Statistical significance and confidence intervals.
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Data Interpretation, Statistical↗
Biomedical subjects
G Berry
Publications and source records attributed to G Berry.
The Australian Mesothelioma Surveillance Program 1979-1985.
The Australian Mesothelioma Surveillance Program was planned in 1977 in order to improve diagnostic criteria, to monitor the incidence of the disease, to develop methods of counting lung fibres, and to explore occupational and other associations of mesothelioma. This paper presents a preliminary analysis of data that were collected between January 1, 1980 and December 31, 1985 on the pathological findings and the work and environmental history of 858 cases of mesothelioma. The annual incidence rate of mesothelioma in Australia was 15 per million population who were aged 20 years and over. This is more than the incidence rate of mesothelioma in any other country for which data are available. However, uncertainty over diagnostic criteria and the degree of ascertainment of cases places doubt on the validity of such comparisons. In 69% of cases, a history of work with or other exposure to asbestos was obtained. Due to the long interval between the first exposure to asbestos and the provisional diagnosis of a mesothelioma (up to 60 years), more than three-quarters of the 456 exposed cases first contacted asbestos in the years of its heavy use between 1930 and 1959. This article analyses cases by the industry and the occupation in which exposure to asbestos first occurred.
Adult↗
Mortality from myocardial infarction in different types of hospitals.
Hospitals ranging from large urban teaching hospitals to small country hospitals were stratified into four levels of care and examined for their effectiveness of coronary care in relation to these levels. The crude hospital mortality among 2265 patients admitted for definite or possible acute myocardial infarction was 21% at level 1 (the most elaborate level), 22% at level 2, 21% at level 3, and 19% at level 4 (the least elaborate). Adjustment for age or other prognostic factors produced no significant differences across levels either for coronary care unit care or for combined coronary unit and ward care. Success in resuscitation was also similar across levels. These findings suggest that increased resources for coronary care units--whether for new services or for upgrading existing ones--may not be required.
Age Factors↗
Statistical guide-lines and statistical guidance.
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Australia↗
Flow properties of modified packed red cells.
We investigated free gravitational blood flow of modified packed red cells. Variables affecting free flow included final haematocrit, duration of blood storage at 4-6 degrees C and the centrifugal force required in preparation of this blood component. Irrespective of the duration of storage, free blood flow of modified packed red cells was not different from whole blood, provided the haematocrit did not exceed 0.63.
Blood Flow Velocity↗
Statistical significance and confidence intervals.
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Humans↗
A case-control study of breast cancer in relation to the use of steroid contraceptive agents.
In a case-control study of 141 cases of breast cancer and 279 control patients from the Royal Prince Alfred and Westmead Hospitals during 1980-1982, we found similar risk factors to those reported for other populations. There was no statistically significant evidence of an increased risk of cancer from the use of oral contraceptive agents; the crude estimate of relative risk for patients who had used oral contraceptive agents at some time was 1.3 with 95% confidence limits of 0.8 and 1.9. After adjustment for other risk factors (age at first live birth, age at menarche, number of pregnancies, menopausal status, bilateral oophorectomy and years of education), the estimate of the relative risk of ever having used an oral contraceptive agent was 0.9 with 95% confidence limits of 0.6 and 1.5. Further analysis in terms of duration of use and dosage also provided no evidence of an increased risk.
Adult↗
Preventable causes of death and disability from neurotrauma.
Preventable causes of death and disability have been studied retrospectively in a series of 1161 cases of neurotrauma occurring in New South Wales in 1977-78, and prospectively in 153 cases of neurotrauma occurring in country districts in South Australia in 1981-82. In the first study, it was found that at least 80 deaths could be attributed to preventable causes; chiefly, transfer to an inappropriate hospital and/or delay in instituting treatment. Apparent failures in initial management of shock and airway obstruction were evident in this study and also in the South Australian study, which identified major deficiencies in cardiorespiratory management in 7% of cases transferred from country areas. These studies confirm that there is a need for better training, at all levels, in the management of neurotrauma. They also provide powerful arguments for the concept of an integrated regional trauma service.
Australia↗
Experience with extradural haematomas in New South Wales.
A retrospective study of 126 patients with extradural haematomas was made to determine whether their outcome could be modified by alteration of their management. Poor outcome occurred in those over 65 years of age, in motor smash victims, in those with fixed pupils, in those with major associated injuries or those comatose on hospital admission. The detection of skull fracture or of a lucid interval was not prognostically useful. A graduation in mortality according to the type of hospital was present but did not reach statistical significance. Failure to correct shock and delay in instituting definitive treatment were the major preventable factors which could be modified to improve outcome.
Adolescent↗
Experience with multiple intracranial haematomas in New South Wales.
A retrospective survey of head injuries in NSW in 1977 and 1978 was conducted by the Trauma Subcommittee of the Neurosurgical Society of Australasia. This paper describes the findings for 129 patients who had more than one significant intracranial haematoma. Overall, the case fatality rate for these patients was 85%. The presence of low or fluctuating blood pressure was associated with a significantly higher mortality than in the rest of the group. Bilateral reacting pupils or an improvement in level of consciousness following decompressive surgery carried a more favourable prognosis. There was 100% fatality if surgery was not carried out or if the bleeding was not found at operation. A subset of patients who died was selected on the basis of a calculated prognostic variable, and compared with a similar subset of survivors. A higher proportion of patients who died had a delay in the provision of definitive treatment and failure to correct shock. This comparison was made on two criteria. Using the first accepted optimal treatment in 1984, nearly all cases were treated suboptimally, as might be expected. Using the second, acceptable treatment in 1977-78, it was calculated that between nine and 12 patients died with MIH in NSW in the 2 years of the survey, whose deaths might have been prevented.
Accidents, Traffic↗
Experience with acute subdural haematomas in New South Wales.
A retrospective survey of head injuries in NSW in 1977 and 1978 was conducted by the Trauma Subcommittee of the Neurosurgical Society of Australasia. Two hundred and ninety patients, who were found to have acute or subacute subdural haematomas, were considered. The mortality rate was 76%, with 19% making a satisfactory recovery. Several factors were found to produce significant improvement in outcome. The availability of neurosurgical facilities at the time of admission made a significant difference. Those patients who had decompressive operations also fared better. No patient survived without operation. Shock, defined as a systolic blood pressure lower than 90 mmHg for more than 60 min was associated with significantly increased mortality. The chance of developing a significant hypotensive episode was greater if two or more other parts of the body were injured. If three other areas were injured, the mortality was 100%. A case control study suggested that some 35 (16%) of all deaths could have resulted from preventable causes, notably delay in instituting definitive treatment and/or inadequate treatment of shock.
Acute Disease↗
Epidemiology and clinical outcomes of neurotrauma in New South Wales.
This study of 1161 neurotrauma patients in New South Wales hospitals was designed to examine the role of preventable causes of death and disability in cases of spinal injury, extradural, subdural and multiple intracranial haematomas in order to make recommendations for improvements in accident, emergency, ambulance and hospital services. Methods have been developed for standardizing diagnosis in different classes of hospital for the assessment of severity in terms of the patient's age, sex, physical signs, head and spine injuries and other injuries. Estimates have been made of the number of preventable deaths by a case control study of each category of neurotrauma under study.
Adolescent↗
Experience with spinal injuries in New South Wales.
Two hundred and two patients with acute and severe spinal injuries were treated in various hospitals in New South Wales during 1977 and 1978. Of these, 132 (65%) were cervical, 60 (30%) thoracic, eight (4%) lumbar and two were inadequately recorded. A major concurrent injury to the head was present in every third patient, to the chest in every fourth patient, and to the limbs in every fifth patient. The outcomes of patients reported in this series make it one of the worst in the literature. Sixty-nine (34%) patients died in hospital; of the 133 survivors, only 22 (11%) have resumed work, the remainder being partially or totally disabled. It is estimated that another 302 patients died before arrival in hospital. In country areas, the time lags between accident and ambulance notification, and between notification and arrival at hospital, were uncertain in many cases, but periods in excess of 2 hours were recorded in 28 (14%). One-man ambulances or private vehicles were used in at least 43 cases (21%). After admission, 139 patients were transferred to other hospitals for definitive treatment, arriving after an average time of 22 h (median time 9 h); for such patients, the original hospital presumably served as a first aid station. A case control study suggests that preventable delay in transport, inappropriate treatment, and failure to correct shock may have been causative factors in 16 deaths in this series. Reduction of the time lag between accident and institution of definitive treatment will save lives, and may avoid some crippling neurological deficits.(ABSTRACT TRUNCATED AT 250 WORDS)
Accidents↗
Experience with chronic subdural haematomas in New South Wales.
This study considered 135 cases of chronic subdural haematoma following head injury in 1977 and 1978. The majority were in the older age group and more often males. Falls were the commonest cause. Among intracranial haematomas they carry a much better prognosis. However, there was a mortality rate of 9% and delay in diagnosis was the most likely preventable factor contributing to this. Accordingly the possibility of this complication after head injury should be known to those concerned in the later hospital treatment and follow-up management especially of older patients and alcoholics. When the diagnosis has been made, the preferred surgical method of treatment is drainage through burrholes. Follow-up CT scanning should be arranged usually about 8 weeks afterwards unless there are clinical indications for an earlier examination.
Adolescent↗
Phosphatidylinositol:myo-inositol exchange activity in intact nerve endings: substrate and cofactor dependence, nucleotide specificity, and effect on synaptosomal handling of myo-inositol.
Micromolar concentrations of CMP produced a large increase in Mn2+-dependent phosphatidylinositol:myo-inositol exchange activity in isolated nerve endings or synaptosomes. The apparent Km for CMP was 2 microM, and that for myo-inositol was 38 microM. Only cytidine nucleotides were capable of enhancing activity, and this effect is probably specific for CMP, because the synaptosomal preparation rapidly converted CTP or CDP to CMP. Manganese did not affect the uptake of myo-inositol into the synaptosomal cytosolic fraction or myo-inositol levels. Determinations of myo-inositol specific activity showed that the Mn2+-enhanced labeling of phosphatidylinositol was not accompanied by a decrease of label content in free myo-inositol. This lack of an effect on intrasynaptosomal myo-inositol and the dependence of exchange on cytidine nucleotides whereas cytidine itself was previously found to be without effect show that for the bulk of Mn2+-dependent exchange activity, it is the myo-inositol in the incubation medium that is being directly incorporated into membrane-bound phosphatidyl-inositol. Because CMP dependence is the hallmark of exchange catalyzed by CDP-diacylglycerol:inositol phosphatidyl transferase, this enzyme is likely to be responsible for most of the exchange activity in synaptosomes. The strong affinity of this exchange system for CMP suggests that endogenous levels of this nucleotide might support Mn2+-dependent exchange in the absence of added nucleotide.
Animals↗
Systolic blood pressure in relation to occupation and perceived work stress.
This paper outlines the methods used in a five-year prospective study of 4,607 Australian government employees and presents initial cross-sectional results examining associations between systolic blood pressure, occupation, and subjects' perceptions of work stress as ascertained in a questionnaire survey. The questionnaire items were grouped by means of principal component analysis into six factors representing adverse job characteristics. There were appreciable occupational differences in the mean scores for all six factors and in systolic blood pressure. The differences in systolic blood pressure among men from different occupational categories could not be explained by variation in the level of occupational stress perceived and reported by the subjects. Age, occupation, body mass index, and level of perceived stress arising from financial problems were significantly associated with systolic blood pressure level. A multiple linear regression model was used to determine the relationship between systolic blood pressure, age, and occupation after adjustment for the effects of the other variables.
Blood Pressure↗
Tobacco and ethics.
Tobacco is both dangerous and addictive. Its production and use thus raise ethical questions which involve the smoker, parents, teachers, producers, distributors and the State. The moral responsibilities of the various parties are examined critically and legal restrictions are considered to be justified.
Ethics↗
Combined effect of asbestos and smoking on mortality from lung cancer and mesothelioma in factory workers.
The mortality of over 1250 male and 420 female asbestos factory workers was observed over the period 1971-80. Smoking habits were obtained from the subjects in 1971 before the start of the follow up period. Mortality due to lung cancer and to mesothelioma was related to smoking habits. After allowing for the effect of smoking on lung cancer the relative risk due to asbestos was highest for those who had never smoked, lowest for current smokers, and intermediate for ex-smokers; the trend was statistically significant (p less than 0.05). There was no significant association between smoking and deaths due to mesothelioma. Data from several studies are reviewed, and although overall non-smokers have a relative risk of lung cancer due to asbestos that is 1.8 times that of smokers, there is some uncertainty on the accuracy of this figure because of possible biases and sampling variation. Overall the evidence is that mesothelioma risk is independent of smoking.
Adolescent↗