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Biomedical subjects

B Jalaludin

Publications and source records attributed to B Jalaludin.

At least 19 recordsLinked to original sources
PubMed2006

Childhood asthma and return to school in Sydney, Australia.

OBJECTIVES: To describe the seasonal pattern of hospital admissions for childhood asthma in Sydney, Australia and investigate the relationship between these admissions and time of return to school. STUDY DESIGN: Time-series analysis of daily hospital admissions for childhood asthma in Sydney from 1994 to 2000. METHODS: We defined the time series of all asthma-related hospital admissions in Sydney between 1994 and 2000 for age groups 1-4 and 5-14 years. We analysed the time series for each age group using a generalized additive model with a log-link function, an offset term and quasi-likelihood estimation. Daily admissions were modelled using penalised regression splines adjusting for long term trends, school terms and holidays, weekday and influenza epidemics. RESULTS: After adjusting for potential confounding, the risk of asthma admission increased to a peak between 2 and 4 weeks after the first day of school in each term and varied between 1.5 and 3 times the risk prior to return to school for both age groups. The largest increase in asthma risk occurring in term one after the long summer holiday. The increase in admission risk began soon after the first day of school of each term for school age children 5-14 years, but not in pre-school age children 1-4 years. CONCLUSIONS: Returning to school after term holidays is strongly associated with increased risk of hospital admissions for asthma in children, especially following the long summer holiday. Preventive measures focused on return to school have the potential to substantially decrease admissions for asthma in children.

Absenteeism↗
PubMed2006

The influence of antenatal and maternal factors on stillbirths and neonatal deaths in New South Wales, Australia.

This study identified the influences of maternal socio-demographic and antenatal factors on stillbirths and neonatal deaths in New South Wales, Australia. Bivariate and multivariate analyses were used to explore the association of selected antenatal and maternal characteristics with stillbirths and neonatal deaths. The findings of this study showed that stillbirths and neonatal deaths significantly varied by infant sex, maternal age, Aboriginality, maternal country of birth, socioeconomic status, parity, maternal smoking behaviour during pregnancy, maternal diabetes mellitus, maternal hypertension, antenatal care, plurality of birth, low birth weight, place of birth, delivery type, maternal deaths and small gestational age. First-born infants, twins and infants born to teenage mothers, Aboriginal mothers, those who smoked during the pregnancy and those of lower socioeconomic status were at increased risk of stillbirths and neonatal deaths. The most common causes of stillbirths were conditions originating in the perinatal period: intrauterine hypoxia and asphyxia. Congenital malformations, including deformities and chromosomal abnormalities, and disorders related to slow fetal growth, short gestation and low birth weight were the most common causes of neonatal deaths. The findings indicate that very low birth weight (less than 2,000 g) contributed 75.6% of the population-attributable risks to stillbirths and 59.4% to neonatal deaths. Low gestational age (less than 32 weeks) accounted for 77.7% of stillbirths and 87.9% of neonatal deaths. The findings of this study suggest that in order to reduce stillbirths and neonatal deaths, it is essential to include strategies to predict and prevent prematurity and low birth weight, and that there is a need to focus on anti-smoking campaigns during pregnancy, optimizing antenatal care and other healthcare programmes targeted at the socially disadvantaged populations identified in this study.

Adult↗
PubMed2005

Direct comparison of 18F-fluorodeoxyglucose coincidence gamma camera tomography with gallium scanning for the staging of lymphoma.

BACKGROUND: The present study compared the performance of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) using a coincidence dual-head gamma camera (FDG Co-PET) with 67gallium scinti graphy (GS) in pretreatment staging of lymphoma. METHODS: A total of 46 patients underwent FDG Co-PET, computed tomography (CT) scanning and GS for pretreatment staging of lymphoma (40 newly diagnosed and recurrence) between November 1997 and December 1999. RESULTS: Histological subgroups comprised low grade (8 patients), intermediate grade (25) high-grade (3) non-Hodgkin's lymphoma and Hodgkin's disease (10). Based on clinical assessment, CT scan findings and biopsy, 100 nodal sites and 15 extra-nodal sites were deemed positive. FDG Co-PET was superior to GS in nodal site positivity rate (97%vs 79%, P < 0.0001). Compared with GS, FDG Co-PET detected 39 more abnormal sites in 22 patients (48%), of which 28 sites were validated by biopsy, CT and/or progress FDG Co-PET scanning. There was only one proven false negative FDG site in the spleen. CT + FDG Co-PET led to upstaging in 2 patients (4%), compared to CT + GS. CONCLUSION: FDG Co-PET shows potential for providing an accurate means for pretreatment staging of lymphoma and can detect extra sites of disease activity compared to GS.

Adult↗
PubMed2005

Impact of ambient air pollution on birth weight in Sydney, Australia.

BACKGROUND: Studies in Asia, Europe, and the Americas have provided evidence that ambient air pollution may have an adverse effect on birth weight, although results are not consistent. METHODS: Average exposure during pregnancy to five common air pollutants was estimated for births in metropolitan Sydney between 1998 and 2000. The effects of pollutant exposure in the first, second, and third trimesters of pregnancy on risk of "small for gestational age" (SGA), and of pollutant exposure during pregnancy on birth weight were examined. RESULTS: There were 138,056 singleton births in Sydney between 1998 and 2000; 9.7% of babies (13,402) were classified as SGA. Air pollution levels in Sydney were found to be quite low. In linear regression models carbon monoxide and nitrogen dioxide concentrations in the second and third trimesters had a statistically significant adverse effect on birth weight. For a 1 part per million increase in mean carbon monoxide levels a reduction of 7 (95% CI -5 to 19) to 29 (95% CI 7 to 51) grams in birth weight was estimated. For a 1 part per billion increase in mean nitrogen dioxide levels a reduction of 1 (95% CI 0 to 2) to 34 (95% CI 24 to 43) grams in birth weight was estimated. Particulate matter (diameter less than ten microns) in the second trimester had a small statistically significant adverse effect on birth weight. For a 1 microgram per cubic metre increase in mean particulate matter levels a reduction of 4 grams (95% CI 3 to 6) in birth weight was estimated. CONCLUSION: These findings of an association between carbon monoxide, nitrogen dioxide, and particulate matter, and reduction in birth weight should be corroborated by further study.

Air Pollutants↗
PubMed2002

An assessment of basic treatment equivalent at Cookridge Hospital.

The Australian model of Basic Treatment Equivalent (BTE) for measuring radiotherapy treatment productivity was developed for and tested within a busy UK radiotherapy centre and the results assessed against three other BTE models. The department's productivity was compared for three different models of treatment machine. Treatment fraction durations were timed for 362 consecutive treatment episodes on three treatment machines at Cookridge Hospital. Leeds. The treatment factors found to have a statistically significant impact on fraction duration were: initial fraction; patient mobility; number of fields; treatment intent and the type of treatment machine. In comparison with the Australasian study, shorter mean fraction times were shown for a number of types of treatment, carried out on one particular linac type, which had multileaf collimation (MLC). The average non-operational time was 17% at Cookridge (31% in Australasia) with overall productivity gains. This efficiency may have been achieved partly by a higher number of staff per machine (five rather than four) and the presence of newer technology such as MLC. A BTE model was derived for Cookridge using the significant treatment factors and compared to other published models. The Cookridge model was most sensitive in predicting productivity. BTE models developed by other groups were also excellent in predicting treatment duration. The development of a BTE model is potentially applicable in the U.K. radiotherapy community at a time when optimizing activity per radiographer is key to minimizing waiting times.

Adolescent↗
PubMed2001

Trauma case management and clinical pathways: prospective evaluation of their effect on selected patient outcomes in five key trauma conditions.

BACKGROUND: This study evaluated the implementation of clinical pathways and case management between July 1998 and July 1999 in five key trauma conditions: severe head injury, fractured ribs, fractured pelvis, blunt abdominal trauma, and fractured femurs presenting to a single trauma service. METHODS: Thirteen key elements of care with expected outcomes were defined for each key trauma condition. Deviations from expected outcome were defined as variances. Attainment of the expected outcomes was measured before (stage 1) and after introduction (stages 2 and 3) of clinical pathways and case management. Nonattained outcomes were quantified and categorized into time of occurrence, and relationship to staff, patient, or system. RESULTS: Two hundred thirty-five patients were studied, with a mean age of 41.8 (SD, 20.6) years and mean Injury Severity Score (ISS) of 11.7 (SD, 11.0). The mean number of observed variances per patient for stage 1 was 51.7 (SD, 43.5); stage 2, 42.3 (SD, 32.9); and stage 3, 23.2 (SD, 21.7) (p = 0.0001 for both stage 1 and stage 2 compared with stage 3). There was a significant improvement in outcomes achieved from stage 1 (92.7%; 95% confidence interval, 92.5-92.9%), to stage 3 (96.7%; 95% confidence interval, 96.5-96.9%). Of the total number of variances seen, 0.2% related to system errors, 25% related to patient factors, and 75.8% related to staff. The proportion of staff-related variances was significantly reduced in stage 3. CONCLUSION: Clinical pathways and case management identified areas in need of remedial action and improved the delivery of patient care to our trauma population. It has set a template for the future management of our trauma service.

Abdominal Injuries↗
PubMed2000

Acute effects of bushfires on peak expiratory flow rates in children with wheeze: a time series analysis.

OBJECTIVES: To determine the effects of the January 1994 Sydney bushfire on evening peak expiratory flow rates (PEFR) in children with wheeze. METHODS: Children with a history of wheeze were enrolled in the longitudinal study and completed a daily asthma diary. We obtained daily air pollution, meteorological, pollen and alternaria data. We then used generalised estimating equation techniques to determine associations between the bushfire period and particulate matter less than 10 microns (PM10) and PEFR. RESULTS: The maximum daily PM10 level peaked at 210 ug/m3, which was nearly seven times the usual PM10 level for the rest of January and February 1994. There was no significant association between mean PM10 and PEFR (beta-coefficient = -0.009, p = 0.86). Children without bronchial hyper-reactivity had a significant negative association between PEFR and PM10 (beta-coefficient = -0.1029, p = 0.03). The bushfire period was not significant in any of the models. CONCLUSIONS: We did not find an association between the bushfire period or PM10 and evening PEFR, although in a subgroup of children without bronchial hyper-reactivity, a significant negative association was present between PM10 and evening PEFR. IMPLICATIONS: We conclude that the high levels of particulate pollution caused by the Sydney bushfires did not lead to any clinically significant reductions in PEFR in symptomatic children. Our results have implications for community risk communication during future bushfires.

Air Pollution↗
PubMed1999

Validation of a predictive model for asthma admission in children: how accurate is it for predicting admissions?

We studied 364 index presentations to the Emergency Department of a children's hospital with a diagnosis of asthma. The admission rate for this group of children was about 31%. We developed a parsimonious multiple logistic regression model to predict asthma hospital admission based on asthma severity indicators. We then evaluated the model's predictive ability using two methods of cross-validation, using the same sample that was used for the predictive model, and using data from a split sample. The logistic regression model had a predictive accuracy of 90% (95% confidence interval 85-95%). The sensitivity and specificity were 86% and 88%, respectively. Cross-validation models confirmed that the predictive ability of the model was stable. In studies with limited sample sizes, it is possible to validate a model without setting aside a split sample for cross-validation.

Acute Disease↗
PubMed1998

Association between Der p 1 concentration and peak expiratory flow rate in children with wheeze: a longitudinal analysis.

BACKGROUND: House dust mite (HDM) allergen exposure has been well documented as an environmental cause of airway hyperresponsiveness (AHR) and asthma symptoms. The relationship between asthma morbidity and exposure to low concentrations of HDM allergen suggests that there may be no safe exposure threshold to HDM allergen. OBJECTIVE: We aimed to investigate the associations between Der p 1 in bedding and lung function in 30 children with a history of wheezing in a longitudinal study. METHODS: After a cross-sectional study of school children, which included histamine challenge for AHR and skin testing for dust mite atopy, we made repeated measurements of HDM allergens in children with a history of wheeze over a 12-month period. These children also kept a daily asthma diary in which they recorded their peak expiratory flow rates (PEFRs). We used a repeated measures model to determine the association between PEFR and HDM allergen concentration. RESULTS: There was a significant association between PEFRs and HDM allergen concentration (beta-coefficient = -14.17, P = .0024) in children with HDM atopy. An association was not found in children without HDM atopy. CONCLUSIONS: These findings support the hypothesis that HDM allergens have an adverse effect on the lung function of children with wheeze and highlight the importance of maintaining low dust mite allergen levels throughout the year in the home environment of children sensitized to HDMs.

Allergens↗
PubMed1998

A cluster of meningococcal disease in western Sydney, Australia initially associated with a nightclub.

Fourteen cases of meningococcal disease (MD) occurred in August September 1996 in western Sydney, Australia. Seven of the 10 young adults affected had a direct or indirect link with a local nightclub. Ten of 11 systemic meningococcal isolates had the phenotype C:2a:P1.5 and showed close genetic relationship by pulsed-field gel electrophoresis (PFGE). Organisms of this phenotype have not previously caused outbreaks in Australia, but have been associated with outbreaks and hyperendemic serogroup C MD in Europe, Canada, and the United States. This is the largest cluster of serogroup C MD reported in urban Australia, and the first involving a nightclub. The strain differentiation results were available rapidly enough to augment epidemiological investigations on a daily basis. Public health staff could thus establish links between cases quickly, follow the spread of new cases in the community, give accurate information to health officials and the press, and utilize existing knowledge about the characteristics of this phenotype to predict likely developments during the outbreak and afterwards. The strain differentiation data was also very helpful when the role of vaccination was considered, and existing guidelines on the management of outbreaks of MD could be used effectively for the first time in western Sydney.

Adolescent↗
PubMed1998

Admission rates as an indicator of the prevalence of severe asthma in the community.

BACKGROUND: A reliable indicator of the prevalence of severe asthma in the community is needed to monitor population-based asthma control strategies. We examined the potential use of asthma admissions to hospital as such an indicator. METHODS: We recruited subjects from the Emergency Department (ED) of a children's hospital. The attending doctor completed the 'physician questionnaire' which included questions on the patient's asthma severity and interval severity/chronicity of asthma. The parent/guardian completed the 'parent questionnaire'. It included questions on demography, asthma knowledge and attitudes, asthma history and social support. We performed univariate and multiple logistic regression to determine predictors for hospital admission. RESULTS: Interval severity of asthma, pre-treatment severity of wheeze and low post-treatment pulse oximetry best predicted whether children presenting with asthma were admitted. Demographic variables, factors associated with access to health services and factors related to the asthma history and management were not significant predictors of admission. DISCUSSION: At the population level, it may be possible to utilise routine hospital admission rates as an indicator of the prevalence of severe asthma in the community, especially within the context of monitoring trends in asthma prevalence. Our study was conducted in a metropolitan tertiary paediatric hospital. The reliability of hospital admission rates as indicators of the prevalence of severe asthma in other hospital settings, in different population groups and over time remains to be established.

Adolescent↗
PubMed1998

Cancer incidence and mortality around a hazardous waste depot.

The Castlereagh Regional Waste Disposal Depot (CRWDD) has been the focus of community concerns regarding the impact of hazardous waste disposal on their health and that of their local environment. As part of a phased epidemiological approach to investigate the levels of illness in people living in the vicinity of the CRWDD, routinely collected data were used to determine the rates of cancer and mortality in the area around the site and whether these rates were higher than expected when compared with New South Wales (NSW). The area investigated was based on eight census collection districts around the boundary of the CRWDD. Cancer incidence and mortality in the study area were calculated and compared to NSW using the indirect method of age and sex standardisation. Over an 18-year period, brain cancer in males (six cases) was the only cancer where the incidence in the study area was significantly higher than expected (SIR 380, 95% CL 139.4, 826.6). When this data were examined over smaller (arbitrary) time periods, there was an apparent cluster of brain cancer in males (three cases) between 1989 and 1991 (SIR 905, 95% CL 187,2646). There was a significant concentration of cases of cancers of the breast in females and cancers of the uterus over the smaller time periods. Although continued surveillance of these cancers is recommended, there are several basic limitations associated with small area data analysis that prevent a clear interpretation of these results. This limits our ability categorically to resolve the concerns of those living in the vicinity of the CRWDD.

Adult↗
PubMed1998

Environmental investigation of a legionellosis outbreak in western Sydney: the role of molecular profiling.

This investigation used DNA profiling in an attempt to identify the environmental source of a community outbreak of 11 cases of Legionnaires' disease. Nine of these cases were culture positive and a single strain (DNA profile) of Legionella pneumophila serogroup 1 was isolated from eight cases. Spot water samples were collected from 51 cooling towers implicated by case exposure histories; this same strain was isolated from four towers at three separate locations up to 6 km apart. None of these locations had been frequently implicated by case histories. Because we did not perform an analytic epidemiological investigation, we were unable to identify a single environmental source for the outbreak. It is also possible that this outbreak was multifocal. The use of molecular profiling should not overshadow the importance of epidemiological methods in these environmental investigations. More data is needed regarding the prevalence, distribution, and clinical significance (virulence) of environmental L. pneumophila strains. This would aid interpretation of molecular profiling used in investigations of community legionellosis outbreaks.

Australia↗
PubMed1996

Asthma presentations to emergency departments in western Sydney during the January 1994 Bushfires.

BACKGROUND: From 5 to 12 January 1994, the state of New South Wales suffered from the worst bushfires seen this century. High levels of particulate air pollution were recorded in western Sydney from 7 to 14 January 1994, with nephelometry readings reaching 10.24 beta scat (10(-4)/m) and particulate matter < 10 mu readings peaking at 250.00 micrograms/m3. The aim of this study was to determine whether there was an increase in the proportion of asthma presentations to emergency departments (ED) in western Sydney as a result of the bushfire-generated particulate air pollution. METHOD: We retrospectively analysed the emergency room attendance books for asthma presentations from seven public hospitals serving the Western Sydney and Wentworth Health Areas over two 6-7 week periods, 17 December 1992 to 31 January 1993, and 17 December 1993 to 31 January 1994. Air pollution and meteorological data were obtained from local monitoring stations. RESULTS: The difference in the proportion of all ED presentations that were due to asthma during the week of the bushfire-generated air pollution, compared with the same week 12 months before, after adjusting for baseline changes over the 12-month period, was 0.0067 (95% CI: -0.0007, 0.0141). The maximum daily nephelometry reading was not a significant predictor of the daily number of asthma presentations to ED in any of the Poisson regression models. CONCLUSIONS: The bushfire-generated particulate air pollution in January 1994 did not result in an increase in asthma presentations to ED in western Sydney.

Adolescent↗
PubMed1996

The asthma health outcome indicators study.

Health outcomes have become an important public health policy focus in Australia. The New South Wales Health Department's Health Outcomes Program includes asthma as one of its priority areas. This study combined a survey of a non-random sample of 14 asthma researchers and clinicians and the results of a literature review to determine the current status and validity of outcome indicators used in relation to asthma. A written questionnaire was used to present individual patient, clinical trial, school intervention and public health scenarios, and respondents were asked to nominate asthma outcome indicators they would use in each scenario as well as their estimate of the indicators' validity. The results provide a critical appraisal of a variety of asthma outcome indicators with regard to their repeatability, and their concurrent and predictive validity.

Adolescent↗
PubMed1996

Clostridium perfringens food-borne outbreak: an epidemiological investigation.

On 3 April 1994, the Western Sector Public Health Unit was notified of an outbreak of gastroenteritis at a Christian youth camp. Attending the camp were 820 people; 241 (42 per cent) of 574 camp participants who completed a questionnaire reported illness. Of these, 230 met the case definition. Main symptoms reported were stomach cramps (78 per cent), diarrhoea (67 per cent) and nausea (46 per cent). Bacterial analysis of leftover chicken grew 2.3 x 10(7) and 3.3 x 10(7) colonies/g of Clostridium perfringens, and we identified Type A enterotoxin of C. perfringens in four of seven stool samples collected from ill people. Camp participants who consumed chicken at lunch on the second day of the camp were nearly four times as likely to be ill than those who did not (relative risk 3.81, 95 per cent confidence interval 3.07 to 4.72). There were deficiencies in hygiene and food preparation. We highlight the importance of time and temperature controls in food preparation and storage to prevent contamination and subsequent poisoning by C. perfringens or other food pathogens. This investigation demonstrates the importance of a multidisciplinary team when investigating disease outbreaks.

Adolescent↗
PubMed1995

Increasing response rates in telephone surveys: a randomized trial.

BACKGROUND: Sampling frames and mode of contact and administration of questionnaires are important factors contributing to response rates and selection bias in population-based research. The purpose of this paper is to evaluate whether contact by mail before contact by telephone increases response rate, and to assess the concurrent validity of telephone surveys for collecting health research and service data. METHODS: Two thousand households were randomly selected from electronic white pages. Half were randomly allocated to receive or not to receive an explanatory letter before telephone contact. Interviewers were blinded to whether a household received a letter. Respondents aged 18 years or over were randomly selected from within each household using a Kish grid and interviewed by telephone. RESULTS: The overall response rate was 68 per cent [confidence interval (CI) 66-70]. The response rate of those who received the letter was 76 per cent (CI 73-79), and of those who did not receive the letter was 60 per cent (CI 56-63). Use of the Kish grid to select randomly a respondent decreased the response rate by less than 10 per cent. The internal validity of the data was as follows: in a 10 per cent sub-sample, the Kish grid had been correctly applied in 93 per cent of households, and in 99 per cent of households the exclusion criteria had been correctly adhered to. The external validity was as follows: comparisons with data obtained from the same reference population using similar instruments administered face-to-face revealed no meaningful or significant differences in population estimates. CONCLUSIONS: Mail-out before telephone contact greatly increases response rates at low cost. Telephone surveys can yield valid, useful data for health research and service evaluation.

Adult↗