Abstract

Design - Population based case-control study. Comparison of vitamin K exposure in children with leukaemia or other common tumours with two control groups.

Setting - State of Lower Saxony (north western part of Germanyu; case recruitment from the German childhood cancer registry.

Subjects - 272 children with leukaemia, nephroblastoma, neuroblastoma, rhabdomyo-sarcoma, and tumours of the central nervous system diagnosed between 1 July 1988 and 30 June 1993; children were aged between 30 days and 15 years at diagnosis. 334 population based controls without diagnoses of cancer matched to the leukaemia cases for age and sex.

Main exposure measures - Parenteral vitamin K prophylaxis (intramuscular and subcutaneousu versus oral and no vitamin K prophylaxis.

Results - An association between parenteral vitamin K exposure and childhood cancer (leukaemias and other tumours combinedu could not be confirmed (odds ratio 1.04, 95% confidence interval 0.74 to 1.48u. For leukaemias the observed odds ratio was only 0.98 (0.64 to 1.50u (comparison of leukaemia cases with local controls 1.24 (0.68 to 2.25u; state controls 0.82 (0.50 to 1.36uu. These odds ratios remained almost unchanged when several potential confounders were considered in the logistic regression model.

Conclusions - This population based study adds substantial evidence that there is no association between parenteral vitamin K and childhood cancer.

Kinderklinik der Heinrich-Heine-Universitoft,
40225 Dusseldorf,
Germany
Rudiger von Kries,
paediatric epidemiologist
Ulrich Gobel,
head of paediatric haematology and oncology
Alexandra Hachmeister,
medical documentalist

Institut fur Medizinische Statistik und Dokumentation,
Johannes Gutenberg-Universitoft,
55131 Mainz
Uwe Kaletsch,
statistician
Jorg Michaelis,
head

Correspondence to: Professor R von Kries,
Institute for Social Paediatrics and Adolescent Medicine,
Ludwig-Maximilians-University,
Heiglhofstr 63,
81377 Munich,
Germany.

Home visiting by general practitioners in England and Wales

Abstract

Design - Survey of diagnostic data on all home visits by general practitioners.

Setting - 60 general practices in England and Wales.

Subjects - 502,493 patients visited at home between September 1991 and August 1992.

Main outcome measures - Home visiting rates per 1,000 patient years and home visiting ratios standardised for age and sex.

Results - 10.1% (139,801/1,378,510) of contacts with general practitioners took place in patients' homes. The average annual home visiting rate was 299/1,000 patient years. Rates showed a J shaped relation with age and were lowest in people aged 16-24 years (103/1,000) and highest in people aged >85 years (3009/1000). 1.3% of patients were visited five or more times and received 39% of visits. Age and sex standardised home visiting ratios increased from 69 (95% confidence interval 68 to 70) in social class I to 129 (128 to 130) in social class V. The commonest diagnostic group was diseases of the respiratory system. In older age groups, diseases of the circulatory system was also a common diagnostic group. Standardised home visiting ratios for the 60 practices in the study varied nearly eightfold, from 28 to 218 (interquartile range 67 to 126).

Conclusions - Home visits remain an important component of general practitioners workload. As well as the strong associations between home visiting rates and patient characteristics, there were also large differences between practices in home visiting rates. A small number of patients received a disproportionately high number of home visits. Further investigation of patients with high home visiting rates may help to explain the large differences in workload between general practices and help in allocation of resources to practices.

Office for National Statistics,
London WC2B 6JP
Paul Aylin,
medical statistician

Department of Public Health Sciences,
St George's Hospital Medical School,
London SW17 0RE
F Azeem Majeed,
lecturer in public health medicine
Derek G Cook,
reader in epidemiology