Case-control study of leukaemia and non-Hodgkin's lymphoma among children aged 0-4 years living in west Berkshire and north Hampshire health districts.

OBJECTIVE--To investigate the relation between parental employment in the nuclear industry and childhood leukaemia and non-Hodgkin''s lymphoma. DESIGN--Case-control study. SETTING-West Berkshire and Basingstoke and North Hampshire District Health Authorities. SUBJECTS--54 children aged 0-4 years who had leukaemia or non-Hodgkin''s lymphoma diagnosed during 1972-89, who were born in the study area and were resident there when cancer was diagnosed. Six controls were selected for each case: four from hospital delivery registers and two from livebirth registers maintained by the NHS central register. Controls were matched for sex, date of birth (within six months), and area of residence at birth and time of diagnosis. MAIN OUTCOME MEASURES--Parents'' employment by the nuclear industry and exposure to ionising radiation at work. RESULTS--Five (9%) of the 54 cases and 14 (4%) of the 324 controls had fathers or mothers, or both, who had been employed by the nuclear industry (relative risk 2.2, 95% confidence interval 0.6 to 6.9). Nuclear industry employees who work in areas where exposure to radiation is possible are given film badges to monitor their exposure to external penetrating ionising radiation. Three fathers of cases and two fathers of controls (and no mothers of either) had been monitored in this way before their child was conceived (relative risk 9.0, 95% confidence interval 1.0 to 107.8). No father (of a case or control) had accumulated a recorded dose of more than 5 mSv before his child was conceived, and no father had been monitored at any time in the four years before his child was conceived. A dose-response relation was not evident among fathers who had been monitored. CONCLUSIONS--These results suggest that the children of fathers who had been monitored for exposure to external penetrating ionising radiation in the nuclear industry may be at increased risk of developing leukaemia before their fifth birthday. The finding is based on small numbers and could be due to chance. If the relationship is real the mechanisms are far from clear, except that the effect is unlikely to be due to external radiation; the possibility that it could be due to internal contamination by radioactive substances or some other exposure at work should be pursued. The above average rates of leukaemia in the study area cannot be accounted for by these findings.     

Cross sectional survey of socioeconomic variations in severity and mechanism of childhood injuries in Trent 1992-7

ObjectiveTo determine the relation between morbidity from injury and deprivation for different levels of injury severity and for different injury mechanisms for children aged 0-14 years.DesignCross sectional survey of routinely collected hospital admission data for injury 1992-7.Setting862 electoral wards in Trent Region.Subjects21 587 injury related hospital admissions for children aged 0-4 years and 35 042 admissions for children aged 5-14.ResultsBoth total number of admissions for injury and admissions for injuries of higher severity increased with increasing socioeconomic deprivation. These gradients were more marked for 0-4 year old children than 5-14 year olds. In terms of injury mechanisms, the steepest socioeconomic gradients (where the rate for the fifth of electoral wards with the highest deprivation scores was ⩾3 times that of the fifth with the lowest scores) were for pedestrian injuries (adjusted rate ratio 3.65 (95% confidence interval 2.94 to 4.54)), burns and scalds (adjusted rate ratio 3.49 (2.81 to 4.34)), and poisoning (adjusted rate ratio 2.98 (2.65 to 3.34)).ConclusionThere are steep socioeconomic gradients for injury morbidity including the most common mechanisms of injury. This has implications for targeting injury prevention interventions and resources.

What is already known on this topic?

There is a steep socioeconomic gradient for injury related mortalityThere is conflicting evidence regarding the socioeconomic gradient for injury morbidity, particularly with respect to different injury severity and injury mechanisms

What this study adds

A socioeconomic gradient for injury morbidity exists in children aged <15 years, particularly in those aged <5, which persist for different measures of injury severityThe socioeconomic gradient for injury mechanisms is steepest for pedestrian injuries, burns and scalds, and poisoning, which has implications for targeting injury prevention strategies     

Fallout from Chernobyl and incidence of childhood leukaemia in Finland, 1976-92.

OBJECTIVE--To assess effects of fallout from Chernobyl on incidence of childhood leukaemia in Finland. DESIGN--Nationwide cohort study. External exposure measured for 455 Finnish municipalities with instruments driven 19,000 km throughout the country. Values specific to municipalities corrected for shielding due to houses and fallout from A bomb testing. Internal exposure estimated from whole body measurements on a random sample of 81 children. Mean effective dose for two years after incident calculated from these measurements. Data on childhood leukaemia obtained from Finnish cancer registry and verified through hospitals treating childhood cancers. SETTING--Finland, one of the countries most heavily contaminated by the Chernobyl accident; the population was divided into fifths by exposure. SUBJECTS--Children aged 0-14 years in 1976-92. MAIN OUTCOME MEASURES--Standardised incidence ratio of childhood leukaemia and relative excess risk of childhood leukaemia per mSv. From incidence data of Finnish cancer registry for 1976-85, expected numbers specific to sex and age group (0-4, 5-9, and 10-14 years) were calculated for each municipality for three periods (1976-85, 1986-8, and 1989-92) and pooled as exposure fifths. Dose response was estimated as regression slope of standardised incidence ratios on mean doses for fifths for each period. RESULTS--Population weighted mean effective doses for first two years after the accident were 410 microSv for the whole country and 970 microSv for the population fifth with the highest dose. In all Finland the incidence of childhood leukaemia did not increase 1976-92. The relative excess risk 1989-92 was not significantly different from zero (7% per mSv; 95% confidence interval -27% to 41%). CONCLUSIONS--An important increase in childhood leukaemia can be excluded. Any effect is smaller than eight extra cases per million children per year in Finland. The results are consistent with the magnitude of effect expected.     

Trends in childhood leukaemia in the Nordic countries in relation to fallout from atmospheric nuclear weapons testing.

OBJECTIVE--To obtain further information about the risks of childhood leukaemia after exposure to ionising radiation at low doses and low dose rates before or after birth or to the father''s testes shortly before conception. DESIGN--Observational study of trends in incidence of childhood leukaemia in relation to estimated radiation exposures due to fallout from atmospheric nuclear weapons testing during the 1950s and 1960s. SETTING--Nordic countries. SUBJECTS--Children aged under 15 years. MAIN OUTCOME MEASURES--Incidence rates of leukaemia by age at diagnosis, sex, country, and calendar year of diagnosis or year of birth; exposure category; relation between leukaemia and exposure for children aged 0-14 and 0-4 separately. RESULTS--During the high fallout period the average estimated dose equivalent to the fetal red bone marrow was around 140 mu Sv and the average annual testicular dose 140 mu Sv. There was little evidence of increased incidence of leukaemia among children born in these years. Doses to the red bone marrow of a child after birth were higher, and during the high exposure period children would have been subjected to an additional dose equivalent of around 1500 mu Sv, similar to doses received by children in several parts of central and eastern Europe owing to the Chernobyl accident and about 50% greater than the annual dose equivalent to the red bone marrow of a child from natural radiation. leukaemia incidence and red marrow dose was not related overall, but rates of leukaemia in the high exposure period were slightly higher than in the surrounding medium exposure period (relative risk for ages 0-14: 1.07, 95% confidence interval 1.00 to 1.14; for ages 0-4: 1.11, 1.00 to 1.24). CONCLUSIONS--Current predicted risks of childhood leukaemia after exposure to radiation are not greatly underestimated for low dose rate exposures.     

Wartime evacuation and mortality from childhood leukaemia in England and Wales in 1945-9.

OBJECTIVE--To discover whether the wartime government evacuation of children from London and other population centres to rural districts was associated with any increase in childhood leukaemia. DESIGN--Observational study of mortality from leukaemia among the childhood population of England and Wales in relation to the unique population movements during the second world war. The 476 rural districts of England and Wales were ranked according to the ratio of government evacuees (two thirds of them children) to local children in September 1941. The districts were divided into three categories, each with similar numbers of children in 1947 but with different ratios of evacuees to local children ("low," "intermediate," "high"). Mortality from childhood leukaemia was examined in these three rural categories in 1945-9. Urban areas were also examined according to their exposure to evacuees. SETTING--Local authority areas of England and Wales. SUBJECTS--Children aged under 15. RESULTS--47% excess of leukaemia at ages 0-14 years occurred in 1945-9 in the rural "high" category for evacuees relative to the "low" category, with a significant trend across the three categories. There were increases in both the 0-4 and 5-14 year age groups, but these were larger in the older age group. Rates 25% lower than average occurred in rural areas with few evacuees. CONCLUSION--These findings suggest that wartime evacuation increased the incidence of childhood leukaemia in rural areas and that other forms of population mixing may have contributed to the increases in past decades. Overall, they add to the appreciable evidence for an infective basis in childhood leukaemia.     

Incidence of leukaemia and other cancers in birth and schools cohorts in the Dounreay area.

OBJECTIVE--To determine whether a raised incidence of leukaemia in the Dounreay area occurred in children born to local mothers (birth cohort) or in those who moved to the area after birth (schools cohort) and also whether any cases of cancer have occurred in children born near Dounreay who may have moved elsewhere. DESIGN--Follow up study. SETTING--Dounreay area of Caithness, Scotland. SUBJECTS--4144 children born in the area in the period 1969-88 and 1641 children who attended local schools in the same period but who had been born elsewhere. MAIN OUTCOME MEASURES--Cancer registration records linked to birth and school records with computerised probability matching methods. RESULTS--Five cancer registrations were traced from the birth cohort compared with 5.8 expected on the basis of national rates (observed to expected ratio 0.9, 95% confidence interval 0.3 to 2.0). All five cases were of leukaemia (2.3, 0.7 to 5.4). In the schools cohort three cases were found (2.1, 0.4 to 6.2), all of which were of leukaemia (6.7, 1.4 to 19.5). All eight children were resident in the Dounreay area at the time of diagnosis; thus no cases were found in children who were born in or had attended school in the study area but who subsequently moved away. CONCLUSION--The raised incidence of leukaemia in both the birth and schools cohorts suggests that place of birth is not a more important factor than place of residence in the series of cases of leukaemia observed near Dounreay area.     

Risk of acute childhood leukaemia in Sweden after the Chernobyl reactor accident. Swedish Child Leukaemia Group.

OBJECTIVE--To evaluate the risk of acute childhood leukaemia in areas of Sweden contaminated after the Chernobyl reactor accident in April 1986. DESIGN--Population based study of childhood leukaemia diagnosed during 1980-92. SETTING--Coordinates for places of residence of all 1.6 million children aged 0-15 years; aerial mapped areas of Sweden heavily contaminated after the Chernobyl accident. SUBJECTS--888 children aged 0-15 years with acute leukaemia diagnosed in Sweden during 1980-92, identified with place of birth and residence at diagnosis. MAIN OUTCOME MEASURES--Risk of leukaemia in areas contaminated after the Chernobyl accident compared with the rest of Sweden and in the same areas before the accident. RESULTS--During six and a half years of follow up after the accident the odds ratio for acute leukaemia was 0.9 (95% confidence interval 0.6 to 1.4) in highly contaminated areas (> or = 10 kBq/m2) compared with the same areas before the accident. For the subgroup acute lymphoblastic leukaemia in children aged under 5 years at diagnosis the odds ratio was 1.5 (0.8 to 2.6). For all cases diagnosed after May 1986 in highly contaminated areas compared with areas of low contamination the odds ratio was 0.9 (0.7 to 1.3). For acute lymphoblastic leukaemia in children aged under 5 years at diagnosis the odds ratio was 1.2 (0.8 to 1.9) in highly contaminated areas compared with areas of low contamination. Dose-response analysis showed no correlation between the degree of contamination and the incidence of childhood leukaemia. CONCLUSION--There has been no significant increase in the incidence of acute childhood leukaemia in areas of Sweden contaminated after the Chernobyl reactor accident.     

Cancer in Cumbria and in the vicinity of the Sellafield nuclear installation, 1963-90.

OBJECTIVE--To reappraise the epidemiological findings reported by the Black Advisory Group concerning a possible excess of malignant disease, particularly of childhood acute lymphoid leukaemia and non-Hodgkin lymphomas, in the vicinity of the Sellafield nuclear installation, and to determine whether any excess of malignant disease had occurred among people aged 0-24 years in the area in the years after the Black report--that is, from 1984 to 1990. DESIGN--Calculation of incidence of cancer using data from population based cancer registries and special surveys. SETTING--England and Wales; county of Cumbria; county districts Allerdale and Copeland within Cumbria; Seascale ward within Copeland. SUBJECTS--All residents under the age of 75 years in the above areas, but with particular reference to those aged 0-24 years. MAIN OUTCOME MEASURES--Numbers of cases and incidence particularly of lymphoid leukaemia and non-Hodgkin lymphomas in those aged 0-24 years, but including other cancers and age groups. RESULTS--Previous reports of an increased incidence of cancer, especially of leukaemia, among those aged 0-24 years in Seascale during the period up to and including 1983 are confirmed. During 1984-90 there was an excess of total cancer among those aged 0-24 years. This was based on four cases including two cases of non-Hodgkin lymphoma but none of leukaemia. There was an increased, but nonsignificant, incidence of other cancers, based on two cases (one pinealoma and one Hodgkin''s disease) occurring among those aged 15-24 years during 1984-90. This was not observed in the younger age group or in previous years. For the immediately surrounding area--that is, the county districts of Allerdale and Copeland excluding Seascale and in the remainder of Cumbria--there was no evidence of an increased incidence of cancer among those aged 0-24 years in either period. CONCLUSIONS--During 1963-83 and 1984-90 the incidence of malignant disease, particularly lymphoid leukaemia and non-Hodgkin lymphomas, in young people aged 0-24 in Seascale was higher than would be expected on the basis of either national rates or those for the surrounding areas. Although this increased risk is unlikely to be due to chance, the reasons for it are still unknown.     

Risk of cancer in Finnish children living close to power lines.

OBJECTIVE--To investigate the risk of cancer in children living close to overhead power lines with magnetic fields of > or = 0.01 microteslas (microT). DESIGN--Cohort study. SETTING--The whole of Finland. SUBJECTS--68,300 boys and 66,500 girls aged 0-19 years living during 1970-89 within 500 m of overhead power lines of 110-400 kV in magnetic fields calculated to be > or = 0.01 microT. Subjects were identified by record linkages of nationwide registers. MAIN OUTCOME MEASURES--Numbers of observed cases in follow up for cancer and standardised incidence ratios for all cancers and particularly for nervous system tumours, leukaemia, and lymphoma. RESULTS--In the whole cohort 140 cases of cancer were observed (145 expected; standardised incidence ratio 0.97, 95% confidence interval 0.81 to 1.1). No statistically significant increases in all cancers and in leukaemia and lymphoma were found in children at any exposure level. A statistically significant excess of nervous system tumours was found in boys (but not in girls) who were exposed to magnetic fields of > or = 0.20 microT or cumulative exposure of > or = 0.40 microT years. CONCLUSIONS--Residentia magnetic fields of transmission power lines do not constitute a major public health problem regarding childhood cancer. The small numbers do not allow further conclusions about the risk of cancer in stronger magnetic fields.     

Rising incidence of insulin dependent diabetes in children aged under 5 years in the Oxford region: time trend analysis. The Bart's-Oxford Study Group.

OBJECTIVES: To monitor incidence of insulin dependent diabetes in children in Oxford health region since 1985, and to look for any evidence of disproportionate increase in children aged under 5. DESIGN: Primary ascertainment of cases of childhood diabetes was by prospective registration of all patients with insulin dependent diabetes diagnosed before age 15 years between 1985 and 1996 and resident in Oxford region at time of diagnosis. This was supplemented by examination of centralised hospital discharge records and death certificates. Secondary case ascertainment was by postal surveys of general practitioners in 1987 and 1996. SETTING: Area formerly administered by Oxford Regional Health Authority. SUBJECTS: 1037 children presenting with insulin dependent diabetes under age of 15 years. MAIN OUTCOME MEASURES: Incidence of insulin dependent diabetes in children aged 0-4, 5-9, and 10-14 years during 1985-95. RESULTS: Overall incidence of diabetes in children aged 0-15 was 18.6 cases/100000/year and showed an annual increase of 4% from 1985 to 1996. This was mainly due to a rapid increase in children aged 0-4 years, in whom there was an annual increase of 11% (95% confidence interval 6% to 15%, P < 0.0001), while the annual increase in those aged 5-9 was 4% (0 to 7%, P = 0.05) and in those aged 10-14 was 1% (-2% to 4%, P = 0.55). CONCLUSIONS: Incidence of insulin dependent diabetes in children aged under 5 years has risen markedly in the Oxford region over the past decade. The cause of the increase is unknown, but environmental influences encountered before birth or in early postnatal life are likely to be responsible.     

Distribution of childhood leukaemias and non-Hodgkin's lymphomas near nuclear installations in England and Wales.

OBJECTIVE--To examine the relation between the risk of childhood leukaemia and non-Hodgkin''s lymphoma and proximity of residence to nuclear installations in England and Wales. DESIGN--Observed and expected numbers of cases were calculated and analysed by standard methods based on ratios of observed to expected counts and by a new statistical test, the linear risk score test, based on ranks and designed to be sensitive to excess incidence in close proximity to a putative source of risk. SETTING--Electoral wards within 25 km of 23 nuclear installations and six control sites that had been investigated for suitability for generating stations but never used. SUBJECTS--Children below age 15 in England and Wales, 1966-87. MAIN OUTCOME MEASURE--Registration of any leukaemia or non-Hodgkin''s lymphoma. RESULTS--In none of the 25 km circles around the installations was the incidence ratio significantly greater than 1.0. The only significant results for the linear risk score test were for Sellafield (P = 0.00002) and Burghfield (P = 0.031). The circles for Aldermaston and Burghfield overlap; the incidence ratio was 1.10 in each. One of the control sites gave a significant linear risk score test result (P = 0.020). All the tests carried out were one sided with P values estimated by simulation. CONCLUSION--There is no evidence of a general increase of childhood leukaemia or non-Hodgkin''s lymphoma around nuclear installations. Apart from Sellafield, the evidence for distance related risk is very weak.     

Childhood cancer in relation to distance from high voltage power lines in England and Wales: a case-control study

Objective To determine whether there is an association between distance of home address at birth from high voltage power lines and the incidence of leukaemia and other cancers in children in England and Wales.Design Case-control study.Setting Cancer registry and National Grid records.Subjects Records of 29 081 children with cancer, including 9700 with leukaemia. Children were aged 0-14 years and born in England and Wales, 1962-95. Controls were individually matched for sex, approximate date of birth, and birth registration district. No active participation was required.Main outcome measures Distance from home address at birth to the nearest high voltage overhead power line in existence at the time.Results Compared with those who lived > 600 m from a line at birth, children who lived within 200 m had a relative risk of leukaemia of 1.69 (95% confidence interval 1.13 to 2.53); those born between 200 and 600 m had a relative risk of 1.23 (1.02 to 1.49). There was a significant (P < 0.01) trend in risk in relation to the reciprocal of distance from the line. No excess risk in relation to proximity to lines was found for other childhood cancers.Conclusions There is an association between childhood leukaemia and proximity of home address at birth to high voltage power lines, and the apparent risk extends to a greater distance than would have been expected from previous studies. About 4% of children in England and Wales live within 600 m of high voltage lines at birth. If the association is causal, about 1% of childhood leukaemia in England and Wales would be attributable to these lines, though this estimate has considerable statistical uncertainty. There is no accepted biological mechanism to explain the epidemiological results; indeed, the relation may be due to chance or confounding.     

Deprivation and general practitioner workload.

OBJECTIVES--To examine general practitioner consultations by demographic and socioeconomic variables and to derive a method of measuring the impact of relative deprivation on general practitioner workload. DESIGN--The study was based on general practitioner consultations reported in the general household surveys of 1983-7, covering a sample of 129,987 individuals in Great Britain. Odds ratios for general practitioner consultations were obtained for selected variables among children (0-15 years), men (16-64), women (16-64), and elderly people (greater than or equal to 65). These were then used to derive deprivation indices specific to electoral wards for use in general practice. SETTING--Great Britain, with particular findings illustrated by English electoral wards and the conurbations of London, Manchester, Merseyside, and the West Midlands. RESULTS--Council tenure increased the likelihood of consultation significantly in all four groups. Odds ratios were raised in children, men, and women with no access to a car. Birth in the New Commonwealth or Pakistan yielded high odds ratios in men, women, and elderly people but not in children. Marginally increased consultation rates were evident in the manual socioeconomic groups in women, elderly people, and children with a single parent mother. The deprivation indices for general practice derived using these odds ratios varied substantially among English electoral wards with, for example, anticipated general practitioner consultations in the electoral ward of Hulme, Manchester, being 24% higher than the average ward in England as a result of local attributes, and consultations in the Cheam South ward of Sutton, London, 11% lower than average. CONCLUSION--This deprivation index for general practice overcomes several shortcomings expressed about the underprivileged area score, which has been adopted in the 1990 contract as a basis for allocating deprivation supplements to general practitioners. The proposed index can be applied nationwide.     

Prospective study of incidence of juvenile diabetes mellitus over 10 years in Dar es Salaam,Tanzania.

OBJECTIVE--To ascertain the annual incidence of diabetes requiring treatment with insulin in children and adolescents aged 0-19 years in Dar es Salaam, Tanzania, during a 10 year period from 1 January 1982 to 31 December 1991. DESIGN--Prospective registration at a major urban hospital of all patients with newly diagnosed diabetes who were resident in Dar es Salaam. SETTING--Muhimbili Medical Centre, Dar es Salaam, Tanzania. PATIENTS--86 patients: 45 male, 41 female. RESULTS--The annual incidence of juvenile diabetes for both sexes was 1.5 per 100,000 population aged 0-19 years (95% confidence interval 1.3 to 1.7). Incidence per 100,000 population per year increased with age: 0.6 (0.0 to 0.13) in the age group 0-4 years, 0.5 (0.3 to 0.7) at 5-9 years, 2.2 (1.8 to 2.6) at 10-14 years, and 3.4 (2.9 to 3.9) at 15-19 years. CONCLUSION--Juvenile diabetes mellitus is fairly rare in sub-Saharan Africa. If environmental factors such as infection and material deprivation were important determinants of insulin dependent diabetes in Africans, as they may be in Europeans, much higher rates would have been expected unless genetic factors possibly exert a protective role. The eightfold greater incidence in African Americans than in Tanzanians may be related to greater genetic admixture in African Americans with people from countries in Europe with a high incidence.     

Evidence for an environmental effect in the aetiology of insulin dependent diabetes in a transmigratory population.

OBJECTIVE--To examine whether children of families moving from an area of low incidence of childhood diabetes to one which is higher show a corresponding rise in disease incidence. DESIGN--Disease incidence study over 12 years. SETTING--Bradford District Metropolitan Council area. SUBJECTS--All subjects aged 0-16 years resident within the study area. MAIN OUTCOME MEASURES--The incidences of childhood diabetes in Asian and non-Asian families. RESULTS--The incidence of diabetes in Asian children increased from 3.1/100,000 per year in 1978-81 to 11.7/100,000 per year in 1988-90 (chi 2 for trend = 4.95, df = 1, p = 0.026) whereas that for other children remained constant at 10.5/100,000 per year. Over the entire study period rates were lower in Asian females (4.9/100,000 per year) than in Asian males (8.8/100,000 per year) whereas the reverse was true for other children (males 9.2/100,000 per year; females 12.0/100,000 per year) (test for common odds ratio: chi 2 = 3.81, df = 1, p = 0.052). CONCLUSIONS--Offspring of this transmigratory population had a rising incidence of childhood diabetes which was approaching that of the indigenous population. The data provide strong evidence for an environmental effect in the aetiology of insulin dependent diabetes.     

Effect of population mixing and socioeconomic status in England and Wales, 1979-85, on lymphoblastic leukaemia in children.

OBJECTIVE: To examine the effects of migration, diversity of migrant origins, commuting, and socioeconomic status on the incidence of acute lymphoblastic leukaemia in childhood. DESIGN: Poisson regression analysis of incidence rates in relation to the variables of interest. SETTING: The 403 county districts of England and Wales during 1979-85. SUBJECTS: Children aged under 15 years. RESULTS: There were significant trends in the incidence of lymphoblastic leukaemia at ages 0-4 and 5-9 years with the proportion of children in a district who had recently entered the district. While there was no consistent relation between the proportion of recent incomers in the total population of a district and its incidence rate, the combination of higher migration with greater diversity of origins or distance moved was associated with higher incidence in both age groups. Incidence increased significantly at age 0-4 with the level of employment in a district and at age 5-9 with the proportion of households with access to a car. No significant trends were found with commuting. CONCLUSIONS: The results for level of child migration and diversity of total migration provide evidence of an effect of population mixing on the incidence of childhood leukaemia which is not restricted to areas experiencing the most extreme levels of mixing.     

Unemployment rate as predictor of rate of psychiatric admission.

OBJECTIVE--To examine the relation between rates of psychiatric admissions and both the rate of unemployment and the underprivileged area score within small areas. DESIGN--Calculation of correlation coefficients and explanatory power by using data on psychiatric admissions from April 1990 to March 1992. Crude and age standardised rates were used based on all admissions and also on the number of people admitted regardless of the number of times each person was admitted. SETTING--Sectors with an average population of 45,000 consisting of aggregations of neighbouring wards in Bristol and District Health Authority and electoral wards with an average population of 9400 in the city of Bristol. RESULTS--Unemployment rates explained 93% of the variation in the crude person based admission rates standardised for age for those aged under 65 in the sectors. Person based rates correlated more strongly with unemployment than did rates based on all separate admissions. Inclusion of people aged 65 and over weakened the relation. Within electoral wards unemployment rates explained only about 50-60% of the variation but were still more powerful than the underprivileged area score. There was a significant negative correlation between average length of stay and readmission rates--that is, sectors with short lengths of stay were more likely to have patients readmitted (r = -0.64, 95% confidence interval -0.25 to -0.85). CONCLUSIONS--Unemployment rates are an extremely powerful indicator of the rates of serious mental illness that will need treatment in hospital in those aged under 65. This should be considered in the process of resource allocation, particularly to fundholders in general practice, or people with serious mental illness living in areas of high unemployment could be considerably disadvantaged.     

Predicting psychiatric admission rates.

OBJECTIVE--To determine the numbers of actual and expected psychiatric admissions for the residents of the district health authorities of England and to develop a model to indicate which social, health status, and service provision factors best explain the variation of the actual from the expected psychiatric admissions; to use this model to predict psychiatric admission for district health authorities as an aid to resource allocation. DESIGN--The actual psychiatric admission for district health authority residents were extracted from data of the 1986 Mental Health Enquiry. Expected admissions were calculated using the age, sex, and marital status structure of each district health authority and the national psychiatric admission rates related to age, sex, and marital status. Standardised psychiatric admission ratios were calculated as the ratios of the numbers of actual to expected psychiatric admissions. A wide range of social, health status, and service provision data were used as the explanatory variables in regression analyses to determine which combination of factors best explained the variation between districts of standardised psychiatric admission ratios. SETTING--The 168,652 psychiatric admissions recorded for the 1986 Mental Health Enquiry, after exclusion of mental handicap and psychogeriatric admissions. RESULTS--The actual number of psychiatric admissions varied from 79% above to 54% below the expected number of admissions from age, sex, and marital status for the districts of England. The most powerful variables to explain this variation were the rate of notification of drug misusers, standardised mortality ratios, and levels of illegitimacy in each district. A complex model was developed which could be used to predict district psychiatric admissions as an aid to resource allocation. A simpler model was also developed (which was less powerful than the more complex model) based on the underprivileged area score. One advantage of this model was that it could be used at the level of electoral wards as well as district health authorities.     

Comparison of community based service with hospital based service for people with acute,severe psychiatric illness.

OBJECTIVE--To compare the burden on relatives and outcome of people treated for severe acute psychiatric illness by a community service and a traditional hospital based service. DESIGN--Follow up of patients aged 16-65 who required admission to hospital or home treatment for psychiatric illness during January 1990 to February 1991. SETTING--Two Birmingham electoral wards, Sparkbrook and Small Heath; Sparkbrook has a community based service and Small Heath a traditional hospital based service. SUBJECTS--69 patients from Sparkbrook and 55 from Small Health. MAIN OUTCOME MEASURES--Scores on present state examination, social behaviour assessment schedule, and general health questionnaire. RESULTS--24 (35%) of Sparkbrook patients received some treatment in hospital during the initial episodes. Relatives of Sparkbrook patients were less distressed by their burden at the initial assessment than relatives of Small Health patients (mean score 0.11 v 0.29, p < 0.01). Relatives were also more satisfied with the support they received and the treatment received by patients. More patients from Sparkbrook than Small Health were in contact with a psychiatrist (81% (95% confidence interval 71% to 91%) v 62% (44% to 68%)) and community nurse (56% (44% to 68%) v 14% (13% to 24%)) one year after the initial episode. Sparkbrook patients spent significantly fewer days in hospital during the initial episode (8 days v 59 days) and the first year (20.6 v 67.9 days). CONCLUSION--The community based service is as effective as the hospital based service and is preferred by relatives. It is more effective in keeping people in long term contact with psychiatrists.     

Incidence of leukaemia in young people in the vicinity of Hinkley Point nuclear power station, 1959-86.

The incidence of leukaemia and non-Hodgkin''s lymphoma in young people (aged under 25) living in a predefined area around the nuclear power station at Hinkley Point, Somerset, was examined for the period 1959-86 by using cancer registry data. During the period since Hinley Point began operations--that is, 1964-86--there were 19 cases in the area compared with 10.4 expected from national rates, giving a standardised registration ratio of 1.82 (95% confidence interval 1.10 to 2.85). The incidence in the rest of Somerset was also high, however (standardised registration ratio 1.18; 95% confidence interval 0.98 to 1.41), and the high rate around Hinkley Point may simply have been reflecting the high local incidence (ratio of the two standardised registration ratio''s 1.54; 95% confidence interval 0.90 to 2.52). Analysis of predetermined five year periods showed that the excess cases in the Hinkley Point area were concentrated in the 10 years 1964-73 after commissioning of the station, at a time when rates in the rest of Somerset were close to the national average. In particular the nine cases occurring in the five years 1969-73 were about four times the number expected from national rates (standardised registration ratio 3.96; 95% confidence interval 1.81 to 7.52). Rates in the Hinkley Point area after 1973 were fairly low, especially as compared with the rest of Somerset. In the five years 1959-63 (that is, before Hinkley Point was commissioned) rates throughout Somerset (including the Hinkley Point area) were higher than the national rate. These findings should be interpreted with caution, and further studies are required to test the plausibility of theories relating to radiation and viruses.