Biomedical subjects

C A Mustard

Publications and source records attributed to C A Mustard.

31 records · Page 2Linked to original sources

PubMed1996

Influence of magnetic resonance imaging on diagnosis and therapeutic intention.

RATIONALE AND OBJECTIVES: We assessed the contribution of magnetic resonance (MR) imaging to diagnostic and therapeutic decision making. METHODS: In a before-after observational study, we collected information from clinicians before and after patients were given MR examinations. We studied 406 cases selected from consecutive referrals to a single MR imaging facility in Manitoba between November 1, 1991, and October 30, 1992, for diagnosis of suspected brain, spinal column, or large-joint disorder. We examined changes in diagnoses, changes in clinician diagnostic confidence, and changes in therapeutic intentions after MR examinations. RESULTS: Overall, MR imaging findings contributed to a change in referring physicians' diagnoses or diagnostic confidence in 76% of the cases. Referring physicians reported a change in provisional diagnosis in 42% of the cases. In 67% of these cases, the referring physician's provisional diagnosis was ruled out by normal examination findings; in the remaining 33% of the cases, an alternate diagnosis was offered by the consulting radiologist. In the 58% of the cases in which the provisional diagnosis was not altered by MR imaging findings, clinical confidence in the provisional diagnosis increased in 46% of the cases and decreased in 12% of the cases. Management plans were reported to be altered in 54% of the cases; in 24% of the cases, therapeutic intentions changed from lower to higher levels of intervention. CONCLUSION: Although MR imaging had a substantial influence on clinicians' decisions concerning diagnoses, the influence of MR imaging findings on therapeutic decision making, and therefore on patients' health status, was more moderate.

Brain Diseases↗

PubMed1996

Hospitalization and case-fatality rates for stroke in Canada from 1982 through 1991. The Canadian Collaborative Study Group of Stroke Hospitalizations.

BACKGROUND AND PURPOSE: The purpose of this study was to estimate rates of hospitalization and in-hospital case-fatality for cerebral infarction and intracerebral hemorrhage in Canada and to describe variation in rates by age, sex, and calendar period. METHODS: Data were obtained from hospitalization databases for each of Canada's 10 provinces for the 10 fiscal years of 1982 through 1991. All hospitalizations of persons 15 years of age or older with a primary diagnosis at discharge coded 431, 434, or 436 according to the International Classification of Disease, 9th Revision, were included. Rates per 100,000 population were calculated for intracerebral hemorrhage and cerebral infarction, for men and women, and for five age groups. Annual age- and sex-specific, 30-day, in-hospital case-fatality rates were also calculated. RESULTS: A total of 335,283 discharges for stroke were enumerated over the 10-year period (309,631 cerebral infarctions and 25 652 intracerebral hemorrhages). A significant decline of approximately 1% per year was observed for the rate of cerebral infarctions. For hemorrhages, the reverse was seen. For men there was a 44% increase over the 10-year period, and for women there was a 34% increase. In-hospital case-fatality rates for cerebral infarctions increased with age but did not differ by sex when age was considered. For the five age groups of 15 to 54, 55 to 64, 65 to 74, 75 to 84 and > or = 85 years, rates were 6%, 8%, 12%, 18% and 27%, respectively. For intracerebral hemorrhage, the in-hospital case-fatality rates declined significantly over time from approximately 36% to 29%, 55% to 37%, 49% to 41%, 66% to 45%, and 72% to 59% for the five age groups, respectively. CONCLUSIONS: The possibility that these changes are artifactual could not be ruled out, but because there is no obvious risk in assuming that they are not, it would be prudent to investigate their causes further.

Adolescent↗

PubMed1996

Intensive use of mental health care.

OBJECTIVE: To describe the profile of the intensive use of mental health services over a 4-year period in a population of 1.1 million people. METHODS: Data obtained from computerized hospital separation records and physician reimbursement claims were combined to form patient-based histories of mental health care utilization. Users of mental health services in a 24-month period were hierarchically classified as having a psychotic disorder (ICD-9-CM 295-299) or a nonpsychotic disorder (ICD-9-CM 300-301, 306-309, 311). Intensive use was defined as 12 or more contact months or a minimum of 2 episodes of therapy in the 24-month period. The cohort of intensive users were followed over the subsequent 24-month interval to describe the persistence of intensive use. RESULTS: In the initial observation periods, intensive users constituted 27.4% of individuals in treatment for psychotic disorder and 4.4% of persons in treatment for nonpsychotic disorder. These 2 groups, which represent 7.4% of all users of mental health care, were responsible for 53% of physician services, 72.7% of contacts with psychiatrists, and 64.4% of acute psychiatric bed days in the initial period. In the follow-up period, intensive use status was replicated by 44.6% of the cohort. CONCLUSIONS: The diagnostic and therapeutic characteristics of intensive users of mental health services are heterogeneous. There is substantial persistence of intensive mental health service use over time.

Adolescent↗

PubMed1996

Population health and health care use: an information system for policy makers.

University-based researchers in Manitoba, Canada, have used administrative data routinely collected as part of the national health insurance plan to design a population-based health information system (POPULIS). Decision-makers can use this system to make critical comparisons across regions of residents' health status, socioeconomic risk characteristics, and use of hospitals, nursing homes, and physicians. Policy makers have found this information system useful in providing answers to questions they are often asked: Which populations need more physician services? Which need fewer? Are high-risk populations poorly served or do they have poor health outcomes despite being well served? Does high utilization represent overuse or is it related to high need? Three commentaries follow.

Database Management Systems↗

PubMed1996

Continuity of pediatric ambulatory care in a universally insured population.

OBJECTIVE: To describe the prevalence of continuity of care over a 5-year period in a complete cohort of urban children universally insured for medical care provided under fee-for-service reimbursement. METHOD: All children enrolled in the study were born to women living in metropolitan Winnipeg between July 1, 1987 and December 31, 1988 (N = 12,590). All ambulatory physician services for this group were enumerated from computerized administrative databases for the period from birth through 60 months. Continuity of care, defined as the proportion of total care provided by the most frequently seen physician or physician practice over time, was calculated for each child. Descriptive analyses include an examination of maternal and household characteristics associated with children receiving 80% or more of total ambulatory care from a single provider source. RESULTS: From birth to 24 months, 51% of children received at least 80% of ambulatory visits from a single provider practice. This proportion of the children declined to 28% at 25 through 60 months. Children living in low-income neighborhoods had poorer continuity profiles. Other household factors associated with poor continuity included young maternal age, single maternal marital status, residential mobility, and inadequate maternal use of prenatal medical care. Households affiliated with pediatric practices had better continuity profiles than households affiliated with general medical practices. CONCLUSION: Despite universal medical insurance, barriers to a longitudinally continuous relationship with a primary care provider remain in this setting. Although this study has emphasized the description of those barriers associated with household characteristics, there is evidence that factors related to the organization and delivery of medical care are also relevant.

Adult↗

PubMed1995

Impact of a nurses' strike on the cesarean birth rate.

OBJECTIVE: Our purpose is to describe the impact of a 31-day nurses' strike on the cesarean birth rate in the province of Manitoba, Canada. STUDY DESIGN: Computerized hospital records, obtained for all births over a 24-month period, were used to identify complications of labor indicating cesarean section, method of delivery, and adverse maternal and newborn outcomes. The strike interval was compared with a 16-month prestrike period. RESULTS: The cesarean section rate in the strike interval, 12.5 per 100 deliveries, was significantly lower than the prestrike rate of 14.6 per 100 deliveries (p < 0.05). Reductions occurred primarily among breech deliveries and among women with a previous cesarean section. No differences were observed in the rates of individual adverse maternal or newborn outcomes. However, the pooled incidence of adverse newborn outcomes was significantly higher during the strike than during the prestrike period (10.2 vs 8.1/100 deliveries, odds ratio 1.27, 95% confidence interval 1.07 to 1.52). CONCLUSION: In response to constraints imposed by a reduced nursing complement, physicians increased the frequency of vaginal birth in breech presentation and among women with previous cesarean section.

Breech Presentation↗

PubMed1995

A population-based health information system.

The authors introduce the Population Health Information System, its conceptual framework, and the data elements required to implement such a system in other jurisdictions. Among other innovations, the Population Health Information System distinguishes between indicators of health status (outcomes measures) and indicators of need for health care (socioeconomic measures of risk for poor health). The system also can be used to perform needs-based planning and challenge delivery patterns.

Canada↗

PubMed1995

Socioeconomic status and the health of the population.

To examine the relationship of a population's socioeconomic characteristics to its health status and use of health care services, a composite socioeconomic risk index was developed for the Population Health Information System. From a set of 23 socioeconomic indicators derived from public use census data, a summary index was formed from six indicators to generate profiles for the eight health regions of the province. Regional scores were plotted against an index of health status measures and against measures of health care utilization. Strong regional variations were found in all of these measures, and the socioeconomic risk index explained 87% to 92% of the differences in health status and acute hospitalizations. Moreover, regions with the worst health status on our indicators were found to be among the highest consumers of health services. The socioeconomic risk index appears to be a powerful tool in clarifying which benefits in improved health status might accrue from changing the underlying inequities in amenable socioeconomic risk factors, rather than simply increasing services to regions of low health status.

Adolescent↗

PubMed1994

The relationship of prenatal care and pregnancy complications to birthweight in Winnipeg, Canada.

OBJECTIVES: Prenatal care is commonly understood to have a beneficial impact on birthweight. This study describes socioeconomic differences in utilization of prenatal medical care and birthweight in a population with universal health insurance. METHODS: Measures of prenatal care utilization, incidence of pregnancy complications, and birthweight were obtained from physician reimbursement claims and hospital separation abstracts for 12,646 pregnant women. Maternal socioeconomic status was derived from small-area census data. RESULTS: Infants born to women in the poorest income quintile had lower birthweights than infants born to wealthier women. Much of the difference was associated with a higher prevalence of complications, smoking, unmarried status, and inadequate prenatal care among low-income women. The difference in birthweight between adequate and less than adequate care groups was small, and the benefit associated with prenatal care was no greater among women with pregnancy complications. CONCLUSIONS: The lower utilization of prenatal care by poorer women accounted for a small proportion of the difference in birthweight. Socioeconomic differences in birthweight are primarily attributable to factors not directly influenced by early prenatal medical care.

Adolescent↗

PubMed1994

The influence of referral protocols on the utilization of magnetic resonance imaging: evidence from Manitoba.

The relative scarcity of magnetic resonance imaging (MRI) capacity in most Canadian jurisdictions has created pressures to develop guidelines on appropriate clinical indications for examination by this method. The objective of this study was to assess the influence of referral protocols on the utilization of MRI services. Three neuroradiologists and one radiologist reviewed the indications for MRI for 198 referrals to the facility at St. Boniface General Hospital in Winnipeg (99 from outside Manitoba and 99 from within the province), selected at random from patients seen between Jan. 1 and Dec. 31, 1991, for suspected disorder of the brain or the spine. Out-of-province referrals had not been subject to referral protocols, whereas those from within Manitoba had been subject to such protocols. At least three of the four radiologists agreed on whether an examination was appropriate in 175 of the 198 cases (88.4%). Out-of-province referrals were significantly more likely to be considered inappropriate for MRI: 24 (24%) of the referrals from outside Manitoba were judged inappropriate by three or more reviewers, whereas only 10 (10%) of the referrals from within Manitoba were judged inappropriate (chi 2, p < 0.01). Of the 19 cases that were judged inappropriate for MRI by three or more reviewers and that yielded abnormal findings, unique clinical information was derived from the examination in only 1 (5%); in contrast, of the 85 cases that were judged appropriate for MRI by three or more reviewers and that yielded abnormal findings, unique information was found in 47 (55%).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical Protocols↗

PubMed1993

Registries and administrative data: organization and accuracy.

In this article the organization and accuracy of the population registry and administrative data base in Manitoba, Canada are discussed. The overall data management strategy and a framework for analyzing the accuracy of such data are presented. The generally high quality of the Manitoba registry file (necessary to track individuals over time) and the hospital claims is supported by comparisons with other data sources. Hospital claims' main quality problems concern the reliability of certain secondary diagnoses and the level of aggregation necessary for reasonable agreement with other data collection methods (such as chart reviews). Finally, some of the research possibilities associated with population registries and administrative data are outlined.

Adolescent↗

PubMedDate not supplied

Widening regional inequality in premature mortality rates in Manitoba.

OBJECTIVE: To describe regional trends in premature mortality in Manitoba. DESIGN: Comparison of all-cause and cause-specific mortality of persons less than age 75 in 11 Regional Health Authority populations over two time periods: 1985-89 and 1990-94. RESULTS: The provincial premature mortality rate declined over the two time periods (4.00/1,000 to 3.72/1,000). Declines were also observed in 9 of 11 regional populations. Premature mortality increased, however, in the 2 regional populations with the highest mortality rates in the first observation period. CONCLUSION: Declining premature mortality in low mortality populations and rising premature mortality in high mortality populations has resulted in a widening of regional mortality rates in Manitoba. Recent policy initiatives in many provinces, including the devolution of authority for the management and delivery of health services and the implementation of population need-based funding formulas to share health care resources among regional health authorities, if implemented, have the potential to partially mitigate the processes producing these widening regional health inequalities.

Adolescent↗

PubMedDate not supplied

Work-related population health indicators.

OBJECTIVE: To provide evidence-based recommendations for work-related population health indicators. METHODS: Drawing on a framework of work-related experiences, we systematically reviewed studies that assess the association between these experiences and health and reviewed related measures at the population level that could be used as indicators. RESULTS: We recommend (and grade the strength of evidence supporting our recommendation for) the following indicators for which data are already routinely collected: unemployment rate (strong), long-term unemployment rate (limited), and permanent lay-off rate (limited). As well, we recommend and grade our support for the following new indicators: insecurity associated with pending job loss (limited), with possible major organizational change (limited), and with actual major organizational change (limited); and job strain (medium). CONCLUSION: These evidence-based indicators can be used to monitor work-related determinants of health and thus to inform the conceptualization, development, and evaluation of policies and programs related to these determinants.

Canada↗