What happens when the lights are left on? Transcriptomic and phenotypic habituation to light pollution

Artificial light at night (ALAN) is a ubiquitous pollutant worldwide. Exposure can induce immediate behavioral and physiological changes in animals, sometimes leading to severe health consequences. Nevertheless, many organisms persist in light-polluted environments and may have mechanisms of habituating, reducing responses to repeated exposure over time, but this has yet to be tested experimentally. Here, we tested whether zebra finches (Taeniopygia guttata) can habituate to dim (0.3 lux) ALAN, measuring behavior, physiology (oxidative stress and telomere attrition), and gene expression in a repeated measures design, over 6 months. We present evidence of tolerance to chronic exposure, persistent behavioral responses lasting 8 weeks post-exposure, and attenuation of responses to re-exposure. Oxidative stress decreased under chronic ALAN. Changes in the blood transcriptome revealed unique responses to past exposure and re-exposure. Results demonstrate organismal resilience to chronic stressors and shed light on the capacity of birds to persist in an increasingly light-polluted world.

Comparison of all-cause mortality in England with Europe and the USA: January 2020 to February 2021

Background

Assessing mortality during the COVID-19 pandemic is vital for informing public health strategies and policy decision making. All-cause excess mortality provides an objective measure of the impact of the pandemic including both the direct and indirect effects. Our study considers the burden of mortality in the UK, Europe and the USA. We examine variation between countries, by age and sex. We explore the extent to which this variation is associated with COVID-19 case rates and other population characteristics.

Methods

The study is a secondary analysis of routine administrative population and mortality data. Weekly death occurrences and population estimates were obtained from Eurostat and national statistical agencies. Contextual information on COVID-19 case rates, population-level risk factors and healthcare were obtained from various open-source databases. Weekly age-standardised mortality rates (ASMRs) were calculated and presented relative to a baseline average from the preceding 5-year period. Relative cumulative (rc) ASMRs were then calculated to provide a comparable assessment of excess mortality at a point in time.

Results

Preliminary results show that, by end of the analysis period, England had an overall rcASMR of 10.09%. Higher excess mortality was identified for some countries (eg USA 14.58%) and lower - even below average mortality - for others (eg Norway -6.8%). Under 65 rcASMR showed substantial variation between countries. Cumulative COVID-19 case rates showed a moderate effect size (R2 = 0.51) when used to explain the proportion of variation observed between rcASMRs. Other population factors showed a smaller effect.

Conclusions

The burden of mortality experienced between countries and populations over the COVID-19 pandemic period has shown significant variation. Factors which may have contributed to the position of some countries should be further explored in order to inform ongoing management of Covid-19 and future pandemic events.

Key messages

Significant variation in all-cause excess mortality has been identified across the COVID-19 pandemic period between nations and particularly in younger age groups.

COVID-19 case rates are associated with relative cumulative all-cause excess mortality among the nations assessed.

Evidence-based practice in Steeltown: a good start on needed cultural change

At the Canadian Health Services Research Foundation we talk a lot about the need to improve the 'receptor capacity' for research in the health sector (Canadian Health Services Research Foundation 2000). To create a demand for research as well as a supply of it. To encourage and assist clinicians, managers and policymakers in the health system to pull research from academe with as much fervor as applied researchers now bring to publishing it. Browman, Snider and Ellis have done more than talk about and encourage these things - they have implemented them at their own workplace in Hamilton. Their formula is:1. Design a policy-learning forum (Clinical Policy Committee'), where the use of available research is encouraged and expected 2. Create champions (knowledge stewards') responsible for marshalling and presenting the evidence. 3. Provide rules (negotiation') for the dialogue between the operational implications of the research and its budgetary reality. 4. Use story telling to uncover local implementation barriers and make tacit knowledge explicit. The approach is reminiscent of political scientist Paul Sabatier's description of the circumstances under which policy learning occurs (Sabatier and Jenkins-Smith 1993) and Brown and Duguid's compelling outline of how information permeates corporate structures (Brown and Duguid 2000). Sabatiers advocacy coalition framework highlights the optimal conditions for learning as: balanced coalitions (in this case, of those behind the research and those behind the finances), enough resources for each side to produce a steady flow of information, an organized forum for debate and clear rules of engagement. In 'The Social Life of Information, 'Brown and Duguid highlight the extent to which modern corporations often leave unrecognized and under-utilized their greatest asset - the tacit knowledge accumulated by each employee over his or her career. They, too, recommend storytelling as a way to liberate this knowledge for wider use. Browman and colleagues 'practical realization of Sabatier' advocacy coalition framework and Browns social view of information is refreshing on a number of levels.

Aberrant methylation of multiple genes in neuroblastic tumours. relationship with MYCN amplification and allelic status at 1p

Aberrant hypermethylation occurs in tumour cell CpG islands and is an important pathway for the repression of gene transcription in cancers. We investigated aberrant hypermethylation of 11 genes by methylation-specific polymerase chain reaction (PCR), after treatment of the DNA with bisulphite, and correlated the findings with MYCN amplification and allelic status at 1p in a series of 44 neuroblastic tumours. This tumour series includes five ganglioneuromas (G), one ganglioneuroblastoma (GN) and 38 neuroblastomas (six stage 1 tumours; five stage 2 tumours; six stage 3 cases; 19 stage 4 tumours, and two stage 4S cases). Aberrant methylation of at least one of the 11 genes studied was detected in 95% (42 of 44) of the cases. The frequencies of aberrant methylation were: 64% for thrombospondin-1 (THBS1); 30% for tissue inhibitor of metalloproteinase 3 (TIMP-3); 27% for O6-methylguanine-DNA methyltransferase (MGMT); 25% for p73; 18% for RB1; 14% for death-associated protein kinase (DAPK), p14ARF, p16INK4a and caspase 8, and 0% for TP53 and glutathione S-transferase P1 (GSTP1). No aberrant methylation was observed in four control normal tissue samples (brain and adrenal medulla). MYCN amplification was found in 11 cases (all stage 4 neuroblastomas), whereas allelic loss at 1p was identified in 16 samples (13 stage 4 and two stage 3 neuroblastomas, and one ganglioneuroma). All but one case with caspase 8 methylation also displayed MYCN amplification. Our results suggest that promoter hypermethylation is a frequent epigenetic event in the tumorigenesis of neuroblastic tumours, but no specific pattern of hypermethylated genes could be demonstrated.

CpG island methylation status and mutation analysis of the RB1 gene essential promoter region and protein-binding pocket domain in nervous system tumours

A series of 136 nervous system tumours were studied to determine the methylation status of the CpG island contained within the promoter region of the RB1 gene, as well as mutation analysis of the essential promoter region and exons 20-24 (and surrounding intronic regions) coding for the protein-binding pocket domain. Methylation of the RB1 CpG island was detected in 26 samples corresponding to nine glioblastomas, three anaplastic astrocytomas, one mixed oligo-astrocytoma, one ependymoma, two medulloblastomas, two primary central nervous system lymphomas, two neurofibrosarcomas, and six brain metastasis from solid tumours. No inactivating mutations were found within the RB1 promoter region, whereas one glioblastoma and one oligodendroglioma displayed similar sequence variations consisting of 12 and 8 base pair deletions at intron 21. These results suggest that RB1 CpG island hypermethylation is a common epigenetic event that is associated with the development of malignant nervous system tumours.

Doing better with "bad kids": explaining the policy-research gap with conduct disorder in Canada

Conduct disorder (severe and persistent antisocial behaviour in children and youth) is an important community mental health problem in Canada and has been the focus of considerable recent public policy debate. Good research evidence is available on effective (and ineffective) interventions for conduct disorder. Paradoxically, however, relatively little of the research evidence is incorporated into policy decision-making. There is a policy-research gap. An example (Hamilton, Ontario) is used to illustrate this gap. The gap is then explained using a framework for health policy analysis that incorporates values, institutional structures, and information. Values and institutional structures greatly outweigh research evidence in influencing current Canadian policy-making for the problem of conduct disorder. Possibilities for improving the situation are suggested.

Absence of mutation of the p73 gene in astrocytic neoplasms

In subgroups of astrocytic neoplasms, including glioblastoma (GBM), mutations of the p53 tumour suppressor gene lead to loss of growth-suppressive properties. A p53-related gene termed p73 has recently been identified; its gene product shows structural and functional similarities to p53. After being mapped to chromosome region 1p36, p73 was proposed to act as a tumour suppressor gene, as this region is frequently deleted in a variety of human cancers, including astrocytic tumours. To determine whether p73 is involved in astrocytoma/GBM development, we analysed 10 pilocytic astrocytomas, 15 WHO grade II astrocytomas, 15 WHO grade III anaplastic astrocytomas, and 20 GBM for p73 gene alterations. In parallel, we used six polymorphic markers to determine the allelic status of region 1p36 in this tumour series. Although loss of heterozygosity was evidenced in 12 of 60 cases (20% of samples), PCR-SSCP and direct sequencing failed to detect any gene mutation in the entire coding region and intronic sequences of p73. Eight tumours displayed five distinct polymorphic nucleotide changes, also present in the corresponding normal DNA. These variations consisted of T-->C variation, with no change in Thr173; C-->T transition, with no change in His197; exon 9 simultaneous double change C-->T and T-->C , with no variations in Ala336 and His349, respectively, and C-->T change at exon 9/-24 position of intron 8. These results suggest that, in astrocytic gliomas, p73 may not play a major role as a tumour suppressor, but the relatively high incidence of LOH confirms the presence at 1p36 of an as yet unidentified gene of this category, with a key function in astrocytoma/GBM progression.

Analysis of p73 gene in meningiomas with deletion at 1p

The p73 gene has been mapped to 1p36.33, a chromosome region that is frequently deleted in a wide variety of neoplasms including meningiomas. The protein encoded by p73 shows structural and functional similarities to p53 and may thus represent a candidate tumor suppressor gene. To determine whether p73 is involved in the development of meningiomas, we examined 30 meningioma samples with proven 1p deletion for mutations of p73. Sequence analysis of the entire coding region of the p73 gene revealed previously reported polymorphisms in eight cases. A tumor-specific missense mutation as a result of an A-to-G transition with an Asn204Ser change was found in one meningioma that nevertheless retained the normal allele. These results suggest that if p73 plays a role in meningioma carcinogenesis, it must be in a manner different from the Knudson two-hit model.

Inhibition of Fas signaling prevents hepatic injury and improves organ blood flow during sepsis

BACKGROUND

Fas/Fas ligand (FasL) system is one of the major pathways triggering apoptosis that has been shown to play an important role in development and pathogenesis of various diseases including liver and gastrointestinal diseases. Studies indicate that FasL deficiency provides a survival advantage in mice subjected to polymicrobial sepsis. However, the extent to which Fas/FasL contributes to organ injury during sepsis is unclear. Thus, the aim of this study was to determine whether in vivo administration of a Fas-signaling inhibitor during sepsis preserves organ function.

METHODS

Male adult C3H/HeN mice were subjected to cecal ligation and puncture (CLP) or sham CLP (sham). Twelve hours after CLP, mice received either Fas-receptor fusion protein (FasFP) (200 microg/kg body weight) or the saline vehicle. Twenty-four hours after the onset of sepsis, cardiac output and organ blood flow were measured with radioactive microspheres. Plasma levels of alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase were assessed as indexes of liver damage. Changes in systemic cytokines were measured by enzyme-linked immunosorbent assay. RESULTS. The data indicate that although cardiac output and organ blood flow in the liver, intestine, kidneys, spleen, and heart decreased markedly at 24 hours after CLP, treatment with FasFP maintained the measured hemodynamic parameters and improved hepatic, intestinal, and heart blood flow (P <.05) and partially restored spleen and renal blood flow. Moreover, FasFP treatment markedly attenuated the systemic rise in alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and interleukin 10 (P <.05).

CONCLUSIONS

These results not only indicate that there is a role for Fas/FasL-mediated processes in the induction of organ injury but suggest that inhibition of Fas/FasL pathway may represent a novel therapeutic modality for maintaining organ perfusion and preventing liver injury during sepsis.

Mutation analysis of the p73 gene in nonastrocytic brain tumours

Loss of heterozygosity (LOH) involving the distal chromosome 1 p36 region occurs frequently in nonastrocytic brain tumours, but the tumour suppressor gene targeted by this deletion is unknown. p73 is a novel gene that has high sequence homology and similar gene structure to the p53 gene; it has been mapped to 1 p36, and may thus represent a candidate for this tumour suppressor gene. To determine whether p73 is involved in nonastrocytic brain tumour development, we analysed 65 tumour samples including 26 oligodendrogliomas, 4 ependymomas, 5 medulloblastomas, 10 meningiomas, 2 meningeal haemangiopericytomas, 2 neurofibrosarcomas, 3 primary lymphomas, 8 schwannomas and 5 metastatic tumours to the brain, for p73 alterations. Characterization of allelic loss at 1 p36-p35 showed LOH in about 50% of cases, primarily involving oligodendroglial tumours (22 of 26 cases analysed; 85%) and meningiomas (4 of 10; 40%). PCR-SSCP and direct DNA sequencing of exons 2 to 14 of p73 revealed a missense mutation in one primary lymphoma: a G-to-A transition, with Glu291Lys change. 8 additional cases displayed no tumour-specific alterations, as 3 distinct polymorphic changes were identified: a double polymorphic change of exon 5 was found in one ependymoma and both samples derived from an oligodendroglioma, as follows: a G-to-A transition with no change in Pro 146, and a C-to-T variation with no change in Asn 204: a delG at exon 3/+12 position was identified in 4 samples corresponding to 2 oligodendrogliomas, 1 ependymoma and 1 meningioma, and a C-to-T change at exon 2/+10 position was present in a metastatic tumour. Although both LOH at 1 p36 and p73 sequence changes were evidenced in 4 cases, it is difficult to establish a causal role of the p73 variations and nonastrocytic brain tumours development.

Delay in onset of awareness of acute hypoglycemia and of restoration of cognitive performance during recovery

OBJECTIVE

To examine the time course for the onset of, and recovery from, acute hypoglycemia in healthy subjects.

RESEARCH DESIGN AND METHODS

Eight healthy male volunteers were studied on 2 occasions in random order using a hyperinsulinemic (1.5 mU x kg(-1) x min(-1)) glucose clamp technique. During control studies, euglycemia (5.01 +/- 0.02 mmol/l) was maintained for 225 +/- 3 min. On the other occasion, after a euglycemic baseline period, arterialized plasma glucose was allowed to fall rapidly to 2.65 +/- 0.02 mmol/l, then maintained at this nadir for 90 min before euglycemia was rapidly restored.

RESULTS

Cognitive function assessed by a battery of sensitive tests (4-choice reaction time, Stroop word, and color-word test) became impaired immediately at onset of hypoglycemia (P < 0.05 for all in the hypoglycemic study vs. those in the euglycemic study). Counterregulatory hormone responses (epinephrine, norepinephrine, glucagon, cortisol, and growth hormone) and symptomatic awareness of hypoglycemia (assessed by a questionnaire) were relatively delayed, being detected 20 min after the onset of hypoglycemia. There was no diminution (adaptation) of any responses, cognitive, humoral, or symptomatic, during sustained hypoglycemia. During recovery, the 4-choice reaction time continued to be abnormal even after resolution of symptomatic awareness (P = 0.025).

CONCLUSIONS

During hypoglycemia, cognitive performance may become impaired before symptomatic awareness. During recovery from hypoglycemia, recovery of cognitive function lags behind the restoration of glucose levels and resolution of symptoms. Our findings have implications for the design of studies examining experimental hypoglycemia and need to be investigated in people with diabetes.

Needs-based primary medical care capitation: development and evaluation of alternative approaches

OBJECTIVE

To develop and evaluate alternative methods of adjusting primary medical care capitation payments for variations in relative need for health care among enrolled practice populations.

METHODS

We developed alternative needs-based capitation formulae and applied them to a sample of capitation-funded primary care practices to assess each formula's performance against a reference standard of capitation payments based on age, sex and self-assessed health status of the enrolled populations. The alternative formulae were based on: (1) age and sex; (2) age, sex and individually-measured socioeconomic characteristics; (3) age, sex and socioeconomic characteristics imputed from census data for enrollees' neighbourhood of residence; (4) age, sex and standardized mortality ratio for enrollees' neighbourhood of residence.

RESULTS

Age/sex-adjusted capitation payments for the six practices studied ranged from 10% higher to 18% lower than the reference standard payments. Capitation formulae based on socioeconomic and mortality data did not perform consistently better than the current age/sex-based formula.

CONCLUSIONS

Primary medical care capitation payments adjusted only for age and sex do not reflect the relative health care needs of enrolled practice populations. Our alternative formulae based on socioeconomic and mortality data also failed to reflect relative needs. Methods that use other approaches to adjusting for differences in relative need among enrolled populations should be investigated.

Evidence of self-report bias in assessing adherence to guidelines

OBJECTIVE

To assess trends in the use of self-report measures in research on adherence to practice guidelines since 1980, and to determine the impact of response bias on the validity of self-reports as measures of quality of care.

METHODS

We conducted a MEDLINE search using defined search terms for the period 1980 to 1996. Included studies evaluated the adherence of clinicians to practice guidelines, official policies, or other evidence-based recommendations. Among studies containing both self-report (e.g. interviews) and objective measures of adherence (e.g. medical records), we compared self-reported and objective adherence rates (measured as per cent adherence). Evidence of response bias was defined as self-reported adherence significantly exceeding the objective measure at the 5% level.

RESULTS

We identified 326 studies of guideline adherence. The use of self-report measures of adherence increased from 18% of studies in 1980 to 41% of studies in 1985. Of the 10 studies that used both self-report and objective measures, eight supported the existence of response bias in all self-reported measures. In 87% of 37 comparisons, self-reported adherence rates exceeded the objective rates, resulting in a median over-estimation of adherence of 27% (absolute difference).

CONCLUSIONS

Although self-reports may provide information regarding clinicians' knowledge of guideline recommendations, they are subject to bias and should not be used as the sole measure of guideline adherence.

Home is where the governing is: social capital and regional health governance

The relationship between the civic nature of a community and effective political governance by regional health boards in Canada is explored. A model is proposed that identifies components of social capital such as trust, commitment and identity, associationalism, civic participation and collaborative problem-solving. These concepts are then theoretically linked to effective governance, in particular to reflection of health needs, policy implementation, population health, fiscal responsibility and administrative efficiency. The generalizability of this model is discussed, as are current research directions and policy implications for governments. The conclusion is that governments might want to incorporate a dual perspective encompassing both the political institutions and the community structure.

Social capital and health: implications for public health and epidemiology

Public health and its "basic science", epidemiology, have become colonised by the individualistic ethic of medicine and economics. Despite a history in public health dating back to John Snow that underlined the importance of social systems for health, an imbalance has developed in the attention given to generating "social capital" compared to such things as modification of individual's risk factors. In an illustrative analysis comparing the potential of six progressively less individualised and more community-focused interventions to prevent deaths from heart disease, social support and measures to increase social cohesion faired well against more individual medical care approaches. In the face of such evidence public health professionals and epidemiologists have an ethical and strategic decision concerning the relative effort they give to increasing social cohesion in communities vs expanding access for individuals to traditional public health programs. Practitioners' relative efforts will be influenced by the kind of research that is being produced by epidemiologists and by the political climate of acceptability for voluntary individual "treatment" approaches vs universal policies to build "social capital". For epidemiologists to further our emerging understanding of the link between social capital and health they must confront issues in measurement, study design and analysis. For public health advocates to sensitise the political environment to the potential dividend from building social capital, they must confront the values that focus on individual-level causal models rather than models of social structure (dis)integration. The evolution of explanations for inequalities in health is used to illustrate the nature of the change in values.

Reduced counterregulation during hypoglycemia with raised circulating nonglucose lipid substrates: evidence for regional differences in metabolic capacity in the human brain?

We have investigated the potential for the human brain to use lipid fuels during acute hypoglycemia. Nine healthy male subjects underwent hyperinsulinemic (1.5 mU/kg x min) stepped hypoglycemic clamps on two occasions, infusing Intralipid (20%) and heparin (0.1 U/kg x min) on one occasion only (ILH), with an identical study without infusion of ILH acting as a control. Five subjects also underwent euglycemic clamping with Intralipid/heparin infusion. During hypoglycemia, ILH raised circulating levels of nonesterified fatty acids, glycerol, and beta-hydroxybutyrate, although the latter did not rise until after the onset of counterregulation. With ILH, epinephrine responses [area under the curve (AUC), 127.9 +/- 31.7 vs. 175.1 +/- 27.4 nmol/L x 180 min; P = 0.03] and GH responses (AUC, 260 +/- 91 vs. 1009 +/- 150, P < 0.01) were reduced and delayed (glucose thresholds, 2.8 +/- 0.04 vs. 3.0 +/- 0.1 mmol/L; P = 0.04), with a trend toward reduced cortisol responses. Similarly, hypoglycemic symptom scores were diminished during ILH (AUC, 647 +/- 162 vs. 1222 +/- 874; P = 0.03). However, there was no significant effect on the deterioration in four-choice reaction time, one measure of cognitive deterioration [glucose thresholds, 2.6 +/- 0.1 vs. 2.7 +/- 0.1 mmol/L, ILH vs. control (P = 0.75); AUC, 1420 +/- 710 vs. 2250 +/- 1080 ms/min (P = 0.59)]. During euglycemic clamping with Intralipid/heparin infusion studies, there was no rise in hormones, four-choice reaction time, or symptoms other than hunger and tiredness. Both nonesterified fatty acids and glycerol can penetrate the mammalian brain and be metabolized. Raised levels were able to reduce neurohumoral responses to hypoglycemia, but could not protect cognitive function. This suggests that regional differences exist in human brain metabolism between glucose-sensing and cognitive areas of brain, which may be important in the understanding of the mechanisms of glucose sensing and in the genesis of hypoglycemia unawareness in insulin-dependent diabetes.

Free-standing health care facilities: financial arrangements, quality assurance and a pilot study

Free-standing health care facilities now deliver many diagnostic and therapeutic services formerly provided only in hospitals. The financial arrangements available to these facilities differ according to whether the services are uninsured or insured. For an uninsured service, such as cosmetic surgery, the patient pays a fee directly to the service provider. For an insured service, such as cataract surgery, the provincial government uses tax revenues to fund the facility by paying it a facility fee and remunerates the physician who provided the service with a professional fee. No comprehensive, proactive quality assurance efforts have been implemented for either these facilities or the clinical practice provided within them. A pilot study involving therapeutic facilities in Ontario has suggested that a large-scale quality improvement effort could be undertaken in these facilities and rigorously evaluated.

Effects of glycemic control on protective responses against hypoglycemia in type 2 diabetes

OBJECTIVE

To determine the effects of glycemic control on the counterregulatory responses to hypoglycemia in type 2 diabetes.

RESEARCH DESIGN AND METHODS

Seven poorly controlled type 2 diabetes patients (mean HbA1c, 11.3 +/- 1.1%) were studied by stepped hyperinsulinemic hypoglycemic clamp (nadir, 2.4 mmol/l) before and after improving glycemic control with insulin treatment. Counterregulatory hormones, symptoms, and four-choice reaction time were measured at each glucose plateau.

RESULTS

In patients with poorly controlled type 2 diabetes, counterregulatory hormone responses began at higher plasma glucose levels than did those in healthy subjects (epinephrine, 4.4 +/- 0.2 vs. 3.7 +/- 0.2 mmol/l, P = 0.011). After significant improvement in glycemic control (mean HbA1c, 8.1 +/- 0.9%, P < 0.001) was achieved without severe hypoglycemia, hormonal responses started at much lower plasma glucose levels (e.g., epinephrine, 3.5 +/- 0.3 mmol/l, P = 0.005) and were significantly reduced in magnitude (e.g., area under epinephrine response curve, 306 +/- 93 vs. 690 +/- 107 nmol.min-1.l-1, P = 0.012). This was accompanied by a change in the plasma glucose threshold at which hypoglycemic symptoms first developed from 3.6 +/- 0.2 to 3.0 +/- 0.2 mmol/l (P = 0.019). In contrast, the plasma glucose threshold at which four-choice reaction time deteriorated did not change significantly (3.1 +/- 0.1 vs. 2.9 +/- 0.1 mmol/l, P = 0.125).

CONCLUSIONS

Counterregulatory responses begin at normoglycemia in poorly controlled type 2 diabetes. Improving glycemic control with insulin therapy normalizes hormonal responses but lowers the plasma glucose levels at which hypoglycemic symptoms develop to levels associated with impairment of four-choice reaction time, a marker of cognitive function. This process potentially increases the risk of severe hypoglycemia, but to a lesser extent than occurs in type 1 disease.

Regional differences in cerebral blood flow and glucose utilization in diabetic man: the effect of insulin

To determine the effect of insulin on regional cerebral blood flow (rCBF) and glucose metabolism (CMRglu), we performed quantitative dynamic PET scanning of labeled water (H215O) and deoxyglucose (18FDG) using two protocols in 10 diabetic men. In protocol A, to test reproducibility of the technique, insulin was infused at 1.5 mU.kg-1.min-1 twice (n = 5). In protocol B, low (0.3 mU.kg-1.min-1) and high (3 mU.kg-1.min-1) dose insulin was given on separate occasions (n = 5). Euglycemia (5 mmol/L) was maintained by glucose infusion. In protocol A, CMRglu was 6% higher during the first infusion, and catecholamines were also increased, indicating stress. Blood flow was not different. Changing free insulin levels from 20.5 +/- 4.8 to 191 +/- 44.5 mU/L (P < 0.001, low versus high dose, protocol B) did not alter total or regional CMRglu (whole brain 36.6 +/- 4.0 versus 32.8 +/- 6.2 mumol.100 g-1.min-1, P = 0.32) or CBF (41.7 +/- 5.1 and 45.6 +/- 9.7 mL.100 g-1.min-1, P = 0.4) or rCBF. In cerebellum, CMRglu was lower than in cortex and the ratio between rate constants for glucose uptake and phosphorylation (K1 and k3) was reversed. There are regional differences in cerebral metabolic capacity that may explain why cerebral cortex is more sensitive to hypoglycemia than cerebellum. Brain glucose metabolism is not sensitive to insulin concentration within the physiologic range. This suggests that intracerebral insulin receptors have a different role from those in the periphery.

Physician relations in Canada: shooting inward as the circle closes

As economic disputes between physicians become more frequent, discussions between physicians are becoming increasingly important. Those seeking insight into how physician organizations might mediate these disputes may be able to learn from others who have had negotiating responsibilities for over a quarter of a century--the provincial medical associations in Canada. In this article we examine the structure, process, and outcomes of negotiations between physicians, with a focus on responses to new physician expenditure caps in Ontario, Alberta, and British Columbia. Early negotiations between physicians over changes in relative fees favored general practitioners because they were the dominant voting block within the associations. Despite fewer gains in the fee arena, specialists were willing to remain in the associations because all physicians generally enjoyed similar income growth. Under new physician expenditure caps, however, physicians have been unable to resolve conflicts over how to allocate income limits across specialties. Negotiations between physicians face expanding economic issues and diverging interests as expenditure caps force physicians to concentrate on total costs.

Physician responses to global physician expenditure budgets in Canada: a common property perspective

Global expenditure budgets in the fee-for-service physician sector create management problems for both funders and physicians. Global expenditure cap policies must be designed, and appropriate institutional structures created, to mitigate perverse utilization incentives, manage collective utilization, and diffuse the internal professional and the funder-profession tensions created by a capped budget. Two Canadian provinces that adopted different approaches to the design of their physician expenditure cap policies experienced different outcomes in utilization growth. The outcomes, however, are the opposite to what one would predict based on an analysis of the incentive structures embodied in the two provinces' policies. An analytic framework developed for the study of common-property resources is applied to the differing physician responses to global budgets across the two provinces. The insights offered by this framework can guide policy design for global physician budgets, and they indicate the critical importance of physician acceptance of such a policy.

Medical necessity in Canadian health policy: four meanings and ... a funeral?

Four meanings of medical necessity have emerged, evolved, and dominated past and current health policy debates about the appropriate level of service coverage under Canada's health insurance program. To explore the shift in definition, provincial government and national health care association position papers responding to federal legislative and policy reviews of Canada's health insurance program from 1957 to 1984 were examined, as were more current reports on medical necessity. Four meanings of medical necessity predominated: "what doctors and hospitals do"; "the maximum we can afford"; "what is scientifically justified"; and "what is consistently funded across all provinces." These meanings changed with time as different stakeholder associations and governments redefined the concept of medical necessity to achieve different policy objectives for health service coverage under Canada's health insurance program.

Defining the practice population in fee-for-service practice

OBJECTIVE

To develop and validate a technique for defining a practice population of discrete individuals based on multiyear family practice fee-for-service billings data.

DATA SOURCES/STUDY SETTING

Nineteen family physicians in Ontario, Canada who converted from fee-for-service to capitation payment. Data sources were fee-for-service billings data for the three-year period prior to the conversion from fee-for-service to capitation payment and the rosters of enrolled patients for the first and third years after the change to capitation payment.

STUDY DESIGN

The billings-based definition of the physician's practice population was compared against the Year 1 roster. We also compared the billings-based practice population and the Year 1 roster to the physician's Year 3 roster to identify patients who might have been missed during the roster development process. Our principal analyses were an assessment of the sensitivity of the billings-based definition of the practice population (EPP), the positive predictive value of EPP, and the agreement between EPP and the rostered patient population (RPP). We also examined the ratio between EPP and RPP to determine EPP's accuracy in estimating the practice denominator.

DATA COLLECTION/EXTRACTION METHODS

The practice population for each physician at the time of conversion from fee-for-service to capitation payment was defined as (a) all persons for whom the physician billed the provincial health insurance plan for at least one visit during the year immediately prior to joining the capitation-funded program; and (b) all additional patients for whom the physician billed the plan for at least one service in each of the two preceding years. Data extraction was carried out within the Ministry of Health in order to preserve the anonymity of patients and physicians. Data were provided to the investigators stripped of patient and physician identifiers.

PRINCIPAL FINDINGS

The mean sensitivity and positive predictive value of EPP were 95.3 percent and 87.4 percent, respectively. The level of agreement between EPP and RPP averaged 84.4 percent. The mean ratio of EPP to RPP was 1.21 (95 percent C.I. 1.030-1.213). Correction for roster false-negatives increased the sensitivity, positive predictive value, and agreement between EPP and the practice population, and reduced the mean ratio of EPP to the practice population to 1.068 (95 percent C.I. 1.010-1.127).

CONCLUSIONS

The practice population can usefully be defined in fee-for-service family practice on the basis of multiyear fee-for-service billings data. Further research examining alternative encounter-based practice population definitions would be valuable.

Reluctant rationers: public input to health care priorities

Members of the public can adopt any one of at least three roles when providing input to public decision-making: taxpayer, collective community decision-maker, or patient. Each of these potential roles can be mapped onto three areas of public policy decision-making in health care: funding levels and organization for the system, the services we choose to offer under public funding, and the characteristics of those who should receive the offered services. The increasing desire to involve the public across the spectrum of health care decision-making has yet to result in a clear delineation of either which of the areas are most appropriate for public input or which of the roles we wish individual participants to adopt. The average citizen (as opposed to the self-interested patient, the provider or the manager) has so far shown little interest in contributing and rarely has the requisite skills for most of the tasks asked of him or her. The widespread motivation of governments and others for seeking public input appears to be to get the public to take or share ownership in the tough rationing choices consequent on fiscal retrenchment in health care. Evaluation of existing literature leads to the conclusion that there are only limited areas where we might wish to obtain significant public input if we adopt this widespread policy motivation. Specifically, the general public should be asked to give input to, but not determine, priorities across the broad service categories that could potentially be publicly funded. Members of the public have neither the interest nor the skills to do this at the level of specific services. The role expected of such members of the public should be made explicit and should focus on collective views of the community good rather than self-interested views of individual benefit. Groups of patients, however, should be the source of input when socio-demographic characteristics are being used to decide who should receive offered services. The role expected of these consumers is not, however, to take a self-interested perspective; rather, it is to adopt Rawls' 'veil of ignorance' to reflect compassionate views of priorities across socio-demographic characteristics. Finally, there appears to be no best method for obtaining public input that overcomes the common problems of poor information upon which to base priorities, difficulty in arriving at consensus, poor representativeness of participants, and lack of opportunity for informed discussion prior to declaring priorities. There is some suggestion, however, that panels of citizens or patients, convened on an ongoing basis and provided with the opportunity to acquire relevant information and discuss its implications prior to making consensus recommendations, offer the most promising way forward.

Devolving authority for health care in Canada's provinces: 4. Emerging issues and prospects

Devolution or authority for health care is evaluated in the context of 3 objectives of provincial governments--community empowerment to garner new allies for health care restructuring, service integration to create a true "system" and conflict containment as spending is cut. Devolved authorities cannot pursue each of these objectives with equal vigour because they must balance the competing pressures from their provincial government, their providers and their local citizens. Each devolved authority accommodates these pressures in its own way, through different trade-offs. Appointed board members are generally well intentioned in representing the interests of their entire community but are unlikely to overcome formidable barriers to community empowerment in health care. Unless future board elections attract large and representative voter turnouts, they may fragment board members' accountability (by making them more accountable to multiple interest groups) rather than solidify it (by making them more accountable to the community). Although boards have integrated and rationalized parts of the institutional sector, integration of the community sector is hampered by structural constraints such as the lack of budgetary authority for a broader scope of services, including physicians' fees and drugs. Devolved authorities will deflect blame from provincial governments and contain conflict only while they believe that there is still slack in the system and that efficiency can be improved. When boards no longer perceive this, they are likely to add their voices to local discontent with fiscal retrenchment. Continuing evaluation and periodic meetings of authorities to share experiences and encourage cross-jurisdictional policy learning are needed.

Devolving authority for health care in Canada's provinces: 3. Motivations, attitudes and approaches of board members

OBJECTIVE

To obtain information from the members of the boards of devolved health care authorities on their motivations, attitudes and approaches, to evaluate their relative orientations to the expectations of provincial governments, local providers and community members, and to evaluate the influence of members' being employees in health care or social services and being willing to stand for election.

DESIGN

Mail survey conducted in cooperation with the devolved authorities during the summer of 1995.

SETTING

Three provinces (Alberta, Saskatchewan and Prince Edward Island) with established boards and 2 provinces (British Columbia and Nova Scotia) with immature boards.

PARTICIPANTS

All 791 members of the boards of devolved authorities in the 5 provinces, of whom 514 (65%) responded.

OUTCOME MEASURES

Respondents' declared motivations, levels of confidence in board performance and attitudes toward accountability; differences between members who were willing to run for election to boards and others and differences between members who were employees in health care or social services and others.

RESULTS

The main motivations of board members were an interest in health care and a desire to be part of decision-making and their main concern was inadequacy of data for decision-making. Almost all (93%) felt that they made good decisions, and 69% thought that they made better decisions than those previously made by the provincial government. Most (72%) felt that they were accountable to all of the local citizens, although nearly 30% stated that they represented the interests of a specific geographic area or group. Attitudes toward their provincial governments were polarized, with half agreeing and half disagreeing that provincial rules restrict the board members. The board members who were employed in health care and social services and those who were willing to stand for election did not differ substantially from their counterparts, although potential electoral candidates were less likely than others to feel accountable to provincial-level constituencies (such as taxpayers and the minister of health) and more likely to represent the interests of a specific geographic area or group. Only a modest number of differences were found among members from different provinces.

CONCLUSIONS

Board members' strong feelings of accountability to and representation of local citizens could counteract the structural influences leading board members to favour the interests of provincial governments and providers.

Devolving authority for health care in Canada's provinces: 2. Backgrounds, resources and activities of board members

OBJECTIVE

To obtain information from the members of the boards of devolved health care authorities and evaluate their orientations in meeting the expectations of provincial governments, local providers and community members.

DESIGN

Mail survey, conducted in cooperation with the devolved authorities, in the summer of 1995.

SETTING

Three provinces (Alberta, Saskatchewan and Prince Edward Island) with established boards and 2 (British Columbia and Nova Scotia) with immature boards.

PARTICIPANTS

All 791 members of boards of devolved authorities in the 5 provinces, of whom 514 (65%) responded.

OUTCOME MEASURES

Sociodemographic background, training, experience and activities of board members as well as their use of information.

RESULTS

There were systematic differences between established and immature boards in regard to training, information use and actual and desired activities. Members spent 35 hours per month, on average, on work for their board. Members were largely middle-aged, well educated and well off. Only 36% were employed full time. Nine out of 10 had previous experience on boards, more often in health care than in social services. They were least pleased with their training in setting priorities and assessing health care needs and most pleased with their training in participating effectively in meetings and understanding their roles and responsibilities. The information for decision-making most available to them was information on service costs (68% said it was available "most of the time" or "always") and utilization (64%); the least available information was that on key informants' opinions (47%), service benefits (37%) and citizens' preferences (28%). Board activity was dominated by setting priorities and assessing needs, secondarily occupied with ensuring the effectiveness and efficiency of services and allocating funds, and least concerned with delivering services and raising revenue. The match between activities desired by members and actual activities was significantly poorer for members of immature boards than for those of established boards.

CONCLUSIONS

The responses concerning these structural variables suggest that board members are most likely to meet the expectations of provincial governments. Fewer appear well equipped to accommodate the views of their providers and even fewer to incorporate the perspectives of their community.

Altered hierarchy of protective responses against severe hypoglycemia in normal aging in healthy men

OBJECTIVE

To investigate the effect of normal aging on the protective responses against hypoglycemia, in view of the fact that type II diabetes is primarily a disease of aging, and its treatment is associated with risk of hypoglycemia with cognitive impairment.

RESEARCH DESIGN AND METHODS

Plasma glucose was lowered stepwise from 5 to 2.4 mmol/l and restored by manipulation of an infusion of 20% glucose during 220-min intravenous infusion of 1.5 mU.kg-1.min-1 soluble insulin in 14 men; 7 were aged 60-70 years and the other 7 were 22-26 years. Changes in neurohumoral responses, subjective awareness, and choice reaction time were assessed.

RESULTS

Hormonal responses were similar in the two groups, but symptoms began earlier in the younger men (at a plasma glucose of 3.6 +/- 0.1 vs. 3.0 +/- 0.2 mmol/l, P = 0.02) and were more intense (P = 0.03). Four-choice reaction time, a measure of psychomotor coordination, deteriorated earlier in the older men (at a plasma glucose of 3.0 +/- 0.1 vs. 2.6 +/- 0.1 mmol/l, P = 0.07) and to a greater degree. The difference between the glucose level for subjective awareness of hypoglycemia and the onset of cognitive dysfunction was lost in the older men (0.0 +/- 0.2 vs. 0.8 +/- 0.1 mmol/l, P < 0.007).

CONCLUSIONS

Older men are prone to more severe cognitive impairment during hypoglycemia than younger men and are less likely to experience prior warning symptoms if blood glucose falls. This effect of normal aging may contribute to the risk of severe hypoglycemia in older diabetic patients treated with sulfonylureas and insulin.

Devolving authority for health care in Canada's provinces: 1. An introduction to the issues

In 9 of Canada's 10 provinces, much of the decision-making in health care has recently been devolved to local authorities. Provincial governments want this new governance structure to at least contain costs and improve service integration. However, there has been little evaluation of devolution to determine whether these and other goals are being met. Although devolved structures in the provinces vary somewhat with respect to the number of tiers, accountability mechanisms, degree of authority and method of funding, the only structural element that varies substantially is the scope of services under the authority of local boards. The real authority of the boards depends, however, on their negotiated compromises among 3 areas of tension: the provincial government's expectations, the providers' interests and the local citizens' needs and preferences. The boards' abilities to negotiate acceptable compromises will largely determine their effectiveness. This article introduces a survey of the members of 62 boards in 5 provinces for which the response rate was 65%, with 514 of 791 board members responding.

In search of informed input: a systematic approach to involving the public in community decision making

Given the task of distributing scarce resources, decision makers are faced with the question of how to involve an increasingly threatened and disenfranchised public in decisions affecting their communities. This article introduces a systematic approach to public involvement in community decision-making and identifies key elements in the design of institutional driven public participation exercises. Examples are drawn from the health care system restructuring experiences of three Ontario communities.

Review of the multi-hospital arrangements literature: benefits, disadvantages and lessons for implementation

The multi-hospital arrangements literature is reviewed for Canada and the United States. There is a notable lack of evaluations on the outcomes of these arrangements, especially in the Canadian context. For evaluations that do make it to the literature, generalizability of conclusions is difficult because most is based on case studies and relates to "for-profit" U.S. hospitals. We are forced to conclude, however, that there is little definitive evidence that quality of care is improved by multi-hospital arrangements or to support or refute the claims of better human resources deployment. The most striking organizational benefit appears to be that institutions considering merger or other arrangements are forced into explicit considerations of their mission and goals. Many of the potential disadvantages of multi-hospital arrangements may be ameliorated with appropriate strategic planning and attention to detail during negotiation of the arrangement. As new multi-institutional arrangements may cause harm as well as reap benefits, careful evaluation is needed.