The respiratory health effects of nitrogen dioxide in children with asthma.

There is growing evidence that asthma symptoms can be aggravated or events triggered by exposure to indoor nitrogen dioxide (NO(2)) emitted from unflued gas heating. The impact of NO(2) on the respiratory health of children with asthma was explored as a secondary analysis of a randomised community trial, involving 409 households during the winter period in 2006 (June to September). Geometric mean indoor NO(2) levels were 11.4 µg · m(-3), while outdoor NO(2) levels were 7.4 µg · m(-3). Higher indoor NO(2) levels (per logged unit increase) were associated with greater daily reports of lower (mean ratio 14, 95% CI 1.12-1.16) and upper respiratory tract symptoms (mean ratio 1.03, 95% CI 1.00-1.05), more frequent cough and wheeze, and more frequent reliever use during the day, but had no effect on preventer use. Higher indoor NO(2) levels (per logged unit increase) were associated with a decrease in morning (-17.25 mL, 95% CI -27.63- -6.68) and evening (-13.21, 95% CI -26.03- -0.38) forced expiratory volume in 1 s readings. Outdoor NO(2) was not associated with respiratory tract symptoms, asthma symptoms, medication use or lung function measurements. These findings indicate that reducing NO(2) exposure indoors is important in improving the respiratory health of children with asthma.

Sources of nitrogen dioxide (NO2) in New Zealand homes: findings from a community randomized controlled trial of heater substitutions.

UNLABELLED: Houses in New Zealand have inadequate space heating and a third of households use unflued gas heaters. As part of a large community intervention trial to improve space heating, we replaced ineffective heaters with more effective, non-polluting heaters. This paper assesses the contribution of heating and household factors to indoor NO2 in almost 350 homes and reports on the reduction in NO2 levels due to heater replacement. Homes using unflued gas heaters had more than three times the level of NO2 in living rooms [geometric mean ratio (GMR) = 3.35, 95% CI: 2.83-3.96, P < 0.001] than homes without unflued gas heaters, whereas homes using gas stove-tops had significantly elevated living room NO2 levels (GMR = 1.42, 95% CI: 1.05-1.93, P = 0.02). Homes with heat pumps, flued gas heating, or enclosed wood burners had significantly lower levels of NO2 in living areas and bedrooms. In homes that used unflued gas heaters as their main form of heating at baseline, the intervention was associated with a two-third (67%) reduction in NO2 levels in living rooms, when compared with homes that continued to use unflued gas heaters. Reducing the use of unflued gas heating would substantially lower NO2 exposure in New Zealand homes. PRACTICAL IMPLICATIONS: Understanding the factors influencing indoor NO2 levels is critical for the assessment and control of indoor air pollution. This study found that homes that used unflued gas combustion appliances for heating and cooking had higher NO2 levels compared with homes where other fuels were used. These findings require institutional incentives to increase the use of more effective, less polluting fuels, particularly in the home environment.

Retrofitting houses with insulation to reduce health inequalities: aims and methods of a clustered, randomised community-based trial.

This paper describes the purpose and methods of a single-blinded, clustered and randomised trial of the health impacts of insulating existing houses. The key research question was whether this intervention increased the indoor temperature and lowered the relative humidity, energy consumption and mould growth in the houses, as well as improved the health and well-being of the occupants and thereby lowered their utilisation of health care. Households in which at least one person had symptoms of respiratory disease were recruited from seven predominantly low-income communities in New Zealand. These households were then randomised within communities to receive retrofitted insulation either during or after the study. Measures at baseline (2001) and follow-up (2002) included subjective measures of health, comfort and well-being and objective measures of house condition, temperature, relative humidity, mould (speciation and mass), endotoxin, beta glucans, house dust mite allergens, general practitioner and hospital visits, and energy or fuel usage. All measurements referred to the three coldest winter months, June, July and August. From the 1352 households that were initially recruited, baseline information was obtained from 1310 households and 4413 people. At follow-up, 3312 people and 1110 households remained, an 84% household retention rate and a 75% individual retention rate. Final outcome results will be reported in a subsequent paper. The study showed that large trials of complex environmental interventions can be conducted in a robust manner with high participation rates. Critical success factors are effective community involvement and an intervention that is valued by the participants.

Could mainstream anti-smoking programs increase inequalities in tobacco use? New Zealand data from 1981-96.

OBJECTIVE: To examine changes in the socio-economic and ethnic distribution of smoking in the New Zealand population from 1981 to 1996, and to consider the implication of these data for policies aimed at reducing tobacco consumption. METHODS: Cross-sectional data were taken from 4.7 million respondents to the 1981 and 1996 New Zealand Censuses and 4,619 participants in a 1989 national survey, aged 15 to 79 years. Smoking prevalence rates were calculated by socio-economic position and ethnicity. RESULTS: Smoking prevalence fell in the period 1981-96 in every population group. However, socio-economic and ethnic differences in smoking increased in relative terms. Smoking prevalence ratios comparing the least advantaged with the most advantaged groups increased in men from 1.20 to 1.53 by income, 1.54 to 1.85 by education, and 1.49 to 1.67 by ethnicity. In women, prevalence ratios increased from 1.17 to 1.51 by income, 1.55 to 2.02 by education, and 1.85 to 2.20 by ethnicity. The greatest increase in socio-economic differences may have occurred during the 1980s, the period of greatest overall decline in total population smoking. CONCLUSIONS: Socio-economic and ethnic disparities in New Zealanders' smoking patterns increased during the 1980s and '90s, a period of significant decline in overall smoking prevalence. IMPLICATIONS: Public health programs aimed at reducing tobacco use should pay particular attention to disadvantaged, Indigenous and ethnic minority groups in order to avoid widening relative inequalities in smoking and smoking-related health outcomes.

Housing standards: a glossary of housing and health.

This glossary has been designed to provide definitions that take account of different disciplinary and policy traditions and to consider the aspects of housing that provide scope for possible concerted research and action.

Translating research findings into health policy.

Evidence of the influence of research on health policy is paradoxical. While there is scant evidence that research has had any impact on the direction or implementation of widespread health reforms, research on evidence-based medicine has dramatically increased, despite limited evidence that it has affected clinical practice. These developments have occurred in the context of a general decline in state intervention and provision and a post-modern questioning of researchers' authority. Models of the relationship between research and policy range from one where empirical research rationally informs decision-making, through research incrementally affecting policy, to an "enlightenment" or "infiltration" model, which may operate on a conceptual level. Health research that contributes to large-scale socio-political change may require more methodological pluralism and greater focus on key institutional structures. Case studies reviewed suggest that dissemination is enhanced if researchers involve managers and policy-makers in the development of the framework for and focus of research and if investigators assume a responsibility for seeing their research translated into policy. Public health research is more influential if topical, timely, well-funded and carried out by a collaborative team that includes academics. Evaluations are more influential if, in addition, they are commissioned by health authorities but based on local collection of data, and instruments and incentives to implement policy are available. In some areas, such as the recent policy focus on careers in the community, researchers were largely responsible for raising this policy issue, whereas in other areas, such as the relationship between unemployment and health, researchers are just one of the groups of experts making competing claims about causality. In conclusion, clear research findings are not always a passport to policy, but researchers can reframe the way health policy issues are seen, and collaboration with policy-makers initially can enhance implementation later.

Does the frame affect the picture? A study into how attitudes to screening for cancer are affected by the way benefits are expressed.

OBJECTIVE: To find out how presenting information about the benefits of screening for cancer in different ways affects an individual's decision to accept or reject screening. METHODS: A telephone survey of the Wellington region, New Zealand was carried out. RESULTS: A response rate of 75.6% was obtained. Respondents were most likely to accept screening when the benefits of screening were presented as a relative risk reduction. They were most likely to reject screening when the benefits were presented as numbers needed to screen to save on life. CONCLUSIONS: An individual's decision about screening for cancer is affected by the way the benefits are framed. Health professionals must choose between framing the benefits of screening in the most positive light, to enhance participation rates, and presenting information in such a way as to reduce framing effects--for example, by expressing the benefits in a variety of forms. Clearly there may be a tension between these approaches; the former is arguably manipulation, and the latter may enhance informed choice, but may also reduce participation rates in screening programmes.

Why do Australians live longer than New Zealanders?

The aim of this study was to compare patterns of mortality in Australia and New Zealand, using routinely collected data. Life expectancy at birth is greater in Australia than in New Zealand (in 1996 the gap was 1.5 years for women and 1.1 years for men). Prior to 1970, mortality was lower in New Zealand than Australia. Possible reasons for the divergence in life expectancies include slower economic growth in New Zealand, more marked increases in economic inequalities which have affected Maöri in particular and, to a modest extent, differentials in health care.

Open houses and closed rooms: Tokelau housing in New Zealand.

The migrant Tokelau community in New Zealand, through the Wellington Tokelau Association, is playing an active role in partnership with the Wellington School of Medicine to develop a research program to help improve the health of its people. The relationship between crowded homes and health was investigated in six focus groups. While cultural patterns were an essential part of Tokelau hospitality, the decision to "double up" households was often the result of "rational" economic decision making in relation to household expenditures such as rent and food. The implication for public health practitioners is that while overcrowding may be a health hazard for residents, the most effective solutions by the community are higher household income and more flexible housing designs that accommodate multifamily households.

Second-hand smoke at work: the exposure, perceptions and attitudes of bar and restaurant workers to environmental tobacco smoke.

OBJECTIVES: To investigate the knowledge of, and perceptions, attitudes and exposure to second-hand smoke (SHS) of staff in the New Zealand hospitality industry. METHOD: Face-to-face interviews with bar staff, waiters, and bar and eating-place managers and owners in Wellington during the 1999-2000 summer. An analysis was made of the 1999 New Zealand Electoral Roll to find the number of those most exposed to SHS. RESULTS: 435 interviews with full data recovery were completed at 364 locations; 59% of interviewees were exposed to SHS, including 77% of those at licensed premises. More than half of those exposed to workplace smoke reported irritation from SHS to their throat or lungs. Less than a third were aware of the risk of strokes from SHS. Three-quarters of interviewees wanted some sort of smoking restriction in bars. CONCLUSIONS: The majority of interviewees were at risk of premature death and disease because of exposure to workplace smoke, and had an incomplete knowledge of the dangers to which they were exposed. More than 5,000 similar workers in New Zealand appear to share this risk. IMPLICATIONS: This industry needs legislation to make it smoke free.

The New Zealand Socioeconomic Index: developing and validating an occupationally-derived indicator of socio-economic status.

OBJECTIVE: Following revision of the international standard classification (ISCO88), to update and validate on health data an occupationally derived indicator of socio-economic status (SES) adapted to changing occupational and demographic conditions. METHOD: The development of the New Zealand Socioeconomic Index (NZSEI) is based on a 'returns to human capital' model of the stratification process and uses data from the 1991 New Zealand Census (n = 1,051, 926) to generate scores for 97 occupational groups. The construct validation of the scale is carried out on data from the 1992-93 nationwide Household Health Survey (n = 3,000) using three health indicators (self-assessed health, cigarette smoking, general practitioner visits). RESULTS: In general, the results are consistent with expected socio-economic patterns drawn from the literature for the three indicators. CONCLUSIONS: While further work is required on a number of methodological and conceptual issues, the NZSEI provides a robust, standardised and internationally comparable occupational scale of SES for both males and females in either full- or part-time employment. IMPLICATIONS: The NZSEI can be used on routinely collected occupational data. It has a clear conceptual rationale, updates existing SES scales, and provides a link to international standards in SES and occupational classification.

Survey of drug and alcohol use by lesbian women in New Zealand.

The objective of this study is to describe the prevalence of alcohol and drug use and attitudes towards alcohol use in a group of New Zealand lesbian women. The method used is 1,222 copies of a postal questionnaire (the Lesbian Mental Health Survey [LMHS]) were distributed via lesbian newsletters over a 4-month period. Responses were received from 561 women, an estimated response rate of 50.8%. The respondents were predominantly New Zealand European, highly educated, urban women in the 25- to 50-year age bracket; 30.1% smoked cigarettes, and 90.2% had drunk alcohol at some time in the past year, over half once per week or less. The median number of drinks per week was 1.5 drinks, equivalent to 22.5 ml alcohol per week. Despite a comparatively low reported use of alcohol, 48.1% of respondents expressed the view that alcohol is used excessively in the lesbian community; 75.8% had used cannabis at least once, 32.6% in the past year; 30.8% had used recreational drugs other than cannabis and alcohol at some time, 4.5% in the past year.

Doing the splits: contracting issues in the New Zealand health service.

The purchaser-provider split is an integral part of the New Zealand and UK health care reforms. The split is seen as an opportunity to introduce competition by increasing the number of players. The assumption is that competition among providers, purchasers or indeed funders, increases efficiency and provides more consumer choice. This paper looks at the issue of contracting in the New Zealand health services within the framework of transaction cost analysis. It examines evidence about the effects of formal contracting rather than the more traditional, informal negotiations that take place within a hierarchy. A number of potential problems with an indiscriminate provider split are highlighted and the conclusion drawn, that the outcome of such a split is likely to be more unpredictable than official expectations. In the absence of pilots, monitoring the implementation will be critically important to be able to compare the outcomes of different ways of organising the health care system.

Blood ties: accountability for blood quality in New Zealand.

Blood donations are 'gifts' that do not fit easily into a more market-oriented health care system. The new commercial organisational arrangements in New Zealand for the collection, manufacture and distribution of blood and blood products are compared in this paper with the old organisational arrangements. The particular case of screening blood for hepatitis C is examined. A socio-legal framework, which looks at the regulation of social institutions, is used to explore the different ways in which people have tried to maintain the quality of blood and blood products, both in New Zealand and internationally. One conclusion drawn is that blood production and distribution cannot be commercialised without affecting supply and quality.

Public purchasing and private priorities for healthcare in New Zealand.

The 1993 Health and Disability Services Act heralded a range of structural reforms in the New Zealand health care system. Despite these reforms considerable resources being spent on convincing consumers of their merits, have failed to gain widespread public approval. This paper examines two key issues that have arisen during the reform process. These are the difficulties associated with trying to set priorities in ways which are effective and politically acceptable, and the relationship between the public and private sectors. Unacknowledged conflicts of interest have helped to undermine the priority setting process. The discussion suggests that it may be increasingly difficult for any government in future to determine the allocation of resources without taking private sector interests and rising public concern into account. It remains to be seen which of these factors is more powerful.

Shopping for health: purchasing health services through contracts.

The 1993 New Zealand health service reforms were based on the purported efficiencies of the purchaser/provider split. Purchasers are required to contract for services that will maintain, improve and restore the health of the populations they serve. The purchasing role, which requires the development of contracting skills as well as the setting of strategic directions and priorities, is new and as yet poorly developed. This paper describes the role of purchasing agents in setting priorities, the different approaches that are being taken to contracting for services and some of the problems that have arisen in the first year of contracting. It explores the trade-off that is evident between the potential for improving efficiency through contestable contracting and the need to minimise transaction costs associated with the contracting process. The purchasers' accountability to the public and the Minister is analysed in the broader political context of the purchasers' role in shaping a public health service and improving the health of the population.

Evaluation of effectiveness of aftercare in alcoholism treatment.

Providing aftercare to alcoholic patients upon discharge is seen as an important factor in recovery. The purpose of this study was to investigate whether providing contractual aftercare would increase the aftercare attendance and influence their drinking. The subjects were 55 patients who underwent inpatient treatment over a one year period. They either signed a contract to attend a specified number of meetings and upon failure to do so were actively followed up (contract group, n = 28) or did not sign a contract but were only verbally encouraged to attend the meetings (control group, n = 27). Six months after discharge, patients in both groups were followed up and data obtained on drinking and social stability measured. A multiple regression analysis showed that although the use of a contract was effective in increasing patients' return rate to the unit, attendance of aftercare meetings was not a significant predictor of drinking. The significant predictor was the employment situation. Patients' perceptions of aftercare provided was evaluated and the necessity for providing aftercare based on patients' needs was seen as important.

A cut above: the rising Caesarean section rate in New Zealand.

AIM: To examine the trends in frequency of Caesarean section in New Zealand. METHODS: Caesarean section rates (CSR) were calculated from the National Minimum Data Set between 1988/89 and 1994/95. Demographic data relating to women having Caesarean sections were examined for 1994/95. The results were checked with regional health authorities and Crown health enterprises containing teaching hospitals. RESULTS: The national CSR, which was 9.6% in 1983/84, increased from 11.6% in 1988/89 to 15.3% in 1994/95. Previous Caesarean and dystocia are reported to be the indicators for nearly half of all Caesareans. CONCLUSIONS: The national CSR is high and continues to increase. The international literature shows that national recommendations to reduce the CSR are less effective than hospital-based initiatives.

Promotion of smoking cessation by New Zealand general practitioners: a description of current practice.

AIMS: To describe the advice and support New Zealand general practitioners (GPs) reported providing to patients about smoking cessation, to explore barriers encountered in providing this advice, and to compare reported practice with recommended best practice. METHODS: 450 GPs were surveyed from four different localities using a structured postal questionnaire. RESULTS: Questionnaires were returned by 283 GPs, giving a response rate of 63%. Approximately one-third of GPs asked every adult patient about their smoking status. Fewer recorded this information in the patient's notes. GPs, based on their own experience, considered nicotine replacement therapy (NRT) and their own advice to quit to be the two most useful smoking cessation strategies. They perceived patient resistance and time pressures as the main barriers limiting their ability to give advice to patients about smoking cessation. CONCLUSIONS: GPs provide smoking cessation advice to many patients, but this needs to be viewed in the context of the New Zealand fee-for-service primary care system and competing demands placed on the limited time available within a consultation. There is potential to increase the practice nurse's involvement in providing smoking cessation advice.

Smoking hygiene: a study of attitudes to passive smoking.

AIM: To study the attitudes and knowledge of adults in the Wellington area about the effects of passive smoking and measures to reduce exposure to smoke. METHODS: A sample of 200 people, randomly selected in the Wellington area, answered a telephone survey on passive smoking. RESULTS: Of the 200 respondents, 160 (80%) were males, 40 (20%) were females and approximately one-third (30%) were smokers. Most people (85.5%) thought public and private areas should be smoke-free when there were children around, but only half (53.5%) thought that smoking should be banned in cars when there are passengers. Most people (92.5%) correctly defined passive smoking. Half were aware that passive smoking negatively contributed to all the following diseases (asthma, cancer, heart disease, respiratory problems) and cot death but a higher percentage identified cancer (75.5%) and cot deaths (68.5%) specifically. Most smokers reported that they smoke at home or in their cars rather than in public places. Half the smokers (50.9%) did not smoke in front of children; a further 17.3% reported that they smoked less. CONCLUSIONS: In this sample there was a relatively low level of awareness of the effects of passive smoking on health and a high prevalence of smoking in the presence of children. Smokers and non-smokers were almost equally divided on whether there should be a law restricting smoking in private cars, although the majority agreed that cars carrying children should be smoke-free. Public health efforts to reduce the harm from passive smoking should be focused on discouraging smoking, in settings in which children are exposed, including private cars when children are passengers.