Modelling the effects of increased physical activity on coronary heart disease in England and Wales

OBJECTIVE

To investigate the use of computer models as tools for policy makers in evaluating physical activity interventions aimed at reducing deaths from coronary heart disease (CHD).

DESIGN

The cell-based computer model Prevent, adapted to simulate risk factor interventions for an English and Welsh population, was used to simulate the effect of two strategies for increasing physical activity levels in respect of CHD mortality over 25 years. The first strategy involved a 25% increase in the proportion of 15-64 year olds who were moderately active, while the second strategy involved a similar increase in the proportion who were vigorously active. The effects of focusing on narrower age ranges and on people at different initial activity levels were also explored.

MAIN RESULTS

The simulations showed a small reduction in the CHD death rates--less than 0.15% and 0.06% for men and women respectively. The strategies would postpone up to 12,100 deaths over 25 years, comparable to the effect of a 2% reduction in smoking prevalence. The strategies seemed as if they would be more effective if they concentrated on men rather than women, on those over 45 years of age as opposed to all or younger age groups, and on the least active members of the population rather than those already taking some exercise.

CONCLUSION

The use of computer modelling for stimulating physical activity strategies has shown that concentrating these interventions on older sedentary men will produce the greatest health gain, but efforts to encourage smoking cessation may be more effective in terms of years of life saved.

Medical Research Council randomised trial of endometrial resection versus hysterectomy in management of menorrhagia

BACKGROUND

The most frequent indication for hysterectomy is menorrhagia, even though the uterus is normal in a large number of patients. Transcervical resection of the endometrium (TCRE) is a less drastic alternative, but success rates have varied and menorrhagia can recur. We have tested the hypothesis that the difference in the proportion of women dissatisfied and requiring further surgery within 3 years of TCRE or hysterectomy would be no more than 15%.

METHODS

202 women with symptomatic menorrhagia were recruited to a multicentre, randomised, controlled trial to compare the two interventions. TCRE and hysterectomy were randomly assigned in a ratio of two to one. The primary endpoints were women's satisfaction and need for further surgery. The patients' psychological and social states were monitored before surgery, then annually with a questionnaire. Analysis was by intention to treat.

FINDINGS

Data were available for 172 women (56 hysterectomy, 116 TCRE); 26 withdrew before surgery and four were lost to follow-up. Satisfaction scores were higher for hysterectomy than for TCRE throughout follow-up (median 2 years), but the differences were not significant (at 3 years 27 [96%] of 28 in hysterectomy group vs 46 [85%] of 54 in TCRE group were satisfied; p = 0.16). 25 (22%) women in the TCRE group and five (9%) in the hysterectomy group required further surgery (relative risk 0.46 [95% CI 0.2-1.1], p = 0.053). TCRE had the benefits of shorter operating time, fewer complications, and faster rates of recovery.

INTERPRETATION

TCRE is an acceptable alternative to hysterectomy in the treatment of menorrhagia for many women with no other serious disorders.

Pain levels after total hip replacement: their use as endpoints for survival analysis

We have assessed the relative value of various outcome measures after THR, by the analysis of follow-up data from over 2000 patients. They had been reviewed clinically and radiologically six months after operation, at one year, and then every two years, some for 16 years. At each review their pain level, stiffness and opinion of progress were scored and a radiograph taken. We found that pain level was the most informative outcome as a predictor of revision and correlated well with the patients' opinions. We made a comparison between the six types of implant in the series, using survival analysis and log-rank testing with different pain levels as endpoints. This analysis revealed differences which were not detected by survival analysis using the traditional endpoint of revision. We therefore recommend the use of different levels of pain as the main outcome measures after total hip replacement.

Breast cancer and hormonal contraceptives: further results. Collaborative Group on Hormonal Factors in Breast Cancer

The Collaborative Group on Hormonal Factors in Breast Cancer has brought together and reanalysed the worldwide epidemiological evidence on breast cancer risk and use of hormonal contraceptives. Original data from 54 studies, representing about 90% of the information available on the topic, were collected, checked and analysed centrally. The 54 studies were performed in 26 countries and include a total of 53,297 women with breast cancer and 100,239 women without breast cancer. The studies were varied in their design, setting and timing. Most information came from case-control studies with controls chosen from the general population; most women resided in Europe or North America and most cancers were diagnosed during the 1980s. Overall 41% of the women with breast cancer and 40% of the women without breast cancer had used oral contraceptives at some time; the median age at first use was 26 years, the median duration of use was 3 years, the median year of first use was 1968, the median time since first use was 16 years, and the median time since last use was 9 years. The main findings, summarised elsewhere, are that there is a small increase in the risk of having breast cancer diagnosed in current users of combined oral contraceptives and in women who had stopped use in the past 10 years but that there is no evidence of an increase in the risk more than 10 years after stopping use. In addition, the cancers diagnosed in women who had used oral contraceptives tended to be less advanced clinically than the cancers diagnosed in women who had not used them. Despite the large number of possibilities investigated, few factors appeared to modify the main findings either in recent or in past users. For recent users who began use before age 20 the relative risks are higher than for recent users who began at older ages. For women whose use of oral contraceptives ceased more than 10 years before there was some suggestion of a reduction in breast cancer risk in certain subgroups, with a deficit of tumors that had spread beyond the breast, especially among women who had used preparations containing the highest doses of oestrogen and progestogen. These findings are unexpected and need to be confirmed. Although these data represent most of the epidemiological evidence on the topic to date, there is still insufficient information to comment reliably about the effects of specific types of oestrogen or of progestogen. What evidence there is suggests, however, no major differences in the effects for specific types of oestrogen or of progestogen and that the pattern of risk associated with use of hormonal contraceptives containing progestogens alone may be similar to that observed for preparations containing both oestrogens and progestogens. On the basis of these results, there is little difference between women who have and have not used combined oral contraceptives in terms of the estimated cumulative number of breast cancers diagnosed during the period from starting use up to 20 years after stopping. The cancers diagnosed in women who have used oral contraceptives are, however, less advanced clinically than the cancers diagnosed in never users. Further research is needed to establish whether the associations described here are due to earlier diagnosis of breast cancer in women who have used oral contraceptives, to the biological effects of the hormonal contraceptives or to a combination of both. Little information is as yet available about the effects on breast cancer risk of oral contraceptive use that ceased more than 20 years before and as such data accumulate it will be necessary to re-examine the worldwide evidence.

Long-term comparison of Charnley and Stanmore design total hip replacements

We reviewed the records of the long-term outcome of 208 Charnley and 982 Stanmore total hip replacements (THR) performed by or under the supervision of one surgeon from 1973 to 1987. The Stanmore implant had a better survival rate before revision at 14 years (86% to 79%, p = 0.004), but the difference only became apparent at ten years. The later Stanmore implants did better than the early ones (97% to 92% at ten years, p = 0.005), the improvement coinciding with the introduction of a new cementing technique using a gun. Most of the Charnley implants were done before most of the Stanmore implants so that the difference between the results may in part be explained by improved methods, but this is not the complete explanation since a difference persisted for implants carried out during the same period of time. We conclude that improved techniques have reduced failure rates substantially. This improvement was much greater than that observed between these two designs of implant. Proof of the difference would require a very large randomised controlled trial over a ten-year period.

LONG-TERM COMPARISON OF CHARNLEY AND STANMORE DESIGN TOTAL HIP REPLACEMENTS

We reviewed the records of the long-term outcome of 208 Charnley and 982 Stanmore total hip replacements (THR) performed by or under the supervision of one surgeon from 1973 to 1987. The Stanmore implant had a better survival rate before revision at 14 years (86% to 79%, p = 0.004), but the difference only became apparent at ten years.

The later Stanmore implants did better than the early ones (97% to 92% at ten years, p = 0.005), the improvement coinciding with the introduction of a new cementing technique using a gun. Most of the Charnley implants were done before most of the Stanmore implants so that the difference between the results may in part be explained by improved methods, but this is not the complete explanation since a difference persisted for implants carried out during the same period of time.

We conclude that improved techniques have reduced failure rates substantially. This improvement was much greater than that observed between these two designs of implant. Proof of the difference would require a very large randomised controlled trial over a ten-year period.

Endovascular grafting of abdominal aortic aneurysms. A preliminary study

OBJECTIVE

The authors report the experience of a single investigational center involving two Phase I and a Phase II clinical trials approved by the Food and Drug Administration (FDA) for the transfemoral implantation of woven Dacron grafts for abdominal aortic aneurysms.

SUMMARY BACKGROUND DATA

In 1993, EndoVascular Technologies, Inc. ([EVT]; Menlo Park, CA), began an FDA-approved clinical trial of repair of abdominal aortic aneurysms by transfemoral placement of a tube endograft. Subsequently, a bifurcated endograft trial was started. This the first single institution report using the EVT endograft for both tube and bifurcated aortic replacement.

METHODS

Seventeen patients were enrolled in two Phase I and one Phase II clinical trials. The Phase I tube graft trial and the Phase I bifurcated graft trial were nonrandomized studies. The Phase II tube graft trial consisted of a randomized prospective control trial of open endoaneurysmorrhaphy versus transfemoral placement of an endograft.

RESULTS

Seventeen patients were enrolled in the trial. The graft was placed successfully in all but one patient. Five patients randomized to open procedure and one declined to participate. Eleven patients with endografts are available for follow-up. One graft has been explanted for attachment system migration. One patient is a late failure because of persistent filling of the aneurysm sac.

CONCLUSION

Transfemoral placement of an endovascular graft is a viable and effective treatment of abdominal aortic aneurysms in the short term. Use of a bifurcated endograft will open the procedure to more patients. The ideal attachment system and graft material await long-term implantation follow-up.

Hormone replacement therapy in a risk-benefit perspective

The relative cost-effectiveness of different treatment strategies for hormone replacement therapy (HRT) was assessed within the framework of a computer model. Where data were lacking, it was necessary to make assumptions about the effects of HRT, particularly in relation to combined oestrogen-progestogen therapy and cardiovascular disease; however, sensitivity analyses were performed to assess the impact of changing these assumptions on the cost-effectiveness equation. It appears that net expenditure by the NHS will depend critically on the direct costs of treatment, rather than on any indirect costs incurred or saved as a result of side-effects. In terms of mortality, a reduction in cardiovascular disease risk would have greatest impact and would overshadow any small increase in breast cancer risk which may be associated with long-term use. If the cardioprotective effect of oestrogen is real, our results suggest that long-term prophylactic treatment of hysterectomised women would be relatively cost-effective. Treatment of symptomatic menopausal women for any period of time appears to offer very good value for money. The lack of data relating to combined oestrogen-progestogen therapy and cardioprotection, and the major importance of the latter in the equation of benefits and risks, make it more difficult to draw conclusions about the cost-effectiveness of treating non-hysterectomised asymptomatic women for prophylactic reasons.

The effect of prostatectomy on symptom severity and quality of life

OBJECTIVE

To determine the effectiveness of prostatectomy in reducing symptom severity and bother and in improving disease-specific and general quality of life.

PATIENTS AND METHODS

A prospective, cohort study was performed in National Health Service and private hospitals in the Northern, Wessex, Mersey, and South-West Thames Health Regions which comprised 5276 men undergoing prostatectomy recruited by 101 of the 106 (96%) surgeons (specialist and non-specialist) performing prostatectomy during a 6-month period. Patients were assessed using the American Urological Association (AUA) Symptom Index Score, the AUA symptom bother score, disease-specific and generic quality-of-life scores, the occurrence of adverse events (urinary incontinence, erectile impotence and retrograde ejaculation) and three global (general) questions on the results of their treatment. The outcome was assessed 3 months after surgery.

RESULTS

Prostatectomy was effective in reducing both symptoms (initial mean score 20.1 reduced to 7.4, P < 0.001) and symptom bother (initial mean score 14.4 reduced to 4.3, P < 0.001). Not all men experienced a good reduction in symptoms; 121 (3.9%) were worse, 301 (9.6%) were the same, and 721 (23%) experienced only slight improvement. The type of operation, grade of principal operator and use of pre-operative investigations were not associated with the extent of symptomatic improvement. Changes in symptom severity were highly correlated with changes in bothersomeness++ and disease-specific quality of life but not with generic quality of life. A third of men who were continent before surgery reported some incontinence 3 months later, although only 6% found it a problem. Two-thirds of men experienced retrograde ejaculation and 31% experienced some erectile impotence following surgery.

CONCLUSIONS

Prostatectomy is effective in reducing symptoms in most men. Men who experience a substantial reduction in symptoms were more likely to report a favourable outcome. The study confirmed that approximately one-third of men reported an unfavourable result 3 months after their operation.

Response of women aged 65-74 to invitation for screening for breast cancer by mammography: a pilot study in London, UK

OBJECTIVE

To investigate the response and benefits to be gained from mammographic screening for breast cancer in women aged 65-74, who are not normally invited for screening.

DESIGN

This was a pilot study comprising women aged 65-74 who are not currently invited for routine screening under the NHS breast screening programme. The results from this study were compared with the results of routinely screened women (aged 50-64) from the same health district.

SETTING

A mobile breast screening unit in the grounds of the Royal Free Hospital.

SUBJECTS

These comprised 5004 women aged 65-74 registered with GPs in the district of Hampstead and on the family health services authority (FHSA) lists. A total of 168 (3.4%) were initially excluded by the general practitioner or FHSA, and 286 (5.9%) of the invitation letters were returned by the Post Office or by other people as not deliverable for some reason.

MAIN OUTCOME MEASURES

Response rates to the invitation were assessed using three indices: crude population coverage rate, crude invited population coverage rate, and corrected invited population coverage rate.

RESULTS

With regard to response rates, 1684 women aged 65-74 (37% of all those invited, excluding those who were not available) were screened, compared with 2894 (42%) women aged 50-64. The three response rates were higher for younger women than older: the crude population coverage rate was 37.1%, the crude invited population coverage rate was 38.9%, and the corrected invited population coverage rate was 42.1% for women aged 50-64, compared with 32.9%, 34.4%, and 36.8% respectively for women aged 65-69 and 34.3%, 35.2%, and 37.2% for women aged 70-74. The rate of assessment increased significantly with increasing age, with 3.18% of the 50-64 population screened being assessed, as compared with 4.14% and 4.83% of the women aged 65-69 and 70-74, respectively. Most biopsies done in the older women gave positive results, as did the biopsies from the 50-64 age group. However, the biopsy rate increased significantly with increasing age. The cancer detection rates in the women aged 65-69 and 70-74 were 14.2/1000 and 13.2/1000 compared with an incident screening round rate of 4.5/1000 in women aged 50-64.

CONCLUSIONS

These results show that there is potential for similar attendance at routine screening by older women if they are invited in the same way as younger women. As the assessment, biopsy, and cancer detection rates in the older women are significantly higher than in the 50-64 year olds, the costs and benefits of including them in the NHS screening programme should be reassessed.

The feasibility and cost of a large multicentre audit of process and outcome of prostatectomy

Objective--To determine the feasibility of performing multicentre process and outcome audits of common interventions taking prostatic procedures as an example. Design--Prospective, cohort study. Setting--All National Health Service and independent hospitals in Northern, Wessex, Mersey, and South West Thames health regions. Patients--5361 men undergoing prostatectomy identified by 103 of the 107 urologists and general surgeons performing prostatectomy in the study regions. Main measures-- Rates of participation by surgeons and patients; completeness of clinical data provided by surgeons; patient response rate and completeness of patient derived data; and cost. Results--Most surgeons (103,96%) agreed to participate. Overall, the proportion of eligible patients invited to take part was high (89%), although this was only measured in South West Thames, where dedicated data collectors were employed. Few men (80, 1.5%) declined to participate. Of those surviving for three months after surgery, 82.4% (4226) completed and returned the postal questionnaire. The response rate was higher in South West Thames (86.7%) than in the other regions (80.6%-80.8%). The audit was well received: 91% of patients found the questionnaire easy to complete and only 2.3% of them disapproved. Completeness of data was high with both the hospital and patient questionnaires. Missing data occurred in less than 5% of responses to most questions. The attributable cost was 34.50 pounds per patient identified or 44 pounds for patients in whom either the treatment outcome or vital status was known three months after their prostatectomy. Conclusions--This multicentre audit of process and outcome of prostatectomy proved feasible in terms of surgeon participation, patient identification, and the quantity and quality of data collection. Whether the cost was warranted will depend on how surgeons use the audit data to modify their practice.

Emergency appendicectomy and meat consumption in the UK

STUDY OBJECTIVE

To compare the rates of reported emergency appendicectomies in a cohort study of vegetarians and non-vegetarians by participants' history of meat consumption.

DESIGN

This was a prospective cohort study in which participants were asked about their lifetime history of meat consumption/avoidance and, separately, whether they had had an appendicectomy. Appendicectomy was described as either "emergency" or "non-emergency" according to details supplied by the participant.

SETTING

The United Kingdom.

PARTICIPANTS

These comprised more than 11000 people, of whom 4852 (44%) completed both an appendicectomy form and a dietary questionnaire giving details of their lifetime history of meat consumption.

MAIN RESULTS

The percentage who reported an emergency appendicectomy was higher among lifelong meat eaters (10.7%) than either lifelong non-meat eaters (7.8%) or those who had stopped eating meat (8.0%); and the operations were performed at an earlier age in this first group (mean values 18.9, 26.0, and 19.6 years respectively). The overall age adjusted emergency participants who did not eat mean with those who ate meat was 0.47 (95% confidence interval 0.35, 0.65).

CONCLUSION

The results suggests that people who do not eat meat have a 50% lower risk of requiring an emergency appendicectomy than those who do. The data do not, however, allow the reliable testing of other hypotheses, so meat consumption may simply be a marker for another dietary, lifestyle, or socioeconomic factor.

Utilisation of hormone replacement therapy by women doctors

OBJECTIVES

To ascertain the prevalence and duration of use of hormone replacement therapy by menopausal women doctors.

DESIGN

Postal questionnaire.

SETTING

General practices in the United Kingdom.

SUBJECTS

Randomised stratified sample of women doctors who obtained full registration between 1952 and 1976, taken from the current principal list of the Medical Register.

MAIN OUTCOME MEASURES

Prevalence and duration of use of hormone replacement therapy; menopausal status.

RESULTS

Overall, 45.7% (436/954) of women doctors aged between 45 and 65 years had ever used hormone replacement therapy. When the results from women still menstruating regularly were excluded, 55.2% (428) were ever users and 41.2% (319) current users. The cumulative probability of remaining on hormone replacement therapy was 0.707 at five years and 0.576 at 10 years.

CONCLUSIONS

Women doctors have a higher prevalence of use of hormone replacement therapy than has been reported for other women in the United Kingdom, and most users seem to be taking hormone replacement therapy for more than five years. The results may become generalisable to the wider population as information on the potential benefits of hormone replacement therapy is disseminated.

The National Prostatectomy Audit: the clinical management of patients during hospital admission

OBJECTIVE

To determine everyday practice in the hospital management of men undergoing prostatectomy and the extent of its variation.

PATIENTS AND METHODS

A total of 5361 patients, who represented 89% of all those undergoing prostatic procedures in four health regions (Mersey, Wessex, Northern and South West Thames) and one test site (within Trent) were recruited by 103 (97%) surgeons. Clinical information was collected on a pre-coded data collection form which was completed during the hospital stay by the principal operator. Patient identification occurred at the time of surgery.

RESULTS

Important findings included: (i) both older men and those of higher social class were more likely to undergo prostatectomy with fewer symptoms; (ii) men who waited longer for surgery had worse symptoms by the time of their operation; (iii) there were unexplained differences in routine pre- and post-operative investigation and treatment. Half the men had their flow rate or residual urine measured as part of their pre-operative assessment. About half the men received prophylactic antibiotics; (iv) when large groups were analysed, a consistent proportion of men throughout the study (12%) were undergoing the operation for a second time. The clinical course of men having a repeat operation differed in many ways from those having a first time procedure; (v) the larger proportion of men (62%) had surgery for strong indications as opposed to symptoms alone; (vi) although most operations were performed by consultants, emergency admissions, though symptomatically more severe and sicker, were more likely to be operated on by trainee surgeons; (vii) significant variation in mean pre-operative symptom severity and bother scores were seen between surgeons.

CONCLUSION

The clinical management of prostatectomy has been defined in a large and representative UK sample. In some circumstances consistent variations have been identified. It is not yet clear whether these variations influence outcome. These data can be used by surgeons wishing to compare their own patient management with that described here.

ABC of breast diseases. Breast cancer--epidemiology, risk factors and genetics

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