Effect of side-chain asymmetry on the intermolecular structure and order-disorder transition in alkyl-substituted polyfluorenes.

We study relations among the side-chain asymmetry, structure, and order-disorder transition (ODT) in hairy-rod-type poly(9,9-dihexylfluorene) (PF6) with two identical side chains and atactic poly(9-octyl-9-methyl-fluorene) (PF1-8) with two different side chains per repeat. PF6 and PF1-8 organize into alternating side-chain and backbone layers that transform into an isotropic phase at T^{ODT}(PF6) and T_{bi}^{ODT}(PF1-8). We interpret polymers in terms of monodisperse and bidisperse brushes and predict scenarios T^{ODT}

[Formation of desmoids in postoperative lumbar scars--a case report]. / Desmoidbildung in postoperativer lumbaler Narbe -- kasuistischer Beitrag.

Desmoids are tumours of the connective tissue cells with aggressive growth. Frequent recurrences of these tumours have often been described. Genetic and endocrine factors as well as local tissue biomechanics are thought to be responsible for the pathogenesis. This case report should contribute to the discussion about possible pathogenetic factors.

Assessing socioeconomic effects on different sized populations: to weight or not to weight?

OBJECTIVE: Researchers in health care often use ecological data from population aggregates of different sizes. This paper deals with a fundamental methodological issue relating to the use of such data. This study investigates the question of whether, in doing analyses involving different areas, the estimating equations should be weighted by the populations of those areas. It is argued that the correct answer to that question turns on some deep epistemological issues that have been little considered in the public health literature. DESIGN: To illustrate the issue, an example is presented that estimates entitlements to primary physician visits in Manitoba, Canada based on age/gender and socioeconomic status using both population weighted and unweighted regression analyses. SETTING AND SUBJECTS: The entire population of the province furnish the data. Primary care visits to physicians based on administrative data, demographics and a measure of socioeconomic status (SERI), based on census data, constitute the measures. RESULTS: Significant differences between weighted and unweighted analyses are shown to emerge, with the weighted analyses biasing entitlements towards the more populous and advantaged population. CONCLUSIONS: The authors endorse the position that, in certain problems, data analyses involving population aggregates unweighted by population size are more appropriate and normatively justifiable than are analyses weighted by population. In particular, when the aggregated units make sense, theoretically, as units, it is more appropriate to carry out the analyses without weighting by the size of the units. Unweighted analyses yield more valid estimations.

Needs-based planning for generalist physicians.

OBJECTIVES: The Manitoba Centre for Health Policy and Evaluation (MCHPE) collaborated with a provincially-appointed Physician Resource Committee in an assessment of provincial physician resources. RESEARCH DESIGN: Beginning with map-based analyses of physician supply and contacts across the province, compared with the health and socioeconomic characteristics of local populations, the study moved to a needs-based, regression-based approach to physician resource planning. RESULTS: The results challenged the popular belief that Manitoba suffers from an increasing shortage of physicians. A handful of high-need, low-supply and low-use areas are identified, as is the expensive surplus of generalist physicians in Winnipeg. (Generalist physicians include general and family practitioners as well as general internists and pediatricians.) No relationship between physician supply and health characteristics of populations, or between high physician supply and low hospital use patterns were found. Given the Committee's interest in what drives high physician contact rates, analyses of visit patterns of hypertensive patients were undertaken. We found that patients who had more complex medical conditions made more contacts, but that after controlling for this and other key patient characteristics, the patient's primary care physician's patient recall rate was a strong influence on how frequently visits were made.

Managing health services: how the Population Health Information System (POPULIS) works for policymakers.

OBJECTIVES: University-based researchers in Manitoba, Canada, have used administrative data routinely collected as part of the national health insurance plan to design an integrated database and population-based health information system. This information system is proving useful to policymakers for answering such questions as: 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? More specifically, this system provides decision makers with the capability to make critical comparisons across regions and subregions of residents' health status, socioeconomic risk characteristics and use of hospitals, nursing homes, and physicians. The system permits analyses of demographic changes, expenditure patterns, and hospital performance in relation to the population served. The integrated database has also facilitated outcomes research across hospitals and countries, utilization review within a single hospital, and longitudinal research on health reform. The discussion highlights the strengths of integrated population-based information in analyzing the health care system and raising important questions about the relationship between health care and health.

Managing health services: how administrative data and population-based analyses can focus the agenda.

University-based researchers in Manitoba, Canada, have used administrative data routinely collected as part of the national health insurance plan to design an integrated database and population-based health information system. This information system is proving useful to policymakers for providing answers to such questions as: 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 utilization related to high need? More specifically, this system provides decision-makers with the capability to make critical comparisons across regions and subregions of residents' health status, socioeconomic risk characteristics, and use of hospitals, nursing homes, and physicians. The system permits analyses of demographic changes, expenditure patterns, and hospital performance in relation to the population served. The integrated database has also facilitated outcomes research across hospitals and counties, utilization review within a single hospital, and longitudinal research on health reform. A particularly interesting application to planning physician supply and distribution is discussed. The discussion highlights the strengths of integrated population-based information in analyzing the health care system and raising important questions about the relationship between health care and health.

Needs-based planning: the case of Manitoba.

OBJECTIVE: To illustrate the use of needs-based planning in the identification of physician surpluses and deficits and of resource misallocations within a provincial medical system at a time when provincial governments and medical associations across the country are faced with funding constraints for physician services. DESIGN: For each of 4 regions in Manitoba, the authors analysed residents' rates of physician visits (whether within the resident's own or another region). Residents' need for physician contact was estimated by means of a statistical analysis of the data on contacts in relation to age, sex and health-related indicators, and the rates of visits needed and actually made were compared. PARTICIPANTS: All Manitoba residents. OUTCOME MEASURES: Numbers of generalist physicians (general practitioners, family physicians, general internists and general pediatricians) needed to serve each region, and the extent of physician surplus and deficit in each region. RESULTS: There appeared to be a surplus of physicians in most of urban Manitoba but deficits in northern Manitoba and some parts of the rural south. General internists and general pediatricians in Winnipeg provide a significant part of the ambulatory care that is provided by general practitioners in other parts of the province. The provincial government currently spends more per resident to provide physician services in areas of physician surplus than in areas of physician deficit, although the patterns are inconsistent. CONCLUSIONS: Needs-based planning is possible. If provinces are intent on controlling physician numbers and expenditures, it makes sense to manage the implications of doing so.

A regional comparison of socioeconomic and health indices in a Canadian province.

In most jurisdictions, information on socioeconomic attributes of geographic areas is readily available. As well, limited measures of health, such as mortality rates or indicators derived from health service use, are also routinely collected for geographically defined populations. In this paper we present a methodology for selecting and combining measures of area socioeconomic characteristics to produce a composite index which is relevant for health-related research. The performance of this composite index in this setting was consistent with deprivation indices developed in the United Kingdom, and showed strong associations with measures of population health status and health service utilization.

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.

Stability and trends over 3 years of data.

Because the health status of a population does not usually respond immediately to interventions, whether social or medical, the ability to analyze change over time is important. Therefore, patterns of change and stability in health status and health care use of Manitoba residents during a 3-year period from 1990 to 1992 were analyzed using the Population-based Health Information System. This article presents summary findings and discusses methodological and policy issues arising from the analyses. A small but significant decrease in premature mortality (the primary health status indicator) was observed in most regions of the province, but two remote, northern regions, those whose residents scored at high socioeconomic risk, remained distinguished for their poor health status. These "poor health" regions also had the highest contact rates with primary caregivers, raising questions about the role of the health care system in improving the health of the population. A persistent increase in surgery was observed in several regions, led by increases in outpatient surgery over and above increases in the elderly population and beyond substitution for inpatient procedures. This trend (not obvious before these analyses) is important as hospitals move to expand their outpatient facilities in response to restraints on inpatient care.

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.

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.