Biomedical subjects

R A Webster

Publications and source records attributed to R A Webster.

At least 19 recordsLinked to original sources

PubMed2003

'Online' monitoring and retrospective analysis of hospital outcomes based on a scan statistic.

Statistical tests based on the scan statistic are introduced for detecting possible increases in the occurrence of hospital events. The tests use a moving window and the theoretical aspects of the tests are investigated using Markov chain theory. The main objective of this study is to provide a statistical technique to assist hospital staff in deciding whether the variation they observe is greater than usually expected under random variation. In this paper we develop the test for Poisson data and apply the theory to monitor the occurrence of orthopaedic wound infection and Methicillin-resistant Staphylo- coccus aureus colonization. We find that this method is sensitive in detecting the change in the process parameter which may not be detected by standard control chart methods. Both online and retrospective analyses are considered.

Australia↗

PubMed1999

Multicenter clinical and analytical evaluation of the AxSYM troponin-I immunoassay to assist in the diagnosis of myocardial infarction.

We evaluated the AxSYM troponin I (cTnI) immunoassay for assisting in the detection of acute myocardial infarction (AMI). At four sites, the total imprecision (CV) over 20 days was 6.3-10.2%. The minimum detectable concentration was 0.14 +/- 0.05 microgram/L. Comparison of cTnI measurements between the AxSYM and Stratus (n = 406) over the dynamic range of the AxSYM assay demonstrated good correlation, r = 0.881, with a proportional bias: AxSYM cTnI = 3.50(Stratus cTnI) - 1. 10. The confidence intervals (95%) for the slope and intercept were 3.39-3.64 and -1.32 to -0.95, respectively. The expected cTnI concentration in healthy individuals was </=0.5 microgram/L, whereas the ROC curve-determined cutoff for AMI was 2.0 microgram/L. This gave a diagnostic sensitivity of 91.8% and specificity of 92.4% when tested in serial samples collected within 24 h of admission in 633 patients presenting with chest pain, of which 122 had an AMI. The concordances of the AxSYM cTnI with the Stratus cTnI, OPUS cTnI, and Access cTnI were 95.3%, 95.1%, and 94.3%, respectively, from patients with suspected AMI. The AxSYM cTnI demonstrated excellent clinical specificity, >/=96%, in skeletal muscle injury, chronic renal disease, and same-day noncardiac surgery patients.

Evaluation Studies as Topic↗

PubMed1998

Recovery from post-earthquake psychological morbidity: who suffers and who recovers?

OBJECTIVE: We sought to identify the psychosocial characteristics of high earthquake exposure subjects that were associated with the development of post-disaster morbidity and with recovery. METHOD: Data reported are from 515 participants in a longitudinal study of the psychosocial effects of the 1989 Newcastle (Australia) earthquake. Subjects were allocated to three subgroups (low morbidity; recovered; and persistent morbidity) on the basis of their Impact of Event Scale scores across the four phases of the study. Differences between these subgroups were examined on a broad range of variables. RESULTS: Several background, dispositional, coping style and exposure-related factors characterised those who developed psychological morbidity, only a small subset of which differentiated between those who recovered and those with persistent morbidity. CONCLUSIONS: Post-earthquake morbidity persists longer in those who are older, have a history of emotional problems, have higher neuroticism, use more neurotic defenses, and report higher levels of post-disaster life events.

Adaptation, Psychological↗

PubMed1997

A synthesis of the findings from the Quake Impact Study: a two-year investigation of the psychosocial sequelae of the 1989 Newcastle earthquake.

This paper summarises the major findings from the Quake Impact Study (QIS), a four-phase longitudinal project that was conducted in the aftermath of the 1989 Newcastle (Australia) earthquake. A total of 3,484 subjects participated in at least one component of the QIS, comprising a stratified sample of 3,007 drawn from community electoral rolls and 477 from specially targeted supplementary samples (the injured, the displaced, the owners of damaged businesses, and the helpers). Subjects' initial earthquake experiences were rated in terms of weighted indices of exposure to threat and disruption. Psychological morbidity was measured at each phase using the General Health Questionnaire (GHQ-12) and the Impact of Event Scale (IES). Selected findings and key conclusions are presented for each of six areas of investigation: service utilisation during the first 6 months post-disaster; patterns of earthquake experience and short-term (6-month) psychosocial outcome; earthquake exposure and medium term (2-year) psychosocial outcome; vulnerability factors and medium-term psychosocial outcome; specific community groups at increased risk (e.g., the elderly and immigrants from non-English-speaking backgrounds); the effects of stress debriefing for helpers. Threshold morbidity (i.e., likely caseness) rates are also presented for a broad range of subgroups. In addition to presenting an overview of the QIS, this paper synthesises the major findings and discusses their implications for future disaster management and research from a mental health perspective.

Adult↗

PubMed1997

Psychosocial sequelae of the 1989 Newcastle earthquake: II. Exposure and morbidity profiles during the first 2 years post-disaster.

BACKGROUND: A sample of 1089 Australian adults was selected for the longitudinal component of the Quake Impact Study, a 2-year, four-phase investigation of the psychosocial effects of the 1989 Newcastle earthquake. Of these, 845 (78%) completed a survey 6 months post-disaster as well as one or more of the three follow-up surveys. METHODS: The phase 1 survey was used to construct dimensional indices of self-reported exposure to threat the disruption and also to classify subjects by their membership of five 'at risk' groups (the injured; the displaced; owners of damaged small businesses; helpers in threat and non-threat situations). Psychological morbidity was assessed at each phase using the 12-item General Health Questionnaire (GHQ-12) and the Impact of Event Scale (IES). RESULTS: Psychological morbidity declined over time but tended to stabilize at about 12 months post-disaster for general morbidity (GHQ-12) and at about 18 months for trauma-related (IES) morbidity. Initial exposure to threat and/or disruption were significant predictors of psychological morbidity throughout the study and had superior predictive power to membership of the targeted 'at risk' groups. The degree of ongoing disruption and other life events since the earthquake were also significant predictors of morbidity. The injured reported the highest levels of distress, but there was a relative absence of morbidity among the helpers. CONCLUSIONS: Future disaster research should carefully assess the threat and disruption experiences of the survivors at the time of the event and monitor ongoing disruptions in the aftermath in order to target interventions more effectively.

Adult↗

PubMed1997

Psychosocial sequelae of the 1989 Newcastle earthquake: III. Role of vulnerability factors in post-disaster morbidity.

BACKGROUND: This paper examines the contributions of dispositional and non-dispositional factors to post-disaster psychological morbidity. Data reported are from the 845 participants in the longitudinal component of the Quake Impact Study. METHODS: The phase 1 survey was used to construct dimensional indices of threat and disruption exposure. Subsequently, a range of dispositional characteristics were measured, including neuroticism, personal hopefulness and defence style. The main morbidity measures were the General Health Questionnaire (GHQ-12) and Impact of Event Scale (IES). RESULTS: Dispositional characteristics were the best predictors of psychological morbidity throughout the 2 years post-disaster, contributing substantially more to the variance in morbidity (12-39%) than did initial exposure (5-12%), but the extent of their contribution was greater for general (GHQ-12) than for post-traumatic (IES) morbidity. Among the non-dispositional factors, avoidance coping contributed equally to general and post-traumatic morbidity (pr = 0.24). Life events since the earthquake (pr = 0.18), poor social relationships (pr = -0.25) and ongoing earthquake-related disruptions (pr = 0.22) also contributed to general morbidity, while only the latter contributed significantly to post-traumatic morbidity (pr = 0.15). CONCLUSIONS: Medium-term post-earthquake morbidity appears to be a function of multiple factors whose contributions vary depending on the type of morbidity experienced and include trait vulnerability, the nature and degree of initial exposure, avoidance coping and the nature and severity of subsequent events.

Adaptation, Psychological↗

PubMed1997

Effect of L-dopa alone and with benserazide on the spontaneous activity of striatal neurones in normal and 6-hydroxydopamine-lesioned rats.

1. The effects of L-dopa methylester (LDME), an analogue of levodopa, on the spontaneous activity of dopamine sensitive neurones in the rat striatum, after 6-hydroxydopamine induced degeneration of the nigrostriatal tract were compared with those in unlesioned animals both in the absence and presence of benserazide, a peripheral DOPA decarboxylase inhibitor (PDI). 2. Studies were performed at 5-7 days post lesion (group 1 animals), at 21 days (group 2) when denervation supersensitivity was evident by contralateral turning to apomorphine and at the same time but following 7 days dosing with LDME plus benserazide (group 3). 3. In unlesioned animals, LDME alone inhibited spontaneous firing by some 45% over 60 min including a marked but transient early phase which was still present in all lesioned animals even though the later inhibition was significantly reduced in group 1 and 3 animals. 4. When given after benserazide in unlesioned animals LDME still produced a similar level of overall inhibition but without the early phase. The lesion reduced the overall inhibition, except in group 2 animals, and after chronic dosing (group 3) it was almost absent. 5. It is proposed that since the early inhibition with LDME alone is still seen after lesion of the nigrostriatal tract but not after the PDI benserazide, it is caused by peripherally formed dopamine and that as the delayed inhibition with LDME alone and after benserazide are all reduced by nigrostriatal lesions, as is its amphetamine like ipsilateral turning, that this depends on locally (striatal) synthesized dopamine. 6. This study also shows the chronic levodopa/PDI treatment reduces the compensating increased activity of surviving dopaminergic neurones and the functional supersensitivity to dopamine and suggests that the long term administration of levodopa may reduce its own utilization and activity in the striatum and in the treatment of Parkinson's Disease [corrected].

Animals↗

PubMed1996

Stress debriefing and patterns of recovery following a natural disaster.

Stress debriefing has been used extensively following traumatic events; however, there is little evidence of its effectiveness. This paper reports the effects of stress debriefing on the rate of recovery of 195 helpers (e.g., emergency service personnel and disaster workers) following an earthquake in Newcastle, Australia (62 debriefed helpers and 133 who were not debriefed). Post-trauma stress reactions (Impact of Event Scale) and general psychological morbidity (General Health Questionnaire: GHQ-12) were assessed on four occasions over the first 2 years postearthquake. There was no evidence of an improved rate of recovery among those helpers who were debriefed, even when level of exposure and helping-related stress were taken into account. More rigorous investigation of the effectiveness of stress debriefing and its role in posttrauma recovery is urgently required.

Disasters↗

PubMed1995

Psychosocial sequelae of the 1989 Newcastle earthquake: I. Community disaster experiences and psychological morbidity 6 months post-disaster.

A stratified random sample of 3007 Australian adults completed a screening questionnaire 6 months after the 1989 Newcastle earthquake. Information was obtained on initial earthquake experiences and reactions, use of specific services, social support, coping strategies and psychological morbidity. This questionnaire was the first phase of the Quake Impact Study, a longitudinal project investigating the psychosocial impact of the earthquake. Two weighted indices of exposure were developed: a threat index, which measured exposure to injury or the possibility of injury; and a disruption index, which measured experiences of property damage, displacement and other losses. Levels of exposure to threat and disruption events were significant predictors of morbidity on both the General Health Questionnaire and Impact of Event Scale, as were coping style and gender. Effects of exposure to threat and disruption were largely additive, with higher exposure being associated with greater use of support services, higher perceived stressfulness and more severe psychological morbidity. Use of avoidance as a coping strategy, female gender, lower social support and being older were also associated with higher post-disaster psychological distress. It was estimated that 14.8% of the population was exposed to high levels of threat or disruption, of whom approximately 25% experienced moderate to severe psychological distress as a direct result of the disaster. It was further estimated that 18.3% of those exposed to high levels of threat were at risk of developing post-traumatic stress disorder, representing approximately 2% of the city's adult population.

Adaptation, Psychological↗

PubMed1995

The experiences of patients and their partners 1 month after a heart attack.

The purpose of this study was to explore any patterns that may be evident in the experiences of 20 patients and their partners 1 month after a first heart attack. An interpretive research approach was used to illuminate the illness experience of patients and its impact on their partners. Semi-structured interviews were conducted with the participants, and qualitative analysis of the data revealed six major categories. These were: expectations about advice and information; feelings about the future; reactions of the partner; playing down the significance of the heart attack; wanting to get back to normal; and the effect on the couple's relationship. These findings are discussed in relation to the theoretical literature and other empirical research. The results of this study may provide pointers to the implications for practice of nurses, particularly on ways to improve support for patients and their partners during early convalescence.

Adaptation, Psychological↗

PubMed1995

Effects of a natural disaster on immigrants and host population.

The psychosocial effects of the 1989 Newcastle earthquake on 250 immigrants from non-English-speaking backgrounds (NESB) were compared with a matched sample of 250 Australian-born subjects. The NESB subjects had higher levels of both general (General Health Questionnaire-12) and event-related (Impact of Event Scale) psychological morbidity. Furthermore, NESB females had the highest levels of distress, particularly those who were older on arrival in Australia and those who experienced high levels of disruption. The results suggest that NESB immigrants, particularly women, appear to be more at risk for developing psychological distress following a natural disaster. However, level of exposure and an avoidance coping style contributed more substantially to psychological distress than ethnicity.

Adaptation, Psychological↗

PubMed1995

Effects of 3-O-methyl on L-dopa-facilitated synthesis and efflux of dopamine from rat striatal slices.

1. The effect of L-dopa on the spontaneous and KCl-evoked efflux of dopamine from rat striatal slices, measured by high performance liquid chromatography (h.p.l.c.) with electrochemical detection (e.c.d.) was investigated in the absence and presence of 3-O-methyl dopa (OMD), an O-methylated metabolite of L-dopa. 2. The addition of exogenous L-dopa (10 microM) significantly increased both the spontaneous efflux of dopamine and that evoked by KCl. 3. In the presence of 50 microM OMD, the effects of L-dopa on the spontaneous and KCl-evoked efflux of dopamine were smaller but only the former was significantly different from that in the absence of OMD. However, the total efflux of dopamine during the overall superfusion time (70 min) including KCl depolarization was significantly lower than in the absence of OMD. 4. Analysis of tissue content after superfusion revealed that the levels of dopa and dopamine in slices superfused with L-dopa in the presence of OMD were significantly higher than those superfused with L-dopa alone. 5. The finding that OMD significantly reduced the efflux of dopamine whilst increasing its concentration in striatal slices after L-dopa superfusion could explain the reduced efficacy seen after long-term therapy with L-dopa and a peripheral dopa decarboxylase inhibitor in Parkinsonian patients when plasma and brain OMD are very high.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1994

Derivatization reactions for neurotransmitters and their automation.

Many reagents suitable for the derivatization of neurotransmitters are selective for the amino function. Others, however, are selective for the carboxyl-, thiol- and hydroxyl function, and recently, reagents selective for more than one function have been produced. Interest persists in the established reagents, with their well understood behaviour which assists automation of analysis as much as new technology. Workers appear reluctant to tackle the optimization of many novel reagents. Chiral reagents may become important if d-amino acids are shown to be significant from a physiological point of view. Solid-phase reagents offer better regulated chemistry and combined derivatization/solid-phase extraction, which make them an exciting prospect.

Automation↗

PubMed1994

Coronary care unit patients' and nurses' ratings of intensity of ischaemic chest pain.

In 100 patients admitted to a coronary care unit with a history of chest pain thought to be due to myocardial infarction, the intensity of pain was independently rated by the patient and the primary nurse caring for the patient soon after admission. Pain intensity was assessed using a visual analogue scale designed to yield a score of 0-100. 10 experienced coronary care nurses who had participated in a short programme of pain assessment and management were included in the study. A strong positive correlation between the patients' and nurses' ratings was found. Possible explanations for these findings are discussed.

Chest Pain↗

PubMed1994

A telephone survey of medical patients 1 week after discharge from hospital.

The telephone is an effective means of communication and its use is growing as a means of offering members of the public access to health-care agencies for advice and support. Acute hospital beds are at a premium and as lengths of stay in hospital continue to fall there is an increasing need for effective discharge planning and post-discharge support. Eighty-five patients (58 men and 27 women) were interviewed over the telephone 1 week after discharge from a medical ward. Over half of the patients reported health problems and one-fifth reported social problems. Almost half of the patients sought advice. Telephone follow-up would appear to be a useful means of monitoring a patient's progress and providing an opportunity for patients seeking, or nurses offering, advice and support.

Adult↗

PubMed1994

Peer and parental influences on adolescents' substance use: a path analysis.

Five hundred and seven 14-to-16-year-old students gave self-report responses to a substance use questionnaire. The questionnaire assessed adolescents' use, preferences, and norms and also their perceptions of their parents' and peers' use and norms in relation to alcohol, tobacco, and tea/coffee. Path analysis revealed that adolescents' internalization of parental and peer pressures is a stronger predictor of substance use than are direct effects. Internalized effects occur by means of preferences rather than norms, and peer pressure is predominantly through modeling behavior, whereas parental influence is through perceived normative standards. Peers' influence is stronger in relation to tobacco use, parental influence is stronger in relation to tea/coffee use, and both are equally important in relation to alcohol use. These findings are discussed in relation to preventive strategies.

Adolescent↗

PubMed1994

Personality and sociodemographic influences on adolescents' substance use: a path analysis.

Five hundred and seven students 14- to 16-years-old gave self-report responses to a substance use questionnaire, the Norwicki-Strickland Locus of Control Scale, and The Piers-Harris Children's Self-Concept Scale. Path analysis revealed that the influence of peers' and parents' use and norms on adolescents' alcohol and tobacco use is mediated by personality, age, sex, and social status effects. Adolescents with external locus of control or low self-esteem "behavior" were more influenced by their peers to smoke. Younger students and girls were more influenced by parental norms than were older students and boys, but only for alcohol and not for tobacco use. Other findings were that girls were not as strongly influenced by their own norms and that girls and low social status adolescents were more influenced by their friend's smoking and drinking. The peers' findings are discussed in relation to substance prevention strategies.

Adolescent↗

PubMed1992

Patterns of service utilisation following the 1989 Newcastle earthquake: findings from phase 1 of the Quake Impact Study.

A screening questionnaire was distributed to 5,000 adult members of the community six months after the 1989 Newcastle earthquake, with a response rate of 63 per cent (n = 3,007). The mean age of respondents was 46.7 years and 58 per cent were female. Subjects' earthquake experiences were rated in terms of weighted indices of exposure to threat and disruption. Psychological morbidity was measured using the General Health Questionnaire and the Impact of Event Scale. Subjects were asked to indicate which of a range of general and disaster-related support services they had used in dealing with the stressful effects of the earthquake. It was estimated that 21.3 per cent of the adult population used general and/or disaster-related support services. Users of these services reported greater exposure to threat and/or disruption and had higher levels of psychological distress than nonusers. However, a high level of use of general services and reliance on medical services were related more to psychological morbidity than degree of exposure to earthquake-related events. Overall, the Newcastle community's needs for assistance in the aftermath of the earthquake were effectively absorbed by the existing support services and the resources marshalled to supplement those services. Individuals and organisations mobilised following natural disasters need to be strengthened by enhancing the capacity of support service workers to identify and manage psychological distress in their clients.

Adult↗