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R Bonita

Publications and source records attributed to R Bonita.

At least 19 recordsLinked to original sources
PubMed1995

Geographical variations in the organisation of general practice.

AIMS: To describe organisational characteristics of New Zealand general practice and to investigate inter-regional variations in these characteristics. METHODS: Data were collected by standardised questionnaires from general practitioners in Auckland, Waikato and Taranaki. The Waikato data were collected in July-August 1991 by postal survey, the Taranaki data were collected May-June 1992 by postal survey and the Auckland data were collected December 1990 to January 1991 by face-to-face interview. RESULTS: The response rates were Auckland 98% (167/171), Waikato 84% (185/220) and Taranaki 79% (79/100). There were significantly more overseas trained graduates in rural areas than in urban areas. Average practice size was 2.3 full time equivalent doctors, with each 100 doctors employing 71 nurses and 77 receptionists. The number of patients seen per week ranged from 109-141. Almost all (95%) general practitioners operated appointment systems. One in five general practitioners had patients in private hospitals, and more than half (58%) had patients in rest homes. At the time of interview, 29% of Auckland general practitioners used computers in their practices compared with over 50% in Waikato and Taranaki (p < 0.05). A smaller proportion of Auckland general practitioners had access to age/sex registers and fewer Auckland general practitioners had a recall system. Of Auckland general practitioners with recall systems, a greater proportion used them for mammograms, blood pressure and lipid measurements compared with elsewhere. CONCLUSIONS: There are some significant regional variations in the functional characteristics of general practice in New Zealand which should be taken into account when planning primary care services in different regions. Should budget holding and managed care be introduced, computerised practices will be required. This will have significant resource implications.

Adult↗
PubMed1995

Approaches to the problems of measuring the incidence of stroke: the Auckland Stroke Study, 1991-1992.

BACKGROUND: Stroke registers are the preferred choice for determining incidence, case-fatality and severity of acute stroke in defined populations. This paper highlights some of the problems likely to be encountered in this endeavour by describing the experience of measuring acute stroke prospectively. METHODS: The Auckland Stroke Study is a community-based study among 945,000 residents of the Auckland region, New Zealand. Standard definitions and overlapping case-finding methods were used to identify all new acute stroke events occurring during the 12-month period ending 1 March 1992. Particular attention was directed at including non-fatal strokes managed outside hospital. The latter were identified by use of a cluster sample, a technique suitable for populations where residents have a personal primary health care physician. RESULTS: The comprehensive sources of referral to the study involved the review of 5736 records, less than one-third of which met the criteria for inclusion. The majority of included acute stroke events (n = 1803) were found through routinely available sources such as hospital admission records (63%) and death registrations (10%). The remainder (27%) were identified through intensive efforts at case-finding of stroke events managed outside hospital. The 1803 events were registered in 1761 people, 817 men and 944 women; for 587 (72%) men and 718 (76%) women, the stroke was the first ever experienced. CONCLUSIONS: While time-consuming, costly and demanding, there appears to be no easier alternative to a register to estimate incidence. This study demonstrates the importance of the use of comprehensive case-finding sources and suggests approaches to overcoming the difficulties in monitoring stroke incidence in large populations.

Adolescent↗
PubMed1995

Multinational comparisons of stroke epidemiology. Evaluation of case ascertainment in the WHO MONICA Stroke Study. World Health Organization Monitoring Trends and Determinants in Cardiovascular Disease.

BACKGROUND AND PURPOSE: As part of the WHO MONICA Project (World Health Organization Monitoring Trends and Determinants in Cardiovascular Disease), mortality and incidence rates of acute stroke in 14 centers covering 21 populations from 11 countries were compared. METHODS: In this report, coverage and quality of the MONICA stroke registers were evaluated on five key indicators using data submitted to the MONICA Data Center. RESULTS: A low ratio of MONICA stroke register to routine statistics of stroke mortality and a low proportion of nonfatal out-of-hospital events were the most common biases; they indicate that identifications of fatal cases and/or case finding of nonfatal events occurring outside the hospital were inadequate in many MONICA centers. In 10 populations, the data quality analyses suggested that clarification of possible biases would be needed before these populations can be included in a comparative study. Data from the remaining 11 populations meet the data quality standards for multinational comparisons with respect to case ascertainment. CONCLUSIONS: These results show that multinational comparisons of stroke incidence involve considerable problems in developing and maintaining appropriate standards of data quality. However, after considerable efforts to ensure quality, comparisons of stroke data within the MONICA Project are possible among a large number of the MONICA populations. Our observations also indicate that results from multinational comparisons of stroke mortality based on routine statistics must be interpreted with caution.

Acute Disease↗
PubMed1995

Inadequacy of clinical scoring systems to differentiate stroke subtypes in population-based studies.

BACKGROUND AND PURPOSE: We undertook to examine the usefulness for epidemiological studies of two well-known validated clinical scoring methods, the Guys' Hospital Stroke score and the Siriraj Hospital Stroke score, to classify strokes into the two main types, hemorrhagic and ischemic, in epidemiological studies. METHODS: Patients from a population-based stroke register who received either a CT scan or an autopsy were retrospectively scored using the two clinical scoring methods. The scores were then compared with the CT scan and autopsy results to determine the sensitivity, specificity, and positive predictive value for intracranial hemorrhage (primary intracerebral and subarachnoid hemorrhage) and ischemic stroke. RESULTS: Over a 12-month period, 554 patients from a population-based study underwent CT scanning. Films or autopsy reports were available for 521 patients, and of these, sufficient clinical information to calculate the Guys' Hospital Stroke score and the Siriraj Hospital Stroke score was available for 464 and 475 patients, respectively. For the Guys' Hospital Stroke score, the sensitivity and specificity for intracranial hemorrhage were 31% and 95%, respectively; the positive predictive value was 73%. The sensitivity and specificity for ischemic stroke were 78% and 70%, respectively, and the positive predictive value was 86%. For the Siriraj Hospital Stroke score, the sensitivity and the specificity for intracranial hemorrhage were 48% and 85%, respectively; the positive predictive value was 59%. The sensitivity and specificity for ischemic stroke were 61% and 74%, respectively, and the positive predictive value was 84%. CONCLUSIONS: This validation study suggests that both clinical scores lack sufficient validity to be used in epidemiological studies for classification of stroke types and should probably not be used in the randomization of patients into treatment trials using thrombolytic or antithrombotic drugs in the absence of diagnostic information based on neuroimaging techniques.

Adult↗
PubMed1994

The worldwide problem of stroke.

Cardiovascular disease is the leading cause of death worldwide with almost one third of all cardiovascular deaths ascribed to stroke. In contrast to coronary heart disease, most of the strokes occur in developing countries; China alone has about 1 million deaths from stroke each year. From a global perspective the stroke situation is changing rapidly, and considerable progress has been made in documenting the changes in stroke mortality. Despite the favorable trends in stroke mortality in many countries, stroke will become an increasingly important health problem as the world's population continues to age.

Aged↗
PubMed1994

Stroke incidence and case fatality in Australasia. A comparison of the Auckland and Perth population-based stroke registers.

BACKGROUND AND PURPOSE: Population-based studies are crucial for identifying explanations for the decline in mortality from stroke and for generating strategies for public health policy. However, the present particular methodological difficulties, and comparability between them is generally poor. In this article we compare the incidence and case fatality of stroke as assessed by two independent well-designed incidence studies. METHODS: Two registers of acute cerebrovascular events were compiled in the geographically defined metropolitan areas of Auckland, New Zealand (population 945,369), during 1991-1992 for 12 months and Perth, Australia (population 138,708), during 1989-1990 for 18 months. The protocols for each register included prospective ascertainment of cases using multiple overlapping sources and the application of standardized definitions and criteria for stroke and case fatality. RESULTS: In Auckland, 1803 events occurred in 1761 residents, 73% of which were first-ever strokes. The corresponding figures for Perth were 536 events in 492 residents, 69% of which were first-ever strokes. Both studies identified a substantial proportion of nonfatal strokes managed solely outside the hospital system: 28% in Auckland and 22% in Perth of all patients registered. The age-standardized annual incidence of stroke (all events) was 27% higher among men in Perth compared with Auckland (odds ratio, 1.27; P = .016); women tended to have higher rates in Auckland, although these differences were not statistically significant. In both centers approximately a quarter of all patients died within the first month after a stroke. There were significant differences in the prevalence of hypertension among first-ever strokes. CONCLUSIONS: These two studies emphasize the importance of identifying all patients with stroke, both hospitalized and nonhospitalized, in order to measure the incidence of stroke accurately. The incidence and case fatality of stroke were remarkably similar in Auckland and Perth in the early 1990s. However, there are differences in the sex-specific rates that correspond to differences in the pattern of risk factors.

Adolescent↗
PubMed1993

Changes in stroke incidence and case-fatality in Auckland, New Zealand, 1981-91.

The explanation for the substantial decline in stroke death rates can be investigated only by measuring trends in stroke incidence and case-fatality. Two community-based studies carried out in Auckland, New Zealand, in 1981 and 1991 used comparable methods and definitions, met criteria for well-designed studies, and had the power to detect small changes in incidence and case-fatality rates. 703 events (representing 50% of all strokes) were registered in 1981 and 1735 events in 1991. 521 (74.1%) and 1255 (72.3%) events in 1981 and 1991, respectively, were first-ever (in a lifetime) strokes. Although there was no change in overall stroke incidence between 1981 and 1991, there were changes in age and sex groups. The incidence rate among women younger than 75 years rose by a fifth (rate ratio 1.23 [95% CI 1.04-1.47]), whereas that in men of 75 years and older fell by a third (rate ratio 0.67 [0.54-0.82]). The 28-day case-fatality declined from 27.1 (21.7-32.6)% to 21.9 (18.1-25.7)% in men and from 37.6 (31.8-43.5)% to 25.8 (22.3-29.4)% in women from 1981 to 1991, but the decline was not statistically significant in any age or sex group. These findings suggest that we need to reappraise strategies for the prevention of stroke and assess the implications of improved survival in elderly stroke patients.

Adolescent↗
PubMed1993

Stroke trends in Australia and New Zealand: mortality, morbidity, and risk factors.

Stroke death rates are declining in Australia and New Zealand as in many other industrialized countries. An explanation for the decline in mortality requires information from population-based incidence studies. Two studies that meet the criteria for well-designed stroke studies have been conducted, one in Auckland, New Zealand, in 1991 and the other in Perth, Western Australia, in 1988 to 1989. Comparisons between the two studies reveal similar incidence and case-fatality rates for both men and women, reflecting the similar mortality rates. The Auckland study repeats one carried out 10 years earlier and allows an insight into the changes in incidence, case fatality, and severity of stroke in a large urban population. Between the two study periods there was no overall change in the incidence rates but case-fatality rates improved in both men and women. Although there have been significant improvements in the level of smoking in both Australia and New Zealand during the 1980s, only marginal improvements in mean population blood pressure have occurred, despite efforts and resources directed at identification of individuals with raised blood pressure. This high-risk strategy has apparently had only a very limited impact on reducing the incidence of stroke in the population.

Aged↗
PubMed1992

The development and evaluation of Basic Epidemiology: Student's Text.

This paper describes the development and evaluation of a World Health Organization book Basic Epidemiology: Student's Text. This book was a response to a need identified by members of the WHO Global Environmental Epidemiology network. A draft was commented on by members of the Network and then at an editorial meeting. Two thousand copies of a pre-publication version were prepared and this version was formally evaluated by 13 teachers of introductory courses of epidemiology and less formally by members of the Epidemiology Network. A high response was received to the evaluation questionnaires; 45% of the students rated the test overall as 'very useful' and another 54% as 'useful'; many useful comments were received and were incorporated into the final version which will be published by WHO in 1993.

Attitude of Health Personnel↗
PubMed1991

The extent of cervical screening in New Zealand women.

To estimate the extent of cervical screening coverage of New Zealand women, a national survey of 1000 randomly selected women with a supplement of 200 Maori women was carried out by the National Research Bureau in August 1990 for the Department of Health. The results indicate a high level of screening in women aged 20-64 and improvements in coverage over the last three years, probably in response to the Cartwright inquiry. Overall, 77% of women reported having had a smear test within the previous three years and after adjustment for hysterectomy, this proportion increased to 82%. Screening coverage, however, was unevenly spread according to ethnic group, age and household income. Only 15% of European women reported no smear test in the last three years compared with 27% of Maori and Pacific Island women. The likelihood of having had a smear test in the last three years increased with increasing income. The survey confirms a high level of very frequent screening throughout New Zealand (2.4 smear tests per woman in the previous three years); the most frequent screening occurred in women 20-24 years of age (2.9 smears). Because an organised national screening programme has the potential to maintain and extend screening coverage to all age and ethnic groups, as well as reduce the number of unnecessary smears, it is likely to be more cost effective than the current screening practice.

Adolescent↗