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S Hales

Publications and source records attributed to S Hales.

At least 19 recordsLinked to original sources
PubMed2006

Impact of a national external quality assessment scheme for breast pathology in the UK.

BACKGROUND: This article presents the results and observed effects of the UK National Health Service Breast Screening Programme (NHSBSP) external quality assurance scheme in breast histopathology. AIMS/METHODS: The major objectives were to monitor and improve the consistency of diagnoses made by pathologists and the quality of prognostic information in pathology reports. The scheme is based on a twice yearly circulation of 12 cases to over 600 registered participants. The level of agreement was generally measured using kappa statistics. RESULTS: Four main situations were encountered with respect to diagnostic consistency, namely: (1) where consistency is naturally very high-this included diagnosing in situ and invasive carcinomas (and certain distinctive subtypes) and uncomplicated benign lesions; (2) where the level of consistency was low but could be improved by making guidelines more detailed and explicit-this included histological grading; (3) where consistency could be improved but only by changing the system of classification-this included classification of ductal carcinoma in situ; and (4) where no improvement in consistency could be achieved-this included diagnosing atypical hyperplasia and reporting vascular invasion. Size measurements were more consistent for invasive than in situ carcinomas. Even in cases where there is a high level of agreement on tumour size, a few widely outlying measurements were encountered, for which no explanation is readily forthcoming. CONCLUSIONS: These results broadly confirm the robustness of the systems of breast disease diagnosis and classification adopted by the NHSBSP, and also identify areas where improvement or new approaches are required.

Breast Neoplasms↗
PubMed2006

The NHS breast screening programme (pathology) EQA: experience in recent years relating to issues involved in individual performance appraisal.

BACKGROUND: The original role of the National Health Service breast screening programme (pathology) external quality assessment (EQA) scheme was educational; it aimed to raise standards, reinforce use of common terminology, and assess the consistency of pathology reporting of breast disease in the UK. AIMS/METHODS: To examine the performance (scores) of pathologists participating in the scheme in recent years. The scheme has evolved to help identify poor performers, reliant upon setting an acceptable cutpoint. Therefore, the effects of different cutpoint strategies were evaluated and implications discussed. RESULTS/CONCLUSIONS: Pathologists who joined the scheme improved over time, particularly those who did less well initially. There was no obvious association between performance and the number of breast cancer cases reported each year. This is not unexpected because the EQA does not measure expertise, but was established to demonstrate a common level of performance (conformity to consensus) for routine cases, rather than the ability to diagnose unusual/difficult cases. A new method of establishing cutpoints using interquartile ranges is proposed. The findings also suggest that EQA can alter a pathologist's practice: those who leave the scheme (for whatever reason) have, on average, marginally lower scores. Consequently, with the cutpoint methodology currently used (which is common to several EQA schemes) there is the potential for the cutpoint to drift upwards. In future, individuals previously deemed competent could subsequently be erroneously labelled as poor performers. Due consideration should be given to this issue with future development of schemes.

Breast Neoplasms↗
PubMed2003

Social deprivation and the public health risks of community drinking water supplies in New Zealand.

STUDY OBJECTIVE: Quantitative evidence linking environmental exposures and social status at sub-national scales is surprisingly limited. This study investigated the public health risks associated with community water supplies in relation to social status in New Zealand. DESIGN: An ecological study using a Geographic Information System (GIS) to compare the grade of community water supplies with an index of social deprivation for small areas. SETTING: New Zealand. PARTICIPANTS: The New Zealand population usually resident in meshblocks (census areas) with a community water supply (70% of the 1996 population of 3.6 million people). MAIN RESULTS: People living in deprived areas are exposed to greater public health risks from community water supplies. In urban areas, the odds of water supplies being high risk were 3.76 times greater for the most deprived decile compared with the least deprived decile (95% CI: 2.95 to 4.78). CONCLUSIONS: It is probable that deprived communities in New Zealand are experiencing a disproportionate burden of adverse health effects as a result of poor water quality.

Adolescent↗
PubMed2001

Use of a computer model to identify potential hotspots for dengue fever in New Zealand.

AIMS: To describe the areas of potential dengue fever risk in New Zealand for present climatic conditions and projected scenarios of climate change. METHODS: A computer model, the HOTSPOTS System, was developed. This allowed the integration of climatic, topographical, entomological, demographic, trade and travel data to generate spatial information describing vector introduction risk, potential vector distribution and dengue fever risk. RESULTS: Under present climatic conditions, Auckland and Northland, and some coastal areas of other northern parts of the North Island, have a potential risk for dengue outbreaks supported by the vector Aedes albopictus. Greenhouse gas induced climate change could make these areas also receptive to Aedes aegypti--the more efficient tropical dengue vector--and increase the potential distribution of A. albopictus to much of the South Island. CONCLUSIONS: Given the introduction of a competent vector, there is an appreciable risk of dengue fever occurring in New Zealand under present climatic conditions. Greenhouse gas induced climate change would substantially increase the magnitude and spatial extent of this risk.

Climate↗
PubMed2001

The influence of climate variation and change on diarrheal disease in the Pacific Islands.

Freshwater resources are a high-priority issue in the Pacific region. Water shortage is a serious problem in many small island states, and many depend heavily on rainwater as the source of their water. Lack of safe water supplies is an important factor in diarrheal illness. There have been no previous studies looking specifically at the relationship between climate variability and diarrhea in the Pacific region. We carried out two related studies to explore the potential relationship between climate variability and the incidence of diarrhea in the Pacific Islands. In the first study, we examined the average annual rates of diarrhea in adults, as well as temperature and water availability from 1986 to 1994 for 18 Pacific Island countries. There was a positive association between annual average temperature and the rate of diarrhea reports, and a negative association between water availability and diarrhea rates. In the second study, we examined diarrhea notifications in Fiji in relation to estimates of temperature and rainfall, using Poisson regression analysis of monthly data for 1978-1998. There were positive associations between diarrhea reports and temperature and between diarrhea reports and extremes of rainfall. These results are consistent with previous research and suggest that global climate change is likely to exacerbate diarrheal illness in many Pacific Island countries.

Child, Preschool↗
PubMed2000

Daily mortality in relation to weather and air pollution in Christchurch, New Zealand.

OBJECTIVE: To investigate the relationship between the daily number of deaths, weather and ambient air pollution. METHOD: An ecological study. We assembled daily data for the city of Christchurch, New Zealand (population 300,000) from June 1988 to December 1993. We used Poisson regression models, controlling for season using a parametric method. RESULTS: Above the third quartile (20.5 degrees C) of maximum temperature, an increase of 1 degree C was associated with a 1% (95% CI: 0.4 to 2.1%) increase in all-cause mortality and a 3% (0.1 to 6.0%) increase in respiratory mortality. An increase in PM10 of 10 micrograms/m3 was associated (after a lag of one day) with a 1% (0.5 to 2.2%) increase in all-cause mortality and a 4% (1.5 to 5.9%) increase in respiratory mortality. We found no evidence of interaction between the effects of temperature and particulate air pollution. CONCLUSIONS: High temperatures and particulate air pollution are independently associated with increased daily mortality in Christchurch. The fact that these results are consistent with those of similar studies in other countries strengthens the argument that the associations are likely to be causal. IMPLICATIONS: These findings contribute to evidence of health consequences of fuel combustion, both in the short term (from local air pollution) and in the long term (from the global climatic effects of increased atmospheric CO2).

Adolescent↗
PubMed2000

Protecting human health in a changing world: the role of social and economic development.

The biological and physical environment of the planet is changing at an unprecedented rate as a result of human activity, and these changes may have an enormous impact on human health. One of the goals of human development is to protect health in the face of rapid environmental change, but we often fail to do this. The aim in this paper is to distinguish between socioeconomic aspects of development that are likely to be protective and those that are likely to increase vulnerability (the capacity for loss resulting from environmental change). Examples include climate change in the Pacific. We conclude that protecting human health in a changing world requires us to take steps to minimize harmful change wherever possible, and at the same time to be prepared for surprises. The goals of mitigation (reducing or preventing change) and adaptation (response to change) are not mutually exclusive. In fact, steps to make populations more resilient in the face of change are often similar to those that are needed to lighten the load on the environment. We need social policies that convert economic growth into human development. Wider application of sustainable development concepts is part of the solution. In particular, there is a need to promote health as an essential asset of poor and vulnerable populations. It is their key to productivity and to surviving shocks; it is also the key to achieving broader development goals such as universal education. For these reasons it is in the interests of all sectors--economic, social and environmental--to play their particular roles in protecting and improving health.

Adult↗
PubMed1999

Asthma prevalence and deprivation: a small area analysis.

STUDY OBJECTIVE: To investigate the relation between the prevalence of asthma symptoms in adults and deprivation in the area of residence. DESIGN: Two complementary surveys carried out between 1991-1993 yielding adult asthma symptom prevalence throughout New Zealand. Deprivation is measured by the NZDep91 index of deprivation for small areas. SETTING: New Zealand. PARTICIPANTS: A random sample of 25,042 adults aged 20-50 years. MAIN RESULTS: After controlling for possible confounding by age, gender, and ethnicity, the 12 month period prevalence rates of asthma in this representative sample of New Zealand adults are significantly higher in the three most deprived area categories than in the least deprived (tenth) category. The prevalence ratio for the most deprived category compared with the least deprived category is 1.29 with 95% confidence intervals (CI) 1.14, 1.47. There is a linear increase in asthma prevalence with increasing area deprivation (chi 2(1) = 32.20, p < 0.001). Independently, the rates are also 1.41 (95% CI 1.29, 1.54) times higher among Maori and 1.29 (95% CI 1.10, 1.52) times higher among the Pacific Island group than among the remaining, mostly European, respondents. CONCLUSIONS: The relation between asthma in adults and area deprivation is unlikely to be attributable to study biases or confounding. Further work should examine the possible role of modifiable deprivation factors in this relation.

Adolescent↗
PubMed1999

El Niño and arboviral disease prediction.

Recent El Niño events have stimulated interest in the development of modeling techniques to forecast extremes of climate and related health events. Previous studies have documented associations between specific climate variables (particularly temperature and rainfall) and outbreaks of arboviral disease. In some countries, such diseases are sensitive to El Niño. Here we describe a climate-based model for the prediction of Ross River virus epidemics in Australia. From a literature search and data on case notifications, we determined in which years there were epidemics of Ross River virus in southern Australia between 1928 and 1998. Predictor variables were monthly Southern Oscillation index values for the year of an epidemic or lagged by 1 year. We found that in southeastern states, epidemic years were well predicted by monthly Southern Oscillation index values in January and September in the previous year. The model forecasts that there is a high probability of epidemic Ross River virus in the southern states of Australia in 1999. We conclude that epidemics of arboviral disease can, at least in principle, be predicted on the basis of climate relationships.

Arbovirus Infections↗
PubMed1999

El Niño and the dynamics of vectorborne disease transmission.

The objective of the study was to investigate the relationship between reported incidence of dengue fever and El Niño southern oscillation (ENSO) in 14 island nations of the South Pacific. Using a mixed ecological study design, we calculated correlations between annual averages of the southern oscillation index (SOI), local temperature and rainfall, and dengue fever. We also calculated temporal correlations between monthly reports of dengue fever cases on different islands. There were positive correlations between SOI and dengue in 10 countries. In five of these (including all of the larger islands) there were also positive correlations between SOI and estimates of local temperature and/or rainfall. There were temporal correlations between monthly reports of dengue cases within two groups of countries. Climate changes associated with ENSO may trigger an increase in dengue fever transmission in larger, more populated islands where the disease is endemic. There was also evidence of propagation of infection from larger islands to smaller neighbors. Unlike the initiation of epidemics, this transfer between islands appears to be independent of interannual climate variations, pointing to the importance of modulating factors in dengue transmission such as population density and travel. In the future, models of the impact of climate change must attempt to account for these factors.

Climate↗
PubMed1998

Prevalence of adult asthma symptoms in relation to climate in New Zealand.

We conducted an ecological study linking prevalence of adult asthma symptoms with climate in the 93 New Zealand general electorates. For each electorate, the 12-month period prevalence of self-reported asthma symptoms was determined using a random sample of adults aged 20-44 on the 1991 New Zealand electoral roll. Long-term average climate was estimated using a national climate database and a geographic information system. Asthma prevalence was calculated within quartiles of the exposure variables. Independent effects of climate variables were assessed using linear regression models, with adjustment for confounding by climate, social deprivation, and geographic variables. There was a statistically significant association between asthma prevalence and mean temperature, with the lowest quartile of mean temperature having an approximately 2% lower asthma prevalence. After adjusting for confounding, there was a monotonic increase in asthma prevalence within quartiles of temperature. The results of this study are in agreement with other research suggesting a lower prevalence of asthma at low temperatures. Although on short (day-to-day) time scales, low temperatures may have a direct effect resulting in acute exacerbations of asthma symptoms, warmer average temperatures are associated with increased asthma prevalence. The reasons for this are unclear, although it is possible that on longer term (annual) time scales, higher temperatures are associated with higher levels of allergen exposure.

Adult↗
PubMed1997

Geographical variation in the prevalence of asthma symptoms in New Zealand.

AIMS: To examine geographical variations in the prevalence of asthma symptoms in a random population sample of New Zealand adults aged 20-44 years. METHODS: A one page asthma symptom questionnaire was sent to 31470 people aged 20-44 years. The questionnaire asked about respiratory symptoms, asthma attacks and asthma treatment. Those who had not responded after two reminder postcards were followed with a telephone call where possible. RESULTS: A response rate of 82% (25664) was achieved. The 12 month period prevalence of asthma (defined as woken by shortness of breath, or an attack of asthma in the past year, or current asthma medication) was 15.2% overall, but was higher in females (17.0%) than in males (13.2%); the prevalence was 22.1% in Maori, 20.6% in Pacific Islanders and 14.3% in non Polynesians. In North Island electorates, the highest age and ethinicity standardised prevalences were found in some of the electorates in the Auckland and Wellington urban regions although prevalence was also high in some rural electorates including Raglan (18.0%), Horowhenua (18.4%) and Wairarapa (18.4%); the lowest prevalences were found in other rural electorates including King Country (5.5%), Matamata (10.1%) and Rotorua (10.3%). In South Island electorates, the highest prevalences were found in some electorates in the Christchurch and Dunedin urban areas, and the lowest prevalences were again found in rural electorates including Clutha (11.3%), Rangiora (9.5%) and Wallace (9.4%). CONCLUSIONS: This study confirms the previously reported high frequency of asthma symptoms in New Zealand adults, with higher symptom prevalence in Maori and in women. It shows significant urban/rural differences, as well as marked differences in prevalence between various rural areas. The reasons for these patterns are unclear and require further study.

Adult↗