Showing papers in "BMJ in 1990"

Analysis of serial measurements in medical research.

Abstract: In medical research data are often collected serially on subjects. The statistical analysis of such data is often inadequate in two ways: it may fail to settle clinically relevant questions and it may be statistically invalid. A commonly used method which compares groups at a series of time points, possibly with t tests, is flawed on both counts. There may, however, be a remedy, which takes the form of a two stage method that uses summary measures. In the first stage a suitable summary of the response in an individual, such as a rate of change or an area under a curve, is identified and calculated for each subject. In the second stage these summary measures are analysed by simple statistical techniques as though they were raw data. The method is statistically valid and likely to be more relevant to the study questions. If this method is borne in mind when the experiment is being planned it should promote studies with enough subjects and sufficient observations at critical times to enable useful conclusions to be drawn. Use of summary measures to analyse serial measurements, though not new, is potentially a useful and simple tool in medical research.

Analysis of serial measurements in medical research.

Abstract: however, it is best that the concentrated necrotising venom is allowed to diffuse freely away from the region. Deaths due to the svstemic effects of the venom are extremely rare, with onlv a couple recorded in published work. Infection often occurs with this type of injury. It should be remembered that marine bacteria comprise a wide range of organisms, and many are resistant to common antibiotics and also may require saline media for culture. It follows that debridement should be assisted by washing the wound well with fresh or preferably sterile water. The drug of first choice is trimethoprim-sulphamethazole. Tetanus prophvlaxis should also receive attention.

Fetal and placental size and risk of hypertension in adult life.

Abstract: OBJECTIVE--To study the effect of intrauterine growth and maternal physique on blood pressure in adult life. DESIGN--A follow up study of infants born 50 years previously whose measurements at birth were recorded in detail. SETTING--Preston, Lancashire. SUBJECTS--449 Men and women born in hospital in Preston during 1935-43 and still living in Lancashire. MAIN OUTCOME MEASURES--Placental weight, birth weight, and blood pressure at age 46 to 54 years. RESULTS--In both sexes systolic and diastolic pressures were strongly related to placental weight and birth weight. Mean systolic pressure rose by 15 mm Hg as placental weight increased from less than or equal to 1 lb (0.45 kg) to greater than 1.5 lb and fell by 11 mm Hg as birth weight increased from less than or equal to 5.5 lb to greater than 7.5 lb. These relations were independent so that the highest blood pressures occurred in people who had been small babies with large placentas. Higher body mass index and alcohol consumption were also associated with higher blood pressure, but the relations of placental weight and birth weight to blood pressure and hypertension were independent of these influences. CONCLUSIONS--These findings show for the first time that the intrauterine environment has an important effect on blood pressure and hypertension in adults. The highest blood pressures occurred in men and women who had been small babies with large placentas. Such discordance between placental and fetal size may lead to circulatory adaptation in the fetus, altered arterial structure in the child, and hypertension in the adult. Prevention of hypertension may depend on improving the nutrition and health of mothers.

Lowering cholesterol concentrations and mortality: a quantitative review of primary prevention trials.

Abstract: OBJECTIVE--To determine the effects of lowering cholesterol concentrations on total and cause specific mortality in randomised primary prevention trials. DESIGN--Qualitative (meta-analytic) evaluation of total mortality from coronary heart disease, cancer, and causes not related to illness in six primary prevention trials of cholesterol reduction (mean duration of treatment 4.8 years). PATIENTS--24,847 Male participants; mean age 47.5 years. MAIN OUTCOME MEASURES--Total and cause specific mortalities. RESULTS--Follow up periods totalled 119,000 person years, during which 1147 deaths occurred. Mortality from coronary heart disease tended to be lower in men receiving interventions to reduce cholesterol concentrations compared with mortality in control subjects (p = 0.06), although total mortality was not affected by treatment. No consistent relation was found between reduction of cholesterol concentrations and mortality from cancer, but there was a significant increase in deaths not related to illness (deaths from accidents, suicide, or violence) in groups receiving treatment to lower cholesterol concentrations relative to controls (p = 0.004). When drug trials were analysed separately the treatment was found to reduce mortality from coronary heart disease significantly (p = 0.04). CONCLUSIONS--The association between reduction of cholesterol concentrations and deaths not related to illness warrants further investigation. Additionally, the failure of cholesterol lowering to affect overall survival justifies a more cautious appraisal of the probable benefits of reducing cholesterol concentrations in the general population.

Protective effect of breast feeding against infection.

Abstract: OBJECTIVE--To assess the relations between breast feeding and infant illness in the first two years of life with particular reference to gastrointestinal disease. DESIGN--Prospective observational study of mothers and babies followed up for 24 months after birth. SETTING--Community setting in Dundee. PATIENTS--750 pairs of mothers and infants, 76 of whom were excluded because the babies were preterm (less than 38 weeks), low birth weight (less than 2500 g), or treated in special care for more than 48 hours. Of the remaining cohort of 674, 618 were followed up for two years. INTERVENTIONS--Detailed observations of infant feeding and illness were made at two weeks, and one, two, three, four, five, six, nine, 12, 15, 18, 21, and 24 months by health visitors. MAIN OUTCOME MEASURE--The prevalence of gastrointestinal disease in infants during follow up. RESULTS--After confounding variables were corrected for babies who were breast fed for 13 weeks or more (227) had significantly less gastrointestinal illness than those who were bottle fed from birth (267) at ages 0-13 weeks (p less than 0.01; 95% confidence interval for reduction in incidence 6.6% to 16.8%), 14-26 weeks (p less than 0.01), 27-39 weeks (p less than 0.05), and 40-52 weeks (p less than 0.05). This reduction in illness was found whether or not supplements were introduced before 13 weeks, was maintained beyond the period of breast feeding itself, and was accompanied by a reduction in the rate of hospital admission. By contrast, babies who were breast fed for less than 13 weeks (180) had rates of gastrointestinal illness similar to those observed in bottle fed babies. Smaller reductions in the rates of respiratory illness were observed at ages 0-13 and 40-52 weeks (p less than 0.05) in babies who were breast fed for more than 13 weeks. There was no consistent protective effect of breast feeding against ear, eye, mouth, or skin infections, infantile colic, eczema, or nappy rash. CONCLUSION--Breast feeding during the first 13 weeks of life confers protection against gastrointestinal illness that persists beyond the period of breast feeding itself.

Psychological outcomes of different treatment policies in women with early breast cancer outside a clinical trial.

Abstract: OBJECTIVES--To assess outside a clinical trial the psychological outcome of different treatment policies in women with early breast cancer who underwent either mastectomy or breast conservation surgery depending on the surgeon's opinion or the patient's choice. To determine whether the extent of psychiatric morbidity reported in women who underwent breast conservation surgery was associated with their participation in a randomised clinical trial. DESIGN--Prospective, multicentre study capitalising on individual and motivational differences among patients and the different management policies among surgeons for treating patients with early breast cancer. SETTING--12 District general hospitals, three London teaching hospitals, and four private hospitals. PATIENTS--269 Women under 75 with a probable diagnosis of stage I or II breast cancer who were referred to 22 different surgeons. INTERVENTIONS--Surgery and radiotherapy or adjuvant chemotherapy, or both, depending on the individual surgeon's stated preferences for managing early breast cancer. MAIN OUTCOME MEASURES--Anxiety and depression as assessed by standard methods two weeks, three months, and 12 months after surgery. RESULTS--Of the 269 women, 31 were treated by surgeons who favoured mastectomy, 120 by surgeons who favoured breast conservation, and 118 by surgeons who offered a choice of treatment. Sixty two of the women treated by surgeons who offered a choice were eligible to choose their surgery, and 43 of these chose breast conserving surgery. The incidences of anxiety, depression, and sexual dysfunction were high in all treatment groups. There were no significant differences in the incidences of anxiety and depression between women who underwent mastectomy and those who underwent lumpectomy. A significant effect of surgeon type on the incidence of depression was observed, with patients treated by surgeons who offered a choice showing less depression than those treated by other surgeons (p = 0.06). There was no significant difference in psychiatric morbidity between women treated by surgeons who offered a choice who were eligible to choose their treatment and those in the same group who were not able to choose. Most of the women (159/244) gave fear of cancer as their primary fear rather than fear of losing a breast. The overall incidences of psychiatric morbidity in women who underwent mastectomy and those who underwent lumpectomy were similar to those found in the Cancer Research Campaign breast conservation study. At 12 months 28% of women who underwent mastectomy in the present study were anxious compared with 26% in the earlier study, and 27% of women in the present study who underwent lumpectomy were anxious compared with 31% in the earlier study. In both the present and earlier study 21% of women who underwent mastectomy were depressed, and 19% of women who underwent lumpectomy in the present study were depressed compared with 27% in the earlier study.) CONCLUSIONS--There is still no evidence that women with early breast cancer who undergo breast conservation surgery have less psychiatric morbidity after treatment than those who undergo mastectomy. Women who surrender autonomy for decision making by agreeing to participate in randomised clinical trials do not experience any different psychological, sexual, or social problems from those women who are treated for breast cancer outside a clinical trial.

Results of case-control study of leukaemia and lymphoma among young people near Sellafield nuclear plant in West Cumbria.

Abstract: OBJECTIVE--To examine whether the observed excess of childhood leukaemia and lymphoma near the Sellafield nuclear plant is associated with established risk factors or with factors related to the plant. DESIGN--A case-control study. SETTING--West Cumbria health district. SUBJECTS--52 Cases of leukaemia, 22 of non-Hodgkin's lymphoma, and 23 of Hodgkin's disease occurring in people born in the area and diagnosed there in 1950-85 under the age of 25 and 1001 controls matched for sex and date of birth taken from the same birth registers as the cases. MAIN OUTCOME MEASURES--Antenatal abdominal x ray examinations, viral infections, habit factors, proximity to and employment characteristics of parents at Sellafield. RESULTS--Expected associations with prenatal exposure to x rays were found, but little information was available on viral illnesses. Relative risks for leukaemia and non-Hodgkin's lymphoma were higher in children born near Sellafield and in children of fathers employed at the plant, particularly those with high radiation dose recordings before their child's conception. For example, the relative risks compared with area controls were 0.17 (95% confidence interval 0.05 to 0.53) for being born further than 5 km from Sellafield 2.44 (1.04 to 5.71) for children of fathers employed at Sellafield at their conception, and 6.42 (1.57 to 26.3) for children of fathers receiving a total preconceptual ionising radiation dose of 100 mSv or more. Other factors, including exposure to x rays, maternal age, employment elsewhere, eating seafood, and playing on the beach did not explain these relationships. Focusing on Seascale, where the excess incidence has predominantly been reported, showed for the four out of five cases of leukaemia and one case of non-Hodgkin's lymphoma whose fathers were employed at Sellafield and for whom dose information was obtained that the fathers of each case had higher radiation doses before their child's conception than all their matched control fathers; the father of the other Seascale case (non-Hodgkin's lymphoma) was not employed at the plant. These results seem to explain statistically the geographical association. For Hodgkin's disease neither geographical nor employment associations with Sellafield were found. CONCLUSIONS--The raised incidence of leukaemia, particularly, and non-Hodgkin's lymphoma among children near Sellafield was associated with paternal employment and recorded external dose of whole body penetrating radiation during work at the plant before conception. The association can explain statistically the observed geographical excess. This result suggests an effect of ionising radiation on fathers that may be leukaemogenic in their offspring, though other, less likely, explanations are possible. There are important potential implications for radiobiology and for protection of radiation workers and their children.

Attitudes to chemotherapy: comparing views of patients with cancer with those of doctors, nurses, and general public.

Abstract: OBJECTIVE--To compare responses of patients with cancer with those of a matched control group, cancer specialists, general practitioners, and cancer nurses in assessing personal cost-benefit of chemotherapy DESIGN--Prospective study of consecutively recruited patients with cancer and other groups by questionnaire; half of the patients received the questionnaire again three months after starting treatment SETTING--A medical oncology ward of a London teaching hospital SUBJECTS--106 Patients with newly diagnosed solid tumours referred to the unit for consideration of treatment with cytotoxic chemotherapy, 100 of whom were able to complete the questionnaire 100 Matched controls, 315 cancer doctors (238 radiotherapists and 77 medical oncologists), 1500 randomly chosen general practitioners, and 1000 randomly chosen cancer nurses MAIN OUTCOME MEASURES--Percentage chance of cure, prolonging life, or palliation of symptoms required to make treatment worth while with two hypothetical chemotherapy treatments, with severe and mild side effects respectively RESULTS--Respondents to the questionnaire comprised 100 patients, 100 controls, 60 (78%) medical oncologists, 88 (37%) radiotherapists, 790 (53%) general practitioners, and 303 (30%) cancer nurses Most patients were willing to accept intensive chemotherapy for a very small chance of benefit The median benefit required to make the hypothetical intensive treatments worth while for patients compared with controls were: for chance of a cure (range 1 to 100%) 1% v 50%, for prolonging life (range three months to five years) 12 months v 24-60 months, and for relief of symptoms (range 1 to 100%) 10% v 75% respectively There were no significant differences in the responses of the 50 patients completing the questionnaire on a second occasion Doctors and nurses were less likely to accept radical treatment for minimal benefit compared with the patients (median scores 10-50%, 12-24 months, and 50-75%, for chance of cure, prolonging life, and relief of symptoms respectively) Significantly more patients than controls accepted treatments giving the minimal benefit for each category (cure 531 v 190%, 670 v 350%; prolonging life 421 v 100%, 530 v 250%; relief of symptoms 426 v 100%, 587 v 190% for intensive and mild treatments respectively, p less than 0001) as was the case for comparison of patients with other groups CONCLUSION--Patients with cancer are much more likely to opt for radical treatment with minimal chance of benefit than people who do not have cancer, including medical and nursing professionals This could be taken into account when discussing treatment options with patients and their relatives

Microalbuminuria as predictor of increased mortality in elderly people.

Abstract: OBJECTIVE--Correlation of the urinary albumin excretion rate and the risk of death among elderly subjects. DESIGN--216 Subjects aged 60-74 whose urinary albumin excretion rate had been determined were followed up 62-83 months later. SETTING--Municipality of Fredericia, Denmark. SUBJECTS--223 People who had been selected as control subjects for diabetics found during a systematic screening for diabetes of all people aged 60-74 living in the municipality of Fredericia, Denmark. Of these subjects, 216 had an extensive clinical and biochemical examination within a few weeks of selection. MAIN OUTCOME MEASURE--Death. RESULTS--The median urinary albumin excretion rate was 7.52 micrograms/min. Eight of those with a rate below the median died compared with 23 with a rate equal to or greater than the median (p = 0.0078). The median albumin excretion rate in the 31 who died was 15.00 micrograms/min. Cardiovascular disease was the most common cause of death in both groups. A multivariate regression analysis of survival data was performed using the proportional hazards model. Besides albumin excretion rate, male sex, serum creatinine concentration, and hypertension were found to be of prognostic value. CONCLUSIONS--The association between the albumin excretion rate and mortality that has been described in recent years in patients with diabetes mellitus may be present in elderly people in general, even when other known risk factors are taken into account.

Has the prevalence of asthma increased in children? Evidence from the national study of health and growth 1973-86.

Abstract: OBJECTIVES--To estimate changes in the prevalence of reported symptoms of respiratory disease and reported diagnoses of asthma and bronchitis in primary school children in England between 1973 and 1986. DESIGN--Mixed longitudinal survey. SETTING--Representative sample of English primary schools in 22 areas. PARTICIPANTS--15,000 Boys and 14,156 girls each studied at least once between 1973 and 1986. DATA COLLECTED--Whether, according to the parent or guardian, the child had wheezed, wheezed on most days or nights, or had attacks of bronchitis or asthma in the past year. RESULTS--Within age groups trends in successive annual cohorts showed an increasing prevalence of asthma for each annual birth cohort (boys, 6.9%, p less than 0.001; girls, 12.8%, p less than 0.001) and of wheeze on most days or nights (boys, 4.3% per cohort, p less than 0.001; girls, 6.1% per cohort, p less than 0.001) and a falling prevalence of bronchitis (boys, -4.7% per cohort, p less than 0.001; girls, -5.8% per cohort, p less than 0.001). There was a smaller increase in the prevalence of wheeze whether or not it occurred on most days or nights, and this increase was significant only among the girls (boys, 1.0% per cohort, p greater than 0.05; girls, 1.7% per cohort, p less than 0.05). Although the rate of increase of "asthma" was greater than the rate of decrease in "bronchitis," the baseline prevalence of asthma was much lower than that of bronchitis, and the total proportion of children with either diagnosis declined slightly over the whole period. The main change was an increase in the proportion of children whose parents stated that they had persistent wheeze and yet did not have a report of either "asthma" or "bronchitis." CONCLUSIONS--These results suggest that there has been a true increase in morbidity that is not simply due to changes in diagnostic fashion. The increase is large enough to explain much if not all of the increase in admission to hospital and mortality, and it underlines the importance of an understanding of the aetiology of asthma in tackling the causes of the recent increase.

Identification of the cystic fibrosis gene.

Abstract: complications such as blindness; but fortunately this is rare. More often activity of the disease seems to decline steadily: relapses are more likely during the initial 18 months of treatment\" and within one year of withdrawal of steroids.9\"1 There is no reliable method of predicting those most at risk, but arteritic relapses in patients who presented with pure polymyalgia rheumatica are unusual,'220 although one study reported a high incidence of complications in polymyalgia rheumatica.2' We recently found that patients with both polymyalgia rheumatica and giant cell arteritis were more likely to experience relapses than those with polymyalgia rheumatica or giant cell arteritis alone. 14 Men were more likely to experience complications of giant cell arteritis than women in one study,'3 but women needed treatment for longer in another.'2 Temporal artery biopsy does not need help in predicting outcome. \" 14 22 The risks of continuing treatment with steroids unnecessarily are those ofsteroid related complications. Between one fifth and a half of patients may experience serious side effects23 24 unless the initial dose of prednisolone is 10 mg or less and maintenance doses of less than 7 5 mg are used.8 20 25 High initial doses, cumulative doses, maintenance doses, and increased duration of treatment have all been associated with increased side effects.'2 23 There is still no reliable guide to which patients are most at risk, and studies need to be done to show whether prophylactic treatment to reduce osteoporotic fracture is of value in polymyalgic rheumatica and giant cell arteritis. Azathioprine has been shown to exert a modest steroid sparing effect.26 Reduction of doses ofprednisolone on alternate days once doses of less than 5 mg are reached makes withdrawal easier, and the addition of a non-steroidal agent at this stage may reduce some of the minor muscular symptoms that patients develop as doses of steroids are reduced. Some patients, however, find it impossible to stop taking the final 2-3 mg, and this level of maintenance dose is probably safe. In summary, patients should be warned to expect treatment for at least two years, while most should be able to stop taking steroids after four to five years. Monitoring for relapse should continue for six months to one year after stopping steroids; thereafter patients should be asked to report back urgently if arteritic symptoms occur. The risk of this happening is small and unpredictable. A few patients may need low dose treatment indefinitely. V KYLE Lecturer in Rheumatology

Lipoprotein (a) and coronary heart disease: a prospective case-control study in a general population sample of middle aged men.

Abstract: OBJECTIVE--To examine the association between the serum lipoprotein (a) concentration and subsequent coronary heart disease. DESIGN--Prospective case-control study based on a six year follow up of a general population sample of men aged 50 at baseline in 1983-4. Serum samples were frozen at the time of the baseline examination and kept at -70 degrees C for six years, after which the lipoprotein (a) concentrations in the samples were measured in cases and controls. SETTING--City of Gothenburg, Sweden. SUBJECTS--26 Men, from a general population sample of 776 men, who had sustained a myocardial infarction or died of coronary heart disease during the six years and 109 randomly selected controls from the same sample who had remained free of myocardial infarction. In neither cases nor controls was there a history of myocardial infarction at baseline. MAIN OUTCOME MEASURES--Proportion of myocardial infarction or deaths from coronary heart disease, or both, in relation to the serum lipoprotein (a) concentration. RESULTS--Men who suffered coronary heart disease had significantly higher serum lipoprotein (a) concentrations than controls (mean difference 105 mg/l; 95% confidence interval 18 to 192 mg/l). Men with the highest fifth of serum lipoprotein (a) concentrations (cut off point 365 mg/l) suffered a coronary heart disease rate which was more than twice that of men with the lowest four fifths of concentrations. Logistic regression analysis showed the serum lipoprotein (a) concentration to be significantly associated with coronary heart disease independently of other risk factors. CONCLUSION--The serum lipoprotein (a) concentration in middle aged men is an independent risk factor for subsequent myocardial infarction or death from coronary heart disease.

Terminal cancer care and patients' preference for place of death: a prospective study.

Abstract: OBJECTIVE--To assess the preference of terminally ill patients with cancer for their place of final care. DESIGN--Prospective study of randomly selected patients with cancer from hospital and the community who were expected to die within a year. Patients expected to live less than two months were interviewed at two week intervals; otherwise patients were interviewed monthly. Their main carer was interviewed three months after the patient9s death. SETTING--District general hospital, hospices, and patients9 homes. MAIN OUTCOME MEASURE--Stated preferred place of final care; actual place of death; reason for final hospital admission for those in hospital; community care provision required for home care. RESULTS--Of 98 patients approached, 84 (86%) agreed to be interviewed, of whom 70 (83%) died during the study and 59 (84%) stated a preferred place of final care: 34 (58%) wished to die at home given existing circumstances, 12 (20%) in hospital, 12 (20%) in a hospice, and one (2%) elsewhere. Their own home was the preferred place of care for 17 (94%) of the patients who died there, whereas of the 32 patients who died in hospital 22 (69%) had stated a preference to die elsewhere. Had circumstances been more favourable 67% (41) of patients would have preferred to die at home, 16% (10) in hospital, and 15% (9) in hospice. CONCLUSION--With a limited increase in community care 50% more patients with cancer could be supported to die at home, as they and their carers would prefer.

Interaction between bedding and sleeping position in the sudden infant death syndrome: a population based case-control study.

Abstract: OBJECTIVE--To determine the relation between sleeping position and quantity of bedding and the risk of sudden unexpected infant death. DESIGN--A study of all infants dying suddenly and unexpectedly and of two controls matched for age and date with each index case. The parents of control infants were interviewed within 72 hours of the index infant's death. Information was collected on bedding, sleeping position, heating, and recent signs of illness for index and control infants. SETTING--A defined geographical area comprising most of the county of Avon and part of Somerset. SUBJECTS--72 Infants who had died suddenly and unexpectedly (of whom 67 had died from the sudden infant death syndrome) and 144 control infants. RESULTS--Compared with the control infants the infants who had died from the sudden infant death syndrome were more likely to have been sleeping prone (relative risk 8.8; 95% confidence interval 7.0 to 11.0; p less than 0.001), to have been more heavily wrapped (relative risk 1.14 per tog above 8 tog; 1.03 to 1.28; p less than 0.05), and to have had the heating on all night (relative risk 2.7; 1.4 to 5.2; p less than 0.01). These differences were less pronounced in the younger infants (less than 70 days) than the older ones. The risk of sudden unexpected death among infants older than 70 days, nursed prone, and with clothing and bedding of total thermal resistance greater than 10 tog was increased by factors of 15.1 (2.6 to 89.6) and 25.2 (3.7 to 169.0) respectively compared with the risk in infants of the same age nursed supine or on their side and under less than 6 tog of bedding. CONCLUSIONS--Overheating and the prone position are independently associated with an increased risk of sudden unexpected infant death, particularly in infants aged more than 70 days. Educating parents about appropriate thermal care and sleeping position of infants may help to reduce the incidence of the sudden infant death syndrome.

The Black report on socioeconomic inequalities in health 10 years on.

Abstract: Introduction This month marks the 10th anniversary of the publication of the Black report.' In 1977 the Research Working Group on Inequalities in Health had been convened by David Ennals, then Secretary of State for Social Services, under the chairmanship of Sir Douglas Black, president of the Royal College of Physicians. Its findings were not welcomed by the government when they were published in August 1980,23 but they generated great interest both in the United Kingdom and in other countries. Copies of the \"Black report\" were initially in short supply until Penguin published a paperback version, whose sales have ensured it a wide readership.4 The central finding of the working group -that there were large differentials in mortality and morbidity that favoured the higher social classes and that were not being redressed by health or social services-became widely known. In the 10 years since its publication new information has become available in four areas in particular: the use of alternative measures of socioeconomic position to index mortality risk; the collection of morbidity data; the comparison of inequalities in Britain with those in other industrialised countries; and the understanding of the causes of the differentials. These four areas are reviewed in this paper.

Accuracy of weighed dietary records in studies of diet and health

Abstract: OBJECTIVE--To provide an independent evaluation of seven day weighed dietary records, which are currently accepted as the most accurate technique for assessing habitual dietary intake in studies investigating the links between diet and health. DESIGN--Subjects who had previously participated in the Northern Ireland diet and health study were reselected by stratified random sampling to represent the range of energy intakes in the study as assessed by the seven day weighed dietary record. SETTING--Northern Ireland. SUBJECTS--31 Free living adults (16 men and 15 women). MAIN OUTCOME MEASURES--Energy intake as measured by the seven day weighed dietary record and total energy expenditure estimated concurrently by the doubly labelled water technique. RESULTS--Average recorded energy intakes were significantly lower than measured expenditure in the group overall (9.66 MJ/day v 12.15 MJ/day, 95% confidence interval 1.45 to 3.53 MJ/day). Among those in the upper third of energy intakes the mean (SE) ratio of intake to expenditure was close to 1.0, indicating accurate records (men 1.01 (0.11), women 0.96 (0.08]. In the middle and lower thirds the ratios for men were only 0.74 (0.05) and 0.70 (0.07) respectively and for women 0.89 (0.07) and 0.61 (0.07). CONCLUSIONS--These results show a serious bias in reporting habitual energy intake. If substantiated they may have wide implications for the interpretation of many nutritional studies.

The Read clinical classification.

Abstract: Last month the Secretary of State for Health acquired for the NHS the Read clinical classification-an event of considerable importance for information strategy within the service.' Dr James Read, a general practitioner in Loughborough, has been developing his system of classification for the past eight years, and it is now the most comprehensive medical coding system in the world, with over 250 000 codes, including 150 000 synonyms, and it is still evolving. The classification codes not only diseases but also history and symptoms; examination findings and signs; diagnostic procedures; preventive , operative, therapeutic, and administrative procedures ; drugs and appliances; and occupations and social information. The classification of clinical data has three main purposes.2 It can help in clinical care-by aiding the recording and retrieval of information held as part of a medical record. It can make it easier to analyse data statistically for planning and research purposes. Thirdly, it is a key element in the electronic transmission of data from one computer to another. A standard coding system should ensure that data are transferred reproducibly and received in the form in which they are sent, without corruption or loss of accuracy; whereas if different classifications are used by sender and receiver serious communication problems can arise. The Read clinical classification was developed as a thesaurus of medical terms and a computerised medical language with six key criteria: it is designed to be comprehensive , hierarchical, coded, computerised, cross referenced, and dynamic. It also includes and is cross referenced to all of the widely used standard classifications.* The Read codes are five character alphanumeric codes. At each level the code may be a lower (small) or upper case (capital) letter or a number. There are 58 available characters at each level and so a theoretical maximum of 656 356 768 available codes. Such a large set of possible codes is needed to provide sufficient flexibility and space to incorporate and follow the structure of the large subset classifications included and to allow for the addition of new codes within the existing framework without disturbing the hierarchies. In other words, there is sufficient redundancy in the coding system to cope with any reasonable expansion of entities and synonyms. The advantages of the Read codes were recognised in 1988 by the technical working party of the Joint Computing Group of the Royal College of General Practitioners and by the General Medical …

Detection of pseudodiarrhoea by simple clinical assessment of intestinal transit rate.

Abstract: did not show evidence of Crohn's disease, but there was unequivocal evidence of Crohn's disease elsewhere. Furthermore, the failure of symptoms in patients who do not smoke to respond to treatment suggests peptic ulceration associated with Crohn's disease. Treatment with omeprazole led to prompt relief of symptoms and complete healing of ulceration, which was confirmed by endoscopy. Omeprazole is effective in resistant peptic ulceration,' but there is only one report of its use in Crohn's disease.4 A proton pump inhibitor, it is capable of maintaining high intragastric pH for long periods. Its effectiveness in our two patients suggests that duodenal ulceration in Crohn's disease is dependent on acid. If prolonged active ulceration can cause pyloric stenosis then intermittent omeprazole treatment might prevent this complication in patients with Crohn's disease. Our observations support the view that inhibition of acid production is more likely to heal duodenal ulceration associated with Crohn's disease than steroid treatment, which may lead to complications such as perforation or haemorrhage.

Low back pain of mechanical origin: randomised comparison of chiropractic and hospital outpatient treatment.

Abstract: OBJECTIVE--To compare chiropractic and hospital outpatient treatment for managing low back pain of mechanical origin DESIGN--Randomised controlled trial Allocation to chiropractic or hospital management by minimisation to establish groups for analysis of results according to initial referral clinic, length of current episode, history, and severity of back pain Patients were followed up for up two years SETTING--Chiropractic and hospital outpatient clinics in 11 centres PATIENTS--741 Patients aged 18-65 who had no contraindications to manipulation and who had not been treated within the past month INTERVENTIONS--Treatment at the discretion of the chiropractors, who used chiropractic manipulation in most patients, or of the hospital staff, who most commonly used Maitland mobilisation or manipulation, or both MAIN OUTCOME MEASURES--Changes in the score on the Oswestry pain disability questionnaire and in the results of tests of straight leg raising and lumbar flexion RESULTS--Chiropractic treatment was more effective than hospital outpatient management, mainly for patients with chronic or severe back pain A benefit of about 7% points on the Oswestry scale was seen at two years The benefit of chiropractic treatment became more evident throughout the follow up period Secondary outcome measures also showed that chiropractic was more beneficial CONCLUSIONS--For patients with low back pain in whom manipulation is not contraindicated chiropractic almost certainly confers worthwhile, long term benefit in comparison with hospital outpatient management The benefit is seen mainly in those with chronic or severe pain Introducing chiropractic into NHS practice should be considered

The Kenyan Luo migration study: observations on the initiation of a rise in blood pressure.

Abstract: OBJECTIVE--To demonstrate the magnitude, timing, and cause of changes in blood pressure that occur in migrants from a low blood pressure population on moving to an urban area. DESIGN--A controlled longitudinal observational study of migrants as soon after migration as possible and follow up at three, six, 12, 18, and 24 months after migration. A cohort of controls living in a rural area who were matched for age, sex, and locality were also observed at the same periods. SETTING--35 Villages on the northern shores of Lake Victoria in western Kenya and Nairobi. PARTICIPANTS--325 Members of the Luo tribe aged 15 to 34 years who had migrated to Nairobi and 267 controls living in villages. The numbers of both groups reduced during follow up such that only 63 migrants and 143 controls were followed up for two years. MAIN OUTCOME MEASURES--A medical questionnaire and three 24 hour diet histories were completed by migrants and controls. Height, weight, pulse, and blood pressure were measured. Three 12 hour overnight urine samples were collected from all participants and analysed for sodium, potassium, and creatinine concentrations. RESULTS--The mean systolic blood pressure of migrants was significantly higher than that of controls throughout the study, and the distribution of blood pressure was shifted to the right compared with controls. The mean diastolic blood pressure of the two groups diverged over time. Blood pressure differences were not due to selective migration. The migrants9 mean urinary sodium:potassium ratio was higher than that of controls (p less than 0.001) throughout, and weight and pulse rate were also higher among migrants, although differences diminished with time. CONCLUSIONS--Urinary sodium:potassium ratio, pulse rate, and weight are important predictors of increased blood pressure among migrants from a low blood pressure community and may also be implicated in the initiation of essential hypertension.

Tired, weak, or in need of rest: fatigue among general practice attenders.

Abstract: OBJECTIVES--To determine the prevalence and associations of symptoms of fatigue. DESIGN--Questionnaire survey. SETTING--London general practice. PARTICIPANTS--611 General practice attenders. MAIN OUTCOME MEASURES--Scores on a fatigue questionnaire and reasons given for fatigue. RESULTS--10.2% Of men (17/167) and 10.6% of women (47/444) had substantial fatigue for one month or more. Age, occupation, and marital status exerted minor effects. Subjects attributed fatigue equally to physical and non-physical causes. Physical ill health, including viral infection, was associated with more severe fatigue. Women rather than men blamed family responsibilities for their fatigue. The profile of persistent fatigue did not differ from that of short duration. Only one person met criteria for the chronic fatigue syndrome. CONCLUSIONS--Fatigue is a common complaint among general practice attenders and can be severe. Patients may attribute this to physical, psychological, and social stress.

Evaluation of peak flow and symptoms only self management plans for control of asthma in general practice.

Abstract: OBJECTIVE--To compare a peak flow self management plan for asthma with a symptoms only plan. DESIGN--Randomisation to one of the self management plans and follow up for a year. SETTING--Four partner, rural training practice in Norfolk. SUBJECTS--115 Patients (46 children and 69 adults) with asthma who were having prophylactic treatment for asthma and attending a nurse run asthma clinic. MAIN OUTCOME MEASURES--The number of doctor consultations, courses of oral steroids, and short term nebulised salbutamol treatments and the number of patients who required doctor consultations, courses of oral steroids, and short term nebulised salbutamol. RESULTS--Both self management plans produced significant reductions in the outcome measures but there were no significant differences in the degree of improvement between the groups. The results were similar for children and adults. The proportions of patients requiring a doctor consultation fell from 98% (50/51) to 66% (34/51) in the peak flow group and from 97% (62/64) to 53% (34/64) in the symptoms only group and the proportions requiring oral steroids from 73% (34/46) to 47% (21/46) and 52% (31/60) to 12% (7/60). The median number of doctor consultations was reduced from 8.0 to 2.0 in the peak flow group and from 4.5 to 1.0 in the symptoms only group. CONCLUSIONS--The peak flow meter was not the crucial ingredient in the improved illness of the two groups. Teaching patients the importance of their symptoms and the appropriate action to take when their asthma deteriorates is the key to effective management of asthma. Simply prescribing peak flow meters without a system of self management and regular review will be unlikely to improve patient care.

The population mean predicts the number of deviant individuals.

Abstract: OBJECTIVE--To examine the relation between the prevalence of deviation and the mean for the whole population in characteristics such as blood pressure and consumption of alcohol. DESIGN--Re-examination of standardised data from the Intersalt study, an international, multicentre study on the determinants of blood pressure. SETTING AND SUBJECTS--Samples of adults representing 52 populations in 32 countries. MAIN OUTCOME MEASURES--The relations, expressed as correlation coefficients, between the mean population values for blood pressure, body mass index, alcohol consumption, and sodium intake and the prevalence of, respectively, hypertension (greater than or equal to 140 mm Hg), obesity (body mass index greater than or equal to 30 kg/m2), high alcohol intake (greater than or equal to 300 ml/week), and high sodium intake (greater than or equal to 250 mmol/day). RESULTS--There were close and independent associations between the population mean and the prevalence of deviance for each of the variables examined: correlation coefficients were 0.85 for blood pressure, 0.94 for body mass index, 0.97 for alcohol intake, and 0.78 for sodium intake. CONCLUSIONS--These findings imply that distributions of health related characteristics move up and down as a whole: the frequency of "cases" can be understood only in the context of a population's characteristics. The population thus carries a collective responsibility for its own health and well being, including that of its deviants.

Prediction of hip fracture in elderly women: a prospective study.

Abstract: OBJECTIVE--To assess the relative importance of osteoporosis of the os calcis, cognisance, and mobility in the risk of subsequent fracture of the hip in elderly women. DESIGN--Prospective study of elderly women in residential care over two years. SETTING--21 Private or 38 local authority residential homes for the elderly and 4 geriatric hospitals in Doncaster and Hull. SUBJECTS--1414 Ambulant women aged over 69, in private or local authority residential care or geriatric care. Those who had had bilateral hip surgery were excluded. MAIN OUTCOME MEASURES--Broad band ultrasonic attenuation (BUA) index, Clifton assessment procedures for the elderly test (for cognisance), and mobility on a six point scale, and fracture of the hip in the subsequent two year period. RESULTS--73 Women fractured their hip during the two years. Their mean age was not significantly different from that of the women who did not have a fracture (85.3 (SD 5.6) v 83.9 (6.3); p = 0.07), but their mean BUA index (40.3 (19.3) v 50.9 (22.2) db/MH2), and score for cognisance (median 19 (interquartile range 10.5-27.0) v 24 (17-30)) were significantly lower (both p less than 0.001). These variables had independent associations with fracture of the hip. Women with fractures had a significantly lower score for the psychomotor component of the cognisance test (4.5 (1-8) v 7 (2-10); p less than 0.0025 and were significantly more mobile (1(1-3) v 3 (1-6); p less than 0.02). Subdividing women according to high, medium, and low scores for BUA index and cognisance testing disclosed a high risk group (118 women) with low BUA index and cognisance score, whose incidence of fracture was 12.8%; in the group at lowest risk (136 women) with high BUA index and cognisance score, the incidence of fracture was only 1.5% (relative risk 8.4 (95% confidence interval -2.0 to 35.5]. Further analysis showed that those most at risk were, additionally, most mobile but that less mobile women with good cognisance had a low incidence of fractures, regardless of the BUA index, (1.2%, high index, v 0.9%, low index). CONCLUSIONS--Elderly women most at risk of sustaining hip fractures were those with low BUA index, low cognisance test score, and high mobility. Improving bone strength and cognisance in elderly women may reduce their incidence of hip fracture.

Prevalence of acute mountain sickness in the Swiss Alps.

Abstract: OBJECTIVE--To assess the prevalence of symptoms and signs of acute mountain sickness of the Swiss Alps DESIGN--A study using an interview and clinical examination in a representative population of mountaineers Positive symptoms and signs were assigned scores to quantify the severity of acute mountain sickness SETTING--Four huts in the Swiss Alps at 2850 m, 3050 m, 3650 m, and 4559 m SUBJECTS--466 Climbers, mostly recreational: 47 at 2850 m, 128 at 3050 m, 82 at 3650, and 209 at 4559 m RESULTS--In all, 117 of the subjects were entirely free of symptoms and clinical signs of acute mountain sickness; 191 had one or two symptoms and signs; and 158 had more than two Those with more than two symptoms and signs were defined as suffering from acute mountain sickness At 4559 m 11 climbers presented with high altitude pulmonary oedema or cerebral oedema, or both Men and women were equally affected The prevalence of acute mountain sickness correlated with altitude: it was 9% at 2850 m, 13% at 3050 m, 34% at 3650 m, and 53% at 4559 m The most frequent symptoms and signs were insomnia, headache, peripheral oedema, and scanty pulmonary rales Severe headache, vomiting, dizziness, tachypnoea, and pronounced pulmonary rales were associated with other symptoms and signs and therefore characteristic of acute mountain sickness CONCLUSION--Acute mountain sickness is not an uncommon disease at moderately high altitude--that is, above 2800 m Severe headache, vomiting, dizziness, tachypnoea, and pronounced pulmonary rales indicate severe acute mountain sickness, and subjects who suffer these should immediately descend to lower altitudes

Patterns of disease activity in multiple sclerosis: clinical and magnetic resonance imaging study.

Abstract: OBJECTIVE--To compare the abnormalities shown by magnetic resonance imaging of the brain in three clinically distinct groups of patients with multiple sclerosis, and to correlate the extent of abnormality with the degree of clinical disability in the three groups. DESIGN--All patients underwent magnetic resonance imaging and full neurological examination, and their disability was scored according to the expanded Kurtzke disability state scale. SETTING--National Hospital for Nervous Diseases (Multiple Sclerosis NMR Research Group). PATIENTS--Three groups of patients with confirmed multiple sclerosis were studied: 12 patients with minimal disability despite a long (greater than 10 years) duration of illness (benign multiple sclerosis), 16 who had developed progressive disability after a relapsing and remitting course (secondary progressive multiple sclerosis), and 13 who had had progressive disability from the onset of the disease (primary progressive multiple sclerosis). MAIN OUTCOME MEASURES--Number and size of lesions in 17 anatomically defined sites; total lesion load, estimated with an arbitrary scoring system weighted for the size of lesions; and disability score. RESULTS--Magnetic resonance imaging showed that all 41 patients had abnormalities. These were extensive in the groups with secondary progressive and benign disease compared with the group with primary progressive disease. The lesions in the patients with secondary progressive disease were larger and more confluent than those in the two other groups (p = 0.007). Most lesions (85%) in the patients with primary progressive disease were under 5 mm in diameter; this percentage was higher than that in the two other groups (p = 0.032). Consequently the patients with primary progressive disease had the lowest mean lesion load (36.7); that in the patients with benign disease was 52.7 and that in the patients with secondary progressive disease 64.6 (p = 0.05). No correlation existed between disability and total lesion load. The distribution of brain lesions and of detectable lesions of the spinal cord, and the frequency of cortical atrophy, were similar in all groups. CONCLUSIONS--No relation was found between the degree of clinical disability and the extent of abnormality shown by magnetic resonance imaging: patients with clinically benign disease often had extensive abnormalities and those with primary progressive disease had surprisingly few lesions. Though magnetic resonance imaging increases knowledge of the disease process in multiple sclerosis and is invaluable in diagnosis, it is not helpful in predicting disability in individual patients.

Palliative care: views of patients and their families.

Abstract: OBJECTIVE--To investigate the current problems and needs of terminally ill cancer patients and their family members, and to discover their views of hospital, community, and support team services. DESIGN--Prospective study of patients and families by questionnaire interviews in the patients' homes. SETTING--Inner London and north Kent (London suburbs). SUBJECTS--65 Patients, each with a member of their family or a career. MAIN OUTCOME MEASURES--Ratings of eight current problems and ratings and comments on three services-hospital doctors and nurses, general practitioners and district nurses, and the support team staff-obtained after a minimum of two weeks' care from palliative care support teams. RESULTS--Effect of anxiety on the patient's nearest career. and symptom control were rated as the most severe current problems by both patients and families; a few patients and families identified other severe problems. Families' ratings of pain control, symptom control, and effect of anxiety on the patient were significantly worse than the patients' ratings (p less than 0.05). Support teams received the most praise, being rated by 58 (89%) patients and 59 (91%) of family members as good as excellent. General practitioners and district nurses were rated good or excellent by 46 (71%) patients and 46 (71%) family members, but six (9%) in each group rated the service as poor or very bad, and ratings in the inner London district were significantly worse than those in the outer London district. Hospital doctors and nurses were rated good or excellent by 22 (34%) patients and 35 (54%) of family members, and 14 (22%) patients and 15 (23%) family members rated this service as poor or very bad. Negative comments referred to communication (especially at diagnosis), coordination of services, the attitude of the doctor, delays in diagnosis, and difficulties in getting doctors to visit at home. Family members were more satisfied with the services than were patients. CONCLUSIONS--Palliative care needs to include both the patient and family because the needs of the family may exceed those of the patient. Support teams and some hospital and community doctors and nurses met the perceived needs of dying patients and families, but better education and organisation of services are needed.