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Biomedical subjects

J J McNeil

Publications and source records attributed to J J McNeil.

At least 37 records · Page 2Linked to original sources
PubMed2001

A model for predicting the future incidence of coronary heart disease within percentiles of coronary heart disease risk.

BACKGROUND: We present a method (The CHD Prevention Model) for modelling the incidence of fatal and nonfatal coronary heart disease (CHD) within various CHD risk percentiles of an adult population. The model provides a relatively simple tool for lifetime risk prediction for subgroups within a population. It allows an estimation of the absolute primary CHD risk in different populations and will help identify subgroups of the adult population where primary CHD prevention is most appropriate and cost-effective. METHODS: The CHD risk distribution within the Australian population was modelled, based on the prevalence of CHD risk, individual estimates of integrated CHD risk, and current CHD mortality rates. Predicted incidence of first fatal and nonfatal myocardial infarction within CHD risk strata of the Australian population was determined. RESULTS: Approximately 25% of CHD deaths were predicted to occur amongst those in the top 10 percentiles of integrated CHD risk, regardless of age group or gender. It was found that while all causes survival did not differ markedly between percentiles of CHD risk before the ages of around 50-60, event-free survival began visibly to differ about 5 years earlier. CONCLUSIONS: The CHD Prevention Model provides a means of predicting future CHD incidence amongst various strata of integrated CHD risk within an adult population. It has significant application both in individual risk counselling and in the identification of subgroups of the population where drug therapy to reduce CHD risk is most cost-effective.

Actuarial Analysis↗
PubMed2000

Automatic external defibrillators: changing the way we manage ventricular fibrillation.

OBJECTIVE: To discuss recent developments in automatic defibrillation and to review the evidence that first-responders equipped with automatic external defibrillators (AEDs) improve survival from out-of-hospital cardiac arrest. DATA SOURCES: MEDLINE search from 1966 to 1999 (articles in English only) and examination of bibliographies. STUDY SELECTION: Published studies of out-of-hospital cardiac arrest and first-responders equipped with AEDs. Studies had to have a control group and to report survival to hospital discharge from ventricular fibrillation (VF). DATA EXTRACTION: Six studies met the selection criteria (two prospective randomised trials, two prospective controlled trials, and one cohort study and one retrospective study, both with historical controls). DATA SYNTHESIS: A random effects meta-analysis of odds ratios for survival from VF. CONCLUSIONS: Meta-analysis suggests that equipping first-responders with AEDs increases the probability of survival to hospital discharge after out-of-hospital cardiac arrest (odds ratio, 1.74; 95% CI, 1.27-2.38; P < 0.001). However, most of the studies lacked sufficient power to draw definitive conclusions. Until the impact of wide deployment of AEDs is fully understood, first-responder defibrillation in Australia should only occur as part of coordinated multicentre research studies.

Australia↗
PubMed2000

Out-of-hospital cardiac arrest.

Out-of-hospital cardiac arrest (OHCA), with its high fatality rate, is a significant public health issue. The aetiology of OHCA is reviewed, and management strategies are discussed, including the "chain of survival", the Utstein method of data collection, and recent developments in advanced cardiac life support emphasising defibrillation.

Australia↗
PubMed2000

Clinical features of tiaprofenic acid (surgam) associated cystitis and a study of risk factors for its development.

A case-control study was performed to describe the clinical course and identify risk factors predisposing to the development of tiaprofenic acid associated cystitis. Cases were identified from reports to the Australian Adverse Drug Reactions Advisory Committee and a two-year (1995-1996) national surveillance programme. Definition of a case was onset of symptoms of cystitis while taking tiaprofenic acid with pyuria (>10 WBC/microl) and/or hematuria (>10 RBC/microl), and no evidence of urinary tract infection. Definitions of "prescriber-matched" and "unmatched" controls were those who had been prescribed tiaprofenic acid by the same prescriber within 12 months of the case without developing cystitis or were identified from the databases of local pharmacies of the cases respectively. 81 of 109 identified cases and 109 of 184 potential controls completed a standardised interviewer-administered questionnaire. Median time between the commencement of tiaprofenic acid and symptom onset was 6. 3 months (range 0.1-47.1 months). Median interval between presentation to doctor and drug cessation was 3.0 months (range 0-24. 5 months). In half the patients, symptoms resolved within 14 days of ceasing therapy. Increasing age was a risk factor for the development of tiaprofenic-acid associated cystitis, age >70 years-odds ratio 3.2 (95% confidence interval 1.3-7.9) compared with age <55 years. Patients taking aspirin had a reduced risk (odds ratio 0.3, 95% confidence interval 0.1-0.9). Dose and amount of fluid consumed per day were not related to the risk of cystitis. Earlier recognition of tiaprofenic acid associated cystitis can potentially reduce the morbidity related to this condition. Apart from an increased risk among older patients, it is likely that this condition represents a drug reaction that cannot be predicted from clinical variables.

Adult↗
PubMed2000

Community-based recruitment strategies for a longitudinal interventional study: the VECAT experience.

This article examines different recruitment strategies for the VECAT Study, a 4-year, double-masked, placebo-controlled, randomized clinical trial of vitamin E in the prevention of cataract and age-related maculopathy. Five recruitment methods were employed: newspaper advertising, radio advertising, approaches to community groups, approaches via general practices, and an electoral roll mail-out. Participants (1204) from the community in Melbourne, Australia were recruited and enrolled within 15 months (age range: 55-80 years, mean 66 years; gender ratio: 57% female, 43% male). The electoral roll mail-out and newspaper advertising were the most efficient methods of recruitment in terms of absolute numbers of participants recruited and cost per participant. Recruitment for the VECAT study was successfully completed within the planned period. Although the electoral roll mail-out and newspaper advertising were the most efficient for this study, other methods may be of value for studies with different subject selection criteria.

Aged↗
PubMed2000

Carotid artery intima-medial thickness is increased in chronic renal failure.

1. Chronic renal failure (CRF) is associated with rapidly progressive atherosclerotic vascular disease. In the present study, carotid arterial intima-medial thickness (IMT) was assessed in a large cohort of patients with CRF and matched controls and related to risk factors. 2. A total of 159 subjects with CRF (serum creatinine > or =0.40 mmol/L) aged > 50 years (mean (+/-SD) 63.8+/-7.7 years) and 159 healthy controls matched for age, sex and smoking status were studied. 3. The IMT was determined using B-mode ultrasound measurements of the far wall of both common carotid arteries and presented as the mean IMT. Fasting plasma homocysteine (tHcy) was measured in the CRF group. 4. Intima-medial thickness was significantly greater in CRF patients than controls (0.89+/-0.17 vs 0.73+/-0.13 mm, respectively) after matching for age, sex and smoking status. Heart rate and pulse pressure were also significantly increased. The tHcy was increased two-fold in the CRF group (27.7+/-11.3 micromol/L; normal < 13.0 micromol/L) and did not correlate with carotid IMT. 5. Compared with controls after adjusting for traditional risk factors, patients with CRF exhibit significantly increased IMT.

Blood Pressure↗
PubMed2000

Methods for detecting age-related maculopathy: a comparison between photographic and clinical assessment.

PURPOSE: To examine the sensitivity, specificity and overall agreement between photographic and clinical assessment in detecting age-related maculopathy (ARM) features in the context of an epidemiological study, the Vitamin E, Cataract and Age-related Maculopathy Study (VECAT). METHODS: A total of 1204 volunteers aged between 55 and 80 years of age, who were enrolled in the VECAT Study, had both slit-lamp biomicroscopy examination and fundus photos taken as part of the baseline ophthalmic examination. The Nidek 3-DX fundus camera (Nidek, Gamagori, Japan) was used to produce paired, one-framed, coloured, 15 degrees stereoslides of the macular area at a fixed angle. An International Classification and Grading System for Age-related Maculopathy and Age-related Macular Degeneration was used to grade the stereoslides. Agreement in the detection of drusen, pigment abnormalities, and late stage ARM features was assessed using unweignted kappa statistic. Cases of disagreement were verified using clinical data records, grading documentation and the review of stereoslides. RESULTS: Macula status was available for 2386 eyes. For drusen of size < 63 microm, sensitivity was 47%, specificity was 68% with a kappa value of 0.20. For drusden > or = 125 microm, sensitivity and specificity were > or =81%. Kappa values ranged from 0.56 to 0.71. Levels of agreement for pigment abnormalities and late ARM were in the substantial range (i.e. kappa values from 0.70 to 1.00). CONCLUSIONS: Slit-lamp biomicroscopy was found to be comparable to photograding (using the Nidek 3-DX fundus camera) for detecting features pertaining to ARM. However, given the objectivity and permanency of stereoslides, photograding is still the more reliable and the preferred system of assessing ARM in the context of an epidemiological study.

Aged↗
PubMed2000

Respiratory symptoms and lung function in alumina refinery employees.

OBJECTIVES: Employees in alumina refineries are known to be exposed to a number of potential respiratory irritants, particularly caustic mist and bauxite and alumina dusts. To examine the prevalence of work related respiratory symptoms and lung function in alumina refinery employees and relate these to their jobs. METHODS: 2964 current employees of three alumina refineries in Western Australia were invited to participate in a cross sectional study, and 89% responded. Subjects were given a questionnaire on respiratory symptoms, smoking, and occupations with additional questions on temporal relations between respiratory symptoms and work. Forced expiratory volume in 1 second (FEV(1)) and forced vital capacity (FVC) were measured with a rolling seal spirometer. Atopy was assessed with prick skin tests for common allergens. Associations between work and symptoms were assessed with Cox's regression to estimate prevalence ratios, and between work and lung function with linear regression. RESULTS: Work related wheeze, chest tightness, shortness of breath, and rhinitis were reported by 5.0%, 3.5%, 2.5%, and 9.5% of participants respectively. After adjustment for age, smoking, and atopy, most groups of production employees reported a greater prevalence of work related symptoms than did office employees. After adjustment for age, smoking, height, and atopy, subjects reporting work related wheeze, chest tightness, and shortness of breath had significantly lower mean levels of FEV(1) (186, 162, and 272 ml respectively) than subjects without these symptoms. Prevalence of most work related symptoms was higher at refinery 2 than at the other two refineries, but subjects at this refinery had an adjusted mean FEV(1) >60 ml higher than the others. Significant differences in FVC and FEV(1)/FVC ratio, but not FEV(1), were found between different process groups. CONCLUSIONS: There were significant differences in work related symptoms and lung function between process groups and refineries, but these were mostly not consistent. Undefined selection factors and underlying population differences may account for some of these findings but workplace exposures may also contribute. The differences identified between groups were unlikely to be clinically of note.

Air Pollutants, Occupational↗
PubMed2000

Stroke incidence on the east coast of Australia: the North East Melbourne Stroke Incidence Study (NEMESIS).

BACKGROUND AND PURPOSE: Community-based stroke incidence studies are the most accurate way of explaining mortality trends and developing public health policy. The purpose of this study was to determine the incidence of stroke in a geographically defined region of Melbourne, Australia. METHODS: All suspected strokes occurring in a population of 133 816 residents in suburbs north and east of Melbourne, Australia, during a 12-month period of 1996 and 1997 were found and assessed. Multiple overlapping sources were used to ascertain cases, and standard definitions and criteria for stroke and case fatality were used. RESULTS: A total of 381 strokes occurred among 353 people during the study period, 276 (72%) of which were first-ever-in-a-lifetime strokes. The crude annual incidence rate (first-ever strokes) was 206 (95% CI, 182 to 231) per 100 000 per year overall, 195 (95% CI, 161 to 229) for males, and 217 (95% CI, 182 to 252) for females. The corresponding rates adjusted to the "world" population were 100 (95% CI, 80 to 119) overall, 113 (95% CI, 92 to 134) for males, and 89 (95% CI, 70 to 107) for females. The 28-day case fatality rate for first-ever strokes was 20% (95% CI, 16% to 25%). CONCLUSIONS: The incidence rate of stroke in our population-based study is similar to that of many European studies but is significantly higher than that observed on the west coast of Australia.

Age Factors↗
PubMed1999

The effects of bonus payments on emergency service performance in Victoria.

OBJECTIVES: To review and analyse the system effects of the Emergency Service Enhancement Program (ESEP): bonus payments made to public hospitals to improve access to care for patients attending emergency departments. DESIGN: A review of the first 3 years' performance data, obtained from the Victorian Emergency Department Minimum Dataset (VEMD). SETTING: 21 public hospital emergency departments in Victoria, Australia (population 4.5 million), with about 700,000 patient attendances per year. The ESEP began in April 1995. MAIN OUTCOME MEASURES: The ESEP indicators of emergency department and inpatient bed access: occasions of "ambulance bypass" (emergency department unable to accept patients arriving by ambulance); emergency waiting times for Category 1, 2 and 3 patients (National Triage Scale) compared with agreed national performance thresholds; and "access block" (> 12 hours' waiting time in the emergency department before admission to hospital). RESULTS: The number of occasions of ambulance bypass per quarter decreased from 600 in 1994 to fewer than 100 in 1997 (P < 0.001). Despite an increased proportion of patient encounters in triage categories 1, 2 and 3 (31% v. 23%), zero waiting times for Category 1 patients were consistently adhered to, and adherence to waiting time thresholds for Category 2 and 3 patients improved significantly (P < 0.001, R2 = 0.74; and P < 0.035, R2 = 0.37, respectively), particularly for Category 2 patients. The number of patients waiting longer than 12 hours in emergency departments decreased non-significantly (P = 0.3, R2 = 0.1). CONCLUSION: Our results show that the ESEP has produced sustained improvements in all the indicators linked with bonus payments.

Diagnosis-Related Groups↗
PubMed1999

The extraction of quality-of-care clinical indicators from State health department administrative databases.

OBJECTIVE: To assess whether three proposed quality-of-care indicators (unplanned readmissions, hospital-acquired bacteraemia, and postoperative wound infection) can be accurately identified from State health department databases. DESIGN: Algorithms were applied to State health department databases to maximise the identification of individuals potentially positive for each indicator. Records of these patients were then examined to determine the percentage of cases that met the precise indicator definitions. SETTING: 10 public, acute-care hospitals from Victoria, South Australia and New South Wales. Data from the 1994-95 and 1995-96 financial years were collected. PARTICIPANTS: Individuals 18 years of age or older who were identified from State health department administrative databases as potentially meeting the indicator criteria. MAIN OUTCOME MEASURES: The proportion of screened cases that met the precise indicator definitions, and the elements of the indicator definitions which could not be extracted from the administrative databases. RESULTS: The proportions of cases confirmed by medical record review to be positive for the indicator events were 76.3% for unplanned readmissions within 28 days, 20% for hospital-acquired bacteraemia, 43.5% for wound infections after clean surgery, and 34.8% for wound infections after contaminated surgery. The clinical elements of each indicator definition were not easily extracted from the administrative databases. CONCLUSIONS: The three proposed clinical indicators could not be extracted from current State health department databases without an extensive process of secondary medical record review. If administrative databases are to be used for assessing quality of care, more systematic recording of data is needed.

Algorithms↗