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Biomedical subjects

S Redman

Publications and source records attributed to S Redman.

At least 55 records · Page 3Linked to original sources
PubMed1994

Notification and follow-up of Pap test results: current practice and women's preferences.

BACKGROUND: This study aimed to determine women's knowledge of their Pap test results and predictors of accurate knowledge, adherence to follow-up recommendations for abnormal results, current methods of notifying women about their Pap test results, women's preferences for notification method, and women's satisfaction with the current notification system. METHOD: A telephone survey was undertaken of 315 women with a recent normal or abnormal Pap test result, drawn from pathology records in Sydney, Australia. RESULTS: Findings revealed that 61% of women with a normal result and 93% of women with an abnormal result self reported having been notified about their result. According to women's reports, 7% of those with abnormal results had not been notified and a further 11% of women with abnormal results were unaware that their result was abnormal, giving a total of 18% of abnormal results not communicated adequately to women. Self-reported adherence with follow-up recommendations among women with an abnormal result was less than optimal. The most common methods of notifying women of their results were initiated by the women such as the woman phoning the doctor or receptionist. However, women strongly preferred doctor-initiated methods, such as a written record from the doctor, the doctor phoning the woman, or consultation with the doctor. CONCLUSION: Results suggest that better methods of notifying and educating women about their Pap test results are necessary to improve women's knowledge and satisfaction and, even more importantly, to improve their level of adherence with follow-up recommendations for abnormal results.

Adult↗
PubMed1994

Statistical analysis of synaptic transmission: model discrimination and confidence limits.

Procedures for discriminating between competing statistical models of synaptic transmission, and for providing confidence limits on the parameters of these models, have been developed. These procedures were tested against simulated data and were used to analyze the fluctuations in synaptic currents evoked in hippocampal neurones. All models were fitted to data using the Expectation-Maximization algorithm and a maximum likelihood criterion. Competing models were evaluated using the log-likelihood ratio (Wilks statistic). When the competing models were not nested, Monte Carlo sampling of the model used as the null hypothesis (H0) provided density functions against which H0 and the alternate model (H1) were tested. The statistic for the log-likelihood ratio was determined from the fit of H0 and H1 to these probability densities. This statistic was used to determine the significance level at which H0 could be rejected for the original data. When the competing models were nested, log-likelihood ratios and the chi 2 statistic were used to determine the confidence level for rejection. Once the model that provided the best statistical fit to the data was identified, many estimates for the model parameters were calculated by resampling the original data. Bootstrap techniques were then used to obtain the confidence limits of these parameters.

Algorithms↗
PubMed1994

Statistical models of synaptic transmission evaluated using the expectation-maximization algorithm.

Amplitude fluctuations of evoked synaptic responses can be used to extract information on the probabilities of release at the active sites, and on the amplitudes of the synaptic responses generated by transmission at each active site. The parameters that describe this process must be obtained from an incomplete data set represented by the probability density of the evoked synaptic response. In this paper, the equations required to calculate these parameters using the Expectation-Maximization algorithm and the maximum likelihood criterion have been derived for a variety of statistical models of synaptic transmission. These models are ones where the probabilities associated with the different discrete amplitudes in the evoked responses are a) unconstrained, b) binomial, and c) compound binomial. The discrete amplitudes may be separated by equal (quantal) or unequal amounts, with or without quantal variance. Alternative models have been considered where the variance associated with the discrete amplitudes is sufficiently large such that no quantal amplitudes can be detected. These models involve the sum of a normal distribution (to represent failures) and a unimodal distribution (to represent the evoked responses). The implementation of the algorithm is described in each case, and its accuracy and convergence have been demonstrated.

Algorithms↗
PubMed1994

The prevalence of drug use in urban aboriginal communities.

The use of both licit and illicit drugs has been identified as a major health issue for Australian Aborigines. However, data on the proportion of people who use such drugs is scant. This cross-sectional survey of a randomly selected sample of urban Aboriginal people provides information on the use of the drugs alcohol, tobacco, marijuana, cocaine, heroin as well as petrol sniffing. Overall, a significantly smaller proportion of Aboriginal people were found to be current alcohol drinkers compared to non-Aboriginal Australians. A larger proportion of these drinkers were, however, found to be drinking at levels that were hazardous to their health. A significantly greater proportion of people from the Aboriginal sample were also found to be smokers compared to their non-Aboriginal counterparts. An examination of the use of the illicit substances revealed that a greater proportion reported they had ever used marijuana, compared to the other substances. The findings are discussed in terms of their implications for the health of Aboriginal people.

Adolescent↗
PubMed1994

Determinants of career choices among women and men medical students and interns.

Women continue to be poorly represented in medical specialties other than general practice. A cross-sectional design was used to explore the development of career plans as medical training progressed; men and women students were compared in their first (n = 316), final (n = 295) and intern (n = 292) years. Women at each stage of training were significantly more likely to choose general practice as the field in which they were most likely to practise. There was little evidence that these differences were influenced by experience during training: women were as likely to choose general practice in first year as in the intern year. The most important determinant of career choice appeared to be the flexibility of training and of practice of medicine: variables such as the opportunity for part-time training, flexible working hours and part-time practice were important determinants of career choice and were of more importance to women than to men. The study also found high rates of discrimination or harassment reported by women medical students and interns. The results indicate the need for continued debate about these issues within medicine and the development of more flexible styles of medical training and practice.

Career Choice↗
PubMed1994

A simulation of action potentials in synaptic boutons during presynaptic inhibition.

1. During presynaptic inhibition, an increased conductance in the membrane of the presynaptic bouton is presumed to reduce the action potential, thereby reducing transmitter release. The object of the simulation has been to determine the magnitude of a chloride conductance required to reduce transmitter release, for various diameters of synaptic boutons, connected to axons with diameters in the range 0.1-1.0 microns. 2. A propagating action potential was simulated in axons connected to either side of a hemispherical bouton. The axons could be myelinated or unmyelinated, while the bouton membrane could be passive, a node of the myelinated nerve, or have the same active properties as the attached unmyelinated nerve. Membrane properties of the axons were derived from mammalian data and scaled to 37 degrees C. 3. A steady-state chloride conductance was included in the bouton membrane, with ECl = -40 mV. The amplitude of the action potential in the bouton was calculated for different diameters of axon and bouton and for different magnitudes of chloride conductance. 4. Using published data on the relationship between the amplitude of a presynaptic action potential and the resulting postsynaptic potential, the relationship between the chloride conductance and the postsynaptic response was calculated for different geometries. Transmitter release was reduced when an action potential was 90 mV or smaller, with no transmission for action potentials smaller than 50 mV. 5. Conductance increases in the range 3 to 10 nS were required to reduce the action potential to 90 mV, depending on the diameter of the axon (0.5-1.0 microns), diameter of the bouton (3-6 microns), whether the bouton had passive or active membrane, and whether the axon was myelinated or unmyelinated. A 3 microns passive bouton connected to a 0.5 micron myelinated axon was most sensitive to the effects of a chloride conductance, while a 6 microns active bouton connected to a 1 micron myelinated nerve was least sensitive to the effects of a chloride conductance. 6. The reduction in the action potential was compared when ECl = -40 mV and when ECl = E(rest) = -80 mV. Inactivation of the sodium conductance by terminal depolarization was the dominant influence on the amplitude of the action potential. 7. Conductances that were sufficient to completely block synaptic transmission at a bouton were insufficient to prevent the spread of the action potential away from that bouton.(ABSTRACT TRUNCATED AT 400 WORDS)

Action Potentials↗
PubMed1994

Electrotonic profiles of interneurons in stratum pyramidale of the CA1 region of rat hippocampus.

1. Whole-cell recordings have been made from interneurons located in stratum pyramidale in the CA1 region of the hippocampus. The responses of these interneurons to brief current pulses were recorded; the neurons were filled with biocytin and their morphology was reconstructed. 2. The interneurons were identified as basket cells on the basis of the regional distribution of their axon collateral network and their location in stratum pyramidale. 3. A compartmental model of the reconstructed neuron was made, and the specific membrane resistivity (Rm), specific cytoplasmic resistivity (Ri), and somatic shunt leakage resistance (Rs) determined by adjusting these parameters until an optimal fit was obtained between the compartmental model's current pulse response and the recorded current pulse response of the neuron. 4. This procedure was successful for six neurons, giving Rm from 7 to 66 k omega cm2, Ri from 52 to 484 omega cm, and Rs from 84 M omega to infinity. The specific membrane capacitance was assumed to be 1 microF/cm2. The electrotonic length of the apical dendrites was 1.06 +/- 0.4, and for the basal dendrites it was 0.51 +/- 0.26 (mean +/- SD). 5. Although the total surface area of the interneurons and the physical length of their dendrites was much smaller than for CA1 pyramidal neurons, their electrotonic profiles were similar. Neurons with small physical profiles cannot be assumed to be more electrotonically compact than larger neurons, especially if the dendrites of the smaller neurons have a proportional reduction in diameter. 6. Two neurons did not require a somatic leakage conductance in their electrical representation. This suggests that when a somatic leakage conductance is required, it is an artifact resulting from electrode damage, rather than a requirement caused by a lower resistivity of the somatic membrane compared with the dendritic membrane. 7. Simulations of synaptic currents evoked in the dendrites of these interneurons while the soma is voltage clamped indicate large errors will occur in the time course measurements and amplitude of these currents. Also the ratio of N-methyl-D-aspartate:alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (NMDA:AMPA) currents at these synapses calculated from currents recorded at the soma will be in error because of the differential attenuation of the faster AMPA currents compared with the NMDA currents.

Animals↗
PubMed1994

Effectiveness of three community based strategies to promote screening for cervical cancer.

OBJECTIVE: Evaluation of three potential methods for increasing Pap smear use: television media, television media combined with letter based recruitment, and television media combined with general practitioner based (GP based) recruitment. SETTING: A trial of each intervention was carried out in three postal regions in New South Wales, Australia-a rural locality (containing about 1000 women), a country town (about 3000 women), and a major rural centre (about 10,000 women). Three control regions were selected to be demographically similar to the corresponding intervention regions. METHODS: Outcome data on regional Pap smear rates were obtained from government health insurance claims for cervical screening, and from pathology service records. Expected Pap smear rates for the three months after the intervention were predicted from 45 pre-intervention months and were compared with observed rates for this period. RESULTS: Television media alone was associated with a significant increase in attendances for screening in one of the three regions where a trial was carried out: 13.3% in the rural centre. The media/letter based campaign was associated with a significant increase in attendances in two out of three regions: 52.7% in the rural locality, 43.2% in the rural centre. The media/GP based campaign was associated with significant increases in attendances in all three regions: 50.2% in the rural locality, 80.8% in the country town, 15.7% in the rural centre. All three interventions were associated with significant increases in the number of women attending for cervical screening above those observed in the control regions. Furthermore, these increases were not restricted to women at low risk. They were also found for older women (aged 50-69 years) and women who had not had a Pap smear within the past three years.

Aged↗
PubMed1994

The relationships between high-risk and problem drinking and the occurrence of work injuries and related absences.

A review of studies on the relationship between alcohol and work injuries revealed that the evidence is contradictory and that many of the studies contain methodological flaws. The present study aimed to determine whether there are relationships between problem drinking and high alcohol consumption and outcomes such as work injuries and related absences. The sample consisted of 833 employees at an industrial worksite. Problem drinking was measured by the Mortimer-Filkins test, while alcohol consumption was measured by a 7-day retrospective diary. Work injury data were obtained from medical reports completed at the worksite medical center, while absences data were obtained from company records. Chi-square analyses revealed significant relationships between problem drinking and work injuries and injury-related absences, but not between high alcohol consumption and work injuries and related absences. Logistic regression analysis revealed that no variables were significant predictors of work injuries. However, when uninjured subjects were excluded, a second analysis revealed that Mortimer-Filkins test scores, recent stressful life events, age and job satisfaction were significant predictors of two or more injuries. Injured subjects were almost twice as likely to have two or more injuries if they had high numbers of recent stressful life events and low levels of job satisfaction. Logistic regression analysis revealed that age, Mortimer-Filkins test categories and job satisfaction significantly predicted injury-related absences. Problem drinkers were 2.7 times more likely to have injury-related absences than non-problem drinkers, and subjects with low levels of job satisfaction were 2.2 times more likely than others to have injury-related absences. The implications of the results for workplace alcohol policies and programs are discussed.

Absenteeism↗
PubMed1994

The role of general practitioners in the control of breast cancer.

Studies demonstrate that general practitioners have a vital role in the management of women with breast cancer. This includes encouraging women over 35 years to practise breast self examination, those over 40 to have annual breast checks, and those over 50 to have two-yearly mammography.

Adult↗
PubMed1992

The use of portable blood glucose monitors by trained lay operators.

OBJECTIVE: To evaluate the use of Reflolux II blood glucose reflectance meters by trained lay operators in a community survey. DESIGN: A random household survey involving assessment of participants' blood glucose levels by Reflolux II. For a random subsample of participants an additional sample of blood was placed onto filter paper strips and stored for later examination and assay. SETTING: The survey was conducted in the Newcastle and Lake Macquarie areas of New South Wales. PARTICIPANTS: Of the 1275 participants 15 years and over, 1229 consented to have their blood glucose assessed and 163 of these also had blood stored on filter paper strips. Data were collected by 25 interviewers. MAIN OUTCOME MEASURES: Application of blood spots to filter paper assessed the interviewers' capacity to collect samples of minimal acceptability for Reflolux II operation. Samples were considered adequate if they covered at least a 6 mm soaked disk and there was no evidence that they had been smeared or applied from both sides of the paper. The Reflolux II readings obtained by the interviewers were compared with the blood glucose values from assay of the filter paper samples. RESULTS: Only 63% of the 163 samples collected on filter paper were of acceptable quality for adequate Reflolux II operation. The overall correlation between Reflolux II blood glucose values and those determined from the blood collected on filter paper was good (r = 0.893). However, three of the eight interviewers who had five or more readings for comparison achieved correlation coefficients of < r = 0.20. Of the survey participants identified as having elevated blood glucose levels (> 8 mmol/L) by the filter paper assay, 58% (7 of 12) were not detected by the lay operated reflectance meters. Twenty-two per cent of the individuals assessed by the reflectance meter, compared with 0.5% of a population sample surveyed by the National Heart Foundation, had blood glucose values of less than 3.5 mmol/L. CONCLUSION: It would appear that there may be a considerable error rate in blood glucose values obtained by lay operators using reflectance meters, resulting in underestimation of blood glucose levels. The findings have implications for community awareness programs for diabetes and highlight the need for careful training and monitoring of lay operators in their obtaining of finger-prick blood samples and their use of reflectance meters.

Adolescent↗
PubMed1992

Drug use in Australia: a community prevalence study.

OBJECTIVE: To estimate the prevalence of drug use in a representative Australian community. DESIGN: Using a Census district sampling framework supplied by the Australian Bureau of Statistics, we randomly selected dwellings for our survey. A household was defined as all those people living permanently at the postal address. All eligible members of each household, 15 years and older, were asked to participate. SETTING: The data were collected in the context of a large scale general population survey of health practices and attitudes, conducted in the Greater Newcastle area of New South Wales, during 1987 and 1988. PARTICIPANTS: Seventy-two per cent of eligible individuals approached (2623) agreed to participate in the survey. MAIN OUTCOME MEASURES: Participants were asked about their use of a number of drug types: medically prescribed drugs, non-prescription drugs, tobacco, alcohol and illicit drugs. For alcohol, only the results for use at a hazardous level according to the National Health and Medical Research Council guidelines are reported here. RESULTS: Seventy-eight per cent (95% confidence interval, 76%-80%) of the community sample reported having recently consumed at least one of these drug types. There were significant age and sex differences in drug use. A greater proportion of women and the older age groups (over 45 years) reported the use of both non-prescription and prescription medications than did men and the younger age groups. Conversely, a significantly greater proportion of men and the younger age groups reported the use of social and illicit drugs. CONCLUSION: The importance of regular, representative, methodologically comparable community studies of drug use is stressed, particularly in view of the inadequacy of the current routine sources of epidemiological data on drug use.

Adolescent↗
PubMed1992

Promotion of attendance for mammographic screening through general practice: a randomised trial of two strategies.

OBJECTIVE: To compare the effectiveness of two strategies--patient education and practitioner recommendation--in encouraging women to attend for mammographic screening. DESIGN: The study was a prospective randomised controlled trial. Women aged between 40 and 70 years attending a general practitioner participated in the study. Consenting, eligible women were randomly allocated to one of the two strategy groups. SETTING: The study was conducted in private general practice in Newcastle, New South Wales. PARTICIPANTS: The general practitioners who took part in the study were a non-random sample of practitioners: 20 were approached, two declined to participate, and five failed to begin recruitment, leaving 13 practitioners who took part in the study. A total of 302 women aged 40-69 were recorded as attending the surgeries during recruitment sessions. Twenty women did not consent to the study and 73 were ineligible. Thirty-four women were not given the intervention because the general practitioner forgot or did not have time. There were 92 women in the simple recommendation group and 83 women in the patient education group. INTERVENTIONS: An intensive patient education approach based on health belief principles was compared with a simple recommendation by the general practitioner that the woman have a mammogram. MAIN OUTCOME MEASURE: Attendance rates were calculated from screening service attendance records. RESULTS: No significant difference in attendance rates was observed between the two groups, 82% of the simple recommendation group and 91% of the patient education group attended for screening. CONCLUSIONS: These results suggest that mammographic screening can be effectively promoted in general practice without extensive patient education.

Adult↗
PubMed1992

Reduction of ischemic heart disease risk markers in the teenage children of heart attack patients.

BACKGROUND: Families of people with ischemic heart disease (IHD) are likely to share high levels of risk markers and to have similar lifestyle patterns. Teenage children in such families were the focus of a behavioral intervention program. METHODS: Families were randomly allocated to either an "early" or a "late" advice group. The late group and a third "control" group (consisting of families with no cardiovascular disease) received the intervention only after baseline measurements were repeated in all three groups at the end of 12 months. Pedigree analysis was used to compare changes across groups. RESULTS: The decrease in self-reported total fat intake was greater among teenagers in the early group (mean = -3.38, SE = 1.00) than among those in the late group (mean = -0.58, SE = 1.06), as was the decrease in saturated fat intake (mean = -2.46, SE = 0.56; mean = -0.54, SE = 0.60, respectively). These differences were statistically significant (P < 0.05). There were no differences between these groups for changes in total or high-density lipoprotein cholesterol levels. There was a statistically significant difference between the change in total cholesterol levels in the control group (mean = +0.08, SE = 0.07) and that in the late group (mean = -0.14, SE = 0.11). CONCLUSIONS: The intervention program appears to have made the teenagers aware of high-fat foods, as stated fat intake was significantly lowered, but it was not successful in decreasing blood cholesterol levels. Having a parent with IHD did, however, influence the teenagers' risk-related behavior, leading to a significant reduction in blood cholesterol levels.

Adolescent↗
PubMed1992

The cost and availability of devices for preventing childhood injuries.

Accidental injury is the major cause of death among Australian children. Many childhood injuries are preventable through the use of safety devices such as those recommended by the Child Accident Prevention Foundation of Australia (CAPFA). It has been suggested that poor availability and the high cost of obtaining and installing safety devices may contribute to their low rates of use among families with young children. This paper assesses the availability and cost of recommended safety devices in a medium sized city in Australia. Of the 17 devices recommended by the CAPFA only 10 were readily available in Newcastle. The cost of purchasing and installing all the devices recommended by CAPFA amounted to $1516, or 21.4% of the annual disposable income, after the purchase of necessities, of families with children and 75.5% of the annual disposable income, after purchase of necessities, of single parents. It is argued that the cost of safety devices may be prohibitively expensive, particularly for those most at risk of suffering from injury.

Accident Prevention↗
PubMed1992

Preventive health behaviours among parents of infants aged four months.

Six preventive health behaviours have been frequently identified as having the potential to reduce mortality and morbidity during infancy: breast-feeding until the age of six months; no solid food until after four months of age; immunisation against whooping cough, diphtheria, poliomyelitis and tetanus; the use of a baby capsule to restrain the infant when travelling in a motor vehicle; regular attendance at a health care provider for preventive health checks; and no maternal smoking. This study surveyed 191 primiparous women four months after the birth of their babies to explore the proportion of parents who perform the recommended preventive health behaviours and the association among the behaviours. Thirty-nine per cent of the women reported that they were no longer breast-feeding by the time their infant was four months old; 35 per cent had introduced solids before 16 weeks of age; 35 per cent did not always use a baby capsule when travelling with their baby in their car, 25 per cent did not regularly attend the early childhood health centres and 22 per cent smoked. Forty-eight per cent of the sample were performing four or fewer of the six preventive health behaviours and 21 per cent were performing three or fewer. The relationship between performing each preventive health behaviour and a range of demographic variables was investigated. A logistic regression indicated that performing three or fewer of the health behaviours was associated with lower levels of education, having public health insurance and being born in a country other than Australia.

Adult↗
PubMed1992

Delay in consulting a medical practitioner about rectal bleeding.

STUDY OBJECTIVE: The aims were to estimate the incidence of rectal bleeding in the community, and to determine the proportion of individuals who delay or fail to seek medical advice after a first episode of rectal bleeding. DESIGN: The data were collected as part of a large scale general population survey of the health practices and attitudes of individuals in a randomly selected sample of 2121 households. SETTING: The survey was conducted in the Newcastle and Lake Macquarie areas of New South Wales, Australia, during 1987-88. PARTICIPANTS: Information about rectal bleeding was collected from 1213 individuals aged 40 years and over. MEASUREMENTS AND MAIN RESULTS: Of the 1213 people aged 40 years and over, 239 (20%) reported noticing rectal bleeding at some time in their life. However, since an estimated 4.5% had noticed rectal bleeding for the first time in the past year the true lifetime incidence of rectal bleeding is likely to be much higher. Of the 77 individuals who had noticed a first occurrence of rectal bleeding more than three months but less than five years prior to the interview, 23 (30%) had either not sought medical advice or had only done so after a period of delay. The most commonly reported reason for delay or failure to consult was thinking that the bleeding was not serious and would clear up by itself. CONCLUSIONS: The data suggest that prompt investigation of rectal bleeding is not occurring in a relatively large proportion of cases. However, in the absence of firm evidence that early detection improves prognosis, and considering the costs of screening, it would be premature to initiate programmes which encourage people to seek care promptly for this symptom.

Adult↗