Hopes, fears, knowledge and misunderstandings: responses of HIV-positive mothers to early knowledge of the status of their baby

Little is known about how HIV-positive mothers experience and react to knowing the HIV status of their baby as diagnosed by the polymerase chain reaction (PCR) test at 4-6 weeks. This qualitative study drew on interviews with 20 mothers of HIV-negative and 18 mothers of HIV-positive babies after receiving their baby's PCR results. Thematic analysis combined exploration of themes that appeared significant to the participants and those relevant to health care. Amongst the themes identified were the following: The period before getting the results involved active mental preparation and was emotionally stressful. Most women accepted the results, but some had doubts about their reliability. Mothers of HIV-negative babies were relieved, but mothers of HIV-positive babies were generally very distressed and expressed a sense of responsibility and guilt. Both groups of mothers had similar hopes for the future of their babies, but the timelines of mothers of HIV-positive babies tended to be shorter. Most women experienced significant levels of stress, but were able to call on support networks and use various individual coping mechanisms to manage their stress. Most women were formula feeding their babies, but regretted not being able to breastfeed. Many women had not planned their current baby and most did not intend to have more children, but many of the latter had not taken active steps to prevent further pregnancy. The findings provide pointers to shortcomings in health worker communication and suggest that more effective communication should take account of normative community views and be more closely attuned to the changing needs and experiences of HIV-positive mothers.

Overview of the pharmacogenetics of asthma treatment

Asthma affects approximately 300 million individuals worldwide. Medications comprise a substantial portion of asthma expenditures. Despite the availability of three primary therapeutic classes of medications, there are a significant number of nonresponders to therapy. Available data, as well as previous pharmacogenetic studies, suggest that genetics may contribute as much as 60-80% to the interindividual variability in treatment response. In this methodologic review, after providing a broad overview of the asthma pharmacogenetics literature to date, we describe the application of a novel family-based screening algorithm to the analysis of pharmacogenetic data and highlight our approach to identifying and verifying loci influencing asthma treatment response. This approach seeks to address issues related to multiple comparisons, statistical power, population stratification, and failure to replicate from which previous population-based or case-control pharmacogenetic association studies may suffer. Identification of such replicable loci is the next step towards the goal of 'individualized therapy' for asthma.

Association of CommonCRPGene Variants with CRP Levels and Cardiovascular Events

C-reactive protein (CRP) is a well-documented marker of atherosclerotic cardiovascular disease risk. We resequenced CRP to identify a comprehensive set of common SNP variants, then studied and replicated their association with baseline CRP level among apparently healthy subjects in the Women's Health Study (WHS; n = 717), Pravastatin Inflammation/CRP Evaluation trial (PRINCE; n = 1,110) and Physicians' Health Study (PHS; n = 509) cohorts. The minor alleles of four SNPs were consistently associated in all three cohorts with higher CRP, while the minor alleles of two SNPs were associated with lower CRP (p < 0.05 for each). Single marker and haplotype analysis in all three cohorts were consistent with functional roles for the 5'-flanking triallelic SNP -286C>T>A and the 3'-UTR SNP 1846G>A. None of the SNPs associated with higher CRP were associated with risk of incident myocardial infarction (MI) or ischemic stroke in a prospective, nested case-control study design from the PHS cohort (610 case-control pairs). One SNP, -717A>G, was unrelated to CRP levels but associated with decreased risk of MI (p = 0.001). Taken together, these data imply significant interactions between both genetic and environmental contributions to the increased CRP levels that predict a greater risk of future atherothrombotic events in epidemiological studies.

Polymorphisms in the interleukin 17F gene (IL17F) and asthma

Interleukin17F (IL17F) is a regulatory cytokine for T-cell-mediated immune responses. The gene coding for IL17F (IL17F) is located on chromosome 6p, a genomic region linked to asthma and asthma-related phenotypes in multiple genome scans. IL17F is expressed in lung tissue, in bronchoalveolar lavage fluid from asthmatic subjects, and in activated CD4+ cells. We were thus interested in testing for association between single-nucleotide polymorphisms (SNPs) and haplotypes in IL17F and asthma. To characterize polymorphisms in IL17F, we sequenced this gene in a group of African Americans and a group of European Americans. A total of 50 SNPs (30 not previously reported in a public database (dbSNP build 118)) and two insertions/deletions were detected in IL17F; five of these polymorphisms were genotyped in participants of the Nurses' Health Study. We then tested for association between SNPs and haplotypes in IL17F and physician-diagnosed asthma in subjects with (cases) and without (control subjects) physician-diagnosed asthma. None of the SNPs or haplotypes tested in IL17F were associated with asthma. The polymorphisms identified in this study may be used in future studies of association between IL17F and phenotypes related to immune responses.

White matter lesions on magnetic resonance imaging and their relationship with vascular risk factors in memory clinic attenders

BACKGROUND

The association between white matter lesions on magnetic resonance imaging (MRI) and the presence of vascular risk factors has been investigated in different populations, and results have varied widely. However, this relationship has not been adequately addressed in memory clinic attenders who have relatively early cognitive impairment.

OBJECTIVES

This study was undertaken to determine the relationship between the severity of white matter lesions and vascular risk factors in elderly subjects referred to a Memory Clinic, irrespective of their diagnoses. Patients attending the Memory Clinic had relatively early, mild cognitive impairment and differed, in this respect, from typical unselected community-based samples and from patients with established dementia. The study also investigated whether periventricular and deep white matter lesions differed in their relationship with vascular risk factors.

METHODS

All patients assessed in the Memory Clinic at Leicester General Hospital between April 1998 and October 2000 who had undergone an MRI scan were included in the study. They received a comprehensive clinical and cognitive assessment, a standard dementia laboratory screen and evaluation of vascular risk factors. MRI scans were reviewed by two independent raters and semi-quantitative ratings of the severity of white matter lesions were made using standardised protocols. The relationship between cerebral white matter lesions and vascular risk factor variables was examined by multiple linear regression.

RESULTS

One hundred and seventy-seven subjects were included in the study. The mean age was 69.8 and the mean MMSE score was 23.2. Of the risk factors investigated, only age and prior cerebrovascular disease were significantly associated with severe periventricular white matter lesions; age, hypertension and diabetes were significantly associated with severe deep white matter lesions.

CONCLUSIONS

Periventricular and deep white matter lesions are differentially influenced by vascular risk factors.

Toll-like receptor 6 gene (TLR6): single-nucleotide polymorphism frequencies and preliminary association with the diagnosis of asthma

Toll-like receptor 6 (TLR6) is one of a series of highly conserved innate immune receptors. We resequenced TLR6 in DNA samples from 24 African Americans, 23 European Americans, and 24 Hispanic Americans, identifying 53 SNPs, 22 with an allele frequency >5%. Significant differences in SNP frequencies among the three populations were noted. In all, 11 SNPs caused amino-acid changes, including one with a frequency >5% in all three populations. Utilizing this SNP (Ser249Pro), we performed exploratory nested case-control disease-association studies, including one involving 56 African Americans with asthma and 93 African American controls. The minor allele of this SNP was associated with decreased risk for asthma (odds ratio 0.38, 95% CI 0.16-0.87, P=0.01), an effect consistent with the known biology of the toll-like receptors. Although replication of this finding in other, larger samples is needed, variation in TLR6 may have relevance to the pathogenesis of immunologically mediated diseases.

National Bioterrorism Syndromic Surveillance Demonstration Program

The National Bioterrorism Syndromic Surveillance Demonstration Program identifies new cases of illness from electronic ambulatory patient records. Its goals are to use data from health plans and practice groups to detect localized outbreaks and to facilitate rapid public health follow-up. Data are extracted nightly on patient encounters occurring during the previous 24 hours. Visits or calls with diagnostic codes corresponding to syndromes of interest are counted; repeat encounters are excluded. Daily counts of syndromes by zip code are sent to a central data repository, where they are statistically analyzed for unusual clustering by using a model-adjusted SaTScan approach. The results and raw data are displayed on a restricted website. Patient-level information stays at the originating health-care organization unless required by public health authorities. If a cluster surpasses a threshold of statistical aberration chosen by the corresponding public health department, an electronic alert can be sent to that department. The health department might then call a clinical responder, who has electronic access to records of cases contributing to clusters. The system is flexible, allowing for changes in participating organizations, syndrome definitions, and alert thresholds. It is transparent to clinicians and has been accepted by the health-care organizations that provide the data. The system's data are usable by local and national health agencies. Its software is compatible with commonly used systems and software and is mostly open-source. Ongoing activities include evaluating the system's ability to detect naturally occurring outbreaks and simulated terrorism events, automating and testing alerts and response capability, and evaluating alternative data sources.

Non-bronchoscopic bronchoalveolar lavage in the microbiological diagnosis of pneumonia in mechanically ventilated patients

A prospective study comparing standardized non-bronchoscopic bronchoalveolar lavage (sNB-BAL) and non-specific endotracheal aspirate (NsETA) in the microbiological diagnosis of pneumonia in mechanically ventilated patients is described. One hundred episodes in 82 mechanically ventilated patients with or without radiological and clinical diagnostic criteria of pneumonia were studied. NsETA and sNB-BAL was performed on the day of study. Fifty-one patients had pneumonia (21 ventilator-associated, 12 hospital-acquired, 18 community-acquired) and 49 had no pneumonia as defined by widely accepted clinico-radiological criteria. The sNB-BAL was found to be significantly more specific (0. 73) compared to NsETA (0.35) for the microbiological diagnosis of pneumonia. Colonization rates with NsETA were significantly higher compared to sNB-BAL (P value <0.0001). No patient had complications attributable to the sNB-BAL procedure. We conlude that sNB-BAL is a safe, effective, sensitive, specific and inexpensive procedure for the serial evaluation of pneumonia in mechanically ventilated patients.

Umbilical cord blood lactate in normal infants: comparison between two methods of measurement

OBJECTIVES

Firstly, to determine the accuracy of the Radiometer ABL 625 lactate electrode (Radiometer Medical Pty Ltd, Nunawading, Victoria, Australia) by comparing the lactate values obtained by this method to those obtained with the Hitachi 917 lactate analyser (Boehringer Mannheim Corporation, Charlottetown, Prince Edward Island, Canada). Secondly, to determine the effect of delay in measurement on blood lactate levels.

METHODOLOGY

Umbilical venous (UCV) blood samples were obtained from healthy term infants delivered vaginally. Lactate levels were measured with the Radiometer ABL 625 lactate electrode in the Neonatal Intensive Care Unit, Westmead Hospital and with the Hitachi 917 lactate analyser in 49 paired samples. In addition 26 UCV blood samples were placed in ice slurry and a further 26 samples at room temperature and blood lactate was measured at 5-min intervals for 30 min to determine the change of lactate levels with time.

RESULTS

The lactate levels obtained from the Radiometer ABL 625 lactate electrode were consistently lower than the levels obtained from the Hitachi 917 lactate analyser (mean difference - 0.24), but the correlation was high (r = 0.97). The blood lactate levels increased at the rate of 0.012 mmol/L per min if the blood was left at room temperature. The lactate levels remained stable for 20 min if the blood was placed in ice slurry.

CONCLUSION

The Radiometer ABL 625 lactate electrode was easy to use and there was high correlation with the values obtained by the standard laboratory method. The blood specimen must be place in an ice slurry if a delay in analysis is anticipated.

Prevalence and prognostic significance of malnutrition in chronic renal insufficiency

OBJECTIVE

Malnutrition is present in a significant proportion of patients commencing dialysis. However, the prevalence and prognostic significance of malnutrition within the chronic renal insufficiency (CRI) population before the initiation of dialysis is poorly characterized. The aim of this study was to determine the prevalence and prognostic significance of malnutrition in an unselected group of patients with CRI.

DESIGN

Cohort analytic study.

SETTING

Ambulatory care practice of a university teaching hospital.

PATIENTS

Fifty patients with CRI (serum creatinine concentration > or = 1.7 mg/dL) were enrolled. Patients with a recent acute illness, nephrotic syndrome, intercurrent steroid therapy, gastrointestinal disease, or other severe organ failure that may have independently influenced nutritional status were excluded.

INTERVENTION

At baseline, patients had a nutritional assessment consisting of subjective global assessment (SGA), measurement of body mass index (BMI), midarm circumference (MAC), serum albumin concentration, total lymphocyte count, and single frequency bioelectrical impedance analysis. Patients received standard medical care and were followed prospectively at quarterly intervals for 12 months.

RESULTS

At baseline assessment, 28% of patients had evidence of malnutrition by SGA criteria. The malnourished group of patients had a significantly lower creatinine clearance (18.9 +/- 9.8 v 36.5 +/- 14.0 mL/min/1.73 m(2), mean +/- SD, P <.001), glomerular filtration rate (20.7 +/- 10.9 v 28.5 +/- 12.5 mL/min/1.73 m(2), P =.04), BMI (22.7 +/- 2.9 v 29.0 +/- 5.0 kg/m(2)), and MAC (24.3 +/- 4.9 v 30.7 +/- 4.8 cm, P <.001), but there were no differences in serum albumin concentration or total lymphocyte count between the groups. At the 12-month follow-up, there was significantly increased mortality (21% v 3%, P =.04), composite endpoint of death or dialysis (50% v 11%, P =.02), and likelihood of acute hospitalization (78% v 23%, P =.001) in the malnourished group. A significant association was observed between baseline nutritional status and subsequent admission to hospital and baseline glomerular filtration rate and progression to end-stage renal failure.

CONCLUSION

These data suggest that SGA provides a useful means of assessing nutritional status and is helpful in identifying patients with increased risk of morbidity and mortality in the setting of CRI.

Cost of dental services provided in private general practice for an insured population in New South Wales, Australia

OBJECTIVE

To determine cost of dental services provided to a cohort of insured population 18 years and over, who used private general dental practice in New South Wales, Australia.

BASIC RESEARCH DESIGN

This cohort study used the person-years method and Weibull regression for analysis. Setting Data were derived from claims records submitted for rebates by members of a health insurance fund for services they received in private general dental practice during 1 January 1992-31 December 1995.

PARTICIPANTS

75,501 members from New South Wales.

MAIN OUTCOME MEASURES

To determine, by age groups, the cost per item of dental service, cost of services received at a visit and cost of services received per year.

RESULTS

The median cost per item of dental service received for all ages was A$36.7; with cost increasing with age until 55-64 year age group where an apparent plateau occurred. The median cost of services received at a visit for all ages was Australian dollars 93.5. Cost of services received at a visit increased with age, reaching a plateau in the middle aged groups. The median cost of providing services for all age groups per year was Australian dollar 183.6. The cost of services per year when compared with the youngest age group (18-24 years) increased by about 20% for each successive age group up to the 45-54 year age group. From 55 years onwards the cost levelled off at approximately 70% more than the youngest age group.

CONCLUSION

The cost of providing dental services increased with age to reach a plateau in the middle age groups.

Australian dentists' views on toothbrush wear and renewal

The purpose of this study was to survey the views of Australian dentists on toothbrush wear, toothbrush renewal periods and recommendations to patients and to investigate the relationship between dentists' views on patients' toothbrush renewal intervals and dentists' own renewal habits. Questionnaires were mailed to 5,596 Australian general dental practitioners and replies received from 3,406 (61 per cent response rate). The majority of respondents (85.7 per cent) felt patients should renew their toothbrushes more often. However, only 45.3 per cent usually made a recommendation to their patients as to when they should renew their toothbrush and only 41.7 per cent thought patients actually followed such recommendations. Most respondents (56.6 per cent) thought the average adult patient should renew a toothbrush every two-three months. A renewal period of one month or earlier was recommended by 23.8 per cent of dentists; four-five months by 8 per cent; and six months or longer by 11.5 per cent. A highly significant correlation was found between the renewal periods recommended for patients and the intervals selected by the dentists for their personal brushes (p < 0.001; chi-square test). Bending and splaying of bristles was the sign identified by the majority of dentists (70 per cent) as indicating the need for a new brush. The findings suggest dentists' recommendations concerning toothbrush renewal intervals may be based on their own toothbrush renewal habits. It is also concluded that dentists think patients comply poorly with their recommendations on toothbrush renewal.

Prevalence of Huntington disease in New South Wales in 1996

OBJECTIVE

To estimate the prevalence of Huntington disease (HD) in New South Wales on Australian Census Day (6 August) 1996.

DESIGN

Survey of records of the Huntington Disease Service and major hospitals, and of neurologists, psychiatrists, clinical geneticists and genetic counsellors.

SUBJECTS AND SETTING

All patients in NSW who, on Census Day 1996, either had a definite diagnosis of HD (motor signs of chorea or ataxia and family history of HD or positive DNA test result) or would have had signs and later received a definite diagnosis (assessed 1 April 1997 to 1 July 1999).

MAIN OUTCOME MEASURES

Prevalence (HD patients per 100,000 population); patient characteristics; year and basis of diagnosis.

RESULTS

380 patients with definite HD were identified, giving a prevalence of HD in NSW in 1996 of 6.29 per 100,000 population (95% CI, 5.68-6.96). A third of HD patients were aged 60 years or older. Diagnosis was confirmed by DNA testing for 171 patients (45%), including 30 (8%) with no recorded family history. Average numbers of new diagnoses per year were 11.8 (1984-1988), 21.8 (1989-1993) and 28.6 (1994-1998). Estimated number of people with a 50% risk of inheriting the HD mutation was 25.2 per 100,000 population. Estimated incidence of HD in 1996 was 0.65 per 100,000 population.

CONCLUSIONS

Prevalence of HD in NSW is similar to estimated prevalence in other Australian and Western populations. Increasing numbers of cases are being diagnosed, and the 18 chronic care beds currently designated for HD patients in NSW are unlikely to be sufficient.

Change in body mass index in Australian primary school children, 1985-1997

BACKGROUND

Childhood obesity is an important, potentially modifiable risk factor for a range of concurrent and later morbidities. Despite concerns about recent increases in children's body mass index (BMI), supporting data in Australia (as elsewhere) are scant.

OBJECTIVE

To seek anthropometric evidence of a recent secular increase in BMI in primary school children in Victoria, Australia.

DESIGN

Data from two cross-sectional population-based surveys of primary school children (the Victorian subsample of the 1985 Australian Health and Fitness Survey and the 1997 Health of Young Victorians Study) were compared. Similar stratified random sampling and standardized measurement methods were employed in the two studies. Subjects were all children aged 7-12 y with complete height and weight data. Body mass index (BMI (weight/height2)) was used as the index of relative adiposity. Non-parametric and parametric methods were used to examine the pattern and magnitude of change in BMI over the 12 y interval.

RESULTS

Data for 1421 children (50% male, 68% response) from the 1985 survey and 2277 children (51% male, 75% response) from the 1997 survey were analysed. At all ages, mean height and median weight were greater in 1997 than 1985 for both boys and girls. Median BMI was significantly higher in the 1997 sample for all but 12 y-old girls and for boys aged 7, 8 and 10 y (Mann-Whitney U test). The magnitude of the overall increase in BMI was estimated using analysis of covariance for log-transformed BMI adjusted for exact age, which indicated an increase of 1.03 kg/m2 for boys and 1.04 kg/m2 for girls (both P<0. 001). Plots of BMI against BMI percentile clearly showed a pattern of higher BMI at any given percentile, especially at the upper percentiles, for all ages and both genders.

CONCLUSIONS

Primary school children in Victoria have become more obese over the last decade. Increases in BMI are most marked at the heavier end of the distribution. Lesser increases in median and mean BMI (confirmed by both parametric and non-parametric statistical models) may also have major public health implications.

Long-term mortality trends in patients with traumatic brain injury

Comparison of long-term mortality rates between patients with traumatic brain injury (TBI) and the general population has not been adequately investigated. This project aimed to obtain information on the long-term mortality rate of patients with TBI. Using a rehabilitation database of a major teaching hospital, the search identified 476 patients, of whom 27 were deceased. This mortality rate (5.7%) was compared with the expected mortality rate for an equivalent population without TBI (1.5%) using Australian Life Table data. It was found that patients with TBI had a significantly higher mortality rate than the general population (chi2 = 12.2, p < 0.001). Possible reasons for this finding are discussed.

Use of self-report to monitor overweight and obesity in populations: some issues for consideration

OBJECTIVE

To examine the validity of self-reported height and weight data reported over the telephone in the 1997 NSW Health Survey, and to determine its accuracy to monitor overweight and obesity in population surveys.

METHOD

Self-reported and measured heights and weights were collected from 227 people living in Western Sydney, who had participated in the NSW Health Survey 1997.

RESULTS

Self-reported (SR) weights and heights led to misclassification of relative weight status. BMI, based on measured weights and heights, classified 62% of males and 47% of females as overweight or obese, compared with 39% and 32%, respectively, from self-report.

CONCLUSIONS

Caution should be used when interpreting SR height and weight data from surveys, because BMI derived from these is likely to underestimate the true prevalence of overweight and obesity.

IMPLICATIONS

SR data have a place in nutrition monitoring because they are relatively inexpensive and easy to collect. However, classifying people into weight categories on the basis of accepted cut-points, using SR heights and weights, yields inaccurate prevalence estimates. Periodic sub-studies of the validity of SR heights and weights are needed to indicate the extent to which the validity of SR is changing.

Dental service provision in private general practice for an insured population in New South Wales, Australia

OBJECTIVE

To determine patterns of dental services provided to a cohort of the insured population 18 years and over, in private general practice in New South Wales, Australia.

BASIC RESEARCH DESIGN

A cohort study using the person-years method and Poisson regression for analysis.

SETTING

Data were derived from claims records submitted by members of a health insurance fund (Government Employees Health Fund-GEHF) for rebates during the study period 1 January 1992-31 December 1995.

PARTICIPANTS

There were 133,467 members aged 18 years and over from New South Wales.

MAIN OUTCOME MEASURES

To determine, by age group, for those members who used private general practice and made a claim (referred to as 'patients') the annual number of visits, total number of services received per year and number of services received at a visit.

RESULTS

The mean number of visits per patient was 2.4 per year with patients under 45 years making fewer visits than the 45-54 age group reference category. Mean number of services utilised per patient-year was 5.9, with services provided increasing from 3.5 for the 18-24-year-old group, reaching a plateau of approximately 6.2 for those aged 45 years or more. The number of services received per visit was 2.4 and there were no differences by age. Service mix was dominated by restorative (35%), diagnostic (27%), and preventive services (18%); with age specific variations observed.

CONCLUSIONS

Age was found to be an important determinant in the use of dental services, independent of membership duration and gender.

Prevalence and socio-demographic predictors of dietary goal attainment in an older population

OBJECTIVE

To describe the measured dietary intakes and anthropometry of a large, free-living population of middle-aged and older Australians who participated in the Australian Blue Mountains Eye Study (BMES), and to identify the socio-demographic characteristics associated with attainment or non-attainment of dietary goals.

METHOD

Anthropometry and dietary intakes were compared with current population dietary goals and Recommended Dietary Intakes for 2,873 people (79% of eligible residents) aged > or = 49 years who participated in the BMES. Nutrient intakes were measured by a validated food frequency questionnaire.

RESULTS

Nutrients for which mean intakes deviated most from nutrition goals included: percentages of energy from total and saturated fat, carbohydrate and alcohol (men), as well as absolute intakes of calcium, zinc and fibre. More than half the men (60%) and women (54%) were overweight or obese. Several micro-nutrient goals were more likely to be met in households where the respondents and/or their spouses were independent. Married men were more likely to meet goals for fibre and iron, but less likely to meet the goal for cholesterol. Several goals were more likely to be met by men and women who had qualifications after leaving school, those with higher job status and non-pensioners, suggesting an socio-economic status dimension.

CONCLUSIONS AND IMPLICATIONS

These results indicate that over- rather than under-nutrition is more prevalent among community-dwelling older people, although under-nutrition should not be overlooked. Particular sub-groups that are less likely to meet some dietary goals may require targeting in community nutrition interventions.

Carrots, carotene and seeing in the dark

Should older people eat more carrots, or at least increase their carotene intake to prevent loss of night vision? Participants in the Blue Mountains Eye Study were asked about their ability to see in the dark. Nutrient and food intake were estimated from a food frequency questionnaire. Associations between self-reported poor night vision and estimated nutrient intake were investigated using logistic regression. Poor night vision among women was associated with higher beta-carotene (P for trend = 0.03) and total vitamin A intake (P for trend = 0.048). Increased consumption of carrots, but no other food high in beta-carotene, was associated with significant increased reporting of poor night vision among women (P for trend = 0.04). While carrot intake may protect against difficulty in seeing at night, it is probable that people attributing poor driving ability to their vision may be eating more carrots in the hope of reversing this decline.

Sociodemographic distribution of measures of body fatness among children and adolescents in New South Wales, Australia

BACKGROUND

Obesity in childhood and adolescence is associated with health problems, increases in cardiovascular disease (CVD) risk factors and a greater likelihood of becoming overweight as an adult. A description of the sociodemographic distribution of overweight and obesity among children and adolescents in the population may allow us to determine if health promotion resources should be differentially allocated to particular groups.

METHODS

The New South Wales Schools Fitness and Physical Activity Survey, 1997 (n = 5518) was a cross-sectional survey which measured height, weight, waist and hip girths and skinfold thicknesses of randomly selected New South Wales students in school years 4, 6, 8 and 10. Height and weight only were measured among Year 2 students. The mean ages of students in school years 2, 4, 6, 8 and 10 were 7.3y, 9.3y, 11.3y, 13.3y and 15.3y, respectively. The values of body mass index (BMI), waist girth, waist-to-hip ratio (WHR) and sum of three skinfolds for students resident in urban and rural areas and in tertiles of socioeconomic status (SES) were compared.

RESULTS

There were no differences on any of the anthropometric measures between urban and rural boys and girls, with the exception that WHR was higher among urban girls. Among boys, there were no differences between the SES tertiles on any of the measures. Among girls, each of the anthropometric measures (except sum of skinfolds) was inversely associated with SES, with body fatness tending to be lower in the high SES tertile, compared with the low and middle SES tertiles. None of the statistical interactions between school year and body fatness was significant, suggesting that the relationship is consistent from childhood to adolescence.

CONCLUSION

On the basis of these results, we suggest that health promotion programs aimed at weight management among Australian girls of lower SES are not warranted. We recommend that health promotion programs emphasize regular physical activity, a healthy diet and acceptance of the normal range of body shapes.

The impact of work related trauma on the psychological health of nursing staff: a cross sectional study

This study aims to investigate the effects of work-related trauma exposure on the health of nursing staff in hospitals. The survey was conducted using a randomised sample of 314 nurses. Half (52.2%, n = 189) of staff surveyed had multiple exposures to different kinds of trauma. Results on the General Health Questionnaire (GHQ) and Beck's Depression Inventory--Revised (BDI-R) suggested that nearly 40% of staff experienced poor health, while nearly 10% experienced moderate to severe depression. Results of the logistic analyses, after adjusting for confounders, suggested that high and long term trauma exposure is detrimental to the mental health of nurses. These findings indicate that hospital nursing staff, in particular those who have high exposure to trauma, are in urgent need of support services such as debriefing and counselling.

Interobserver reliability of the click test: a rapid bedside test to determine surfactant function

OBJECTIVE

To determine the interobserver reliability of the click test, a rapid bedside test of surfactant function.

METHODOLOGY

One hundred samples (48 amniotic fluid, 28 gastric aspirates, 24 tracheal aspirates) were obtained from pregnant women, term and preterm infants managed at two perinatal centres. Gestational ages of the pregnancies or infants at time of sampling ranged from 24 to 40 weeks (mean +/- s.d.: 31+/-5). The click test was performed independently by two observers, with differing levels of experience, and blinded to each other's results. Interobserver reliability was determined for samples classified as negative (no clicking bubbles), equivocal (a few clicking bubbles seen after 2 min of looking), and positive (clicking bubbles seen easily on first look). As negative and equivocal test results suggest surfactant dysfunction, these results were also combined to provide a dichotomised result.

RESULTS

For samples classified as negative, equivocal and positive the interobserver agreement was 0.83, with agreement beyond chance shown by a quadratic weighted Kappa of 0.74 (95% CI = 0.62-0.86). When negative and equivocal results were combined, the simple Kappa was 0.73 (95% CI = 0.59-0.87).

CONCLUSIONS

The click test has a high level of interobserver reliability. It is rapid, simple, accurate and able to be taught to medical and nursing staff with appropriate training. It has many potential applications including the prediction of fetal lung maturity in women with premature rupture of membranes, and in term and preterm infants who require the bedside testing of surfactant function.

Baseline ventilatory function predicts the development of higher levels of fasting insulin and fasting insulin resistance index: the Normative Aging Study

A consistent but as yet unexplained association between baseline ventilatory function and risk of coronary heart disease (CHD) has been reported from many prospective studies. Insulin-resistant states are associated with increased risk of CHD. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and maximal mid-expiratory flow rate (MMEF) at study entry were examined as predictors for indirect measures of insulin resistance after a mean follow-up interval of 20.9 yrs in 1050 nondiabetic male subjects in the Normative Aging Study. Males in the top quintile of insulin or fasting insulin resistance index (FIRI) levels at follow-up were defined as being relatively insulin resistant. FVC was negatively associated with risk of being relatively insulin resistant using the insulin (p=0.002) or FIRI (p=0.0001) criteria at follow-up in logistic regression models adjusting for baseline age, body mass index, fat distribution pattern and cigarette smoking. Similar associations were found for FEV1 and MMEF. Additional adjustment for baseline postcarbohydrate challenge glucose levels made little difference to the results, suggesting that baseline glucose intolerance was not a significant source of bias. These findings are consistent with the possibility that insulin resistance may be one of the factors mediating the previously unexplained prospective association between impairment of ventilatory function and risk of mortality from coronary heart disease.

Impaired ventilatory function and elevated insulin levels in nondiabetic males: the Normative Aging Study

Lower levels of baseline ventilatory function have consistently been associated with increased risk of cardiovascular mortality in prospective studies, but the underlying mechanisms are not known. Increased risk of coronary heart disease is associated with higher serum insulin levels. This report examines the relationship between ventilatory function and indirect measures of insulin resistance. Cross-sectional data from 922 nondiabetic participants in the Normative Aging Study were analysed using multiple linear regression models with adjustment for potential confounders. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were examined in relation to indicators of insulin resistance, i.e. fasting insulin and the fasting insulin resistance index (FIRI). Diabetics were excluded because impaired insulin secretion interferes with the validity of these as measures of insulin resistance. Fasting insulin and FIRI were negatively correlated with FVC and FEV1 (all p< 0.001). These associations persisted after adjusting for potential confounders including age, height, body mass index, waist to hip circumference ratio, physical activity, alcohol intake and smoking in separate multiple linear regression models, for both insulin (all p< or =0.0008) and FIRI (all p< or =0.0001). Negative cross-sectional associations between ventilatory function and indirect measures of insulin resistance were found in nondiabetic males. Insulin resistance may contribute to the previously unexplained association between ventilatory function impairment and cardiovascular mortality. Mechanisms underlying the relationship between insulin resistance and decreased ventilatory function remain to be elucidated.

Effects of body composition and fat distribution on ventilatory function in adults

Clinically, gross obesity is associated with disturbances of ventilatory function, but less severe obesity is not generally thought to have a significant effect on ventilatory function. The purpose of this report was to examine cross-sectional data to determine the effects of body composition and fat distribution on ventilatory function in 1235 adults (621 men and 614 women). Forced vital capacity (FVC) was used as a measure of ventilatory function and was adjusted for age, height, smoking, and bronchial symptoms in separate models for men and women. Body fat and fat-free mass were estimated from skinfold-thickness measurements. Adjusted FVC was not significantly associated with body mass or body mass index, but was negatively associated with percentage body fat in men (P = 0.0003) and women (P = 0.043) and positively associated with fat-free mass in men (P = 0.018) and women (P = 0.0001). Handgrip strength was positively associated with adjusted FVC in both sexes (P < 0.02), suggesting that the effect of fat-free mass may be mediated by muscular strength. Adjusted FVC was negatively associated with subscapular-skinfold thickness in both sexes (P < 0.0003) and with waist circumference (P = 0.01) and waist-to-hip ratio (P = 0.03) in men. Previous reports that considered only body mass index or body mass failed to distinguish the opposing effects of fat-free mass and fat mass on FVC.

Cohort study of vitamin C intake and cognitive impairment

To test the hypothesis that vitamin C protects against cognitive impairment, the authors conducted a cohort study (n=117) in a retirement community in Sydney, Australia. Vitamin C intake was assessed at baseline (1991) with a semiquantitative food frequency questionnaire, and cognitive function was assessed 4 years later (1995). After adjustment for age, sex, smoking, education, total energy intake, and use of psychotropic medications, consumption of vitamin C supplements was associated with a lower prevalence of more severe cognitive impairment (based on scores on the Mini-Mental State Examination; adjusted odds ratio=0.39, 95% confidence interval 0.18-0.84). There were no associations between vitamin C intake and scores on tests of verbal and category fluency. This study suggests that vitamin C might protect against cognitive impairment.

Temporal relations between obesity and insulin: longitudinal data from the Normative Aging Study

Although obesity and insulin levels are generally associated in cross-sectional data, the temporal and causal nature of their association is not yet clear. Increased obesity may have preceded increased insulin levels or vice versa. The authors examined the temporal relations between fasting insulin blood levels and weight in longitudinal data from the ongoing Normative Aging Study. Two insulin measurements from which a rate of change (delta Insulin) could be calculated were available from 376 non-diabetic male subjects (mean age = 62.1 years). Rate of change in weight could be calculated for the previous inter-examination period (delta Weight1), the contemporaneous period (delta Weight2), and the inter-examination period following the second insulin measurement (delta Weight3). delta Weight2 was a significant predictor (p = 0.0005) of delta insulin in multiple linear regression models that included control for potential confounders (body mass index, waist-to-hip ratio, antihypertensive and diuretic medication use, and age) and for correlation between the initial level and change in insulin (mean fasting insulin). delta Weight1 was added to the model and was found not to be statistically significant (p = 0.15). When the model was stratified by age tertile, the regression coefficient on delta Weight1 was -0.44 (p = 0.018) for the youngest stratum, -0.06 (p = 0.72) for the middle stratum, and 0.21 (p = 0.19) for the oldest men. Similarly, delta Insulin was a significant predictor of delta Weight3 (p = 0.026) in a separate regression model. These findings are consistent with both possible temporal sequences of association between changes in insulin and obesity. The intricate homeostatic mechanisms that regulate changes in insulin and obesity may not be readily amenable to description in terms of cause and effect.

Hematological indices in an older population sample: derivation of healthy reference values

Factors affecting hematological values were explored, and healthy reference values were estimated from a cross-sectional survey of a population (n = 4433), ages 49 years or more, residing permanently in a defined geographic region. Nursing home residents were excluded. Details of medication use and medical history were obtained by interview, and participants were asked to return after an overnight fast for blood sampling. The participation rate was 82.4%, of whom 88.4% provided a fasting blood sample. Hemoglobin, hematocrit, and erythrocyte counts were higher in men, whereas platelet counts were higher in women. Statistical associations between each hematological index and smoking, alcohol intake, use of certain drugs, chronic disease, and high creatinine values were tested by unpaired t-tests. Separate reference groups were defined for each hematological index by excluding subjects with any of the factors found to be of importance. The resulting reference values are particularly appropriate for evaluating hematological test results in older individuals.

Effects of body fat on ventilatory function in children and adolescents: cross-sectional findings from a random population sample of school children

Childhood obesity is associated with a range of adverse consequences, and the prevalence is increasing in developed nations. Most of the literature on obesity and ventilatory function in children concerns samples selected for gross obesity with relatively little detail available from random population samples. This report examines the effect of total body fat as a percentage of weight (TBF%) on ventilatory function in a nationally representative sample of 2,464 Australian school children aged 9, 12, and 15 years. Forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were used as measures of ventilatory function. TBF% was estimated from skinfold thickness measurements. Ventilatory function was adjusted (for height and then for both height and weight) using linear regression on a logarithmic scale. Adjustment was performed within separate strata of age and gender. Analysis of covariance was used for hypothesis testing. Height-adjusted FVC and FEV1 values increased significantly with increasing weight within each age and gender group and for all subjects combined (P < 0.0001). The effect of TBF% independent of lean tissue was examined using FVC and FEV1 values adjusted for both height and weight, because body weight measures both lean and fat mass. Adjusted FVC and FEV1 values decreased significantly with increasing TBF% within each age and gender group and for all subjects combined (P < 0.0001). Ventilatory function decreased with increasing proportions of body fat. This is consistent with previous findings on lean tissue mass and ventilatory function. Although the magnitude of the effect was relatively small in clinical terms, from a public health perspective our findings indicate yet another adverse consequence of childhood obesity.

Handgrip strength and insulin levels: cross-sectional and prospective associations in the Normative Aging Study

Hyperinsulinemia is associated with insulin resistance and with the development of diabetes, hypertension, and coronary heart disease. Physical activity appears to be negatively associated with insulin resistance, although the mechanism is unclear. The relationship between physical activity and insulin resistance could be mediated, in part, by direct effects on skeletal muscle, a significant site for insulin-mediated glucose disposal. This report examines the relationship between skeletal muscle strength (as measured by handgrip dynamometry) and fasting insulin levels in a cohort of men in the ongoing Normative Aging Study (NAS). Handgrip strength was negatively associated (P = .013) with logarithmic (log) fasting insulin in cross-sectional data from 655 subjects after adjustment for potential confounders including age, body mass index (BMI), ratio of abdominal girth to hip breadth (AG/HB), usual physical activity level, and alcohol intake in a multiple regression model. In data collected prospectively among 1,195 subjects, handgrip strength measured at study entry was negatively predictive of log fasting insulin (P = .017) measured 22.9 +/- 2.6 years later, after adjustment for age, BMI, and AG/HB at study entry in a multiple linear regression model. A cross-sectional association was confirmed in an analysis of prospective data on the relationship between handgrip strength and fasting insulin levels. The findings suggest that skeletal muscle weakness may precede and predict the development of insulin resistance, and raise the intriguing possibility of some common cause in skeletal muscle pathophysiology.

Effects of body fat on ventilatory function in children and adolescents: cross-sectional findings from a random population sample of school children

Childhood obesity is associated with a range of adverse consequences, and the prevalence is increasing in developed nations. Most of the literature on obesity and ventilatory function in children concerns samples selected for gross obesity with relatively little detail available from random population samples. This report examines the effect of total body fat as a percentage of weight (TBF%) on ventilatory function in a nationally representative sample of 2,464 Australian school children aged 9, 12, and 15 years. Forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were used as measures of ventilatory function. TBF% was estimated from skinfold thickness measurements. Ventilatory function was adjusted (for height and then for both height and weight) using linear regression on a logarithmic scale. Adjustment was performed within separate strata of age and gender. Analysis of covariance was used for hypothesis testing. Height-adjusted FVC and FEV1 values increased significantly with increasing weight within each age and gender group and for all subjects combined (P < 0.0001). The effect of TBF% independent of lean tissue was examined using FVC and FEV1 values adjusted for both height and weight, because body weight measures both lean and fat mass. Adjusted FVC and FEV1 values decreased significantly with increasing TBF% within each age and gender group and for all subjects combined (P < 0.0001). Ventilatory function decreased with increasing proportions of body fat. This is consistent with previous findings on lean tissue mass and ventilatory function. Although the magnitude of the effect was relatively small in clinical terms, from a public health perspective our findings indicate yet another adverse consequence of childhood obesity.

Burden and outcomes of hospitalisation for congestive heart failure

OBJECTIVE

To describe the hospital burden and health outcomes associated with admission for congestive heart failure (CHF).

DESIGN AND SETTING

Descriptive follow-up study in a tertiary-level metropolitan teaching hospital.

PATIENTS

Acute adult inpatients with a clinical diagnosis of CHF for more than 24 hours admitted to Westmead Hospital, Sydney, during the four months from September 1993 to January 1994. At baseline, 122 patients were assessed; 88 patients were assessed at four-month follow-up.

INTERVENTIONS

Usual clinical care.

MAIN OUTCOME MEASURES

Length of stay; hospital bed-days; readmissions; mortality; health related quality of life (SF-36); patient knowledge.

RESULTS

The average age of subjects was 73.4 years. Many were using informal domiciliary care before admission. Mean length of stay for the baseline admission was 13.8 days, accounting for 7.6% of hospital separations and 1683 hospital bed-days, or 4.2% of bed-days for all inpatients aged 65 years and over. Fifteen patients were readmitted for CHF during the following four months, with a total of 26 CHF-related admissions. Twenty-one patients (17.2%) died during the course of the study. Quality of life at baseline was poor compared with population normative data, with a slight improvement among survivors at four-month follow-up. Patient knowledge of CHF was poor in a subsample survey (n = 24).

CONCLUSIONS

CHF represents a significant burden to patients (through morbidity and mortality), their carers (through provision of daily care), and hospitals (through multiple admissions for acute decompensation). It is difficult to monitor the hospital burden of CHF using routine data sources.

Alcohol intake and insulin levels. The Normative Aging Study

Much remains to be clarified in the apparently protective effect of moderate alcohol use against coronary heart disease risk. Insulin levels are positively associated with coronary heart disease risk, so recent reports of decreased insulin sensitivity among nondrinkers and lower fasting insulin levels with increasing alcohol intake suggest the possibility that insulin may play a role. Between 1987 and 1991, the authors examined fasting insulin concentrations and the empiric fasting insulin resistance index in relation to reported alcohol intake (mean, 15.3 g/day; standard deviation, 19.6; range, 0-120.6) and potential confounders. The latter included age, obesity, fat distribution, smoking, energy, saturated fat intake, antihypertensive medication, and physical activity. Participants in this cross-sectional analysis were 938 nondiabetic men from the Boston, Massachusetts, area who were part of the Normative Aging Study. Unadjusted fasting insulin levels were significantly different (p = 0.008) between categories of alcohol intake, as were fasting insulin resistance index values (p = 0.01). After adjustment for potential confounders, analysis revealed that subjects consuming moderate amounts of alcohol had the lowest fasting insulin and fasting insulin resistance index values. Compared with values from moderate drinkers, fasting insulin resistance index values were higher in those subjects reporting no alcohol intake (p = 0.011), low intake (p = 0.004), and high intake (p = 0.04). A similar pattern was observed for fasting insulin values. Among this sample of nondiabetic men, moderate drinkers had the lowest levels of fasting insulin resistance index and fasting insulin, consistent with lower levels of insulin resistance and thus lower risk for coronary heart disease. These findings suggest the possibility that the coronary heart disease-protective effects of moderate alcohol use are at least partially mediated by insulin.

Effects of obesity and fat distribution on ventilatory function: the normative aging study

OBJECTIVE

Although the influence of obesity on ventilatory function has long been recognized, the nature of the relationship and the mechanisms are not yet clear. The purpose of this report was to examine the effects of overall obesity and fat distribution on ventilatory function.

METHODS

Multiple measurements over > 30 years from 507 subjects with lifelong tobacco consumption of < or = 1 pack-year were analyzed separately in five age decades from 30 to 79 years. FVC, FEV1, ratio of FEV1 to FVC, and maximal midexpiratory flow rate (MMEF) were each adjusted for age and stature. Relative adiposity (or obesity) was assessed using the body mass index (BMI). Subscapular skinfold thickness, abdominal girth, and the ratio of abdominal girth to hip breadth (AG/HB) were used as measures of body fat distribution. Multiple linear regression was used to explore the effects of overall adiposity and body fat distribution on ventilatory function.

RESULTS

BMI was positively associated with the ratio of FEV1 to FVC at all ages (p < 0.01), and negatively with FVC and MMEF between 40 and 69 years (p < 0.01). After adjustment for BMI, subscapular skinfold thickness was negatively associated with both FVC and FEV1 (p < or = 0.02) among men aged 30 to 59 years, whereas AG/HB was negatively associated with FVC and FEV1 in men aged 50 to 59 years only (p < or = 0.0004).

CONCLUSIONS

Body fat distribution has independent effects on ventilatory function after adjustment for overall obesity in men. The finding that age modifies this association has implications for future research.

Adiposity and body mass indices in children: Benn's index and other weight for height indices as measures of relative adiposity

OBJECTIVES

Several forms of weight for height or body mass index (BMI) are in widespread epidemiological and clinical use as measures of relative adiposity. The form derived by Benn for adults has been advocated for use in children and practical aspects of this proposition are considered.

METHODS

Height and weight data from 8492 Australian schoolchildren aged 7 to 15 were studied. A subsample of 2753 children aged 9, 12 and 15 years had skinfold thicknesses measured. The sum of four skinfolds and percentage body fat predicted from skinfolds were used as measures of adiposity.

RESULTS

Of the various forms of power type BMI examined, weight/(height)2 was most closely associated with adiposity in this sample. Benn's assumption of low correlation between height and adiposity (which holds in adults) was not satisfied in children.

CONCLUSIONS

Benn's index is not recommended for general use as a body mass index in children. However, Benn's relative weight has advantages as an indirect measure of adiposity which may be of value in epidemiological studies among children.

Body mass index in screening for adiposity in children and adolescents: systematic evaluation using receiver operating characteristic curves

Body mass index (BMI) has been recommended for use in adolescent screening programs to select subjects with excess body fat for appropriate interventions. No systematic evaluation of MBI in screening for high degrees of adiposity was available when these recommendations were formulated. The purpose of this paper was to evaluated the screening performance of BMI using appropriate epidemiologic methods. Percentage body fat (TBF%) was measured by dual-energy X-ray absorptiometry DXA) in a convenience sample of 230 (119 males, 111 females) health Australian volunteers aged 4-20 y inclusive. Receiver operating characteristic (ROC) curves were prepared for detecting TBF% at or beyond the 85th percentile, using BMI as the screening test. Screening performance was slightly better for girls than for boys, but the differences were not significant. Reasonable true-positive (0.71, 95% CI: 0.53, 0.85) and low false-positive (0.05, 95% CI: 0.02, 0.09) rates were observed at the 85th percentile cutpoint for BMI. At the 95th percentile cutpoint for BMI, both true-positive (0.29, 95% CI: 0.15, 0.47) and false-positive (0.01, 95% CI: 0.00, 0.03) rates were lower. Screening for excess adiposity by using an appropriate percentile cutoff for BMI gives acceptable performance. ROC curves facilitate design of screening programs by allowing an explicit tradeoff between true-positive and false-positive rates. Although large sample sizes are required for precise estimates, the cutoff points that have been recommended appear to offer a reasonable compromise between true-and false-positive rates.

Recommended body mass index cutoff values for overweight screening programmes in Australian children and adolescents: comparisons with North American values

OBJECTIVE

Guidelines for screening children and adolescents for overweight have recently been published by a North American Expert Committee. As Australian clinicians might uncritically adopt these recommendations, we explore the consequences of applying North American body mass index (BMI) cutoff values to an Australian population.

METHODOLOGY

The Australian BMI cutoffs were calculated using the methods recommended from height and weight data for 8492 schoolchildren aged 7-15 years old.

RESULTS

Smoothed Australian BMI cutoffs were similar to those derived from the first United States National Health and Nutrition Examination Survey (NHANES-I) values for whites. However, the NHANES-I cutoffs would result in systematic misclassification. Among 7 year olds, the NHANES-I 85th percentile cutoff would wrongly classify 4.6% of normal males and 9.1% of normal females as 'at risk of overweight'. At age 14 years, the NHANES-I 95th percentile cutoff would misclassify 3.5% of children as 'overweight' instead of 'at risk of overweight'.

CONCLUSION

Australian screening programmes should use BMI cutoffs appropriately derived from local measurements, and these are given for Australian children.

Social support, marital status and living arrangement correlates of cardiovascular disease risk factors in the elderly

Marital status and indices of social support are associated with mortality due to coronary heart disease and stroke. This association seems not entirely due to differences in recognised cardiovascular disease risk factors. The Western Sydney Stroke risk in the Elderly Study examined the relationship between marital status, living arrangements, widowhood and extent of social support, and risk factors for cardiovascular disease in men and women aged over 65 years. Unmarried men had the lowest mean HDL-C levels. Men living alone had the highest mean systolic blood pressures. The lower mean HDL-C levels and higher DBP levels seen among widows were not statistically significant after adjustment for differences in past medical history and education levels. The extent of social support was not associated with any significant differences in cardiovascular risk factor levels among men or women. We conclude that some of the increased risk of cardiovascular disease associated with socio-demographic factors among men in this age-group may be due to differences in primary cardiovascular disease risk factors. However, some of the mechanisms underlying risk of cardiovascular disease in this age-group remains obscure.

Repeatability of nutrient intakes estimated by a semiquantitative food frequency questionnaire in elderly subjects

In order to evaluate the repeatability of nutrient values estimated from a semiquantitative food frequency questionnaire being used in a longitudinal study of the relationships between diet, hemostatic factors, and stroke risk in the elderly in Western Sydney, a subsample of 62 participants (24 men, 38 women) completed a repeat questionnaire approximately 1 month after baseline data were collected. The mean age was 78 years (range, 65 to 88; median, 78). Nutrient values calculated from the repeat questionnaire were not significantly different from the baseline results by paired t test. Intraclass correlation coefficients ranged from 0.63 for beta carotene to 0.82 for saturated fat. Quadratic weighted kappa values were calculated for quintile categories and these ranged from 0.50 for fiber to 0.86 for ethanol. These values are comparable to previously published results in elderly subjects and confirm that repeatability of nutrient intakes estimated using semiquantitative food frequency questionnaires is very high in the elderly. Older subjects may be more established in their dietary habits than younger subjects, so any tendency for repeatability to decrease due to impaired memory associated with advanced age is offset by a lower intraindividual variability in dietary habit.

The Western Sydney Stroke Risk in the Elderly Study. A 5-year prospective study

Aging of the Australian population, as in other developed nations, will ensure that stroke remains one of the most important causes of death and disability. The Stroke Risk in the Elderly (SITE) study aims to measure prospectively the independent contribution of dietary, sociodemographic, blood lipid, blood pressure, and hemostatic factors to risk of stroke and other cardiovascular outcomes. The target population included all independently living men and women aged 65 years and over, residents in several retirement villages in western metropolitan Sydney, New South Wales, Australia. The study cohort consists of 225 men and 787 women, selected as a convenience sample from all eligible residents in the local government areas (LGAs) adjacent to Westmead Hospital. Participants attended a baseline session to complete dietary, life-style, medical, and sociodemographic questionnaires. Anthropomorphic variables and blood pressure were measured. Blood was taken for measurement of serum lipid, glucose, and hemostatic factors. Questionnaire results were compared with an age/sex-stratified, randomly selected sample drawn from the community (in the same LGAs), in order to quantify potential sampling and selection biases. The study cohort will be followed for a minimum of 5 years. The attendance rate of eligible residents for a baseline medical, dietary, life-style, and sociodemographic assessment was 72% for males and 69% for females. The study cohort was older, better educated, less ethnically diverse, and among women, less likely to have ever been married compared to people aged over 65 years in the comparison group. The baseline results suggest that hemostatic factors may be of importance in assessing risk of cardiovascular disease, (CVD), particularly in older men.(ABSTRACT TRUNCATED AT 250 WORDS)

Differences in serum lipids in Australian children: is diet responsible?

A total of 5211 schoolchildren aged 10-15 years participated in an Australia-wide sample survey conducted in 1985 and completed dietary and demographic assessment, and the measurement of body mass index: 1017 children aged 12 and 15 years gave blood for serum lipid analysis. Group mean differences in serum lipids and body mass index with age, sex, socioeconomic status and ethnic origin were determined. Nutritional analysis generated group mean values for daily energy intake, per cent kilo-joules from total fat, saturated fat, monosaturated fat and polyunsaturated fat, as well as the polyunsaturated:saturated fat ratio and nutrient density of fibre. In multiple regression analyses, socioeconomic and gender based differences in serum lipids could be explained by differences in diet, whereas age group differences could not. Although there were statistically significant differences in dietary fat intake on the basis of ethnic origin, these were not reflected in differences in serum lipids. For girls, dietary fat variables were more important predictors of serum lipids than body mass index. For boys, the reverse was true. These results suggest that class differences in cardiovascular risk arise from dietary differences that are present from an early age. Sex-based differences in serum lipids seem to reflect different mechanisms in girls and boys. In the former, dietary differences are of importance but for the latter, anthropomorphic (possibly exercise-linked) differences are the most important. These findings imply that cardiovascular risk preventive programmes for children need to take into account the mechanisms of social inequality and sex-based differences.