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Biomedical subjects

D Menon

Publications and source records attributed to D Menon.

At least 37 records · Page 2Linked to original sources
PubMed1999

Introducing "evidence" into board decision-making.

The purpose of this article is to report on the results of a workshop that introduced evidence-based decision-making techniques to Board members of regional health authorities in Alberta. results and conclusions: The workshop demonstrated that it is possible to design a process for the incorporation of evidence in administrative decision-making. The participants demonstrated that they were able to apply scientific evidence in administrative decision making and that the decisions taken were reasonably consistent. Also, in the absence of evidence, values took precedence in the decision-making process and the decisions taken were less consistent.

Alberta↗
PubMed1999

A short history of INAHTA. International Network of Agencies for Health Technology Assessment.

The need for better communication and collaboration between health technology assessment agencies led to the formation of an International Network of Agencies for Health Technology Assessment (INAHTA). The network now comprises 27 agencies and has been successful in improving exchange of information and in undertaking joint health technology assessment projects. Issues for the future include possible changes to criteria for membership and identification of resources for more extensive programs.

Databases, Bibliographic↗
PubMed1999

Will GnRH antagonists provide new hope for patients considered 'difficult responders' to GnRH agonist protocols?

We have assessed the use of cetrorelix, a gonadotrophin releasing hormone (GnRH) antagonist, in conjunction with clomiphene citrate and gonadotrophin in 31 in-vitro fertilization (IVF)/gamete intra-Fallopian transfer (GIFT) cycles for 25 difficult responders. Group I included 18 poor responders (24 cycles) with no live birth in 23 previous IVF cycles with GnRH agonists. Group II included seven patients (seven cycles) with polycystic ovaries. Thirteen previous IVF/GIFT cycles with GnRH agonists had resulted in one live birth and three of these patients had developed ovarian hyperstimulation syndrome (OHSS). The treatment protocol involved a daily dose of clomiphene citrate 100 mg for 5 days and gonadotrophin injections from cycle day 2. Cetrorelix 0.25 mg/day was started when the leading follicle reached 14 mm. The outcome in both groups was favourable compared to previous treatment with GnRH agonists. In group I the abandoned cycle rate was 29 versus 57% (P = 0.06). More oocytes were produced (6.4 versus 4.7 oocytes/cycle) at a lower dose of follicle-stimulating hormone (FSH) (709 versus 1163 IU/oocyte; P = 0.08) and two live births resulted (11.8%). In group II fewer oocytes were produced (10.2 versus 14.5 oocytes/cycle), using a lower dose of gonadotrophin (170 versus 189 IU/oocyte) and resulted in one ongoing pregnancy. No patients experienced OHSS. This report is preliminary and a further controlled randomized study is required.

Clomiphene↗
PubMed1999

The revised Canadian Guidelines for the Economic Evaluation of Pharmaceuticals.

The first edition of the Guidelines for Economic Evaluation of Pharmaceuticals: Canada was published in November 1994. At that time, the Canadian Coordinating Office for Health Technology Assessment (CCOHTA) was assigned the task of maintaining and regularly updating the Canadian Guidelines. Since their introduction, a great deal of experience has been gained with the practical application of the guidelines. Their role has also evolved over time, from being a framework for pharmacoeconomic research to the point where a wide variety of decision-makers use economic evaluations based on the principles set out in the guidelines as a means of facilitating their formulary decisions. In addition, methodologies in certain areas (and the body of related research literature in general) have developed considerably over time. Given these changes in the science and the experience gained, CCOHTA convened a multi-disciplinary committee to address the need for revisions to the guidelines. The underlying principles of the review process were to keep the guidance nature of the document, to focus on the needs of 'doers' (so as to meet the information needs of 'users') and to provide information and advice in areas of controversy, with sound direction in areas of general agreement. The purpose of this review is three-fold: (i) to outline the process which lead to the revision of the Canadian Guidelines; (ii) to describe the major changes made to the second edition of this document; and (iii) to consider the 'next steps' as they relate to the impact of such guidelines and the measurement of outcomes related to economic assessments of pharmaceuticals in general.

Canada↗
PubMed1999

Health economics in the Canadian pharmaceutical industry.

OBJECTIVE: To assess the goals, strategic focus, structure, capabilities, activities and effectiveness of health economics (HE) departments in the Canadian pharmaceutical industry, to examine how these have evolved, and the implications of HE in the future of the pharmaceutical industry. DESIGN AND INTERVENTIONS: A mixture of telephone and face-to-face interviews with members of the HE unit (survey 1) and the chief executive officers (CEOs) [survey 2] of the top 21 Canadian pharmaceutical companies was undertaken in 1997. MAIN OUTCOME MEASURES AND RESULTS: 17 out of 21 companies responded to the first survey, and 12 of the 17 CEOs responded to our second survey. The goals of the HE department in most of the pharmaceutical companies have evolved from supporting efforts to gain reimbursement on government drug plans to include pricing, promotion, internal decision-making and other activities. Members of the HE department perceive their work to be valuable to the company. The CEOs felt that the true value of HE data is not adequately understood by formulary reviewers and, therefore, HE data may be an impediment to market access. CONCLUSIONS: The purpose of the HE department is to demonstrate the value of the company's product to provincial government insurers. However, pharmaceutical companies are having difficulty justifying the importance of the HE department because of inconsistencies in the interpretation of economic evaluations by healthcare payers.

Canada↗
PubMed1999

Comparison of literature searches on quality and costs for health technology assessment using the MEDLINE and EMBASE databases.

Biomedical databases are an important source of information for health technology assessment. However, there is considerable variation in the costs of accessing commercial databases. We sought to measure the quality, amount of overlap, and costs of information retrieved from two of the main database sources--MEDLINE and EMBASE. Librarians at two health technology assessment agencies ran a total of eight literature searches on various medical technologies, using both databases. All search results were independently reviewed by two researchers. The researchers were asked to identify relevant references and to rank each of these according to a level of evidence scale. The results were tabulated to show the number of references identified by each database, the number of relevant references ranked by level of evidence, and the number of these references that were unique to one or the other database. The cost of retrieving references from each source was also calculated. Each database contained relevant references not available in the other. Because of the longer time lag for indexing in MEDLINE, many of the references that originally appeared to be unique to EMBASE were subsequently available in MEDLINE as well. Since our study was conducted, MEDLINE has been made available worldwide, free of charge, via the Internet. Hence, the cost difference between the databases is now even greater. However, notwithstanding the costs, it appears that literature searches that rely on only one or the other database will inevitably miss pertinent information.

Abstracting and Indexing↗
PubMed1998

Adverse effects associated with selective serotonin reuptake inhibitors and tricyclic antidepressants: a meta-analysis.

BACKGROUND: The use of antidepressant medications and the resulting costs have increased dramatically in recent years, partly because of the introduction of selective serotonin reuptake inhibitors (SSRIs). An assessment of the clinical and economic aspects of SSRIs compared with the older tricyclic antidepressants (TCAs) was initiated to generate information for purchasers of these drugs as well as clinicians. One component of this study was an examination of the adverse effects associated with the use of these drugs. METHODS: Searches of bibliographic databases (for January 1980 through May 1996) and manual scanning of both peer-reviewed publications and other documents were used to identify double-blind, randomized controlled trials involving at least one SSRI and one TCA. For the study of adverse effects, only trials that had at least 20 patients in each trial arm and that reported rates of adverse effects in both arms were retained. In total 84 trials reporting on 18 adverse effects were available. Meta-analyses were undertaken to calculate pooled differences in rates of adverse effects. The question of whether the method of eliciting information from patients about adverse effects made a difference in the findings was also examined. Finally, differences in drop-out rates due to adverse effects were calculated. RESULTS: The crude rates of occurrence of adverse effects ranged from 4% (palpitations) to 26% (nausea) for SSRIs and from 4% (diarrhea) to 27% (dry mouth) for TCAs. The differences in the rates of adverse effects between the 2 types of drugs ranged from 14% more with SSRIs (for nausea) to 11% more with TCAs (for constipation). The results did not depend on the method of eliciting information from patients. There were no statistically significant differences between drug classes in terms of drop-outs due to adverse effects. INTERPRETATION: SSRIs and TCAs are both associated with adverse effects, although the key effects differ between the drug classes. Further explanation of the adverse effects and their relation to discontinuation of medication will require better studies involving prospective collection of quality-of-life data.

Antidepressive Agents, Tricyclic↗
PubMed1998

Inscuteable and numb mediate asymmetric muscle progenitor cell divisions during Drosophila myogenesis.

Each larval hemisegment comprises approximately 30 uniquely specified somatic muscles. These derive from muscle founders that arise as distinct sibling pairs from the division of muscle progenitor cells. We have analyzed the progenitor cell divisions of three mesodermal lineages that generate muscle (and pericardial cell) founders. Our results show that Inscuteable and Numb proteins are localized as cortical crescents on opposite sides of dividing progenitor cells. Asymmetric segregation of Numb into one of the sibling myoblasts depends on inscuteable and is essential for the specification of distinct sibling cell fates. Loss of numb or inscuteable results in opposite cell fate transformations-both prevent sibling myoblasts from adopting distinct identities, resulting in duplicated or deleted mesodermal structures. Our results indicate that the muscle progenitor cell divisions are intrinsically asymmetric; moreover, the involvement of both inscuteable and numb/N suggests that the specification of the distinct cell fates of sibling myoblasts requires intrinsic and extrinsic cues.

Animals↗
PubMed1998

Use of economic evaluation guidelines: 2 years' experience in Canada.

Considerable effort has been expended in recent years in the development of methodology guidelines for economic evaluation of pharmaceutical products, driven in part by the desire to improve the rigour and quality of economic evaluations and to help decision making. Canada was one of the first countries to develop such guidelines and to encourage their use. This paper examines the extent to which the economic evaluations that were submitted to the Canadian Coordinating Office for Health Technology Assessment in the last two years adhered to Canadian guidelines. The analytic technique employed by twelve studies as well as the comparator used, the perspective taken, the outcome measure selected, the cost items that were taken into consideration and the extent of sensitivity analyses that were performed are reviewed in this paper. It can be concluded that although studies have been of variable quality, the majority of them were well presented, complete and transparent, due in part to the guidelines. Except for the perspective of the analysis, guidelines were, in many respects, adhered to and did not restrict investigators to specific methodologies or specific techniques. They were also instrumental in ensuring a minimum set of standards.

Canada↗
PubMed1997

Continuous assessment of the cerebral vasomotor reactivity in head injury.

OBJECTIVE: Cerebrovascular vasomotor reactivity reflects changes in smooth muscle tone in the arterial wall in response to changes in transmural pressure or the concentration of carbon dioxide in blood. We investigated whether slow waves in arterial blood pressure (ABP) and intracranial pressure (ICP) may be used to derive an index that reflects the reactivity of vessels to changes in ABP. METHODS: A method for the continuous monitoring of the association between slow spontaneous waves in ICP and arterial pressure was adopted in a group of 82 patients with head injuries. ABP, ICP, and transcranial doppler blood flow velocity in the middle cerebral artery was recorded daily (20- to 120-min time periods). A Pressure-Reactivity Index (PRx) was calculated as a moving correlation coefficient between 40 consecutive samples of values for ICP and ABP averaged for a period of 5 seconds. A moving correlation coefficient (Mean Index) between spontaneous fluctuations of mean flow velocity and cerebral perfusion pressure, which was previously reported to describe cerebral blood flow autoregulation, was also calculated. RESULTS: A positive PRx correlated with high ICP (r = 0.366; P < 0.001), low admission Glasgow Coma Scale score (r = 0.29; P < 0.01), and poor outcome at 6 months after injury (r = 0.48; P < 0.00001). During the first 2 days after injury, PRx was positive (P < 0.05), although only in patients with unfavorable outcomes. The correlation between PRx and Mean index (r = 0.63) was highly significant (P < 0.000001). CONCLUSION: Computer analysis of slow waves in ABP and ICP is able to provide a continuous index of cerebrovascular reactivity to changes in arterial pressure, which is of prognostic significance.

Adolescent↗
PubMed1996

The internationalization of health technology assessment.

Health technology assessment as a formalized set of activities has a relatively short history. At its current stage of development, it is clear that it has global dimensions and impact. In this paper we review the history of health technology assessment, its development as a form of health services research, and its "institutionalization." We then identify the reasons for its internationalization, review current international initiatives, and propose actions to be taken to improve cooperation among countries.

Communication↗
PubMed1996

Transcutaneous electrical nerve stimulation (TENS): a technology assessment.

The scientific evidence for clinical effectiveness of transcutaneous electrical nerve stimulation (TENS) for treatment of acute, chronic, and labor and delivery pain is assessed in this paper, and it is concluded that there is little evidence for other than a limited use of TENS. The utilization of TENS in Canadian hospitals and payments for TENS services are addressed. Some practicalities regarding the use and assessment of health technologies are discussed.

Analgesia, Obstetrical↗
PubMed1996

Severe head injury in the United Kingdom and Ireland: a survey of practice and implications for management.

OBJECTIVE: To study the current intensive care management of patients with severe head injury (defined as a Glasgow Coma Scale score of < or = 8) in neurosurgical referral centers in the United Kingdom (UK) and ireland. DATA COLLECTION: A questionnaire was sent to the directors of the 44 neurosurgical referral units identified from the UK Medical Directory. After 4 wks, a copy of the questionnaire was sent to all nonresponders, with a cover letter urging them to respond. The aim was to collect data regarding the characteristics of the intensive care units (ICU), sedation, monitoring modalities used, the treatment of intracranial hypertension, and general care of severely head-injured patients. DATA EXTRACTION: Forty completed questionnaires were returned. Only 35 (88%) centers provided care for the severely head-injured as defined in the questionnaire. Patients were managed in specialized neurosurgical ICUs in 66% of centers and in general ICUs in the remainder of the centers. The ICUs were coordinated by an anesthesiologist in 66% of instances and by a neurosurgeon in 23%. The mean number of beds per units was 7.9 (range 4 to 16), with 1:1 nurse/bed ratio and 5.5 nurses per bed (total number of nursing staff per bed) (range 2.75 to 8). Annual caseload varied between units with the majority of units (49%) receiving between 25 and 50 patients with severe head injury, 23% receiving between 50 and 100 patients with severe head injury, and 29% receiving > 100 patients with severe head injury. There was considerable variability in both the nature of monitoring and therapy between centers. Although blood and central venous pressures were invasively monitored in > 50% of the patients in 94% and 77% of the centers, respectively, intracranial pressure was only monitored routinely in 57% of the centers. Jugular venous bulb oximetry, transcranial Doppler ultrasonography, electroencephalography, and near-infrared spectroscopy were rarely used. Nearly all centers used propofol and midazolam for sedation, with morphine, fentanyl, and alfentanil as the main analgesics. Muscle relaxation was commonly used, with 40% of the centers employing it in 100% of their patients. Atracurium and vecuronium were the most commonly used agents. Only 68% of the centers had a protocol for the treatment of intracranial hypertension. Although hyperventilation to a Paco2 of 26 to 30 torr (3.5 to 4.0 kPa) was the norm in the majority of centers (56%), two centers aimed for Paco2 values < 26 torr (< 3.5 kPa). A quarter of the units did not aim for a cerebral perfusion pressure of > 60 mm Hg. Mild hypothermia was rarely used and 14% of the centers continued to use corticosteroids for the treatment of intracranial hypertension as a result of head trauma. CONCLUSION: We conclude that there are wide variations in the management of the severely head-injured patient in the UK and Ireland. Some of the therapies employed are not supported by available research findings. Rationalization (using rational management, i.e., based on good evidence) of the intensive care management of severe head injury with the development of widely accepted guidelines may result in an improvement in the quality of care of the head-injured patient.

Brain Injuries↗
PubMed1996

An economic evaluation of finasteride for treatment of benign prostatic hyperplasia.

This evaluation was conducted at the request of a Canadian provincial government considering finasteride for formulary inclusion. The comparator therapies, in accordance with Canadian pharmacoeconomic guidelines, were the most prevalent treatment [transurethral resection of the prostate (TURP)] and the lowest cost treatment (watchful waiting). All costs were measured in 1994 Canadian dollars ($Can), and both costs and outcomes were discounted at 5% per annum. Cost-effectiveness and cost-utility ratios were calculated, and were found to be dependent on initial symptom severity and the anticipated duration of treatment with finasteride. The drug was shown to be the dominant alternative compared with both TURP and watchful waiting for patients with moderate symptoms, when the duration of drug therapy is 3 years or less. However, finasteride is a weak alternative for patients with severe symptoms who are treated for 4 years or more. For other groups of patients (i.e. moderate symptoms and on finasteride for 4 years or more; severe symptoms and on treatment for 3 years or less), the drug can improve health-related quality of life, but at a cost of between $Can3000 and $Can97,000 per incremental quality-adjusted life year (1994 dollars). Our study also indicated that it would cost between $Can2.7 million and $Can5.6 million, depending on the severity mix of the patients, to treat cohort of 10,000 men aged 60 years or older with finasteride.

Aged↗
PubMed1996

Canadian guidelines for economic evaluation of pharmaceuticals. Canadian Collaborative Workshop for Pharmacoeconomics.

In 1994, Canada became the second country to release national guidelines for the economic evaluation of pharmaceuticals. The guidelines were developed over a period of 18 months through an elaborate process of broad consultation with a wide variety of relevant stakeholders. The intent of the guidelines is to provide guidance to doers and users of studies, by laying out the general 'state of the art' regarding methods, and by providing specific methodological advice on many matters. The aim is to improve the scientific quality and integrity of studies, and to enhance consistency and comparability across studies. This article presents the Canadian guidelines, both in summary and in detail. Because the techniques of economic evaluation are widely applicable beyond pharmaceuticals, the guidelines will be of interest to researchers and decision makers in all fields of healthcare. Because the methods are not country specific, the guidelines will be of interest to those in other countries as well as in Canada.

Canada↗
PubMed1996

Hospital-based technology assessment programmes: two Canadian examples.

Interest in Health Technology Assessment (HTA) has grown considerably in recent years. Organizations established specifically to conduct HTA and disseminate HTA results have sprung up in many countries. These have been, to a large extent, financed by governments. However, the relevance of HTA clearly goes beyond governments, and there are many sectors in health care that are potential consumers of HTA information. In particular, those running healthcare facilities are constantly faced with decisions on new equipment to purchase and new clinical procedures to offer. HTA is important not just to the senior administrators of such facilities but those in other levels of hospital management as well. In this paper, a brief review of Canadian and US studies on hospitals' technology assessment and acquisition is presented. Two specific examples of Canadian healthcare facilities and how HTA has been addressed in these institutions are discussed. Finally, this paper contains a discussion of some of the practical issues involved in introducing a formalized programme of HTA in hospitals.

Canada↗