Search PubMed⌕ Search

Biomedical subjects

J Lomas

Publications and source records attributed to J Lomas.

At least 37 records · Page 2Linked to original sources
PubMed1998

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.

3-Hydroxybutyric Acid↗
PubMed1998

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.

Blood Glucose↗
PubMed1997

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.

Canada↗
PubMed1997

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.

Canada↗
PubMed1997

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.

Adult↗
PubMed1997

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.

Canada↗
PubMed1997

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.

Alberta↗
PubMed1997

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.

Attitude to Health↗
PubMed1997

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.

Canada↗
PubMed1997

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.

Alberta↗
PubMed1997

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.

Adult↗
PubMed1997

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.

Adolescent↗
PubMed1996

Do physician-payment mechanisms affect hospital utilization? A study of Health Service Organizations in Ontario.

OBJECTIVES: To determine whether payment of primary care physicians based on capitation, with an additional incentive payment for low hospital-utilization rates, resulted in lower hospital-utilization rates among patients of these physicians than among patients of physicians still paid on a fee-for-service basis. DESIGN: Retrospective cohort study. SETTING: Capitation-based and fee-for-service primary care practices in Ontario. SUBJECTS: Thirty-nine physicians whose method of payment was converted from fee-for-service to capitation during the period from June 1985 to January 1989 and 7 physicians who remained in fee-for-service practice, two of whom were matched with one physician in capitation-based practice on the basis of practice location, type of practice (academic v. community), hours of practice (part-time v. full-time), years since graduation, physician group size, practice size (number of patients), type of group (primary care v. multispecialty), sex, certification in family medicine, country of graduation (Canada v. other) and age. One physician in capitation-based practice was matched with only one physician in fee-for-service practice. OUTCOME MEASURES: Annual hospital-utilization rates (hospital separations or hospital days per 1000 patients in each practice) for the physicians paid on a capitation basis 3 years before, 1 year before and 3 years after they converted from fee-for-service payment and at corresponding periods for the matched physicians still paid on a fee-for-service basis. RESULTS: The mean annual rate of hospital days used, adjusted for the age and sex of patients as well as for their social-program-recipient status, fell from 1085 per 1000 patients (3 years before the conversion date) to 1030 (1 year before conversion) and to 954 (3 years after conversion) in capitation-based practices. For the matched physicians in fee-for-service practice, the rates during the corresponding periods were 1085, 1035 and 956 hospital days per 1000 patients. The pattern was similar for rates of hospital separations, adjusted for patient's age, sex and social-program-recipient status. There were no statistically significant differences between the rates of hospital utilization among patients of physicians in capitation-based practices and the rates among those of physicians in fee-for-service practices during each of the three periods, nor were there significant differences in the changes in rates. CONCLUSION: Capitation payment, with an additional incentive payment to encourage low hospital-utilization rates, did not reduce hospital use. Factors other than the method of physician payment appear to be responsible for the variations in hospital utilization among practices.

Adult↗
PubMed1996

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.

Community Health Planning↗
PubMed1996

Re-minding our Ps and Qs: medical cost controls in Canada.

During the past few years the landscape of Canadian physician reimbursement policy has undergone dramatic change. Rapidly eroding fiscal environments for provincial (and federal) governments have forced provinces to "get serious" about controlling a significant, previously uncontrolled, budget line: physician expenditures. All provinces now impose medical expenditure caps, with eight of these being hard caps under which any overruns are the responsibility of the profession. In addition, policies in five provinces now include individual income caps. One of the effects of this new environment has been a rush to adopt supply-control policies. This paper explores a number of other side effects, such as heightened interest in alternative methods of payment, as well as the emergence of, and difficulties for, joint province/medical association management committees.

Canada↗
PubMed1995

Does the community want devolved authority? Results of deliberative polling in Ontario.

OBJECTIVE: To obtain and contrast the informed opinions of people in five decision-making groups that could have a role in devolved governance of health care and social services. DESIGN: Deliberative polling. SETTING: Three rural and three urban communities selected from the 32 areas covered by a district health council in Ontario. PARTICIPANTS: A total of 280 citizens from five potential decision-making groups: randomly selected citizens, attendees at town-hall meetings, appointees to district health councils, elected officials and experts in health care and social services. INTERVENTION: Participants' opinions were polled during 29 structured 2-hour meetings. MAIN OUTCOME MEASURES: Participants' opinions on their personal willingness and their group's suitability to be involved in devolved decision making, desired type of decision-making involvement, information preferences, preferred areas of decision-making involvement and preferred composition of decision-making bodies. RESULTS: Mean attendance at each meeting was 9.6 citizens. Although there were some significant differences in opinion among the five potential decision-making groups, there were few differences among citizens from different geographic areas. A total of 189 (72%) of people polled were personally willing to take on a role involving responsibility for overall decision-making, but far fewer thought that their group was suited to taking on responsibility (30%) or a consulting role (55%). Elected officials were the most willing (85% personally willing, 50% thought their group was suitable) and randomly selected citizens the least willing (60% personally willing, 17% thought their group was suitable) to take responsibility for overall decision making. Most citizens polled indicated less interest in involvement in specific types of decisions, except for planning and setting priorities, than in overall decision making. Only 24 participants (9%) rated their own group as suitable to take responsibility for raising revenue, 91 (33%) deemed their group suited to distribution of funds and 108 (39%) felt their group was suitable for management of services. People in all five groups ranked health care needs (mean rank 1.5 out of four options) as the most important and preferences (mean rank 3.6) as the least important information. They rated a combination body involving several community groups as the most suitable overall decision-making body (8.8 on 10-point scale). Participants favoured the representation of elected officials, the provincial government and experts on combination bodies responsible for the specific types of decisions. Overall, as the complexity of devolved decision making became clear, participants tended to assign authority to traditional decision makers such as elected officials, experts and the provincial government, but also favoured a consulting role for attendees at town-hall meetings (i.e., interested citizens). CONCLUSION: There are significant differences among groups in the community in their willingness to be involved, desired roles and representation in devolved decision making on health care and social services in Ontario.

Adult↗