New stiletto flies in the genus Anabarhynchus Macquart (Diptera: Therevidae) from Kangaroo Island, South Australia

Anabarhynchus Macquart 1848 is a species-rich genus of stiletto flies (Diptera: Therevidae) belonging to the subfamily Therevinae, with over 113 species described from Australia. These flies are diverse and abundant in Australia's eucalypt woodland and mallee habitats. Here we describe, diagnose and illustrate a further three new Anabarhynchus species in the genus as follows: A. aurantilateralis sp. nov. and A. halmaturinus sp. nov., and A. venabrunneis sp. nov., from Kangaroo Island. These new species bring the total number of described Australian species in the genus to 116, with 13 of these known to occur on Kangaroo Island.

Trends in rates of retinal surgery in England from 1968 to 2004: studies of hospital statistics

AIM

To describe trends over time and geographical variation in rates of vitreo-retinal surgery in England from 1968 to 2004.

METHODS

Routinely collected hospital statistics were analysed for England, using the Hospital In-patient Enquiry and Hospital Episode Statistics from 1968 to 2004, and for the Oxford National Health Service Region using the Oxford Record Linkage Study from 1963 to 2004.

RESULTS

Annual admission rates in England for surgery were about 5 episodes per 100 000 population in the 1960s, rising gradually to about 10 per 100 000 in the early 1990s, and then more sharply to 30 by 2004. The Oxford Record Linkage Study shows that multiple admissions per person were rare, which confirms that the observed increase represents a real increase in the number of people treated. Annual rates in England for buckle procedures declined to about 6 episodes per 100 000 population in 2004, whereas vitrectomy surgery rose to about 26 episodes per 100 000 population in 2004.

CONCLUSION

Vitreo-retinal surgery has developed over the last 40 years in England, rapidly so over the past 15 years. Vitrectomy surgery has become much more common in England and buckle surgery has shown a steady decline. We demonstrate statistically significant geographical variation in the current annual rate of surgery between local authorities in England.

Birth of a biome: insights into the assembly and maintenance of the Australian arid zone biota

The integration of phylogenetics, phylogeography and palaeoenvironmental studies is providing major insights into the historical forces that have shaped the Earth's biomes. Yet our present view is biased towards arctic and temperate/tropical forest regions, with very little focus on the extensive arid regions of the planet. The Australian arid zone is one of the largest desert landform systems in the world, with a unique, diverse and relatively well-studied biota. With foci on palaeoenvironmental and molecular data, we here review what is known about the assembly and maintenance of this biome in the context of its physical history, and in comparison with other mesic biomes. Aridification of Australia began in the Mid-Miocene, around 15 million years, but fully arid landforms in central Australia appeared much later, around 1-4 million years. Dated molecular phylogenies of diverse taxa show the deepest divergences of arid-adapted taxa from the Mid-Miocene, consistent with the onset of desiccation. There is evidence of arid-adapted taxa evolving from mesic-adapted ancestors, and also of speciation within the arid zone. There is no evidence for an increase in speciation rate during the Pleistocene, and most arid-zone species lineages date to the Pliocene or earlier. The last 0.8 million years have seen major fluctuations of the arid zone, with large areas covered by mobile sand dunes during glacial maxima. Some large, vagile taxa show patterns of recent expansion and migration throughout the arid zone, in parallel with the ice sheet-imposed range shifts in Northern Hemisphere taxa. Yet other taxa show high lineage diversity and strong phylogeographical structure, indicating persistence in multiple localised refugia over several glacial maxima. Similar to the Northern Hemisphere, Pleistocene range shifts have produced suture zones, creating the opportunity for diversification and speciation through hybridisation, polyploidy and parthenogenesis. This review highlights the opportunities that development of arid conditions provides for rapid and diverse evolutionary radiations, and re-enforces the emerging view that Pleistocene environmental change can have diverse impacts on genetic structure and diversity in different biomes. There is a clear need for more detailed and targeted phylogeographical studies of Australia's arid biota and we suggest a framework and a set of a priori hypotheses by which to proceed.

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.

Amplification of DNA from preserved specimens shows blowflies were preadapted for the rapid evolution of insecticide resistance

Mutations of esterase 3 confer two forms of organophosphate resistance on contemporary Australasian Lucilia cuprina. One form, called diazinon resistance, is slightly more effective against commonly used insecticides and is now more prevalent than the other form, called malathion resistance. We report here that the single amino acid replacement associated with diazinon resistance and two replacements associated with malathion resistance also occur in esterase 3 in the sibling species Lucilia sericata, suggesting convergent evolution around a finite set of resistance options. We also find parallels between the species in the geographic distributions of the polymorphisms: In both cases, the diazinon-resistance change is absent or rare outside Australasia where insecticide pressure is lower, whereas the changes associated with malathion resistance are widespread. Furthermore, PCR analysis of pinned specimens of Australasian L. cuprina collected before the release of organophosphate insecticides reveals no cases of the diazinon-resistance change but several cases of those associated with malathion resistance. Thus, the early outbreak of resistance in this species can be explained by the preexistence of mutant alleles encoding malathion resistance. The pinned specimen analysis also shows much higher genetic diversity at the locus before organophosphate use, suggesting that the subsequent sweep of diazinon resistance in Australasia has compromised the scope for the locus to respond further to the ongoing challenge of the insecticides.

Trends in mortality after hospital admission for liver cirrhosis in an English population from 1968 to 1999

BACKGROUND

Population based mortality rates from liver cirrhosis, and alcohol consumption, have increased sharply in Britain in the past 35 years. Little is known about the long term trends over time in mortality rates after hospital admission for liver cirrhosis.

AIMS

To analyse time trends in mortality in the year after admission for liver cirrhosis from 1968 to 1999.

SUBJECTS

A total of 8192 people who were admitted to hospital in a defined population of Southern England.

METHODS

Analysis of hospital discharge statistics linked to death certificate data. The main outcome measures were case fatality rates (CFRs) and standardised mortality ratios (SMRs).

RESULTS

At 30 days after admission, CFR was 15.9% and the SMR was 93 (86 in men and 102 in women, compared with 1 in the general population). At one year, the overall CFR was 33.6% and SMR was 16.3. There was no improvement from 1968 to 1999 in mortality rates. SMRs were highest for alcoholic cirrhosis of the liver (27.4 at one year) but lower for biliary cirrhosis (11.4) and chronic hepatitis (10.0). Mortality from most of the main causes of death, including accidents and suicides, was increased.

CONCLUSIONS

The high mortality rates after hospital admission, and the fact that they have not fallen in the past 30 years, show that liver cirrhosis remains a disease with a very poor prognosis. Increased mortality from accidents, suicides, and mental disorders, particularly among those with alcoholic cirrhoses, indicates that prognosis is influenced by behavioural as well as by physical pathology.

Trends in mortality and hospital admission rates for abdominal aortic aneurysm in England and Wales, 1979-1999

BACKGROUND

The aim of this study was to investigate trends in population-based mortality, hospital admission and case fatality rates for abdominal aortic aneurysm (AAA) from 1979 to 1999.

METHODS

This was an analysis of routine statistics from 79 495 death certificates in England and Wales and 3217 hospital inpatient admissions in the Oxford Region.

RESULTS

Mortality rates for all AAAs increased between 1979 and 1999 from 13 to 25 per million in women and from 80 to 115 per million in men. Admission rates increased in the same time interval from three to 22 admissions per million per year in women, and from 52 to 149 per million per year in men. Case fatality rates for all non-ruptured AAAs that were operated on decreased from 25.8 to 9.0 per cent and for all ruptured AAAs from 69.9 to 54.4 per cent.

CONCLUSION

Mortality rates and hospital admission rates for AAA rose in men and even more so in women between 1979 and 1999. Perioperative mortality for ruptured AAA declined a little during the study but nonetheless was still very high at the end. This reinforces the importance of detecting and treating AAA before rupture occurs.

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.

Cancer after cholecystectomy: record-linkage cohort study

We investigated whether cholecystectomy is associated with subsequent cancer and, if so, whether the association is likely to be causal, by undertaking a retrospective cohort study using linked medical statistics, comprising a cholecystectomy group (n=39 254) and a reference cohort admitted for a range of other medical and surgical conditions (n=334 813). We found a short-term significant elevation of rates of cancers of the colon, pancreas, liver, and stomach after cholecystectomy, but no long-term elevation. Excluding colon cancers within 2 years of admission to hospital, the rate ratio for colon cancer after cholecystecomy, compared with the reference cohort, was 1.01 (95% confidence interval 0.90–1.12) and after 10 years or more follow-up it was 0.94 (0.79–1.10). It is highly improbable that the short-term associations between cholecystectomy and gastrointestinal cancers are causal, and we conclude that cholecystectomy does not cause cancer.

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.

Skin cancer in people with multiple sclerosis: a record linkage study

OBJECTIVE

The prevalence of multiple sclerosis (MS) varies with latitude: it increases with distance from the equator in both hemispheres. To seek evidence on whether solar radiation is a protective factor for MS, this study investigated whether skin cancer, as an indicator of solar radiation, is less common in people with MS than in others.

DESIGN

Analysis of a database of linked hospital records and death certificates.

SETTING

The Oxford Region of the National Health Service, England.

SUBJECTS

A cohort comprising all people in the database with MS, and comparison cohorts of people with other diseases.

RESULTS

Skin cancer was significantly less common in people with MS than in the main comparison cohort (rate ratio 0.49; 95% confidence interval 0.24 to 0.91). There was no general deficit of cancer in the MS cohort, and no deficit of skin cancer in cohorts of people with other autoimmune or neurological diseases.

CONCLUSION

The findings support the hypothesis that solar radiation may have a protective influence on the development of MS.

Molecular phylogeny and biogeography of the dung beetle genus Temnoplectron Westwood (Scarabaeidae: Scarabaeinae) from Australia’s wet tropics

The landscape of the Australian Wet Tropics can be described as "islands" of montane rainforest surrounded by warmer or more xeric habitats. Historical glaciation cycles have caused expansion and contraction of these rainforest "islands" leading to consistent patterns of genetic divergence within species of vertebrates. To explore whether this dynamic history has promoted speciation in endemic and diverse groups of insects, we used a combination of mtDNA sequencing and morphological characters to estimate relationships and the tempo of divergence among Australian representatives of the dung beetle genus Temnoplectron. This phylogenetic hypothesis shares a number of well-supported clades with a previously published phylogenetic hypothesis based on morphological data, though statistical support for several nodes is weak. Sister species relationships well-supported in both tree topologies, and a tree obtained by combining the two data sets, suggest that speciation has mostly been allopatric. We identify a number of speciation barriers, which coincide with phylogeographic breaks found in vertebrate species. Large sequence divergences between species emphasize that speciation events are ancient (pre-Pleistocene). The flightless, rainforest species appear to have speciated rapidly, but also in the distant past.

Alcohol, tobacco and breast cancer--collaborative reanalysis of individual data from 53 epidemiological studies, including 58,515 women with breast cancer and 95,067 women without the disease

Alcohol and tobacco consumption are closely correlated and published results on their association with breast cancer have not always allowed adequately for confounding between these exposures. Over 80% of the relevant information worldwide on alcohol and tobacco consumption and breast cancer were collated, checked and analysed centrally. Analyses included 58,515 women with invasive breast cancer and 95,067 controls from 53 studies. Relative risks of breast cancer were estimated, after stratifying by study, age, parity and, where appropriate, women's age when their first child was born and consumption of alcohol and tobacco. The average consumption of alcohol reported by controls from developed countries was 6.0 g per day, i.e. about half a unit/drink of alcohol per day, and was greater in ever-smokers than never-smokers, (8.4 g per day and 5.0 g per day, respectively). Compared with women who reported drinking no alcohol, the relative risk of breast cancer was 1.32 (1.19-1.45, P<0.00001) for an intake of 35-44 g per day alcohol, and 1.46 (1.33-1.61, P<0.00001) for >/=45 g per day alcohol. The relative risk of breast cancer increased by 7.1% (95% CI 5.5-8.7%; P<0.00001) for each additional 10 g per day intake of alcohol, i.e. for each extra unit or drink of alcohol consumed on a daily basis. This increase was the same in ever-smokers and never-smokers (7.1% per 10 g per day, P<0.00001, in each group). By contrast, the relationship between smoking and breast cancer was substantially confounded by the effect of alcohol. When analyses were restricted to 22 255 women with breast cancer and 40 832 controls who reported drinking no alcohol, smoking was not associated with breast cancer (compared to never-smokers, relative risk for ever-smokers=1.03, 95% CI 0.98-1.07, and for current smokers=0.99, 0.92-1.05). The results for alcohol and for tobacco did not vary substantially across studies, study designs, or according to 15 personal characteristics of the women; nor were the findings materially confounded by any of these factors. If the observed relationship for alcohol is causal, these results suggest that about 4% of the breast cancers in developed countries are attributable to alcohol. In developing countries, where alcohol consumption among controls averaged only 0.4 g per day, alcohol would have a negligible effect on the incidence of breast cancer. In conclusion, smoking has little or no independent effect on the risk of developing breast cancer; the effect of alcohol on breast cancer needs to be interpreted in the context of its beneficial effects, in moderation, on cardiovascular disease and its harmful effects on cirrhosis and cancers of the mouth, larynx, oesophagus and liver.

Appendicectomy, tonsillectomy, and inflammatory bowel disease: a case-control record linkage study

STUDY OBJECTIVE

To determine whether appendicectomy and tonsillectomy are associated with ulcerative colitis (UC) or Crohn's disease (CD); and, if so, whether the associations are related to age at operation.

DESIGN

Nested case-control studies using a longitudinal database of linked hospital and death record abstracts.

SETTING

Southern England.

PATIENTS

Statistical records of people diagnosed with UC, CD, or a control condition admitted to hospitals in a defined area.

MAIN RESULTS

Appendicectomy under the age of 20 years was associated with a significantly reduced subsequent risk of UC (relative risk =0.48, 95% confidence interval 0.30 to 0.73). The association appeared strongest for appendicectomy between 10 and 14 years of age (relative risk =0.29, 95% CI 0.09 to 0.68). Appendicectomy at the age of 20 years and over was associated with an increased subsequent risk of CD (relative risk =1.92, 95% CI 1.58 to 2.32), largely confined to those people whose CD was diagnosed within a year of appendicectomy. Appendicectomy under 20 years of age, undertaken five years or more before case or control conditions, was suggestively associated with a reduced risk of CD (relative risk =0.71, 95% CI 0.47 to 1.03). Prior tonsillectomy was not associated with any increase or decrease of risk of either UC or CD.

CONCLUSIONS

Appendicectomy is associated with a reduced risk of UC; and the association is specific to young age groups when the population risk of appendicitis is itself highest. The increased risk of CD after appendicectomy, at short time intervals between the two, is probably attributable to the misdiagnosis of CD as appendicitis.

Depression and anxiety in people with inflammatory bowel disease

STUDY OBJECTIVE

To determine whether depression or anxiety co-occurs with ulcerative colitis (UC) or Crohn's disease (CD) more often than expected by chance, and, if so, whether the mental disorders generally precede or follow the inflammatory bowel diseases (IBD).

DESIGN

Nested case-control studies using a database of linked hospital record abstracts.

SETTING

Southern England.

MAIN RESULTS

Both depression and anxiety preceded UC significantly more often than would be predicted from the control population's experience. The associations were strongest when the mental conditions were diagnosed shortly before UC, although the association between depression and UC was also significant when depression preceded UC by five or more years. Neither depression nor anxiety occurred before CD more often than expected by chance. However, depression and anxiety were significantly more common after CD; the associations were strongest in the year after the initial record of CD. UC was followed by anxiety, but not by depression, more often than expected by chance and, again, the association was strongest within one year of diagnosis with UC.

CONCLUSIONS

The concentration of risk of depression or anxiety one year or less before diagnosis with UC suggests that the two psychiatric disorders might be a consequence of early symptoms of the as yet undiagnosed gastrointestinal condition. The data are also, however, compatible with the hypothesis that the psychiatric disorders could be aetiological factors in some patients with UC. Most of the excess anxiety or depression diagnosed subsequent to diagnosis of IBD occurs during the year after IBD is diagnosed and the probable explanation is that the mental disorders are sequelae of IBD.

Intercurrent drug therapy and perioperative cardiovascular mortality in elective and urgent/emergency surgical patientst

The Oxford Record Linkage Study (ORLS; an epidemiological database) was used to examine relationships between intercurrent cardiovascular drug therapy and cardiac death within 30 days of elective or emergency/urgent surgery under general anaesthesia. Cases identified from the ORLS were paired with matched control patients. Clinical details were obtained from the patients' medical notes. In elective surgical patients, there was no effect of beta-adrenoceptor or calcium entry channel blockade, diuretics or digoxin on cardiac death after adjusting for confounding variables. Use of nitrates was associated with an odds ratio of 4.79 [95% confidence interval (CI) 1.01-22.72] for cardiac death after adjustment for confounding by a history of angina and residual age difference. In emergency/urgent patients, there were significant univariate associations with cardiac death for intercurrent use of angiotensin converting enzyme (ACE) inhibitors (odds ratio 1.18) and diuretics (odds ratio 4.95; 95% CI 1.82-13.46). However, neither maintained significance after adjustment for the confounding effect of cardiac failure. We conclude that, with the possible exception of the use of nitrates in elective surgical patients, chronic intercurrent drug treatment alone does not significantly affect the odds of cardiac death within 30 days of surgery.

Use of large medical databases to study associations between diseases

We describe the use of a dataset of statistical medical records, the Oxford Record Linkage Study (ORLS), to identify diseases which occur together more commonly (association), or less commonly (dissociation), than their individual frequencies in the population would predict. We investigated some conditions known or suspected to enhance the subsequent risk of cancer, some conditions thought to be linked with schizophrenia, and some associations between conditions with a known autoimmune component. Diseases may occur in combination more often (or less often) than expected by chance because one predisposes to (or protects against) another or because they share environmental and/or genetic mechanisms in common. The investigation of such associations can yield important information for clinicians interested in potential disease sequelae, for epidemiologists trying to understand disease aetiology, and for geneticists attempting to determine the genetic basis of variation in disease course among individuals. We suggest that, through the use of datasets like the ORLS, it will be possible to 'map' comprehensively the phenomic expression of co-occurring diseases.

Phylogeny of the syrphoidea (Diptera) inferred from mtDNA sequences and morphology with particular reference to classification of the pipunculidae (Diptera)

Sequence data from 420 bp of mitochondrial 12s ribosomal DNA and 490 bp of 16s rDNA were analyzed for 27 species of Syrphoidea (Diptera) and two outgroup taxa. Morphological data for the Pipunculidae were combined with the pipunculid molecular data set. A partition homogeneity test on these data sets revealed no significant incongruence. The pipunculid phylogeny from molecular data closely resembles the published phylogeny based on morphology, with differences only with respect to the Nephrocerinae. There is very strong support for the monophyly of the Pipunculinae and the Chalarinae. The Nephrocerinae are hypothesized to be paraphyletic. Within the Syrphidae, there is support for a monophyletic Syrphinae and Microdontinae, but the Eristalinae are paraphyletic. More data are needed to resolve the eristaline phylogeny.

Hospital admission and mortality rates for venous thromboembolism in Oxford region, UK, 1975-98

Multiple-cause-coded mortality rates for thromboembolism in the Oxford region of the UK showed a steady decline fom 1975 to 1998. The trend for admission rates was less clear-cut, but recent changes were not specific to women of ages associated with use of oral contraceptives or hormone-replacement therapy.

Close genetic similarity between two sympatric species of tephritid fruit fly reproductively isolated by mating time

Two sibling species of tephritid fruit fly, Bactrocera tryoni and B. neohumeralis, occur sympatrically throughout the range of B. neohumeralis in Australia. Isolation between the two species appears to be maintained by a difference in mating time: B. tryoni mates at dusk, whereas B. neohumeralis mates during the middle of the day. A morphological difference in humeral callus color also distinguishes the two species. Despite clear phenotypic evidence that B. tryoni and B. neohumeralis are distinct species, genetic differentiation as measured by four markers--nuclear DNA sequences from the white gene and the ribosomal internal transcribed spacer (ITS2), and mitochondrial DNA sequences from the cytochrome b (cytb) and cytochrome oxidase subunit II (COII) genes--is very small. Minor fixed differences occur in the ITS2 sequence, however, in all other cases the two species exhibit a high level of shared polymorphic variation. The close genetic similarity suggests either that speciation has occurred very rapidly and recently in the absence of any mitochondrial DNA sorting or that the sharing of polymorphisms is due to hybridization or introgression. A third species within the tryoni complex, B. aquilonis, is geographically isolated. Bactrocera aquilonis is also genetically very similar, but in this case there is clear differentiation for the mitochondrial loci. The three species form a group of considerable interest for investigation of speciation mechanisms.

Higher-level phylogeny of the Therevidae (Diptera: insecta) based on 28S ribosomal and elongation factor-1 alpha gene sequences

Therevidae (stilleto flies) are a little-known family of asiloid brachyceran Diptera (Insecta). Separate and combined phylogenetic analyses of 1200 bases of the 28S ribosomal DNA and 1100 bases of elongation factor-1alpha were used to infer phylogenetic relationships within the family. The position of the enigmatic taxon Apsilocephala Kröber is evaluated in light of the molecular evidence. In all analyses, molecular data strongly support the monophyly of Therevidae, excluding Apsilocephala, and the division of Therevidae into two main clades corresponding to a previous classification of the family into the subfamilies Phycinae and Therevinae. Despite strong support for some relationships within these groups, relationships at the base of the two main clades are weakly supported. Short branch lengths for Australasian clades at the base of the Therevinae may represent a rapid radiation of therevids in Australia.

Hormonal and other factors in relation to survival among breast cancer patients

We have examined the relationship between all-cause mortality and various hormonal and other factors in over 1,200 women with breast cancer recruited into 2 consecutive case-control studies between 1969 and 1984. The age at diagnosis ranged from 24 to 59 years, and the majority (74%) were pre-menopausal at diagnosis. Analyses were based on follow-up to 1 January 1994, by which time 608 (50%) of the women had died. Of the factors examined, weight was most strongly associated with survival, with a significant increase in the risk of death with increasing weight. Two hormonal factors, time since last birth and time since last oral contraceptive use, were also independently associated with survival. All of these associations remained after adjustment for stage and histological nodal status. Our findings provide new evidence to suggest that reproductive factors and exogenous hormones in the form of oral contraceptives may influence survival in women with breast cancer, even after differences in stage and nodal status have been taken into account.

Risk factors for cardiovascular death within 30 days after anaesthesia and urgent or emergency surgery: a nested case-control study

The Oxford Record Linkage Study (an epidemiological database) was used to identify patients who died from a cardiovascular cause within 30 days of emergency or urgent surgery under general anaesthesia. Each case was paired with a control patient (matched for age within 10 yr of the patient, operation and consultant). Additional clinical information was sought from the patient's case notes. Cases and controls were compared for cardiovascular risk factors using conditional logistic regression analysis and a prognostic model was generated. Only one significant risk factor was identified in the final model: a history of cardiac failure (odds ratio 14.84; 95% confidence intervals 2.53-87.13; P = 0.003). Associations between a history of cerebrovascular accident or renal impairment and cardiovascular mortality were seen using univariate analysis but not after adjustment for confounding factors.

Congruence and controversy: toward a higher-level phylogeny of Diptera

The order Diptera (true flies) is one of the most species-rich and ecologically diverse clades of insects. The order probably arose in the Permian, and the main lineages of flies were present in the Triassic. A novel recent proposal suggests that Strepsiptera are the sister-order to Diptera. Within Diptera, evidence is convincing for the monophyly of Culicomorpha, Blephariceromorpha, and Tipulomorpha but weak for the monophyly of the other basal infraorders and for the relationships among them. The lower Diptera (Nematocera) is paraphyletic with respect to Brachycera, and morphological evidence suggests the sister-group of Brachycera lies in the Psychodomorpha. Recent analyses suggest Tipulomorpha are closer to the base of Brachycera than to the base of Diptera. Brachycera are undoubtedly monophyletic, but relationships between the basal lineages of this group are poorly understood. The monophyly of Stratiomyomorpha, Xylophagomorpha, Tabanomorpha, and Muscomorpha is well supported. Eremoneura, and its constituent clades Empidoidea and Cyclorrhapha, are monophyletic. The sister-group of Eremoneura is likely to be part or all of Asiloidea. Several viewpoints on the homology of the male genitalia of eremoneuran flies are discussed. Phylogenetic analyses suggest that lower Cyclorrhapha (Aschiza) are paraphyletic; however, schizophoran monophyly is well supported. The monophyly of Acalyptratae is not well-founded and the relationships between acalyptrate superfamilies remain obscure. Recent advances document the monophyly of the families of Calyptratae and the relationships among them. Areas critical to future advances in understanding dipteran phylogeny include the relationships among the basal infraorders of Diptera and Brachycera and the relationships between the superfamilies of acalyptrates. Progress in dipteran phylogenetics will accelerate with the exploration of novel data sources and the formulation of hypotheses in an explicitly quantitative framework.

Evolution and systematics of Anopheles: insights from a molecular phylogeny of Australasian mosquitoes

Relationships among the genus Anopheles and its many sibling species-groups are obscure despite the importance of anophelines as the vectors of human malaria. For the first time, the interrelationships and the origin of Australasian members of the subgenus Cellia are investigated by a cladistic analysis of sequence variation within the mitochondrial cytochrome oxidase subunit II gene. Estimated divergence times between many Australasian and Oriental taxa predate the mid Miocene collision of Australasia and Southeast Asia. Phylogenetic analysis suggests that two-way exchanges with Oriental mosquitoes rather than only immigration may have been a characteristic of anopheline paleobiogeography in Australasia. The Australasian fauna is mostly included in a large clade. The medically important Punctulatus Group is monophyletic and appears derived from Oriental stock. Populations within this group from as far apart as Australia and Vanuatu were in contact in the recent past (i.e., 0.35-2.44 mya), supporting dispersal rather than vicariance explanations. Some support for the monophyly of the Myzomyia, Neomyzomyia, and Pyretophorus Series was found. However, the subgenera Anopheles and Cellia and the Neocellia Series are paraphyletic, but branch support at these taxonomic levels was poor. The COII gene shows promise for questions concerning alpha taxonomy but appears to be of limited use for resolving deeper relationships within the Anopheles.

Risk factors for cardiovascular death after elective surgery under general anaesthesia

A large epidemiological data set was used to identify 115 patients who died from a cardiovascular cause within 30 days of elective surgery under general anaesthesia. For each patient, a control was identified, matched for age (within 5 yr of the patient), sex, operation and consultant. Patients and controls were compared for cardiovascular risk factors in a matched analysis using conditional logistic regression, and a prognostic model was generated. Three risk factors were included in the final model: previous myocardial infarction (odds ratio 3.18 (95% confidence intervals (CI) 1.22-8.28), P = 0.018), history of hypertension (odds ratio 1.90 (0.99-3.62), P = 0.047) and renal failure (odds ratio 3.56 (1.04-12.10), P = 0.043).

DNA profiling resolves the limited importance of flower colour in defining varieties of Lantana camara

Randomly amplified polymorphic DNA (RAPD), successfully used to establish flower colour, is of limited importance in characterising weedy varieties of Lantana camara. Initially the internal transcribed spacer 1 (ITS1) region was sequenced for common pink and common pink-edged red varieties of L. camara from Australia and L. urticofolia from the neotropics. This proved unhelpful in differentiating varieties due to a lack of variation and the hybrid origin of L. camara, necessitating the utilisation of DNA profiling techniques. Unweighted pair group method arithmetic average (UPGMA) analysis of RAPD data demonstrated that geographical proximity contributes more significantly to genetic relatedness than flower colour. Analysis of molecular variance (AMOVA) likewise demonstrated that geography accounts for a relatively large variance component. These data indicate that the use of flower colour as a primary identification tool needs to be reevaluated. The use of RAPD may prove useful in characterising the weedy varieties of lantana present in Australia and the South Pacific. Since biological control efforts are being hindered by the inadequacy of current morphological taxonomy, it is expected that DNA profiling will underpin continuing studies on the management and control of L. camara.

Hypertension, admission blood pressure and perioperative cardiovascular risk

We performed a retrospective case-control study to investigate hypertension and admission blood pressure as risk factors for postoperative cardiovascular death. We identified records of 76 patients who had died of a cardiovascular cause within 30 days of anaesthesia and elective surgery and 76 matched controls. From the records of each patient (case and control) we recorded the admission blood pressure and details of any history of hypertension. A pre-operative history of hypertension was strongly associated with perioperative cardiovascular death (p < 0.001 with one degree of freedom: odds ratio 4.14, 95% confidence intervals 1.63-11.69). There was no association between systolic or diastolic pressure at admission for operation and perioperative cardiovascular death. The mean admission systolic pressure of the cases was 145.5 mmHg (range 90-250 mmHg) and that of the controls was 146.5 mmHg (range 100-200 mmHg). The mean admission diastolic pressure of the cases was 83.2 mmHg (range 60-130 mmHg), and that of the controls was 84.5 mmHg (range 60-110 mmHg).

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

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

Revision of the Australian bee fly genus Neosardus Roberts (Diptera : Bombyliidae)

The endemic Australian bee fly genus Neosardus Roberts is revised. The genus is diagnosed, and diagnoses are provided for the five species described by previous authors, N. principius Roberts, N. circumdatus Roberts, N. lepidus Roberts, N. nigratus Roberts and N. paramonovi Hull. The following 13 new species are described: N. decus, sp. nov., N. vicinus, sp. nov., N. eremae, sp. nov., N. millstreamensis, sp. nov., N. phaleratus, sp. nov., N. australis, sp. nov., N. danielsi, sp. nov., N. sparsus, sp. nov., N. elegans, sp. nov., N. rieki, sp. nov., N. percultus, sp. nov., N. cosmus, sp. nov., and N. fenestratus, sp. nov. The wings of six species and male genitalia of seven species are illustrated, as are the female genitalia of one species. A key is provided to all species and distributions of all widespread species are mapped.

Revision of the genus Docidomyia White (Diptera : Bombyliidae)

The endemic Australian bee fly genus Docidomyia White (Bombyliidae :Tomomyzinae) is revised. The relationships of the genus to others in the Tomomyzinae is discussed. A total of 15 species are treated: the five described species (D. puellaris White, D. norrisi Paramonov, D. froggatti Paramonov, D. victoriana Paramonov and D. swani Paramonov) are diagnosed and ten new species (D. nicholsoni, sp. nov., D. genualia, sp. nov., D. parva, sp. nov., D. albifrons, sp. nov., D. nigra, sp. nov., D. danielsi, sp. nov., D. brevipilata, sp. nov., D. hespera, sp. nov., D. angusta, sp. nov., and D. isla, sp. nov.) are described. The distributions of all species are mapped, and the male and female genitalia of selected species are illustrated.

Estimating incidence and prevalence of treated psychiatric disorders from routine statistics: the example of schizophrenia in Oxfordshire

STUDY OBJECTIVE

To use routine statistical records to estimate the incidence and prevalence of treated schizophrenia.

DESIGN AND SETTING

Analysis of linked records in Oxfordshire (population 540,000) for all people in contact with specialist psychiatric services from 1975-86.

SUBJECTS

Records of 685 people with a diagnosis of schizophrenia as an inpatient and a further 294 people who received specialist psychiatric care for schizophrenia outside hospital without any record of inpatient care.

MEASUREMENTS AND MAIN RESULTS

The measures most commonly recorded in psychiatric statistics, first admission rates for people in whom schizophrenia was recorded at their first psychiatric admission, were 8.7 per 100,000 males and 5.6 per 100,000 females. First contact rates for people in whom schizophrenia was recorded at any time in the study period and in any setting were 15.1 per 100,000 males and 11.4 per 100,000 females. Whichever patient population was analysed, the broad profile of schizophrenia by age, sex, and calendar time was similar.

CONCLUSIONS

First admission rates for schizophrenia, as identifiable in current routine information systems, are useful indicators of the general pattern of disease but are inadequate absolute indicators of treated incidence. These data are limited to the first ever contact. Reliable information about the treated incidence of disease requires information systems which incorporate information about when and where each diagnosis was first made. Reliable information about treated prevalence requires systems which also incorporate data about death, recovery, and migration into and out of the study population.

Peptic ulcer, cimetidine, and motor neurone disease--a record linkage study

A previous cohort study suggested that there might be an association between use of cimetidine and motor neurone disease. The Oxford Record Linkage Study was used to explore this hypothesis. In the analysis the presence of a peptic ulcer in patients after 1976 was taken as a proxy for cimetidine (and ranitidine) use. The past history of 540 patients with motor neurone disease in this period was compared with that of 1370 patients with multiple sclerosis (neurological controls) and over 240,000 control patients with a variety of other conditions. Among those with motor neurone disease, five had been previously admitted to hospital with peptic ulcer in comparison with an expected number of 7.4 (morbidity ratio 0.68, 95% confidence interval: 0.2 to 1.6). The corresponding figures for those with multiple sclerosis were 12 and 9.7 respectively (morbidity ratio 1.24, 95% confidence interval: 0.6 to 2.2). This study provides some evidence against the possibility that cimetidine (and ranitidine) are related to motor neurone disease.

Use of hospital inpatient care in adolescence

Epidemiological information about detailed patterns of physical morbidity within the adolescent age group is not generally available. To illustrate the distinctive patterns of morbidity indicated by the use of hospital inpatient care, hospital admission rates in the Oxford region (1979-86) were analysed at each single year of age from 10 to 19 years. At the age of 10 years 22% of general hospital admissions were to paediatrics, 24% to general surgery, 23% to ear, nose, and throat surgery, and 20% to trauma and orthopaedics. By 14 years of age only 6% of general hospital admissions were to paediatrics. By 16 years of age 24% of general hospital admissions of young women were to gynaecology and 40% of admissions of young men were to trauma and orthopaedics. The most common reason for hospital admission in young men was head injury and the second most common was appendicectomy. Termination of pregnancy was the single most common reason for admission for girls aged 15 and 16 years; childbirth and terminations were the most common reasons for admission in girls aged 17-19 years and over. Self poisoning was also common in older teenage girls. Younger girls were admitted most commonly for tonsillectomy. Most admissions of adolescents are thus for surgical rather than medical reasons and some of the most common individual reasons for admission are attributable to behavioural factors rather than disease processes.

The epidemiology of hysterectomy: findings in a large cohort study

OBJECTIVE

To examine patterns of hysterectomy in the Oxford-Family Planning Association (Oxford-FPA) study in relation to age, parity, social class and calendar period (-1974, 1975-79. 1980-84, 1985-89).

DESIGN

The Oxford-FPA study is a large scale prospective study of 17,032 women recruited from 1968-74 and still under observation.

SETTING

Seventeen family planning centres throughout England and Scotland.

SUBJECTS

At recruitment the 17,032 women were all white, British, married, aged 25-39 and willing to co-operate. In addition, they were using the pill or an intrauterine device or a diaphragm as their method of contraception.

MAIN OUTCOME MEASURE

Hysterectomy rates per 1000 woman-years of observation in various subclasses of the data.

RESULTS

Up to the end of 1989, 1885 (11.1%) of the 17,032 women in the study were known to have undergone hysterectomy. Fibroids were the most common cause followed closely by menstrual disturbances in the absence of fibroids (hereafter referred to as 'menstrual disturbances'). Social class had a modest influence on hysterectomy rates. Hysterectomy for fibroids, prolapse, endometriosis and 'other reasons' showed little trend with calendar period while hysterectomy for menstrual disturbances and for cancer showed a sharp increase with calendar time especially at ages 30-39. Hysterectomy generally tended to increase with age and showed a strong relation to parity; in particular, hysterectomy for fibroids fell with parity and hysterectomy for menstrual disturbances rose sharply with parity. Using lifetable methods, it was estimated that almost 20% of the women in the study would have had a hysterectomy by age 55.

CONCLUSIONS

The results give insights into factors affecting hysterectomy rates. Of particular interest is the modest influence of social class, the strong influence of parity and the rise in rates with calendar time at ages 30-39 for those undergoing hysterectomy for menstrual disturbances or cancer, but since the cohort is not directly representative of the population, some caution is required in extrapolating these findings. The estimated hysterectomy rate of about 20% by age 55 is in line with other similar estimates for the United Kingdom.

Revision of the Australian bee fly genus Comptosia (Diptera : Bombyliidae)

The Australian bee fly genus Comptosia is revised. Alyosia Rondani, Epidosia Hull, Opsonia Hull, Paradosia Hull and Anthocolon Hull are synonymised with Comptosia Macquart. There are 138 species of Comptosia in collections, of which 58 are treated here. The genus is divided into 19 species-groups that encompass the range of variation found in the described and undescribed species. Characters found most useful in forming the species-groups include: distance between the eyes of males, integumental colour, shape of the antenna1 flagellum, form of the labium and subcranial cavity, and shape of the loop in wing vein R2+3;. Keys to species-groups and to species in each group are provided. All, or almost all, of the species in eight of the species-groups are described. In the remaining species-groups, described species are redescribed, or a single representative species described. The number of recognised, but undescribed, species is given for each species-group. Seven new synonymies are proposed at species level: fenestrata Hull = gemina Hardy; aurifrons Macquart and edwardsi Hardy = praeargentata (Macleay); sobricula (Walker) and anthracina (Thomson) = prosimplex (Hardy); fasciafa (Fabricius) = stria (Walker); duofasciata Hull = tendens (Walker). Lectotypes are designated for the following: C. fascipennis Macquart, C. albofasciata (Thomson), C. tendens (Walker), C. duofasciata Hull, C. fenestrata Hull, C. rnaculipennis Macquart, Anthrax inclusa (Walker) and C. casimira Hull. Twenty-six species are redescribed and 32 species (C. paucispina, C. tutela, C. pitereka, C. pilosa, C. caesariata, C. capillata, C. magna, C. speciosa, C. heliophila, C. neosobria, C. kuranda, C. flava, C. sandaraca, C. xanthobasis, C. aurescens, C. paramonovi, C. nitella, C. flexuosa, C. flavipenna, C. insula, C. neobiguttata, C. mackerrasi, C. soror, C. neoapicalis, C. zona, C. thyris, C. calignea, C. lactea, C. mallota, C. scitula, C. acantha and C. microrhynchus) are described as new. Pupal exuviae of five species are described and illustrated.

Revision of the Australian bee fly genus Aleucosia Edwards (Diptera : Bombyliidae)

Comptosia (Aleucosia) Edwards is diagnosed and Chelina Hull and Paramonovomyia Evenhuis are synonymised with it. The characters of the Australian Lomatiinae are specified and a key to the Australian genera of Lomatiinae is presented. Aleucosia is divided into 8 species-groups based on wing pattern and integumental colour. Cladistic relationships between the species and species-groups are delineated. Keys to these species-groups and to the species within them are presented. For most species the antenna1 flagellum, male and female genitalia and distribution are illustrated. Aleucosia contains at least 38 species; 16 are redescribed and 20 described as new. Alyosia tricellata (Macquart) and Alyosia tripunctata (Macquart) are synonymised under Aleucosia atherix (Newman). Lectotypes are designated for A. triceliata (Macquart), A. cuneata (Edwards), A. norrisi (Hull), A. plena (Walker) and A. serpentiger (Walker). The following new species are described: A. albovittata, A. hyalina, A. saltuaria, A. directa, A. sugillata, A. arguta, A. marginata, A. preclara, A. abdita, A. tridentata, A. affinis, A. aquila, A. guttata, A. multipunctata, A. colona, A. pallida, A. obtusa, A. illota, A. danielsorum and A. adusta.

Epidemiology of carpal tunnel syndrome in women of childbearing age. Findings in a large cohort study

There are few epidemiological data in the scientific literature about the carpal tunnel syndrome. This paper describes the characteristics of the 154 women referred to hospital for management of this condition among the 17,032 taking part in the Oxford-Family Planning Association contraceptive study. Standardized first referral rates for carpal tunnel syndrome doubled as age increased from 25-29 to 50 or more, tripled as smoking increased from zero to 25 or more cigarettes per day, doubled as total duration of oral contraceptive use increased from zero to ten years or more and doubled as Quetelet's obesity index (weight(g)/height(cm)2) increased from up to 1.99 to 2.6 or more. All these trends were statistically significant. Carpal tunnel syndrome was also found to be positively associated with a history of menstrual disorders, gastrointestinal tract symptoms and various orthopaedic conditions. The findings on cigarette smoking are of particular interest but require confirmation or refutation in another study before firm conclusions can be drawn.

Epidemiology of pelvic inflammatory disease in parous women with special reference to intrauterine device use

Up to the end of 1989, 206 parous women in the Oxford Family Planning Association contraceptive study had been referred to hospital with a first episode of pelvic inflammatory disease. Of these, 65 suffered from definite disease described as acute, 81 from definite disease not described as acute and 60 from 'other disease'. Considering all forms of disease together, referral was less common in those aged 25-29 and in those aged 45 or more than in those aged 30-44. Referral was more common in those of low social class, in those who smoked and in those who married young. All these factors were taken into account in analyses considering the effects of contraceptive methods. In these analyses, women currently using the contraceptive pill, the diaphragm, the sheath, female sterilization or an intrauterine device (IUCD) were compared with those currently using other methods or no method of contraception. IUCD ex-users were, however, placed in a separate category, irrespective of their current method of contraception. The relative risks obtained in these analyses, with 95% CI, were as follows: contraceptive pill 0.5 (0.2-0.9), diaphragm 0.6 (0.3-1.2), sheath 1.2 (0.6-2.4), female sterilization 0.7 (0.3-1.5), non-medicated IUCD 3.3 (2.3-5.0), medicated IUCD 1.8 (0.8-4.0), IUCD ex-users 1.3 (0.7-2.3). These data suggest that oral contraceptives, the diaphragm and female sterilization protect against pelvic inflammatory disease and that IUCDs increase the risk. Medicated devices, however, appear to carry only about half the risk of non-medicated devices, and the elevation of risks in IUCD ex-users appears to be small. Special analyses examined the risk associated with use of a Dalkon Shield. Among women currently using an IUCD (of any kind), those who had used a Dalkon Shield (at any time) had nearly five times as great a risk of hospital referral for pelvic inflammatory disease as those who had never used a Dalkon Shield (relative risk 4.7, 95% CI 2.1-9.0).

Mortality among oral contraceptive users: 20 year follow up of women in a cohort study

OBJECTIVE

To see whether the use of oral contraceptives influences mortality.

DESIGN

Non-randomised cohort study of 17,032 women followed up on an annual basis for an average of nearly 16 years.

SETTING

17 Family planning clinics in England and Scotland.

SUBJECTS

Women recruited during 1968-74. At the time of recruitment each woman was aged 25-39, married, a white British subject, willing to participate, and either a current user of oral contraceptives or a current user of a diaphragm or intrauterine device (without previous exposure to the pill).

MAIN OUTCOME MEASURES

Overall mortality and cause specific mortality.

RESULTS

238 Deaths occurred during the follow up period. The main analyses concerned women entering the study while using either oral contraceptives or a diaphragm or intrauterine device. The overall relative risk of death in the oral contraceptive users was 0.9 (95% confidence interval 0.7 to 1.2). Though the numbers of deaths were small in most individual disease categories, the trends observed were generally consistent with findings in other reports. Thus the relative risk of death in the oral contraceptive users was 4.9 (95% confidence interval 0.7 to 230) for cancer of the cervix, 3.3 (95% confidence interval 0.9 to 17.9) for ischaemic heart disease, and 0.4 (95% confidence interval 0.1 to 1.2) for ovarian cancer. There was a linear trend in the death rates from cervical cancer and ovarian cancer (in opposite directions) with total duration of oral contraceptive use. Death rates from breast cancer (relative risk 0.9; 95% confidence interval 0.5 to 1.4) and suicide and probable suicide (relative risk 1.1; 95% confidence interval 0.3 to 3.6) were much the same in the two contraceptive groups. In 1981 the relative risk of death in oral contraceptive users from circulatory diseases as a group was reported to be 4.2 (95% confidence interval 2.3 to 7.7) in the Royal College of General Practitioners oral contraception study. The corresponding relative risk in this study was only 1.5 (95% confidence interval 0.7 to 3.0).

CONCLUSIONS

These findings contain no significant evidence of any overall effect of oral contraceptive use on mortality. None the less, only small numbers of deaths occurred during the study period and a significant adverse (or beneficial) overall effect might emerge in the future. Interestingly, the mortality from circulatory disease associated with oral contraceptive use was substantially less than that found in the Royal College of General Practitioners study.