Association between diet quality with concurrent vision and hearing impairment in older adults.

OBJECTIVES: Published literature shows that individual nutrients could influence the risk of developing vision and hearing loss. There is, however, a lack of population-based data on the relationship between overall patterns of food intake and the presence of concurrent vision and hearing impairment. We aimed to assess the associations between diet quality with the prevalence and 5-year incidence of dual sensory impairment (DSI). DESIGN: Cross-sectional and 5-year longitudinal analyses. SETTING: Blue Mountains, Sydney, Australia. PARTICIPANTS: 2443 participants aged ≥50 from baseline were examined and followed over 5 years. MEASUREMENTS: Dietary data were collected using a semi-quantitative food frequency questionnaire. A modified version of the Healthy Eating Index for Australians was developed to determine total diet score (TDS). Visual impairment was defined as visual acuity less than 20/40 (better eye), and hearing impairment as average pure-tone air conduction threshold greater than 25 dB HL (500-4000 Hz, better ear). RESULTS: After adjusting for age, sex, education, noise exposure, current smoking, and type 2 diabetes, participants in the lowest compared to the highest quintile of TDS had a 2-fold increased likelihood of having prevalent DSI, odds ratio, OR, 2.62 (95% confidence intervals, CI, 1.08-6.36), P-trend=0.04. Significant associations were not observed between TDS and the prevalence of having a single sensory impairment (vision or hearing loss). Baseline TDS was not significantly associated with the 5-year incidence of DSI. Adherence to dietary guidelines was associated with a reduced likelihood of having DSI in cross-sectional, but not in longitudinal analyses. CONCLUSIONS: Further studies with adequate power are warranted to assess the prospective relationship between diet quality and DSI.

Five-year incidence and progression of thyroid dysfunction in an older population.

BACKGROUND: Very few studies have assessed both the incidence and progression of thyroid dysfunction in a single older population-based cohort. In this study, we aimed to assess the 5-year incidence, progression and risk factors for development of thyroid dysfunction in an older Australian population. METHODS: The Blue Mountains Eye Study is a longitudinal population-based cohort study. During 1997-1999, 1768 participants (≥ 55 years) had thyroid function assessed. After excluding participants reporting any form of treatment for their thyroid condition at baseline, 951 participants (91.4%) without thyroid dysfunction and 54 (5.4%) with thyroid dysfunction were re-examined 5 years later. Thyroid dysfunction was defined using serum thyrotropin (thyroid stimulating hormone (TSH)) screen, followed by serum free T4 assessment. RESULTS: The overall 5-year incidence of thyroid dysfunction was 4.7% (95% confidence interval (CI) 3.4-6.1). Obesity (body mass index ≥ 30 kg/m(2) ) and serum TSH > 2 mIU/L at baseline predicted incident overt hypothyroidism (odds ratio (OR) 4.05, CI 1.74-9.41) and (OR 5.46, CI 1.16-25.67) respectively. The 5-year incidence of subclinical hypothyroidism was significantly higher in women than in men, 2.5% versus 0.7% (P= 0.03). Progression to overt hypothyroidism was observed in 17.9% of subjects with subclinical hypothyroidism over 5 years. CONCLUSIONS: The 5-year incidence of thyroid dysfunction in this older population was relatively low, and was associated with obesity and serum TSH level > 2 mIU/L at baseline. Over one in six persons with subclinical hypothyroidism progressed to overt thyroid dysfunction over the 5-year period. Our findings highlight the need for appropriate management of subclinical hypothyroidism among older people.

Relationship of Type 2 diabetes to the prevalence, incidence and progression of age-related hearing loss.

AIMS: Type 2 diabetes and associated microvascular abnormalities are postulated to affect hearing. Our study reports on the relationship between Type 2 diabetes and the prevalence, 5-year incidence and progression of hearing impairment in a representative, older, Australian population. METHODS: The Blue Mountains Hearing Study is a population-based survey of age-related hearing loss conducted in a defined suburban area, west of Sydney. Hearing loss was defined as the pure-tone average of frequencies 0.5, 1.0, 2.0 and 4.0 kHz > 25 decibels hearing level (dB HL) in the better ear (bilateral hearing loss). Type 2 diabetes was defined from reported physician-diagnosed diabetes or fasting blood glucose > or = 7.0 mmol/l. RESULTS: Age-related hearing loss was present in 50.0% of diabetic participants (n = 210) compared with 38.2% of non-diabetic participants (n = 1648), odds ratio (OR) 1.55 [95% confidence interval (CI) 1.11-2.17], after adjusting for multiple risk factors. A relationship of diabetes duration with hearing loss was also demonstrated. After 5 years, incident hearing loss occurred in 18.7% of participants with, and 18.0% of those without diabetes, adjusted OR 1.01 (CI 0.54-1.91). Progression of existing hearing loss (> 5 dB HL), however, was significantly greater in participants with newly diagnosed diabetes (69.6%) than in those without diabetes (47.8%) over this period, adjusted OR 2.71 (CI 1.07-6.86). CONCLUSIONS: Type 2 diabetes was associated with prevalent, but not incident hearing loss in this older population. Accelerated hearing loss progression over 5 years was more than doubled in persons newly diagnosed with diabetes. These data explore further reported links between Type 2 diabetes and age-related hearing loss.

Coronary heart disease epidemics: not all the same.

BACKGROUND: Coronary heart disease (CHD) was an important epidemic in many developed countries in the 20th century and there is concern because the epidemic has affected Eastern Europe, Russia and Central Asia and is starting to affect developing countries. METHODS: The epidemic curves of CHD mortality for 55 countries, which had reliable data and met other selection criteria, were examined using age-standardised death rates 35-74 years from the World Health Organization. Annual male mortality rates for individual countries from 1950 to 2003 were plotted and a table and a graph used to classify countries by magnitude, pattern and timing of its CHD epidemic. RESULTS: The natural history of CHD epidemics varies markedly among countries. Different CHD patterns are distinguishable including "rise and fall" (classic epidemic pattern), "rising" (first part of epidemic) and "flat" (no epidemic yet). Furthermore, epidemic peaks were higher in Anglo-Celtic countries first affected by the epidemic, and subsequent peaks were less, except for the recent extraordinary epidemics in Russia and Central Asian republics. There were considerable differences among some continental or regional geographical areas. Eastern European, South American and Asian countries have quite different epidemic characteristics, including shorter epidemic cycles. CONCLUSIONS: It cannot be assumed that WHO regions or any other geographical regions will be useful when analysing CHD epidemics or deciding upon strategic policies to reduce CHD in individual countries. The needs for action that are urgent in some countries are less so in others, and even regional country groups can have quite different epidemic characteristics.

Nurse-led 24-h hotline for patients with chronic obstructive pulmonary disease reduces hospital use and is safe.

BACKGROUND: Despite recent advances in the management of patients with chronic obstructive pulmonary disease (COPD), interventions to reduce hospitalization have had only modest success. The aim of this study was to report the outcomes of a novel, nurse-led 24-h telephone support line (hotline) for patients with COPD. METHODS: Observational study of patients' use of hotline between September 2002 and November 2004. All patients with COPD referred to a Respiratory Ambulatory Care programme over this period (n = 458) were given access to the hotline. The number and time of calls to the hotline, outcomes of hotline calls and safety of hotline, were assessed. The characteristics of hotline callers and non-callers were compared using an unpaired Student's t-test for normally distributed variables, a chi(2) test for categorical variables and a Mann-Whitney test for non-normally distributed variables. RESULTS: Over the period studied, 675 calls were made to the hotline by 118 patients and 56% of calls were made after hours. For 78 calls (12%), advice and interventions given by hotline staff averted potential 000 calls by patients/carers. Specific advice about interventions for acute exacerbations of COPD (AECOPD) was given in a further 117 calls (17%). Callers had more severe COPD than non-callers (worse lung function, lower exercise capacity and higher prescription of home oxygen, all P < 0.05). No adverse events related to use of the hotline were documented. CONCLUSION: A nurse-led 24-h hotline for patients with COPD is safe, is used by patients and carers and, when used, reduces hospital presentations with AECOPD.

Retinal vascular calibre and the risk of coronary heart disease-related death.

OBJECTIVE: To examine whether retinal vascular calibre independently predicts risk of coronary heart disease (CHD) -related death. METHODS: In a population-based cohort study of 3654 Australians aged > or = 49 years, retinal arteriolar and venular calibres were measured from baseline retinal photographs and the arteriole to venule ratio (AVR) was calculated. CHD-related death was confirmed from the Australian National Death Index. RESULTS: Over nine years, 78 women (4.1%) and 114 men (7.8%) had incident CHD-related deaths. In people aged 49-75 years, wider venules were associated with CHD death, with relative risk (RR) 1.8 (95% confidence interval (CI) 1.1 to 2.7) and RR 2.0 (95% CI 1.1 to 3.6) per standard deviation (SD) increase in venular calibre for men and women, respectively, after adjustment for traditional risk factors. Additionally, in women aged 49-75 years, smaller AVR and narrower arterioles were associated with CHD death (RR 1.5, 95% CI 1.1 to 2.2, and RR 1.9, 95% CI 1.0 to 3.5 per SD decrease in AVR and arteriolar calibre, respectively, after adjustment). These associations were not observed in people aged > 75 years. CONCLUSIONS: These findings suggest that microvascular disease processes may have a role in CHD development in middle-aged people, particularly in women. Retinal photography may be useful in cardiovascular risk prediction.

Retinal microvascular signs and risk of stroke and stroke mortality.

OBJECTIVE: The purpose of this study was to assess the relation of retinal microvascular signs and incident stroke and stroke mortality in an older population. METHODS: The authors took retinal photographs on baseline participants (3,654 patients aged 49+ years) of the Blue Mountains Eye Study (1992 to 1994). They assessed the presence of retinopathy (microaneurysms, retinal hemorrhages) in participants without diabetes and retinal arteriolar signs in all participants using standardized grading protocols. Incident stroke/TIA/cerebrovascular death (combined stroke events) were identified at follow-up examinations during 1997 to 1999. RESULTS: During a 7-year period, 859 participants died, 97 (11.3%) of which died of cerebrovascular causes. Of survivors, 24 had confirmed incident stroke, and 11 had incident TIA. Combined stroke events were more frequent in participants with retinopathy (5.7%), with moderate/severe arteriovenous nicking (4.2%), or with focal arteriolar narrowing (7.2%) compared with those without (1.9%). After controlling for age, sex, systolic blood pressure, smoking, and self-rated health, retinopathy was significantly associated with combined stroke events (relative risk [RR] 1.7, 95% CI 1.0 to 2.8) in persons without diabetes. This association was stronger in those without severe hypertension (RR 2.7, CI 1.2 to 6.2) or in persons with two or more retinal microvascular signs (RR 2.7, CI 1.5 to 5.2). Generalized or focal arteriolar narrowing or arteriovenous nicking was not independently associated with combined stroke events after multivariate adjustment. CONCLUSIONS: In older Australians without diabetes, retinopathy signs predict stroke or stroke-related death independent of traditional stroke risk factors.

Ethics and public health.

This paper examines the differences between clinical and public health ethics and provides several examples of contemporary public health challenges that pose ethical questions. The relations among ethics, rights and obligations are explored, because public health philosophers propose these as different ways for public health to align its activities to what we value. Resources for education in relation to the ethics of public health are identified.

Epidemiology and predictive values of risk factors for neonatal group B streptococcal sepsis.

OBJECTIVES: To determine the incidence of and factors affecting risk factors for neonatal group B streptococcal (GBS) sepsis and their predictive values for intrapartum GBS carriage; to calculate the proportions of women eligible for intrapartum antibiotic prophylaxis (IAP) using different selection protocols. DESIGN: Cohort study. SETTING: Antenatal clinics and labour wards of a community hospital and a tertiary referral centre in western Sydney POPULATION: Women attending antenatal clinics during the study periods were invited to participate. METHODS: Approximately 500 women attending antenatal clinics were screened for GBS carriage at 26-32 weeks gestation and at delivery, using several screening methods. Clinical risk factors for neonatal sepsis were recorded during labour. MAIN OUTCOME MEASURES: Incidence of antenatal anovaginal GBS carriage and clinical risk factors during labour, their predictive values for intra-partum GBS carriage and their relationship, if any, to demographic and obstetric factors. RESULTS: Antenatal and intra-partum GBS carriage rates were similar but varied from 18% to 27%, depending on screening methods. The best positive and negative predictive values of antenatal GBS culture, for intra-partum carriage, were 69% (95% confidence interval (CI) 64-74) and 92% (95% CI 50-94) respectively Clinical risk factors occurred in similar proportions of GBS carriers and non-carriers. CONCLUSIONS: Neither early antenatal screening nor clinical risk factors are reliable predictors of intra-partum GBS carriage. Intra-partum antibiotic prophylaxis based on GBS carriage or risk factors when carrier status is unknown would involve approximately 35% of women, compared with approximately 16% if based on risk factors only Both strategies would prevent similar proportions of neonatal deaths from GBS sepsis. Compliance with a preventive protocol is the most likely determinant of its overall effectiveness.

Ethics and evidence-based medicine.

Concerns about the ethics of evidence-based medicine (EBM) relate to possible alterations in the humane basis of clinical care. In collecting the evidence for EBM, scientists and doctors, not consumers, determine research objectives, interpret the data and implement the findings, and in doing so may disregard patients' priorities. Ethical standards, and what counts as evidence, are determined by socially or commercially powerful groups connected to powerful institutions. Such groups can generate evidence and determine "gold standard" knowledge, filtering out other, "inferior" knowledge. Applying the available evidence to predicting outcomes for individual patients involves uncertainty. Full disclosure of this uncertainty is a component of informed consent, but requires sensitivity to patients' tolerance of ambiguity. Ongoing debate about the ethics of EBM on all levels will ensure that EBM manifests intended and preferred social values and takes its rightful place in the practice of medicine and the development of health policy.

Asthma in preschool children: prevalence and risk factors.

BACKGROUND: The prevalence of asthma in children has increased in many countries over recent years. To plan effective interventions to reverse this trend we need a better understanding of the risk factors for asthma in early life. This study was undertaken to measure the prevalence of, and risk factors for, asthma in preschool children. METHODS: Parents of children aged 3-5 years living in two cities (Lismore, n=383; Wagga Wagga, n=591) in New South Wales, Australia were surveyed by questionnaire to ascertain the presence of asthma and various proposed risk factors for asthma in their children. Recent asthma was defined as ever having been diagnosed with asthma and having cough or wheeze in the last 12 months and having used an asthma medication in the last 12 months. Atopy was measured by skin prick tests to six common allergens. RESULTS: The prevalence of recent asthma was 22% in Lismore and 18% in Wagga Wagga. Factors which increased the risk of recent asthma were: atopy (odds ratio (OR) 2.35, 95% CI 1.49 to 3.72), having a parent with a history of asthma (OR 2.05, 95% CI 1.34 to 3.16), having had a serious respiratory infection in the first 2 years of life (OR 1.93, 95% CI 1.25 to 2.99), and a high dietary intake of polyunsaturated fats (OR 2.03, 95% CI 1.15 to 3.60). Breast feeding (OR 0.41, 95% CI 0.22 to 0.74) and having three or more older siblings (OR 0.16, 95% CI 0.04 to 0.71) decreased the risk of recent asthma. CONCLUSIONS: Of the factors tested, those that have the greatest potential to be modified to reduce the risk of asthma are breast feeding and consumption of polyunsaturated fats.

The childhood asthma prevention study (CAPS): design and research protocol of a randomized trial for the primary prevention of asthma.

The Childhood Asthma Prevention Study is a randomized controlled trial to measure whether the incidence of atopy and asthma can be reduced by house dust mite allergen reduction, a diet supplemented with omega-3 fatty acids, or a combination of both interventions. Six hundred and sixteen pregnant women whose unborn children were at high risk of developing asthma because of a family history were randomized prenatally. Study groups are as follows: Group A (placebo diet intervention, no house dust mite reduction), Group B (placebo diet intervention, active house dust mite reduction), Group C (active diet intervention, no house dust mite reduction), and Group D (active diet intervention, active house dust mite reduction). The house dust mite reduction intervention comprises use of physical and chemical methods to reduce allergen contact. The dietary intervention comprises use of a daily oil supplement from 6 months or at onset of bottle-feeding, and use of margarine and cooking oils based on sunflower or canola oils to increase omega-3 dietary intake. Data is collected quarterly until the infant is 1 year old and then half yearly until age 5 years. Questionnaires are used to collect respiratory illness history and information about diet and home environment. Dust is collected from the child's bed and bedroom and playroom floors. Blinded assessments are conducted at 18 months, 3 years, and 5 years. Skin prick tests to common allergens, blood tests, and detailed illness, medication use, and vaccination histories are collected. Primary outcomes will be the development of allergic sensitization and the presence and severity of asthma. This study is designed to measure the effectiveness of allergen reduction and dietary supplementation, both separately and in combination, for the primary prevention of atopy and asthma. The results of this study may have important implications for public health policies to reduce the incidence of childhood asthma. Control Clin Trials 2001;22:333-354

Incidence of nursing home placement in a defined community.

OBJECTIVE: To assess cumulative incidence and non-cognitive factors predicting nursing home placement in a defined older population. DESIGN AND SETTING: Six-year follow-up of a population-based cohort living west of Sydney. PARTICIPANTS: 3654 non-institutionalised residents aged 49 years or older (82.4% of those eligible) participated in baseline examinations during 1992 to 1994. MAIN OUTCOME MEASURES: Permanent nursing home admission for long-term institutionalised aged care in New South Wales, confirmed by records of approvals by the regional Aged Care Assessment Team and subsidy payments by government. RESULTS: After excluding 384 participants who moved from the area or were lost to follow-up, 162 participants (5.0%) had been admitted to nursing homes on a permanent basis by October 1999. Of participants who died since baseline, 20% had been admitted to a nursing home before death. Of those alive, 1.6% were current nursing home residents. Six-year cumulative incidence rates for nursing home placement were 0.7%, 1.1%, 2.4%, 3.9%, 9.0%, 18.3% and 34.9% for people aged 55-59, 60-64, 65-69, 70-74, 75-79, 80-84 and 85 years or older, respectively. Non-cognitive factors at baseline predicting subsequent nursing home admission included each additional year of age (risk ratio [RR], 1.14), fair or poor compared with excellent self-rated health (RR, 2.9, 3.6), walking difficulty (RR, 3.6) and current smoking (RR, 1.9). People owning their homes had a decreased likelihood of nursing home placement (RR, 0.6). CONCLUSIONS: Incidence rates of institutional aged care doubled for each five-year interval from the age of 60 years. A range of non-cognitive factors predict nursing home placement.

Daycare attendance before the age of two protects against atopy in preschool age children.

Early attendance at daycare has been shown to protect against atopy, as defined by a positive skin prick test. One proposed hypothesis for this association is that early exposure to other children protects against atopy by facilitating the spread of infections among children. An alternative hypothesis is that children attending daycare centers have less atopy due to lower levels of exposure to indoor allergens. Our aim was to determine whether attendance at daycare before age 2 years protects against atopy in Australian preschool age children and to test the two alternative hypotheses, as well as a number of potential confounding factors. We conducted a cross-sectional study of children aged 3-5 years living in one humid coastal city (Lismore, n = 286) and one dry, inland city (Wagga Wagga, n = 364) in New South Wales, Australia, in 1995. Atopy was assessed by skin prick tests to six common allergens. Daycare attendance and other possible risk factors for atopy were measured by a parent-completed questionnaire. Children who attended daycare before age 2 years had a reduced risk of atopy at 3-5 years. The greatest effect was seen in children who attended a daycare center (odds ratio (OR), 0.26; 95% CI, 0.14-0.50) rather than family daycare (OR, 0.66; 95% CI, 0.41-1.04). The results of this study do not support either of the proposed hypotheses, nor can the effect be explained by any of the other potential confounders measured. Further work is needed to determine the exposure that is responsible for the protective effect of daycare attendance on atopy.

Acute effects of low levels of ambient ozone on peak expiratory flow rate in a cohort of Australian children.

BACKGROUND: We enrolled a cohort of primary schoolchildren with a history of wheeze (n = 148) in an 11-month longitudinal study to examine the relationship between ambient ozone concentrations and peak expiratory flow rate. METHODS: Enrolled children recorded peak expiratory flow rates (PEFR) twice daily. We obtained air pollution, meteorological and pollen data. In all, 125 children remained in the final analysis. RESULTS: We found a significant negative association between daily mean deviation in PEFR and same-day mean daytime ozone concentration (beta-coefficient = 0.88; P = 0.04) after adjusting for co-pollutants, time trend, meteorological variables, pollen count and ALTERNARIA: count. The association was stronger in a subgroup of children with bronchial hyperreactivity and a doctor diagnosis of asthma (beta-coefficient = -2.61; P = 0.001). There was no significant association between PEFR and same-day daily daytime maximum ozone concentration. We also demonstrated a dose-response relationship with mean daytime ozone concentration. CONCLUSIONS: Moderate levels of ambient ozone have an adverse health effect on children with a history of wheezing, and this effect is larger in children with bronchial hyperreactivity and a doctor diagnosis of asthma.

Genetically modified foods--food for thought.

We would be wise to hold off until we know more about the health, ecological and economic effects of genetically modified food.

Getting new evidence into medicine.

The rate of transfer of the knowledge gained from health and medical research into evidence-based practice is determined by many factors. Preconditions for the uptake of new evidence are the availability of good evidence, ready access to the evidence, a supportive organisational environment, and effective mechanisms for promoting knowledge uptake. Evidence-based medicine is being promoted in Australia by a body of enthusiastic clinicians, public health practitioners and consumer advocates, supported by initiatives from national, State and local healthcare services and professional bodies. The short to medium term future of evidence-based medicine in Australia is likely to be shaped by three major factors: a reduction in cost and technical barriers which limit access to computerised databases; a trend towards shared decision-making between clinicians and patients; and increased demand for information to fill the gaps in research-based evidence on specific problems.