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Biomedical subjects

J M Simpson

Publications and source records attributed to J M Simpson.

At least 91 records · Page 5Linked to original sources

Teaching statistics to non-specialists.

Teaching statistics to non-specialists is a challenge for which most statisticians are unprepared by their own training within an academic mathematics department. Most statistics courses for medical undergraduates still focus on research statistics, whereas it would be more appropriate to concentrate on statistics relevant to clinical decision-making about an individual patient. Teaching statistics to Master of Public Health students presents further challenges because of the wide variety of their backgrounds and the greater demands from mature postgraduates. Whatever the audience, however, the same principles apply: medical statistics should be taught as non-mathematically as possible, only introducing formulae when absolutely necessary and explaining their components; plenty of practical applications should be given; there should be ample opportunity for practice to gain hands-on experience using both calculators and computers (preferably with MINITAB); and tutorials should be streamed according to perceived mathematical ability, with remedial mathematics teaching available to those who need it.

Curriculum↗

Streptococcus pneumoniae invasive disease in the neonatal period: an increasing problem?

UNLABELLED: A series of 11 cases of invasive infection with Streptococcus pneumoniae, occurring over an 11-year period, is reported. Eight of the 11 cases occurred during the final 2 years of the study suggesting that the incidence of infection may be increasing. Infection carries a high mortality (3/11). Morbidity includes meningitis, convulsions and respiratory failure. In one case S. pneumoniae meningitis occurred in both mother and newborn. Most mothers who carried the organism were asymptomatic at the time of delivery. CONCLUSION: S. pneumoniae should be specifically sought in swabs taken from the pregnant mother and newborn and if isolated, even in the absence of symptoms, antibiotic therapy against the organism should be strongly considered.

Adolescent↗

Human papillomavirus deoxyribonucleic acid as a prognostic indicator in early-stage cervical cancer: a possible role for type 18.

OBJECTIVE: Our purpose was to determine the prognostic significance of human papillomavirus deoxyribonucleic acid in cervical cancers. STUDY DESIGN: The polymerase chain reaction was used to detect human papillomavirus deoxyribonucleic acid types 6, 11, 16, 18, 31, 33, 52, or 58 in tumors from 148 patients (equal numbers of whom were disease free or had relapses) surgically treated for stage IB or IIA cancers in a major Australian hospital. Cox regression modeling was used to assess the effect of human papillomavirus status on tumor recurrence, taking into account patient age, clinical stage, histologic node status, and type of tumor. RESULTS: Seventy of 74 (95%) of the recurring tumors and 62 of 74 (84%) of the nonrecurring tumors were human papillomavirus deoxyribonucleic acid positive. The rates of positivity of types 16 and 18 were 64% versus 31% in the recurrers and 65% versus 14% in the nonrecurrers. Human papillomavirus type 18 positivity was associated with a greater risk of recurrence than was type 16 positivity (hazard ratio 1.8; p = 0.03). Clinical stage, nodal metastasis, and young age (< or = 35 years) also had adverse effects on relapse (hazard ratio for each approximately 2). CONCLUSION: Human papillomavirus type 18 positivity is a risk factor for tumor recurrence in surgically treated cervical cancer.

Adult↗

PEAPS-Q: a questionnaire to measure the psychosocial effects of having an abnormal pap smear. Psychosocial Effects of Abnormal Pap Smears Questionnaire.

We have developed the Psychosocial Effects of Abnormal Pap Smears Questionnaire (PEAPS-Q) which measures distress experienced by women undergoing follow-up investigation after an abnormal Pap smear result. A thorough literature review and qualitative research resulted in the development of a questionnaire which was tested on 350 women attending a Family Planning New South Wales (FPNSW) clinic. This sample included women at different stages of management after detection of a cervical abnormality: 93 first colposcopy clients and 257 follow-up colposcopy clients. Factor analysis identified four dimensions of distress: experience of medical procedures, beliefs/feelings about cervical abnormality and changes in perception of oneself, worry about infectivity and effect on sexual relationships. Repeatability of the PEAPS-Q was indicated by intra-class correlations of 0.88 overall and at least 0.60 for each scale. Internal consistency was shown by Cronbach's alpha of 0.84 overall and at least 0.72 for each scale. Validity was demonstrated by the correlation of scale scores with the 12-item General Health Questionnaire (GHQ) score of 0.32 (95% CI 0.22-0.41). The PEAPS-Q is a valid, reliable and multidimensional instrument for quantifying distress experienced by women with abnormal Pap smears.

Adult↗

The relationship between intelligence and duration of circulatory arrest with deep hypothermia.

A total of 114 children (51 with tetralogy of Fallot, 30 with transposition of the great arteries, and 33 with ventricular septal defect) who had these defects repaired with the use of deep hypothermia and circulatory arrest were assessed for intellectual and neuropsychologic function at an average of 9 to 10 years after the operation. Children with preoperative intellectual handicaps or postoperative neurologic complications were excluded. These children were compared with 54 who had atrial septal defects repaired with the use of cardiopulmonary bypass. The only significant difference in the neuropsychologic measures was that the bypass group had reaction times 2 to 3 seconds shorter on average than those of the hypothermic circulatory arrest group. Although there was no significant difference in intelligence quotient between the groups, a relationship between intelligence quotient and arrest time was found. Regression analysis of intelligence quotient against duration of arrest showed a significant decrease in intelligence quotient with increasing arrest time (slope = -0.36; p = 0.002; 95% confidence interval, -0.59, -0.14) indicating a decrease of 3 to 4 intelligence quotient points for each extra 10 minutes of arrest time. It appears that deep hypothermia with circulatory arrest for cardiac operations in children does not fully protect the brain, with a linear relationship existing between the amount of impairment and the duration of circulatory arrest.

Adolescent↗

Use of simple clinical parameters to assess severity of bronchiolitis.

OBJECTIVE: To determine whether simple clinical parameters could be used to predict the severity of acute bronchiolitis and the need for supplemental oxygen therapy. METHODOLOGY: A prospective study, performed in a tertiary care paediatric hospital. Seventy-one infants under 15 months of age with a clinical diagnosis of acute bronchiolitis were examined on admission. Clinical parameters were recorded, and each infant was re-examined after approximately 12 and 24 h. All infants were examined by one medical student and, when possible, by a doctor, the two being unaware of each other's findings. Parameters recorded included respiratory and heart rates and presence of wheeze, crackles, intercostal recession, sternal retraction and/or cyanosis. The outcome measure was the need for supplemental oxygen, as determined by the independent caring medical team, on the basis of pulse oximetry and clinical judgement. RESULTS: Forty (56%) of the 71 babies required supplemental oxygen. All cyanosed babies required supplemental oxygen, but only 9 (21%) were cyanosed on admission. Intercostal recession (relative risk RR 2.55; 95% CI 1.28, 5.08) and sternal retraction (RR 1.60; 95% CI 1.06, 2.42) predicted the need for supplemental oxygen with moderate accuracy. Interobserver agreement was only fair for most parameters, but was poor for intercostal recession and good for cyanosis. CONCLUSIONS: Simple clinical parameters may help predict the need for oxygen therapy in acute bronchiolitis, although further studies are required to define suitable clinical criteria. Such criteria are extremely important in developing countries where oxygen is a scarce resource.

Bronchiolitis↗

A retrospective cohort study of childhood immunisation status in northern Sydney.

A survey of their children's immunisation status was conducted among mothers of babies from a three-month birth cohort (January to March 1990) in the Northern Sydney Area in 1992. Its aims were to determine the uptake of immunisation in the area, to examine factors associated with immunisation status, and to assess agreement between the parent's reporting of this status and records of councils and general practitioners. Fifty-eight per cent of the questionnaires (1004) were returned. The full immunisation rate was 86 per cent, 14 per cent were partially immunised and only four children had received no immunisations. Between 74 per cent and 82 per cent of vaccinations were on time at two, four and six months; the rate dropped to 21 per cent at 12 months. Logistic regression analysis showed that premature babies are significantly more likely to be fully immunised, whereas children who have had a serious childhood illness, those with a single mother, or whose mothers are more highly educated, are significantly less likely to be fully immunised. There was 60 per cent agreement between the parent's report of immunisation status and a subgroup of 197 council and 82 general practitioner records. Although all councils in the Northern Sydney Area have a reminder system, most immunisations were found to be done in general practices (64 per cent), where reminder systems are not common.

Child, Preschool↗

A prospective cohort study investigating psychosocial predictors of attendance at a mobile breast screening service.

This study aimed to examine whether knowledge, attitudes and concerns predicted attendance at the mobile Breast X-Ray Programme in Sydney. A cohort study design was used, whereby women were surveyed prior to the implementation of the program, and two years later records were checked to determine whether they had attended for screening. Telephone interviews were sought with randomly selected women aged 45 to 70 years living in the central Sydney area (the screening van's catchment area). A total of 285 women was surveyed (response rate: 50 per cent). Of these, 86 (30 per cent) subsequently attended at the mobile van and 199 did not. Attendance did not appear to be related to any of the following factors: knowledge; attitudes; prior experience; perceived susceptibility and morbid concern in relation to breast cancer; the amount of information about screening mammography to which a woman had been exposed. The results are interpreted in light of methodological considerations plus findings from our other research.

Aged↗

Intellectual function and age of repair in cyanotic congenital heart disease.

Eighty one children, comprising 51 with tetralogy of Fallot and 30 children with transposition of the great arteries (TGA) were assessed using the Wechsler intelligence scale for children--revised, and a battery of neuropsychological measures. They were compared with a group of 33 children who had surgery for ventricular septal defect. All children were aged over 10 years when reviewed and were in good health, attending normal schools. No significant negative correlation was found between any component or subtest of the IQ scores and operating age. There was no evidence of a detrimental effect of older age at operation in the children who had cyanotic heart disease as assessed by neuropsychological measures. Delaying surgery for children with TGA or tetralogy of Fallot does not appear to adversely affect their intellectual development. This finding may provide reassurance in cases where surgery has to be delayed for medical, social, or economic reasons.

Age Distribution↗

Accounting for cluster randomization: a review of primary prevention trials, 1990 through 1993.

OBJECTIVES: This methodological review aims to determine the extent to which design and analysis aspects of cluster randomization have been appropriately dealt with in reports of primary prevention trials. METHODS: All reports of primary prevention trials using cluster randomization that were published from 1990 to 1993 in the American Journal of Public Health and Preventive Medicine were identified. Each article was examined to determine whether cluster randomization was taken into account in the design and statistical analysis. RESULTS: Of the 21 articles, only 4 (19%) included sample size calculations or discussions of power that allowed for clustering, while 12 (57%) took clustering into account in the statistical analysis. CONCLUSIONS: Design and analysis issues associated with cluster randomization are not recognized widely enough. Reports of cluster randomized trials should include sample size calculations and statistical analyses that take clustering into account, estimates of design effects to help others planning trials, and a table showing the baseline distribution of important characteristics by intervention group, including the number of clusters and average cluster size for each group.

Bias↗

Efficient study designs to assess the accuracy of screening tests.

Evaluating a screening test often requires estimation of test sensitivity and specificity with appropriately narrow confidence intervals and at least cost. If the major cost is the reference ("gold") standard, savings arise from reducing the large number of test negatives that are verified by the reference standard. On the basis of the formulae of Begg and Greenes (Biometrics 1983;39:207-15), the authors determine the optimal sampling strategy for test positives and test negatives to minimize the total sample size that needs to be verified for a given confidence interval width for sensitivity. Unless sensitivity is very high, verifying more test positives and fewer test negatives than would occur with equal sampling fractions is appropriate. For example, if the sensitivity is 0.7 and the specificity is 0.99, the optimal sampling strategy is for 6.2% of those verified to be test positives, compared with 1.7% in the case of equal sampling fractions. At a disease prevalence of 0.01, the 3.3-fold increase in test positives results in a saving of about 15% in the test negatives and 11% in the total verified sample size. Overall, savings are about 50% for a sensitivity of 0.3, but are negligible when sensitivity is greater than 0.8. Optimal sampling strategies for sensitivity do not materially alter confidence intervals for specificity. Figures are presented from which readers can easily obtain the optimal sampling strategy given an estimate of specificity, approximated by the proportion of screenees who are test negative, and the range of likely sensitivity.

Algorithms↗

Relationship between weight loss, reduction of body cell mass and inflammatory response in patients with cancer.

Reduced food intake is a major cause of continuing weight loss in patients with cancer. Previous work has suggested that an ongoing inflammatory response may also contribute to weight loss and alter the nature of body tissue loss. To examine this, body cell mass was estimated using measurements of total body potassium (TBK) in 31 patients with gastrointestinal cancer and weight loss with or without an inflammatory response (C-reactive protein level above 5 mg/l). Albumin levels, total body water and 24-h urinary creatinine clearance were also measured. When measured TBK was expressed as a percentage of predicted normal values there was a significant reduction in TBK for patients with an inflammatory response compared with that of those without (P = 0.04). However, when a different prediction equation for TBK was used this difference was not significant (P = 0.29). Therefore, it remains uncertain whether an ongoing inflammatory response in patients with cancer and weight loss contributes to loss of body cell mass.

Aged↗

Effect of megestrol acetate on weight loss, body composition and blood screen of gastrointestinal cancer patients.

Reduced food intake is probably the major cause of continuing weight loss in cancer patients. Therefore, agents which stimulate food intake may be of significant benefit to such patients. To examine this, a randomized double-blind placebo controlled study of megestrol acetate was carried out. 38 gastrointestinal cancer patients with weight loss (8-43% of pre-illness stable weight) were entered into the study. 26 were evaluable at 6 weeks and 21 at 12 weeks. Clinical details, serum biochemistry and haematology were examined at 6 and 12 weeks and total body water, total body potassium at 12 weeks after the baseline assessment. There was no significant weight change in either group over the 6 or 12 weeks. Furthermore, there was no significant difference in total body water, total body potassium, blood biochemistry or haematology between the groups over the study period. It does not appear that megestrol acetate at a dose of 480 mg/day results in weight gain in advanced gastrointestinal cancer patients with weight loss.

Journal Article↗

The psychosocial impact of implementing a mammography screening campaign in an Australian community.

We examined the psychosocial impact of implementing a generalised campaign to promote mammography screening in an Australian inner city community. Prior to the campaign, telephone interviews were conducted with 628 randomly selected women aged 45-70, 285 in central Sydney (where the screening programme operated) and 343 from the rest of Sydney. A second cross-sectional survey was conducted two years after the campaign commenced. The campaign achieved an estimated 21% attendance rate in an eligible population of 43,000 women over a period of 22 months. Overall the campaign reached a large section of the eligible community, with 70% of women being aware of the van's existence. In addition, the proportion of women who reported being exposed to 'a moderate amount' or 'quite a lot' of information about screening increased by almost 20%. However, two thirds of women still reported being exposed to 'only a little' or no information at all. Attendance was achieved largely in the absence of improvements in knowledge and attitudes. Where change did happen, it occurred in the community overall, rather than being confined to the campaign's target area. Changes were most likely due to general electronic and print media messages, which were largely positive in their tone of reporting on screening. The campaign in one area of central Sydney, Drummoyne, which was much more intense, was successful in encouraging greater awareness of the van and mammography screening, plus greater attendance than in the rest of central Sydney, but had no impact on knowledge or attitudes. There was no demonstrable impact on psychological morbidity.

Adult↗

Risk factors and outcomes associated with low birthweight delivery in the Australian Capital Territory 1989-90.

The objectives of this study were to describe outcomes of low birthweight (LBW; < 2500 g) babies born in the Australian Capital Territory (ACT) and to identify risk factors associated with LBW in the ACT. A cohort study was conducted involving all births recorded in the ACT Maternal and Perinatal Data Collection sets for 1989-90. Status at discharge is presented for 9373 births each weighing more than 499 g born in 1989 and 1990, classified by birthweight. Other outcomes are given for live births (n = 9309) only. Adjusted odds ratios for significant risk factors for LBW are given for 9084 singleton births whose computer records contained all relevant information. Perinatal mortality rates for LBW babies are consistent with other States, apart from 500-999 and 1500-1999 g babies which have higher rates. Eighteen per cent of LBW babies are transferred to other hospitals. Low birthweight babies are more likely than normal birthweight babies to have 1 and 5 min Apgar scores less than 7, to need resuscitation and to take more than 5 min to establish respiration. Risk of LBW is associated with maternal primiparity, age 35 years or more in primiparous women, history of one or more spontaneous abortions, induced abortions or perinatal deaths, chronic illness, public health insurance and single marital status, and with fetal female sex and congenital anomalies. Babies born weighing less than 2500 g in the ACT have more adverse outcomes and are much more likely to be transferred than normal birthweight babies.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Survey on developmental-behavioural training experiences of Australian paediatric advanced trainees.

In order to monitor whether paediatric education has adapted to meet modern practice 91 paediatric advanced trainees were surveyed to elicit their satisfaction with developmental-behavioural (DB) training. A response of 69% was obtained to a postal questionnaire. The traditional imbalance persists, with trainees considering themselves significantly better informed in the medical disciplines (P < 0.001). Satisfaction with training in the 14 developmental disciplines surveyed is less (P < 0.001) and significantly more variable compared with 11 traditional medical disciplines (P < 0.01). Formal rotations in DB disciplines had been received by all respondents by the 7th year of training. However, 46-67% consider themselves ill-informed in learning/school problems, attention-deficit hyperactivity disorder, adolescent problems, paediatric rehabilitation and language impairment. Thirty-seven per cent found formal postgraduate instruction unhelpful. Paediatric advanced training gives exposure to, but unsatisfactory formal education, in developmental and behavioural paediatrics. Current initiatives for mandatory DB training have serious implications for achieving adequate resources and standards to meet clinical and training demands.

Attitude of Health Personnel↗