The Associations Between Seven Different Types of Physical Activity and the Incidence of Fracture at Seven Sites in Healthy Postmenopausal UK Women

There is a paucity of information on associations between specific types of physical activity and fracture risk at different sites in otherwise healthy postmenopausal women. Therefore, we examined risk of fracture at seven different sites associated with seven different types of physical activity in the population-based prospective UK Million Women Study. A total of 371,279 postmenopausal women (mean age 59.8 years), rating their health as good or excellent and reporting participation in walking, cycling, gardening, doing housework, yoga, dance, and sports club activities, were followed for site-specific incident fracture through record linkage to national databases on day-case and overnight hospital admissions. Cox regression yielded adjusted relative risks (RRs) and, because of the large number of statistical tests done, 99% confidence intervals (CIs) for fracture at seven different sites in relation to seven different physical activities. During an average follow-up of 12 years, numbers with a first site-specific fracture were as follows: humerus (2341), forearm (1238), wrist (7358), hip (4354), femur (not neck) (617), lower leg (1184), and ankle (3629). For upper limb fractures there was significant heterogeneity across the seven activity types (test for heterogeneity p = 0.004), with gardening more than 1 hour/week associated with a lower risk (RR = 0.91; 99% CI, 0.86 to 0.96; p < 0.0001), whereas cycling more than 1 hour/week was associated with an increased risk (RR = 1.11; 99% CI, 1.00 to 1.23; p = 0.008). For fractures of the lower limb (including hip) there was no significant heterogeneity by type of activity, with significant approximately 5% to 15% reductions in risk associated with most activities, except cycling. For hip fractures, there was no significant heterogeneity by type of activity, but with significant 15% to 20% reductions in risk associated with walking for 1 hour/day and participating in yoga and sporting activities. Physical activity is a modifiable risk factor for fracture, but the effects differ between different types of activities and different fracture sites. © 2019 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

Use of oral bisphosphonates and risk of hospital admission with osteonecrosis of the jaw: Large prospective cohort study in UK women

About 1 in 10 postmenopausal UK women are currently prescribed oral bisphosphonates, but there are concerns about their adverse effects. Osteonecrosis of the jaw is a recognised uncommon but important side effect of intravenous bisphosphonates, but epidemiological evidence on risk of osteonecrosis of the jaw associated with oral bisphosphonate use is less conclusive. The incidence of hospital admission with osteonecrosis of the jaw was examined among 521,695 Million Women Study participants, aged 64.7 years at baseline. Cox proportional hazards regression was used to estimate adjusted relative risks (RRs) and 95% confidence intervals (CIs) associated with use of oral bisphosphonates in postmenopausal women followed-up by record-linkage to National Health Service hospital admission databases. During mean follow-up of 8.2 years per woman, 100 women were admitted to hospital with first recorded osteonecrosis of the jaw, at mean age 72.4 years. Almost a third (29/100) of the cases had ever-used oral bisphosphonates. Ever-users had a six-fold increased risk of hospital admission for osteonecrosis of the jaw, when compared with never-users (adjusted RR = 6.09, 95% CI 3.83-9.66; p < 0.0001). The relative risk for osteonecrosis of the jaw in never-users of oral bisphosphonates was increased in women with prior cancer (RR = 3.40, 2.22-5.22, p < 0.0001). The estimated absolute risk of hospital admission for osteonecrosis of the jaw over a 5-year period from age 70 to 74 in women without prior cancer was 0.09 per 1000 in never-users and 0.69 per 1000 in ever-users of oral bisphosphonates. In this UK population of postmenopausal women, use of oral bisphosphonates was associated with a 6-fold increased risk of hospital admission with osteonecrosis of the jaw, accounting for around one-third of cases, with an excess risk of about 0.6/1000 users over 5 years.

Gender identity disorders and multiple sclerosis risk: A national record-linkage study

Background:

An altered balance of gonadal hormones in males with gender identity disorders (GIDs) may increase multiple sclerosis (MS) risk both inherently and secondary to treatment in undergoing male-to-female conversion.

Objective:

We investigated any association between GIDs and MS through analysis of record-linked hospital statistics.

Method:

Analysis of English Hospital Episode Statistics, 1999–2012.

Results:

The adjusted rate ratio (RR) of MS following GIDs in males was 6.63 (95% confidence interval (95% CI) = 1.81–17.01, p = 0.0002). The RR of MS following GIDs in females was 1.44 (95% CI = 0.47–3.37, p = 0.58).

Conclusion:

We report a strong association between GIDs and MS in male-to-females, supporting a potential role for low testosterone and/or feminising hormones on MS risk in males.

Coexistence of eating disorders and autoimmune diseases: Record linkage cohort study, UK

OBJECTIVE

Recent research indicates that eating disorders (ED) are associated with type 1 diabetes and Crohn's disease. The aim of this study was to determine whether, in a hospitalized population, a range of autoimmune diseases (AIDs) occurred more often than expected in people with anorexia nervosa (AN) or bulimia nervosa (BN), and whether AIDs elevated the risk of ED.

METHOD

Retrospective, record-linkage cohort study using national administrative statistical data on hospital care and mortality in England, 1999-2011. In people admitted when aged 10-44, cohorts of 8,700 females and 651 males with AN, and 4,783 females and 330 males with BN were constructed, along with a control cohort with the same age range. Results were expressed as risk ratios comparing each ED cohort with the control cohort.

RESULTS

The overall rate ratio for an AID after admission for AN was 2.04 (95% confidence interval 1.81-2.28) in females, and 1.14 (0.37-2.67) in males; and, for BN, 1.83 (1.56-2.14) in females, and 4.41 (2.11-8.10) in males. Rate ratios for AN after admission for an AID were 3.34 (2.94-3.79) in females, 3.76 (2.06-6.53) in males; and those for BN were 2.57 (2.22-2.97) in females, and 3.10 (1.50-5.90) in males. There were significant associations between ED and several specific individual AIDs.

DISCUSSION

Strong associations between ED and specific AIDs exist, although it is not possible from this study to determine if these are causal. Clinicians should be aware of the co-occurrence of these conditions. © 2016 Wiley Periodicals, Inc.(Int J Eat Disord 2016; 49:663-672).

Conversion from depression to bipolar disorder in a cohort of young people in England, 1999-2011: A national record linkage study

OBJECTIVE

To estimate the conversion rate from unipolar depression (ICD10 codes F32-F33) to bipolar disorder (BP) (ICD10 codes F31) in an English national cohort. It was hypothesised that early-onset BP (age <18 years) is a more severe form of the disorder, with a more rapid, and higher rate of conversion from depression to BP.

METHOD

This record linkage study used English national Hospital Episode Statistics (HES) covering all NHS inpatient and day case admissions between 1999 and 2011.

RESULTS

The overall rate of conversion from depression to BP for all ages was 5.65% (95% CI: 5.48-5.83) over a minimum 4-year follow-up period. The conversion rate from depression to BP increased in a linear manner with age from 10-14 years - 2.21% (95% C: 1.16-4.22) to 30-34 years - 7.06% (95% CI: 6.44-7.55) (F1,23=77.6, p=0.001, R(2)=0.77). The time to conversion was constant across the age range. The rate of conversion was higher in females (6.77%; 95% CI: 6.53-7.02) compared to males, (4.17%; 95% CI: 3.95-4.40) (χ(2)=194, p<0.0001), and in those with psychotic depression 8.12% (95% CI: 7.65-8.62) compared to non-psychotic depression 5.65% (95% CI: 5.48-5.83) (χ(2)=97.0, p<0.0001).

LIMITATIONS

The study was limited to hospital discharges and diagnoses were not standardised.

CONCLUSIONS

Increasing conversion rate from depression to bipolar disorder with age, and constant time for conversion across the age range does not support the notion that early-onset BP is a more severe form of the disorder.

Risk of dementia in patients hospitalised with type 1 and type 2 diabetes in England, 1998-2011: a retrospective national record linkage cohort study

AIMS/HYPOTHESIS

Type 2 diabetes increases the risk of subsequent dementia. Our objective was to determine whether a similar risk of subsequent dementia is associated with type 1 diabetes in a large defined population.

METHODS

This retrospective cohort study examined national administrative record-linked statistical data on hospital care and mortality in England, 1998-2011. Cohorts of people admitted to hospital when aged 30 or over were constructed: 343,062 people with type 1 diabetes; 1,855,141 people with type 2 diabetes; and a reference cohort. Results were expressed as rate ratios (RR) comparing each diabetes cohort with the control cohort.

RESULTS

The overall RR for dementia in people admitted to hospital with type 1 diabetes was 1.65 (95% CI 1.61, 1.68), and for people admitted to hospital with type 2 diabetes was 1.37 (1.35, 1.38). Young age at admission for diabetes appeared to confer a greater rate of subsequent dementia; the RR for dementia in people admitted to hospital with type 1 diabetes aged 30-39 years was 7.10 (4.65, 10.6), which reduced to 4.40 (3.55, 5.40) in those aged 40-49 at admission, and further reduced with increasing age to 1.16 (1.11, 1.20) in those aged 80 or over at admission. A similar pattern was seen with type 2 diabetes.

CONCLUSIONS/INTERPRETATION

Type 1 diabetes, as well as type 2 diabetes, may be associated with an elevated risk of subsequent dementia. The risk of dementia varies with age at admission to hospital with diabetes, and appears to be much greater in the young.

Record-linkage studies of the coexistence of epilepsy and bipolar disorder

PURPOSE

Interest is growing in a possible link between epilepsy and bipolar disorder (BPD). We used two large datasets of hospital admission data to determine whether epilepsy and BPD occur together in the same individuals more commonly than expected.

METHODS

We undertook retrospective cohort studies using the Oxford Record Linkage Study (ORLS) and English national linked Hospital Episode Statistics. We constructed a cohort of people in each dataset admitted with epilepsy (without prior admission for BPD), and a control cohort (without prior admission for BPD), and compared their subsequent admission rates for BPD. Conversely, we constructed a cohort of people in each dataset admitted with BPD and a control cohort (both without prior admission for epilepsy), and compared their subsequent admission rates for epilepsy.

RESULTS

In the epilepsy cohort, compared with the control cohort, the rate ratio (RR) for BPD was significantly high at 3.0 (95 % confidence interval 1.7-5.1) in the ORLS and 3.6 (3.3-3.9) in the all-England dataset. In the BPD cohort, the RR for epilepsy was 2.2 (1.2-3.7) in the ORLS and 4.2 (4.0-4.4) in the all-England cohort. We found no significant differences between RRs for males and females.

CONCLUSIONS

Epilepsy and BPD occur together in individuals more frequently than expected by chance.

Risk of invasive pneumococcal disease in people admitted to hospital with selected immune-mediated diseases: record linkage cohort analyses

BACKGROUND

Invasive pneumococcal disease is a serious infection, and it is an important cause of morbidity and mortality in certain groups of 'at-risk' people. Those considered 'at-risk' in the UK include very young children, people aged 65 years and older and people with certain serious chronic diseases, asplenia or immunosuppression. There is little evidence about whether people with immune-mediated diseases are at increased risk of pneumococcal disease and therefore may benefit from pneumococcal vaccination.

METHODS

Retrospective cohort studies, using linked hospital data, from the longstanding Oxford Record Linkage Study (1963-2008) and from recent English national linked Hospital Episode Statistics (1999-2008); analysis of whether people with immune-mediated diseases are more likely than others to be admitted to hospital for pneumococcal disease; calculation of rate ratio for pneumococcal disease in cohorts with immune-mediated disease compared with control cohorts.

RESULTS

There were elevated rate ratios for many of the immune-mediated diseases, for example, Addison's disease in England 3.8 (95% CI 3.4 to 4.2), autoimmune haemolytic anaemia 4.9 (4.4 to 5.3), Crohn's disease 2.2 (2.1 to 2.3), diabetes mellitus 3.7 (3.4 to 4.1), multiple sclerosis 3.7 (3.5 to 3.8), myxoedema 1.60 (1.58 to 1.63), pernicious anaemia 1.74 (1.66 to 1.83), primary biliary cirrhosis 3.3 (2.9 to 3.7), polyarteritis nodosa 5.0 (4.0 to 6.0), rheumatoid arthritis 2.47 (2.41 to 2.52), scleroderma 4.2 (3.8 to 4.7), Sjogren's syndrome 3.2 (2.9 to 3.5) and systemic lupus erythematosus 5.0 (4.6 to 5.4). Findings in the Oxford and all England data sets were similar.

CONCLUSIONS

People admitted to hospital with immune-mediated diseases are at higher risk than those with invasive pneumococcal disease. Vaccination should be considered in this group of patients.

Coexistence of schizophrenia and epilepsy: record-linkage studies

For many years, there has been interest in a possible link between epilepsy and schizophrenia. A recent study found a strong, bidirectional link between the two conditions: people with one had a higher than average risk of having the other. Using two large data sets of hospital admission data, we investigated whether schizophrenia and epilepsy occur together in individuals more commonly than expected by chance. We undertook a retrospective cohort study using the Oxford Record Linkage Study (ORLS) and English national linked Hospital Episode Statistics to investigate the coexistence of these conditions. There was an elevated risk of epilepsy in people admitted to hospital with schizophrenia (ORLS rate ratio 2.1, 95% confidence interval 1.6-2.6; England 3.0, 2.9-3.1) and an elevated risk of schizophrenia in people admitted to hospital with epilepsy (ORLS 5.1, 4.1-6.2; England 4.5, 4.3-4.6). We found no consistent difference between male and female patients. Schizophrenia and epilepsy occur together in individuals more frequently than expected by chance.

Epilepsy and the subsequent risk of cerebral tumour: record linkage retrospective cohort study

BACKGROUND

Studies suggest that seizures may precede the detection of cerebral tumour by several years. Aim To quantify the risk of cerebral tumour after new onset seizures, with particular interest in long term risk.

METHODS

Using the Oxford Record Linkage Study (ORLS, 1963-1998) and English national linked Hospital Episode Statistics (1999-2005), cohorts of people with a first admission for epilepsy were constructed. Subsequent admissions with cerebral tumour were identified. The rate of occurrence of subsequent cerebral tumour in each epilepsy cohort was compared with that in a comparison cohort and expressed as a rate ratio (RR).

RESULTS

The RR for cerebral tumour after epilepsy, relative to the rate of cerebral tumour in the comparison cohort, was 19.9 (95% CI 17.2 to 22.9) in the ORLS cohort and 19.7 (18.3-21.1) in the England cohort. The RR for malignant tumours were, respectively, 25.6 (21.7 to 30.0) and 27.3 (25.2 to 29.6). The RR for benign tumours were 10.1 (7.38 to 13.6) and 10.4 (9.07 to 11.8), respectively. The risk was highest for those aged 15-44 years at initial admission for epilepsy both in Oxford (24.2, 18.5 to 31.5) and England (38.1, 32.8 to 44.2). The risk of cerebral tumour was still raised several years after initial admission for epilepsy: in the ORLS cohort at 15&emsp14;years or more, the RR was 3.29 (1.39 to 6.66) and, in the England cohort 5-7 years after initial admission, the RR was 5.27 (3.87 to 7.06).

CONCLUSIONS

Seizures may herald the development of cerebral tumour, remote in time as well as soon after onset, with implications for guidelines on continued surveillance of those with new onset seizures.

Trends over time and geographical variation in rates of intravitreal injections in England

AIMS

The recent emergence of antivascular endothelial growth factor (anti-VEGF) drugs has led to increased numbers of patients undergoing intravitreal injection for age-related macular degeneration (AMD). The aims of this study were to report on trends over time and geographical variation in intravitreal injection rates in England, and consider the implications for publicly funded health services of introducing new and expensive treatments.

METHODS

Hospital episode statistics were analysed for annual treatment rates of intravitreal injection between the NHS financial years of 1989/1990 and 2008/1999.

RESULTS

Annual injection rates increased from 0.4 episodes (95% CI 0.37 to 0.49) per 100,000 population in 1989/1990 to 10.7 (10.4-11.0) in 2006/2007. Rates then rose exponentially to 59.5 (58.8-60.2) in 2008/2009, with increasing use of multiple injections per person. The largest growth in injection rates was found in older people, and for AMD. Numbers of treatment episodes increased from 203 (1989/1990) to 30,458 (2008/2009). Geographical analysis showed a very wide variation across local authority areas in injection rates, from 0.9 (0.2-2.2) to 42.2 (38.9-45.7) people per 100,000 population in 2005-2008.

CONCLUSION

Rates of intravitreal injection increased exponentially from 2006/2007. This followed the US Food and Drug Association licensing of ranibizumab for the treatment of neovascular AMD (2006), and its recommendation by National Institute for Health and Clinical Excellence (2008). This study demonstrates some of the major issues which arise with the emergence of expensive new treatments, including speed and cost of adoption, geographical variation in access, and implications for licensing, commissioning and health financing in an ageing society.

Cancer in patients admitted to hospital with diabetes mellitus aged 30 years and over: record linkage studies

AIMS/HYPOTHESIS

The aim of this study was to determine the risk of cancer in people admitted to hospital for diabetes mellitus when aged 30 or older.

METHODS

This study involved the analysis of two statistical datasets of linked hospital and mortality data, in an area in southern England, between 1963 and 1998 (the Oxford Record Linkage Study, ORLS1) and between 1999 and 2008 (ORLS2). Rates of cancer in the diabetes cohorts were compared with rates of cancer in reference cohorts and expressed as rate ratios.

RESULTS

The rate ratio for all cancer in people admitted to hospital with diabetes was 1.01 (95% CI 0.95-1.06, based on 15,898 people with diabetes) for the years 1963-1998; and 1.09 (1.00-1.19, based on 7,771 people with diabetes) in the years 1999-2008. In both datasets, there were significantly high rate ratios for cancers of the liver (ORLS1 and ORLS2, respectively, 2.0 [95% CI 1.4-2.9]; 2.5 [95% CI 1.3-4.3]), pancreas (2.2 [95% CI 1.8-2.7]; 3.5 [95% CI 2.5-4.8]) and uterus (1.5 [95% CI 1.0-2.2]; 2.6 [95% CI 1.4-4.5]). There were significantly low rate ratios for cancer of the prostate (0.6 [95% CI 0.5-0.7]; 0.7 [95% CI 0.5-0.9]) and non-melanoma skin cancer (0.6 [95% CI 0.5-0.8]; 0.8 [95% CI 0.6-0.96]).

CONCLUSIONS/INTERPRETATION

Diabetes mellitus was associated with an elevated risk of some site-specific cancers and a reduction of risk of others. Considering the risk in diabetes of all cancers combined, the elevation of risk, if any, is likely to be small and numerically less important than other known complications of diabetes.

Maternal and perinatal factors associated with hospitalised infectious mononucleosis in children, adolescents and young adults: record linkage study

BACKGROUND

There is current interest in the role of perinatal factors in the aetiology of diseases that occur later in life. Infectious mononucleosis (IM) can follow late primary infection with Epstein-Barr virus (EBV), and has been shown to increase the risk of multiple sclerosis and Hodgkin's disease. Little is known about maternal or perinatal factors associated with IM or its sequelae.

METHODS

We investigated perinatal risk factors for hospitalised IM using a prospective record-linkage study in a population in the south of England. The dataset used, the Oxford record linkage study (ORLS), includes abstracts of birth registrations, maternities and in-patient hospital records, including day case care, for all subjects in a defined geographical area. From these sources, we identified cases of hospitalised IM up to the age of 30 years in people for whom the ORLS had a maternity record; and we compared perinatal factors in their pregnancy with those in the pregnancy of children who had no hospital record of IM.

RESULTS

Our data showed a significant association between hospitalised IM and lower social class (p = 0.02), a higher risk of hospitalised IM in children of married rather than single mothers (p < 0.001), and, of marginal statistical significance, an association with singleton birth (p = 0.06). The ratio of observed to expected cases of hospitalised IM in each season was 0.95 in winter, 1.02 in spring, 1.02 in summer and 1.00 in autumn. The chi-square test for seasonality, with a value of 0.8, was not significant.Other factors studied, including low birth weight, short gestational age, maternal smoking, late age at motherhood, did not increase the risk of subsequent hospitalised IM.

CONCLUSIONS

Because of the increasing tendency of women to postpone childbearing, it is useful to know that older age at motherhood is not associated with an increased risk of hospitalised IM in their children. We have no explanation for the finding that children of married women had a higher risk of IM than those of single mothers. Though highly significant, it may nonetheless be a chance finding. We found no evidence that such perinatal factors as birth weight and gestational age, or season of birth, were associated with the risk of hospitalised IM.

Perinatal and early life risk factors for inflammatory bowel disease

AIM: To investigate associations between perinatal risk factors and subsequent inflammatory bowel disease (IBD) in children and young adults.

METHODS: Record linked abstracts of birth registrations, maternity, day case and inpatient admissions in a defined population of southern England. Investigation of 20 perinatal factors relating to the maternity or the birth: maternal age, Crohn’s disease (CD) or ulcerative colitis (UC) in the mother, maternal social class, marital status, smoking in pregnancy, ABO blood group and rhesus status, pre-eclampsia, parity, the infant’s presentation at birth, caesarean delivery, forceps delivery, sex, number of babies delivered, gestational age, birthweight, head circumference, breastfeeding and Apgar scores at one and five minutes.

RESULTS: Maternity records were present for 180 children who subsequently developed IBD. Univariate analysis showed increased risks of CD among children of mothers with CD (P = 0.011, based on two cases of CD in both mother and child) and children of mothers who smoked during pregnancy. Multivariate analysis confirmed increased risks of CD among children of mothers who smoked (odds ratio = 2.04, 95% CI = 1.06-3.92) and for older mothers aged 35+ years (4.81, 2.32-9.98). Multivariate analysis showed that there were no significant associations between CD and 17 other perinatal risk factors investigated. It also showed that, for UC, there were no significant associations with the perinatal factors studied.

CONCLUSION: This study shows an association between CD in mother and child; and elevated risks of CD in children of older mothers and of mothers who smoked.

Risk of venous thromboembolism in people admitted to hospital with selected immune-mediated diseases: record-linkage study

BACKGROUND

Venous thromboembolism (VTE) is a common complication during and after a hospital admission. Although it is mainly considered a complication of surgery, it often occurs in people who have not undergone surgery, with recent evidence suggesting that immune-mediated diseases may play a role in VTE risk. We, therefore, decided to study the risk of deep vein thrombosis (DVT) and pulmonary embolism (PE) in people admitted to hospital with a range of immune-mediated diseases.

METHODS

We analysed databases of linked statistical records of hospital admissions and death certificates for the Oxford Record Linkage Study area (ORLS1:1968 to 1998 and ORLS2:1999 to 2008) and the whole of England (1999 to 2008). Rate ratios for VTE were determined, comparing immune-mediated disease cohorts with comparison cohorts.

RESULTS

Significantly elevated risks of VTE were found, in all three populations studied, in people with a hospital record of admission for autoimmune haemolytic anaemia, chronic active hepatitis, dermatomyositis/polymyositis, type 1 diabetes mellitus, multiple sclerosis, myasthenia gravis, myxoedema, pemphigus/pemphigoid, polyarteritis nodosa, psoriasis, rheumatoid arthritis, Sjogren's syndrome, and systemic lupus erythematosus. Rate ratios were considerably higher for some of these diseases than others: for example, for systemic lupus erythematosus the rate ratios were 3.61 (2.36 to 5.31) in the ORLS1 population, 4.60 (3.19 to 6.43) in ORLS2 and 3.71 (3.43 to 4.02) in the England dataset.

CONCLUSIONS

People admitted to hospital with immune-mediated diseases may be at an increased risk of subsequent VTE. Our findings need independent confirmation or refutation; but, if confirmed, there may be a role for thromboprophylaxis in some patients with these diseases.

Increased risk of tuberculosis disease in people with diabetes mellitus: record-linkage study in a UK population

BACKGROUND

The authors aimed to determine whether, and by how much, diabetes mellitus (DM) increases the risk of tuberculosis (TB) and conversely whether TB increases the risk of DM.

METHODS

Retrospective cohort analyses using data from two Oxford Record Linkage Study (ORLS) datasets, containing information on hospital admissions and day-case care between 1963 and 1998 (ORLS1) and between 1999 and 2005 (ORLS2), were carried out. The rate ratio (RR) for tuberculosis after admission to hospital with diabetes and for diabetes after hospital admission with tuberculosis was calculated.

RESULTS

In ORLS1, the RR for TB in people admitted to hospital with DM, comparing the latter with a reference cohort, was 1.83 (95% CI 1.26 to 2.60), and in ORLS2 the RR was 3.11 (1.17 to 7.03). RRs for pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB) within ORLS1 were similar at, respectively, 1.80 (1.16 to 2.67) and 1.98 (0.88 to 3.92). In ORLS 2 the RR for PTB was 2.63 (0.91 to 6.30). In ORLS1, there was no indication that TB was a risk factor for DM (RR 1.12, 0.76 to 1.60). The ORLS2 dataset was too small to analyse whether TB led to DM.

DISCUSSION

DM was associated with a two- to threefold increased risk of TB within this predominantly white, English population. The authors found no evidence that TB increases the risk of DM. Our findings suggest that the risks of PTB and EPTB were both raised among individuals with DM. As DM prevalence rises, this association will become increasingly important for TB control and treatment.

Influence of maternal and perinatal factors on subsequent hospitalisation for asthma in children: evidence from the Oxford record linkage study

Background

There is much interest in the possibility that perinatal factors may influence the risk of disease in later life. We investigated the influence of maternal and perinatal factors on subsequent hospital admission for asthma in children.

Methods

Analysis of data from the Oxford record linkage study (ORLS) to generate a retrospective cohort of 248 612 records of births between 1970 and 1989, with follow-up to records of subsequent hospital admission for 4 017 children with asthma up to 1999.

Results

Univariate analysis showed significant associations between an increased risk of admission for asthma and later years of birth (reflecting the increase in asthma in the 1970s and 1980s), low social class, asthma in the mother, unmarried mothers, maternal smoking in pregnancy, subsequent births compared with first-born, male sex, low birth weight, short gestational age, caesarean delivery, forceps delivery and not being breastfed. Multivariate analysis, identifying each risk factor that had a significant effect independently of other risk factors, confirmed associations with maternal asthma (odds ratio (OR) 3.1, 95% confidence interval 2.7-3.6), male sex (versus female, 1.8, 1.7-2.0), low birth weight (1000-2999 g versus 3000-3999 g, 1.2, 1.1-1.3), maternal smoking (1.1, 1.0-1.3) and delivery by caesarean section (1.2; 1.0-1.3). In those first admitted with asthma under two years old, there were associations with having siblings (e.g. second child compared with first-born, OR 1.3, 1.0-1.7) and short gestational age (24-37 weeks versus 38-41 weeks, 1.6, 1.2-2.2). Multivariate analysis confined to those admitted with asthma aged six years or more, showed associations with maternal asthma (OR 3.8, 3.1-4.7), age of mother (under 25 versus 25-34 at birth, OR 1.16, 1.03-1.31; over 35 versus 25-34, OR 1.4, 1.1-1.7); high social class was protective (1 and 2, compared with 3, 0.72; 0.63-0.82). Hospital admission for asthma in people aged over six was more common in males than females (1.4; 1.2-1.5); but, by the teenage years, the sex ratio reversed and admission was more common in females than males.

Conclusion

Several maternal characteristics and perinatal factors are associated with an elevated risk of hospital admission for asthma in the child in later life.

Cancer in patients with motor neuron disease, multiple sclerosis and Parkinson's disease: record linkage studies

OBJECTIVE

To determine the risk of cancer before and after the diagnosis of motor neuron disease (MND), multiple sclerosis (MS) and Parkinson's disease (PD).

METHODS

Analysis of statistical database of linked statistical abstracts of hospital and mortality data in an area in southern England.

RESULTS

Only people with PD showed a significant difference in the overall incidence of cancer compared with controls (rate ratio (RR) 0.76, 95% CIs 0.70 to 0.82 before PD; RR 0.61, 0.53 to 0.70, after PD). RRs were close to 1 for cancer in patients after MND (0.98, 0.75 to 1.26) and after MS (0.96, 0.83 to 1.09). There were high rate ratios for malignant brain cancer (7.4, 2.4 to 17.5) and Hodgkin's lymphoma (5.3, 1.1 to 15.6) in patients diagnosed with MND after cancer. In people with MS, malignant brain cancer also showed an increased RR both before hospital admission with a diagnosis of MS (3.2, 1.1 to 7.6) and after (2.4, 1.2 to 4.5). In people with PD, several specific cancers showed significantly and substantially reduced RRs for cancer, notably smoking related cancers, including lung cancer (0.5, 0.4 to 0.7, before PD; 0.5, 0.4 to 0.8, after PD) but also cancers that are not strongly smoking related, including colon cancer (0.7, 0.6 to 0.9, before PD; 0.5, 0.4 to 0.8, after PD).

CONCLUSIONS

People with MND, or MS, do not have an altered risk of cancer overall. There may sometimes be misdiagnosis between MND or MS and brain tumours. PD carries a reduced risk of cancer overall, of some smoking related cancers and of some cancers that are not smoking related.

Immune-mediated and chronic inflammatory disease in people with sarcoidosis: disease associations in a large UK database

BACKGROUND

Sarcoidosis is a multi-system disorder characterised by non-caseating granulomas. Coexistence of sarcoidosis with immune-mediated and chronic inflammatory diseases has been described in case series. However, the coexistence of two different diseases in individuals can occur by chance, even if each of the diseases is rare.

AIM

To determine whether sarcoidosis necessitating hospital admission or day-case care coexists with a range of immune-mediated and chronic inflammatory diseases more commonly than expected by chance.

DESIGN

Analysis of an epidemiological database of hospital admission and day-case statistics, spanning 30 years.

RESULTS

1510 patients with sarcoidosis were identified (mean age 44 years, median follow-up 19 years) who had been admitted to hospital or day-case care. Significant associations in the sarcoidosis cohort were identified with systemic lupus erythematosus (odds ratio (OR) 8.3; 95% CI 2.7 to 19.4), autoimmune chronic hepatitis (OR 6.7; 95% CI 1.8 to 17.1), multiple sclerosis (OR 3.3; 95% CI 1.7 to 5.6), coeliac disease (OR 3.1; 95% CI 1.01 to 7.3), thyrotoxicosis (OR 2.5; 95% CI 1.4 to 4.0), myxoedema (OR 2.2; 95% CI 1.2 to 3.7) and ulcerative colitis (OR 2.1; 95% CI 1.1 to 3.7). Weaker associations were found for diabetes mellitus with a first admission aged 30-49 years (OR 2.9; 95% CI 2.1 to 4.0) or age >50 (OR 1.7; 95% CI 1.2 to 2.3), but not for people age <30. No significant association with Crohn's disease (OR 1.52; 95% CI 0.61 to 3.14) or primary biliary cirrhosis (OR 3.75; 95% CI 0.77 to 11.0),was found. When all immune-mediated and chronic inflammatory diseases for which associations were sought were combined, the overall rate ratio associated with sarcoidosis was 2.2 (95% CI 1.9 to 2.6).

CONCLUSION

This study adds epidemiological evidence to information from clinical reports that there is a connection between sarcoidosis and other immune-mediated and chronic inflammatory diseases.

Cancer in people with depression or anxiety: record-linkage study

BACKGROUND

It has been suggested that the risk of cancer may be higher in people with psychological disorders, like depression and anxiety, than in the general population.

AIMS

To determine cancer risk in cohorts of people with depression or anxiety, compared with that in a control cohort.

METHOD

Analysis of linked statistical records of hospital admission and mortality.

RESULTS

Lung cancer was more common in those with depression (risk ratio 1.36, 95% confidence intervals 1.19-1.54) or anxiety (1.29, 1.12-1.48) than in others. Excluding lung cancer, the risk ratio for all other cancers combined was 0.98 (0.92-1.04) in the depression cohort and 1.01 (0.95-1.07) in the anxiety cohort. There was a significant association, in the short-term only, between depression, anxiety and the subsequent diagnosis of brain tumours.

CONCLUSIONS

With the exception of lung and brain tumours, cancer risk was not increased in people with depression or anxiety.

Immune-related disease before and after vasectomy: an epidemiological database study

BACKGROUND

Vasectomy can be followed by an autoimmune-antibody response. We aimed to determine whether men with immune-related diseases were more or less likely than others to have a vasectomy and then to determine whether vasectomy is associated with the subsequent development of immune-related diseases.

METHODS

A database of linked records of hospital statistics was analysed. By comparing a population of men who underwent vasectomy with a reference population, we calculated the rate ratios for selected immune-related diseases before and after vasectomy.

RESULTS

Some diseases studied (e.g. asthma and diabetes mellitus) were a little less common, prior to operation, in the vasectomy group than in the reference group. Others were not different. The mean period of follow-up was 13 years. We found no long-term elevation of risk following vasectomy of asthma, diabetes mellitus, ankylosing spondylitis, thyrotoxicosis, multiple sclerosis, myasthenia gravis, inflammatory bowel disease, rheumatoid arthritis or testicular atrophy. There was a short-term elevation of risk of orchitis/epididymitis.

CONCLUSIONS

In this large study, with many years of follow-up, we found no evidence that vasectomy increases the subsequent long-term risk of immune-related diseases.

Cancer and cardiovascular disease after vasectomy: an epidemiological database study

OBJECTIVE

To determine whether vasectomy is associated with an increased long-term risk of cancer or cardiovascular disease.

DESIGN

Analysis of database of linked statistical records of hospital admissions and deaths.

SETTING

Health region in southern England.

PATIENT(S)

Men aged 20-59 years who were admitted to a hospital for vasectomy.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Rates of cancer and cardiovascular disease compared with the corresponding rates in a reference cohort, expressed as a rate ratio.

RESULT(S)

We found no elevation of risk, after vasectomy, of prostate cancer (rate ratio 0.74, 95% confidence interval [CI] 0.45-1.14) or other cancers. The rate ratio for coronary heart disease overall after vasectomy was 0.95 (95% CI 0.88-1.02); and the rate ratio > or =20 years after vasectomy was 0.98 (95% CI 0.80-1.19).

CONCLUSION(S)

Our findings add to the evidence that vasectomy is not associated with an increase in the long-term risk of these diseases.

Schizophrenia and cancer: an epidemiological study

BACKGROUND

For decades there has been interest in the possibility that people with schizophrenia might have some protection against cancer, and that, if this were so, it might hold clues about aetiological mechanisms in schizophrenia.

AIMS

To study cancer incidence in schizophrenia.

METHOD

Cohort analysis of linked hospital and death records was used to compare cancer rates in people with schizophrenia with a reference cohort.

RESULTS

We did not find a reduced risk for cancer overall (rate ratio 0.99,95% CI 0.90-1.08) or for most individual cancers. There was, however, a significantly low rate ratio for skin cancer (0.56,95% CI 0.36-0.83).

CONCLUSIONS

We found no evidence that schizophrenia confers protection against cancer in general. Low rates of cancer are consistent with the hypothesis that sun exposure may influence the development of schizophrenia, although other explanations are also possible.

Hospital admission for selected single virus infections prior to diabetes mellitus

AIMS

To determine whether hospital admission for a range of specified virus infections was followed by a raised admission rate for diabetes mellitus; and, if raised, whether the increase is compatible with the hypothesis that virus infection is a cause of diabetes.

METHODS

Analysis of a database of hospital statistics including admissions for people with diabetes mellitus before the age of 30 years.

RESULTS

There was no evidence of excess risk of diabetes after measles, mumps, rubella, infectious mononucleosis, influenza, infectious hepatitis, varicella and herpes zoster, herpes simplex, aseptic meningitis or bronchiolitis. For example, of 1433 patients admitted for measles, 6 were later admitted with diabetes (risk ratio 1.32; 95% confidence interval 0.5-2.9); of 866 patients admitted for mumps, 2 were later admitted for diabetes (risk ratio 0.74; 0.1-2.7). Numbers of people with diabetes subsequent to infection were too few, however, to rule out the possibility of small effects.

CONCLUSIONS

Our findings do not support the hypothesis that any of these virus infections initiate the processes that lead to the development of diabetes, or that these infections act as a trigger to precipitate active disease in those whose diabetes is already present but latent.

Cancer following hip and knee arthroplasty: record linkage study

Concerns have been raised that degradation of implants used in hip and knee arthroplasty may lead to an increased risk of some cancers, particularly those of the haematopoietic, lymphatic and urinary systems. We used linked statistical records of hospital admissions and deaths to compare cancer rates in cohorts of people who had undergone hip or knee arthroplasty with a comparison cohort. We did not find an elevated risk for cancer, overall, in either the hip or knee cohort or in both combined (rate ratio for both combined 0.99; 95% confidence intervals 0.95–1.02), or for haematopoietic, lymphatic or urinary system cancers. There was also no elevation in risk of cancer more than 10 years after arthroplasty. Our findings add to the evidence that arthroplasty is safe in respect of cancer risk.

Multiple sclerosis after infectious mononucleosis: record linkage study

OBJECTIVE

To ascertain if infectious mononucleosis is a risk factor for the development of multiple sclerosis (MS); and, if it is, whether its effect is close to or remote in time from the onset of MS.

DESIGN

Analysis of database of linked abstracts of records of hospital admission and death.

SETTING

Health region in central southern England.

MAIN OUTCOME MEASURE

Ratio of rate of MS in a cohort of people admitted to hospital with infectious mononucleosis to the rate in a comparison cohort.

RESULTS

Considering all time intervals from admission with infection to admission with MS, there was a non-significant increase of risk of MS in the infectious mononucleosis cohort (rate ratio 2.17, 95% confidence intervals 0.79 to 4.77). At the interval of 10 years or more, there was a significant increase in risk of MS (rate ratio 4.01, 1.48 to 8.93). The mean time from infectious mononucleosis to first admission with MS was 14 years.

CONCLUSION

This study adds support to the evidence that Epstein-Barr virus, the cause of infectious mononucleosis, is associated with MS. Its role is probably as an initiator of the disease process of MS, or as a contributor to its early development, rather than as an activator of latent, existing disease.

Cancers and immune related diseases associated with Down's syndrome: a record linkage study

OBJECTIVE

To determine the risk of cancers and selected immune related diseases in people with Down's syndrome, relative to risk in other people.

DESIGN

Cohort analysis of a linked dataset of abstracts of hospital and death records; results expressed as the ratios of rates of disease in people with and without Down's syndrome.

SETTING

The former Oxford health region, England, 1963-1999.

SUBJECTS

Cohort of 1453 people with Down's syndrome and cohort of 460,000 people with other conditions for comparison.

MAIN OUTCOMES

As expected, the rate ratio for leukaemia was substantially elevated in people with Down's syndrome: it was 19-fold higher (95% confidence intervals 10.4 to 31.5) than the rate in the comparison cohort. For other cancers combined, excluding leukaemia, the rate ratio was not significantly elevated (1.2; 0.6 to 2.2). The risk of testicular cancer was increased (12.0; 2.5 to 35.6), although this was based on only three cases in the cohort of subjects with Down's syndrome. Significantly elevated risks were found for coeliac disease (4.7; 1.3 to 12.2), acquired hypothyroidism (9.4; 3.4, 20.5), other thyroid disorders, and type 1 diabetes mellitus (2.8; 1.0 to 6.1). A decreased risk was found for asthma (0.4; 0.2 to 0.6).

CONCLUSIONS

Our data add to the body of information on the risks of co-morbidity in people with Down's syndrome. The finding on asthma needs to be confirmed or refuted by other studies.