Mortality of employees of the United Kingdom Atomic Energy Authority, 1946-1979.

An analysis was conducted of 3373 deaths among 39 546 people employed by the United Kingdom Atomic Energy Authority between 1946 and 1979, the population having been followed up for an average of 16 years. Overall the death rates were below those prevailing in England and Wales but consistent with those expected in a normal workforce. At ages 15-74 years the standardised mortality ratios (SMRs) were 74 for deaths from all causes and 79 for deaths from all cancers. Mortality from only four causes was above the national average--namely, testicular cancer (SMR 153; 10 deaths), leukaemia (SMR 123; 35 deaths), thyroid cancer (SMR 122; three deaths), non-Hodgkin''s lymphoma (SMR 107; 20 deaths)--but in none was the increase significant at the 5% level. Half of the authority''s employees were recorded as having been monitored for exposure to radiation, their collective recorded exposure being 660 Sv (65 954 rem). Among these prostatic cancer was the only condition with a clearly increased mortality in relation to exposure. Of the 19 men who had a radiation record and died from prostatic cancer at ages 15-74 years, nine had been monitored for several different sources of exposure to radiation. The standardised mortality ratios were 889 (six deaths) in employees monitored for contamination by tritium, 254 (nine deaths) in those monitored for contamination by other radionuclides, and 385 (nine deaths) in those with dosimeter readings totalling more than 50 mSv (5 rem); but the same nine subjects tended to account for each of these significantly raised ratios. Because multiple exposures were common and other relevant information was not available the reason for the increased mortality from prostatic cancer in this population could not be determined and requires further investigation. Excess mortality rates of 2.2 and 12.5 deaths per million person years per 10 mSv (1 rem) were estimated for leukaemia and all cancers, respectively. The confidence limits around these estimates were wide, included zero, and made it unlikely that the International Commission on Radiological Protection''s cancer risk coefficients were underestimated by more than 15-fold. Thus despite this being the largest British workforce whose mortality has been reported in relation to low level ionising radiation exposure, even larger populations will need to be followed up over longer periods before narrower ranges of risk estimates can be derived.     

Transcendental meditation.

A trial of chemoprophylaxis to prevent reactivation of tuberculosis in persons with inactive disease who had never had adequate chemotherapy was conducted in Canada in the mid-1960s. Preventive drug treatment consisted of either isoniazid (INH) alone or INH plus para-aminosalicylic acid (PAS), for a maximum of 18 months. Long-term evaluation in 1974 of 1571 treated patients and 834 control patients demonstrated clearly the substantial and sustained value of adequate chemoprophylaxis in reducing the risk of reactivation. Among those who took INH alone for 6 months or more the annual reactivation rate was 1.2 per 1000 persons, while among those who took INH plus PAS the rate was 0.38/1000. These rates were, respectively, 70 and 90% less than the average rate in the controls, 3.9/1000. Among those who underwent chemoprophylaxis for less than 6 months the annual reactivation rate was 3.7/1000, similar to that in the controls. Cost-benefit analysis showed chemoprophylaxis to be economically sound. Despite the recent increasing application of this preventive measure, there are still many persons living in Canada who could benefit substantially from a course of chemoprophylaxis.     

Meningococcal infections in the Hamilton area during 1978.

During 1978 there was a marked increase in the number of patients with meningococcal infection in the Hamilton area. Of 21 patients admitted to St. Joseph''s Hospital, Hamilton, two thirds were under 5 years of age. Four patients died. All the isolates were sulfonamide-sensitive strains of serogroup B Neisseria meningitidis. Although no infections developed in contacts, several errors were made in the management of the hospital and household contacts of the infected patients: chemoprophylaxis was given to many contacts not considered to be at risk; ineffective antibiotics, particularly penicillin, were given for chemoprophylaxis; and chemoprophylaxis was often delayed while the results of cultures of nasopharyngeal and throat secretions were awaited. Circulation to local physicians of guidelines on proven prophylactic regimens was followed by a reduction in the frequency of these errors.     

Prenatal risk assessment and obstetric care in a small rural hospital: comparison with guidelines.

An assessment was made of the potential usefulness in a small rural hospital of the guidelines for prenatal risk assessment and management of the Newfoundland and Labrador Prenatal Record, a form similar to that in use in other provinces. A retrospective chart review was done for 266 pregnancies followed at the Baie Verte Peninsula Health Centre prior to the introduction of the guidelines. The pattern of practice was to request consultation and to transfer patients for delivery less often than was suggested by the guidelines; only 32% of patients at risk were assessed by an obstetrician. By the time of delivery only 39% of the patients were at no predictable risk according to the guidelines. Nevertheless, neonatal morbidity was present in this group (4% of the infants had an Apgar score of 6 or less at 1 or 5 minutes), though less often than in those at risk (18% of the infants had a low Apgar score). However, the group at no predictable risk required nonelective intervention in 40% of cases, approximately the same rate as that for the group at risk. It is necessary for some small hospitals to have the facilities and the trained staff to handle the problems that occur even in low-risk patients. To maintain the delivery rate necessary to retain skills, the guidelines may help family practitioners and consulting obstetricians to select some patients at risk who can be managed in small hospitals.     

Screening for Down's syndrome based on individual risk.

OBJECTIVE--To evaluate the effectiveness of biochemical screening of individual pregnancies for Down''s syndrome risk. DESIGN--Retrospective determination of risk. SETTING--Obstetric and cytogenetic services in Tayside, Scotland. SUBJECTS--3436 pregnant women who had screening for neural tube defects in the second trimester during November 1988 to March 1990 and whose pregnancies were dated by ultrasonography. Three women with pregnancies associated with Down''s syndrome reported later in 1990. MAIN OUTCOME MEASURES--Individual risk calculated from age at estimated date of delivery; chorionic gonadotrophin and alpha fetoprotein concentrations in serum samples obtained at precisely determined gestational ages in second trimester. Results of karyotype determination and outcome of pregnancy. RESULTS--During November 1988 to March 1990 karyotypes were determined for 5% of pregnancies for reasons of maternal age and genetic history and one of the eight affected fetuses was detected. Individual risk could not be calculated for 347 pregnancies, but screening on this basis would have detected five of the cases and required screening in 194 out of 3089 (6.3%) pregnancies; all three affected pregnancies reported later in 1990 would also have been detected, giving a success rate of 73% (95% confidence interval 39% to 94%). The age distribution of women according to individual risk suggests that women over 35 would be screened effectively. CONCLUSION--Screening based on individual risk would use resources more effectively than screening based on maternal age and genetic history without affecting detection rates in older women.     

Hyperkalaemia in patients in hospital.

Significant hyperkalaemia occurred in 406 out of 29 063 patients admitted to a major Scottish teaching hospital in one year (1.4%). Mortality was higher in these patients than in control patients and was strongly correlated with the severity of the hyperkalaemia. Overall seven deaths were directly due to hyperkalaemia (out of 58 deaths among patients with hyperkalaemia). Factors contributing to a poor prognosis were severity and speed of onset of hyperkalaemia and the presence of appreciable renal impairment. Patients with hyperkalaemia were older and more likely to be male; this trend was present in all diagnostic subcategories. Genitourinary disease, gastrointestinal disease, and cancer were significantly more common among the patients with hyperkalaemia than the controls. Hyperkalaemia due to drug treatment was invariably mild and non-fatal, whereas genitourinary disease was often associated with moderate to severe hyperkalaemia, which in two cases proved fatal. Use of electrocardiographic monitoring was rare, and although the treatment of hyperkalaemia was effective, it was often used when not required. Hyperkalaemia is a potential hazard in diabetic ketoacidosis, and use of potassium supplements should be carefully monitored during correction of the acidosis.     

Deaths of cyclists in London 1985-92: the hazards of road traffic.

OBJECTIVE--To determine the characteristics of cyclists and vehicles involved in fatal cycling accidents. DESIGN--Analysis of data routinely collected by police for each accident from January 1985 to December 1992 and held in a national master file (Stats 19) by the Department of Transport. SETTING--Greater London, which comprises inner London (12 boroughs and the City of London) and outer London (20 boroughs). SUBJECTS--178 cyclists who died (78 in inner London and 100 in outer London; age range 3-88). MAIN OUTCOME MEASURES--Associations between characteristics of cyclists, type of vehicle involved, and place of accident. RESULTS--Motor vehicles were involved in 173 deaths. Heavy goods vehicles were involved in 75 deaths (30/100 (30%) in outer London and 45/78 (58%) in inner London); cars in 74 (54/100) (54%) in outer London and 20/78 (26%) in inner London); light goods vehicles in 12/178 (7%); and buses in 6/178 (3%). Thirty five of the people who died were children aged < or = 16. Female cyclists were especially at risk from heavy goods vehicles in inner London (22 deaths), while male cyclists were especially at risk from cars in outer London (50 deaths). DISCUSSION--Cyclists who died in urban areas are more likely to be adults than children. In inner London, in relation to their traffic volume, heavy goods vehicles are estimated to cause 30 times as many cyclists'' deaths as cars and five times as many as buses. Until the factors leading to this excess risk are understood, a ban on heavy goods vehicles in urban areas should be considered.     

Prenatal diagnosis of genetic disease in Canada: report of a collaborative study.

A study of 1223 amniocenteses carried out during 1020 pregnancies in 990 women showed that 2nd-trimester amniocentesis at about 16 weeks'' gestation is a safe, accurate and reliable procedure for the diagnosis of certain classes of genetic disease when it is monitored by ultrasound, performed by a trained obstetrician and carried out in a major health sciences centre. The percentage of fetal losses (4.7%) and neonatal deaths (0.5%) during the study was not greater than in control samples for women 35 years of age and older. The best results were obtained when needles of gauge 20 or 21 were used. The use of needles of gauge 19 or larger and more than two insertions during a single amniocentesis were associated with a significantly greater frequency of fetal loss than a second or even a third amniocentesis during the same pregnancy. For 39 fetuses (3.8%) a diagnosis of a genetic abnormality was made and 23 male fetuses were found to be potentially hemizygous for an X-linked gene. There were 51 therapeutic abortions as a result of the diagnosis. Sixty-six tests (5.4%) gave an inconclusive result and seven (0.6%) gave an erroneous diagnosis; five of the latter (two false-positives and three false-negatives) resulted from the alpha1-fetoprotein test for neural-tube defects and in two cases the sex was incorrectly determined. The frequency of all chromosome abnormalities was 1:20 when the mother''s age was 40 years or more and 1:60 when the mother''s age was between 35 and 39 years. When a mother had previously had a child with a chromosome abnormality the risk of recurrence of such an abnormality was 1:100 when the age of the mother was 35 years or more.     

Epidemiology of suicide pacts in England and Wales, 1988-92.

OBJECTIVE: To describe the epidemiology of suicide pacts in England and Wales DESIGN: Analysis of the death certificates and coroners'' records of all people who died in pacts between 1 January 1988 and 31 December 1992. SUBJECTS: 124 people who committed suicide in 62 pacts. RESULTS: Suicide in a pact accounted for 0.6% of all suicides (124/19721), a rate of 0.6 per million people aged 15 and over. Forty eight pacts were between married couples and five were between family members. The mean age was 56 years. 99 of the 124 subjects were of occupational social classes I-III. Poisoning by car exhaust fumes and drugs accounted for 116 deaths, with both members of each pair using the same method. CONCLUSIONS: Suicide pacts are rare and less common than they were 35 years ago, although the epidemiological profile is similar. People who commit suicide in a pact are more likely than those who commit suicide alone to be female, older, married, and of a high social class.     

Oral contraceptives and death from myocardial infarction.

We investigated 219 deaths from myocardial infarction in women under the age of 50. Their histories were compared with those of living age-matched controls selected from the same general practices. The frequency of use of oral contraceptives during the month before death was significantly greater in the group with infarction than during the corresponding month in the control group and the average duration of use was longer. No information of cigarette smoking was available but the proportion of women being treated for hypertension or diabetes was greater among those who died than among the controls. This did not alter the overall conclusion that the risk of fatal myocardial infarction was greater in the women using oral contraceptives, particularly in the older age groups.     

Snowmobile-related deaths in Ontario: a 5-year review.

OBJECTIVES: To investigate the demographic characteristics and circumstances surrounding fatal snowmobile accidents in Ontario, to examine the risk factors and to observe any fatality trends over the study period. DESIGN: Case series. PATIENTS: All 131 people who died accidentally while operating a snowmobile in Ontario from 1985-86 to 1989-90. Records were obtained from the chief coroner''s office; registration data were obtained from the Ministry of Transportation. RESULTS: Although the absolute number of deaths increased each year, owing to a rapid increase in the number of registered snowmobiles, the risk of death from snowmobile accidents remained relatively constant. Deaths occurred most frequently in northeastern Ontario. Youths and men predominated among the victims. Fatal accidents occurred more often on lakes (in 66% of the cases in which this information was known) than on roads (in 26%) or trails (in 8%). Weekend fatalities predominated, and deaths occurred most often during times of suboptimal lighting (from 4 pm to 8 am). The driver was killed in 84% of the cases in which the person''s role was known. Alcohol use before death was implicated in 69% of the cases, the level exceeding the Ontario legal limit in 59%. CONCLUSION: Snowmobile-related deaths result from factors that are generally avoidable. Strategies need to be instituted to reduce the rate of these events.     

Prevalence of hepatitis B antibodies in hospital personnel.

Of 426 hospital staff tested for hepatitis B surface antibody (anti-HBS) by the radioimmunoassay method 57 (13.4%) had positive results. Laboratory staff had the highest prevalence, followed by nurses, and both values were significantly higher than that of administrative staff. Clerical staff working in laboratories were at the same risk for hepatitis B as general-duty nurses. Significantly more staff with anti-HBS had a history of hepatitis (19.3%) compared with staff without anti-HBS (79%), and significantly more staff with a history of hepatitis had anti-HBS (25.6%) compared with staff without such a history (12.0%). History of blood transfusions was not related to prevalence of anti-HBS. The risk for hepatitis B is greater in hospital staff who are in direct contact with patients or handle patients'' blood and other specimens. However, contact with patients is less important than contact with patients'' blood and other specimens.     

Evidence of compliance with and effectiveness of guidelines for noninvasive prenatal testing in China: a retrospective study of 189,809 cases

In China,the medical guidelines recommend performing noninvasive prenatal testing (NIPT) with caution for pregnant women aged 35 years or older.However,the Mother and Child Health Care Law suggests that all primiparous women whose age is older than 35 years undergo prenatal diagnosis.These two inconsistent suggestions/recommendations have made obstetricians confused about whether to offer NIPT to these older pregnant women.To face this issue and find out the solution we performed a retrospective study of 189,809 NIPT samples collected from 28 provincial-leveled administrative units in China.Of 1,564women with high-risk pregnancies who underwent NIPT,459 (29.3%) did not participate in follow-up.The compound sensitivity and specificity of NIPT for trisomies 21,18 and 13 detection was 99.1%(95%CI,98.0%-99.6%) and 99.9%(95%CI,98.8%-99.9%),respectively.In secundiparous women,NIPT showed high sensitivity and specificity similar to that in primiparous women.The observed risk for trisomies 21 and 18 significantly increased when the maternal age was 39 and older.After the publication of the current NIPT policy,the follow-up rate at our center was 97.9%;however,a large number of women are not in maternal and infant care networks nationwide,and that makes the follow-up rate outside our center relatively low.Our study shows that to balance the prevention of major aneuploidies and the limited resources for prenatal diagnosis,the cut-off age of 35for invasive prenatal diagnosis might be unnecessary.Although the NIPT guidelines are well written,how to practice it effectively,especially in less industrialized areas,is worth discussing.     

Variability in predicted rates of Down syndrome associated with elevated maternal serum alpha-fetoprotein levels in older women.

Quantitative predictions of rates of Down syndrome offspring as a function of maternal serum alpha-fetoprotein (MSAFP) values and of maternal age were reviewed. Comparisons were made of 35-year-equivalent-risk values by maternal age, that is, MSAFP values (at various maternal ages) that predict the risk (of a Down syndrome offspring) equivalent to that of an average 35-year-old woman irrespective of knowledge of MSAFP. This boundary was chosen because MSAFP values that predict a greater risk than this point for younger women or a lower risk for older women are likely in many jurisdictions to alter a decision about amniocentesis that would be reached without knowledge of MSAFP. There were marked differences among available studies in these 35-year-equivalent-risk values for older women. For instance, for age 41, the values among studies vary from 1.5 MoM to 2.1 MoM and the predicted proportion of 41-year-old women likely to be affected clinically by MSAFP determinations by the above criterion is 4.4%-18%, depending on which rate schedule is used. At age 39, the variation is 1.1 to 1.9 MoM or 7.1% to 38%. Possible explanations for the variation include sampling fluctuation. Relatively few data on Down syndrome have been used to calculate the parameters of the gaussian distributions used by the studies reviewed. It is suggested that great caution be used before employing published rate schedules for genetic counseling of older women, at least until sufficient data are collected and the nature of the discrepancies among studies is clarified.     

Deaths in Canada from lung cancer due to involuntary smoking.

Recently published evidence indicates that involuntary smoking causes an increased risk of lung cancer among nonsmokers. Information was compiled on the proportion of people who had never smoked among victims of lung cancer, the risk of lung cancer for nonsmokers married to smokers and the prevalence of such exposure. On the basis of these data we estimate that 50 to 60 of the deaths from lung cancer in Canada in 1985 among people who had never smoked were caused by spousal smoking; about 90% occurred in women. The total number of deaths from lung cancer attributable to exposure to tobacco smoke from spouses and other sources (mainly the workplace) was derived by applying estimated age- and sex-specific rates of death from lung cancer attributable to such exposure to the population of Canadians who have never smoked; about 330 deaths from lung cancer annually are attributable to such exposure.     

Health inequalities: new concerns about the children of single mothers.

OBJECTIVES--To show that the exclusion from conventional class based analyses of child mortality of children whose parents are classified as "unoccupied" produces a misleading picture of health inequalities. DESIGN--Reanalysis of data published in the childhood supplement of the registrar general''s decennial supplement on occupational mortality in England and Wales, which compares numerator data for registrations of deaths in children over the age of 1 but below their 16th birthday in 1979, 1980, 1982, and 1983 with data about children aged 1-15 who were enumerated at the 1981 census. RESULTS--Parents who are classified as "unoccupied" largely consist of economically inactive single mothers. Their children are estimated to represent 89% of the 614,000 aged 1-15 classified as "unoccupied" in the childhood supplement. They have the worst mortality record of all social groups--an age specific death rate of 68.8/100,000 a year, 42% worse than in social class V (48.4/100,000) and worse than that of social class I (22.8) by a factor of 3. At older ages (10-15 years) these children have a relative risk of death of 4.14 relative to classes I and II; the risk is 2.58 in children 0-4 and 2.56 in those 5-9. Relative risks of child mortality in social classes I and II in comparison to classes IV and V suggests a progressive shallowing from 2.08 at ages 1-4 to 1.37 at ages 10-15. When unoccupied parents were combined with classes IV and V and compared with classes I and II, however, inequalities seemed to be pervasive throughout childhood; the relative risks were 2.21 for those aged 1-4 and 1.98 for those aged 10-15. CONCLUSION--Children classified as unoccupied are almost certainly living in poverty as well as experiencing relatively high risks of mortality. Class based analyses which exclude them therefore produce a misleading picture of inequalities in child health. The implications for health policy are profound. Strategies to promote the nation''s health should acknowledge the importance of material and social deprivation more explicitly.     

Acute cholecystitis and thiazides.

Drugs purchased by a random sample (17 000) of the population of Jämtland county, Sweden, are continuously monitored. Patients who had been admitted to the county''s only hospital with acute cholecystitis and who were part of this sample were studied, and controls matched for age and sex were drawn from the sample. The purchase of thiazides and other drugs prescribed to the patients with acute cholecystitis was compared with that of the controls. The estimated relative risk of developing acute cholecystitis in patients who had purchased thiazides in the year before admission to hospital, as compared with those who had not, was 2.1 (95% confidence limit 1.1-3.9). As it has been reliably reported that the use of thiazides is not itself associated with cholelithiasis, the association found between thiazides and cholecystitis suggests that thiazides may increase the risk of acute cholecystitis developing in a patient with gall stones.     

One year's treatment with propranolol after myocardial infarction: preliminary report of Norwegian multicentre trial.

A prospective, randomised, double-blind study was performed to compare the effects of propranolol and placebo on sudden cardiac death in a high-risk group of patients who survived acute myocardial infarction. Altogether 4929 patients with definite acute myocardial infarction were screened for inclusion: 574 (11.6%) died before randomisation, and 3795 (77%) were excluded. Five hundred and sixty patients aged 35 to 70 years were stratified into two risk groups and randomly assigned treatment with propranolol 40 mg four times a day or placebo. Treatment started four to six days after the infarction. By one year there had been 11 sudden deaths in the propranolol group and 23 in the placebo group (p less than 0.038, two-tailed test analysed according to the "intention-to-treat" principle). Altogether there were 25 deaths in the propranolol group and 37 in the placebo group (P less than 0.12), with 16 and 21 non-fatal reinfarctions respectively. A quarter of the patients were withdrawn from each group. Withdrawal because of heart failure during the first two weeks of treatment was significantly more common among propranolol-treated patients than among the controls, but thereafter the withdrawal rate was the same. The significant reduction in sudden death was comparable with that after alprenolol, practolol, and timolol, which suggests that the mechanism of prevention is beta-blockade rather than any other pharmacological property of the individual drugs.     

The effects of levodopa therapy in patients with Parkinson's disease I. Clinical response

Eighty-eight patients with Parkinson''s disease were treated with levodopa. A group of elderly patients 65 years and older was compared with a second group under the age of 65, and it was found that generally the younger patients could be treated with greater success than the older ones. Most of the elderly could not tolerate the large doses required to produce optimal physical recovery. Severity of complications forced discontinuance of treatment in a larger percentage of elderly patients. The rate of complications was about equal in the two groups, except the incidence of confusion, which was significantly higher in the elderly. Of the two deaths that occurred, both were in the older group. Results of treatment were better in patients whose families gave positive support.     

Controlled investigation of deaths from asthma in hospitals in the North East Thames region.

One hundred and thirty deaths definitely or potentially due to asthma occurring in hospitals in the North East Thames region over one year were identified from death certificates and Hospital Activity Analysis records. Thirty five of these deaths were considered after independent assessment to have been directly due to asthma. Control patients who left hospital alive after acute asthma attacks were selected and matched with cases for sex, age, and hospital. Management was compared in the two groups. Inadequate monitoring, including failure to monitor arterial blood gas values, and inadequate use of nebulised beta agonists occurred significantly more often in fatal cases. Use of sedation, inadequate treatment with steroids, exposure to potentially toxic doses of aminophylline, and inadequate clinical assessment were more common in cases than controls, but not significantly so. Failure to institute artificial ventilation contributed to seven deaths. Assessors considered important defects in management to have occurred in 83% (29/35) of the cases and 40% (14/35) of the controls. Nevertheless, most of the hospital deaths (19/35) were considered not to have been preventable. Eight other deaths in the region were attributed to the complications of asthma or its treatment. Three of these were associated with gastrointestinal bleeding and one with perforation of a duodenal ulcer. Before considering policies aimed at speeding admission to hospital of patients with acute attacks of asthma it is crucial that the general standard of hospital care offered to all patients with asthma should be improved.