Design - Meta-analysis of prospective cohort studies published between 1985 and end of 1994 with a baseline measurement of bone density in women and subsequent follow up for fractures. For comparative purposes, we also reviewed case control studies of hip fractures published between 1990 and 1994.
Subject - Eleven separate study populations with about 90 000 person years of observation time and over 2000 fractures. Main outcome measures-Relative risk of fracture for a decrease in bone mineral density of one standard deviation below age adjusted mean.
Results - All measuring sites had similar predictive abilities (relative risk 1.5 (95% confidence interval 1.4 to 1.6)) for decrease in bone mineral density except for measurement at spine for predicting vertebral fractures (relative risk 2.3 (1.9 to 2.8)) and measurement at hip for hip fractures (2.6 (2.0 to 3.5)).These results are in accordance with results of case-control studies. Predictive ability of decrease in bone mass was roughly similar to (or, for hip or spine measurements, better than) that of a 1 SD increase in blood pressure for stroke and better than a 1 SD increase in serum cholesterol concentration for cardiovascular disease.
Conclusions-Measurements of bone mineral density can predict fracture risk but cannot identify individuals who will have a fracture. We do not recommend a programme of screening menopausal women for osteoporosis by measuring bone density.
Swedish Council on Technology Assessment in Health Care,
Box 16158,
S-10324 Stockholm,
Sweden
Deborah Marshall, research associate
Department of Orthopaedics,
Malm General Hospital, S-21401,
Malm, Sweden
Olof JohnelI, professor
Department of Epidemiology and Biostatistics,
Nordic School of Public Health,
Box 12133, S-40242, Gothenburg, Sweden
Hans Wedel, professor
Correspondence to: Professor Wedel.
Design-Cohort study of national population.
Subjects-People aged 30-64 and economically active in 1970 (927 470 men and 486 130 women).
Main outcome measures-Relative risks for lung cancer estimated with multiplicative Poisson modelling of incidence rates.
Results-Differences in smoking habit explained about 60% of the excess lung cancer risk in Copenhagen for men and 90% for women. After control for smoking, workers had double the lung cancer risk of teachers and academics. There was only a small independent effect of region.
Conclusion-Smoking is the main factor behind the regional differences in lung cancer incidence in Denmark, and occupational risk factors also seem to have an important role. The outdoor air in Copenhagen around 1970 contained on average 50-80 ug/m3 of sulphur dioxide, 80-100 ug/m3 total suspended particulate matter, and up to 10 ug/m3 benzo(a)pyrene and had peak values of daily smoke of 120 ug/m3. Region had only a small effect on incidence of lung cancer in the present study, which suggests that an influence of outdoor air pollution on lung cancer is identifiable only above this pollution level.
Danish Cancer Society,
Division for Cancer Epidemiology,
Box 839,
DK-2100 Copenhagen 0,
Denmark,
Gerda Engholm, statistician,
Elsebeth Lynge, head of department
National Environmental Research Institute,
Box 358, DK-4000
Roskilde,
Denmark,
Finn Palmgren, senior scientist
Correspondence to: Ms Engholm
Design-Cost effectiveness analysis of a randomised controlled trial using clinical and economic data taken from the trial.
Setting-Five general practices in Luton and Dunstable, England.
Subjects-2205 patients who attended a health check in 1989-90 and were scheduled for re-examination in 1992-3 (intervention group); 1916 patients who attended their initial health check in 1992-3 (control group). Participants were men and women aged 35-64 years.
Intervention-Health check conducted by nurse, with health education and follow up according to degree of risk.
Main outcome measures-Cost of health check programme; cost per 1 % reduction in coronary risk.
Results-Health check and follow up cost £29.27 per patient. Estimated programme cost per 1% reduction in coronary risk per participant was between £1.46 and £2.25; it was nearly twice as much for men as women.
Conclusions-The Cost to the practice of implementing Oxeheck-style health checks in an average sized practice of 7500 patients would be £47 000, a proportion of which could be paid for through staff pay reimbursements and Band Three health promotion target payments. This study highlights the considerable difficulties faced when calculating the costs and benefits of a health promotion programme. Economic evaluations should be integrated into the protocols of randomised controlled trials to enable judgments to be made on the relative cost effectiveness of different prevention strategies.
Department of Public Health and Policy
London School of Hygiene and Tropical Medicine
London WC2E 7HT
Susan Langham, lecturer in health economics
Margaret Thorogood, senior lecturer
Charles Normand, professor of health policy
Imperial Cancer Research Fund
General Practice Research Group
University of Oxford
Radcliffe Infirmary
Oxford 0X2 6HF
John Muir, senior research fellow
Lesley Jones, computer scientist
Godfrey Fowler, clinical reader in general practice
Correspondence to: Professor Normand
Design-Cost effectiveness analysis of randomised controlled trial. Clinical and resource use data taken from trial and unit cost data from external estimates.
Setting-13 general practices across Britain.
Subjects-4185 men aged 40-59 and their 2827 partners.
Intervention-Nurse led programme using a family centred approach, with follow up according to degree of risk.
Main outcome measures-Cost of the programme itself; overall short term cost to NHS; cost per 1% reduction in coronary risk at one year.
Results-Estimated cost of putting the programme into practice for one year was £63 per person (95% confidence interval £60 to £65). The overall short term cost to the health service was £77 per man (£29 to £124) but only £13 per woman (-£48 to £74), owing to differences in utilisation of other health service resources. The cost per 1% reduction in risk was £5.08 per man (£5.92 including broader health service costs) and £5.78 per woman (£1.28 taking into account wider health service savings).
Conclusions-The direct cost of the programme to a four partner practice of 7500 patients would be approximately £58 000. Annually, £8300 would Currently be paid to a practice of this size working to the maximum target on the health promotion bands, plus any additional reimbursement of practice staff salaries for which the practice qualified.The broader short term costs to the NHS may augment these costs for men but offset them considerably for women.
Health Economies Research Group
Brunel University
Uxbridge
Middlesex UB8 3PH
David Wonderling, research fellow in health economics
Christine McDermott, research fellow in health economics
Martin Buxton, professor of health economics
Primary Medical Care
Faculty of Medicine
University of Southampton
Aldermoor Health Centre
Southampton SO16 5ST
Ann-Louise Kinmouth, professor of primary medical care
Medical Statistics Unit
London School of Hygiene and Tropical Medicine
London WC1E 7HT
Stephen Pyke, lecturer in medical statistics
Simon Thompson, reader in medical statistics
Department of Clinical Epidemiology
National Heart and Lung Institute
London SW3 6LY
David Wood, honorary consultant cardiologist
Correspondence to: Professor Buxton
Design-Modelling from cost and effectiveness data to estimates of cost per life year gained.
Subjects-Middle aged men and women.
Interventions-Screening for cardiovascular risk factors followed by appropriate lifestyle advice and drug intervention in general practice, and other primary coronary risk management strategies.
Main outcome measures-Life years gained; cost per life year gained.
Results-Depending on the assumed duration of risk reduction, the programme cost per discounted life year gained ranged from £34 800 for a 1 year duration to £1500 for 20 years for the British family heart study and from £29 300 to £900 for Oxcheck. These figures exclude broader net clinical and cost effects and longer term clinical and cost effects other than coronary mortality.
Conclusions-Despite differences in underlying methods, the estimates in the two economic analyses of the studies can be directly compared. Neither study was large enough to provide precise estimates of the overall net cost. Modelling to cost per life year gained provides more readily interpretable measures. These estimates emphasise the importance of the relatively weak evidence on duration of effect. Only if the effect lasts at least five years is the Oxcheck programme likely to be cost effective. The effect must last for about 10 years to justify the extra cost associated with the British family heart study.
Health Economics Research Group
Brunel University
Uxbridge
Middlesex UB8 3PH
David Wonderling, research fellow in health economics
Martin Buxton, professor of health economics
Christine McDermott, research fellows in health economics
Department of Public Health and Policy
London School of Hygiene and Tropical Medicine
London WC1E 7HT
Susan Langham, lecturer in health economics
Charles Normand, professor of health policy
Correspondence to: Professor Buxton.