taken from two main sources: notifications of TB to the Public Health Laboratory Service Communicable Disease Surveillance Centre, and the five yearly National Surveys of 1993 and 1998. Just under half of the cases were in children born outside of the UK and 85% of those were developed within five years of entering the country—demonstrating the need for children in immigrant families to receive BCG immunisation to protect them against severe forms of the disease. Several neonatal BCG policies (with a range of selection criteria) currently operate in London but can be difficult to implement and operate. The authors advise a holistic approach to a rapidly increasing problem, concluding that “ . . .broad based partnerships with public health programmes, community based organisations, and managed care plans must be recognised and adopted if the resurgence in childhood tuberculosis is to be brought to an end.”