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Biomedical subjects

C Weijer

Publications and source records attributed to C Weijer.

At least 19 recordsLinked to original sources
PubMed1999

Placebo-controlled trials in schizophrenia: are they ethical? Are they necessary?

The current controversy as to the proper role of the placebo control in the evaluation of new treatments for schizophrenia requires an analysis that is sensitive to both ethical and scientific issues. Clinical equipoise, widely regarded as the moral foundation of the randomized controlled trial (RCT), requires the use of best available treatment as the control in RCT. Scientific criticisms of the use of an active control are examined and none present an insuperable barrier to the use of an active control. Indeed, scrutiny of the most recent argument for the use of placebo controls, 'assay sensitivity', suggests that the use of placebo may be the cause of the problem pointed to. Scientific, regulatory, ethical and legal advantages of the use of an active control are described. While the use of a placebo control may be acceptable in carefully defined circumstances, in most cases the use of an active control in schizophrenia research is ethically and scientifically preferable.

Antipsychotic Agents↗
PubMed1999

Selecting subjects for participation in clinical research: one sphere of justice.

Recent guidelines from the US National Institutes of Health (NIH) mandate the inclusion of adequate numbers of women in clinical trials. Ought such standards to apply internationally? Walzer's theory of justice is brought to bear on the problem, the first use of the theory in research ethics, and it argues for broad application of the principle of adequate representation. A number of practical conclusions for research ethics committees (RECs) are outlined. Eligibility criteria in clinical trials ought to be justified by trial designers. Research ethics committees ought to question criteria that seem to exclude unnecessarily women from research participation. The issue of adequate representation should be construed broadly, so as to include consideration of the representation of the elderly, persons with HIV, mental illness and substance abuse disorders in clinical research.

Biomedical Research↗
PubMed1998

Bioethics for clinicians: 16. Dealing with demands for inappropriate treatment.

Demands by Patients or their Families for treatment thought to be inappropriate by health care providers constitute an important set of moral problems in clinical practice. A variety of approaches to such cases have been described in the literature, including medical futility, standard of care and negotiation. Medical futility fails because it confounds morally distinct cases: demand for an ineffective treatment and demand for an effective treatment that supports a controversial end (e.g., permanent unconsciousness). Medical futility is not necessary in the first case and is harmful in the second. Ineffective treatment falls outside the standard of care, and thus health care workers have no obligation to provide it. Demands for treatment that supports controversial ends are difficult cases best addressed through open communication, negotiation and the use of conflict-resolution techniques. Institutions should ensure that fair and unambiguous procedures for dealing with such cases are laid out in policy statements.

Adult↗
PubMed1998

A study in contrasts: eligibility criteria in a twenty-year sample of NSABP and POG clinical trials. National Surgical Adjuvant Breast and Bowel Program. Pediatric Oncology Group.

We studied changes in eligibility criteria--the largest impediment to patient accrual--in two samples of clinical trials. Trials from the NSABP (National Surgical Adjuvant Breast and Bowel Program) and POG (Pediatric Oncology Group) were analyzed. After eliminating duplications, the criteria in each protocol were enumerated and classified according to a novel schema. NSABP trials contained significantly more criteria than POG trials, and added precision criteria (making study populations homogeneous) at a faster rate than POG studies. The difference between NSABP studies (explanatory trials) and POG studies (pragmatic trials) suggest that large numbers of eligibility criteria are not necessary for quality studies. We recommend that: (1) the inclusion/exclusion criteria distinction be abandoned; (2) eligibility criteria be explicitly justified; (3) the need for each criterion be assessed when new trials are planned; (4) criteria in phase III trials restricting patient accrual be minimized; and (5) further research be done to assess the impact of criteria on generalizability.

Breast Neoplasms↗
PubMed1998

Assessing the interpretation of criteria for clinical trial eligibility: a survey of oncology investigators.

OBJECTIVE: To investigate whether eligibility criteria that exclude the elderly, persons with psychiatric disease, and persons with substance abuse problems from participation in randomized controlled trials (RCTs) are subjective and hence a source of variability in enrolment decisions and investigator uncertainty. DESIGN: Survey questionnaire. PARTICIPANTS: Cancer investigators from the United States and Canada. INTERVENTIONS: Investigators were presented with clinical vignettes from 3 patient categories--eligible, ineligible and uncertain--for each of 5 eligibility criteria--3 subjective and 2 objective--and were asked whether they would enrol the patient in a trial and how sure they were of this decision. Demographic characteristics of the investigators were also collected. OUTCOME MEASURES: The difference in enrolment decisions between subjective and objective criteria, and the difference in the certainty associated with these decisions. RESULTS: Of 365 questionnaires sent out, 224 usable ones were returned. Compared with the objective criteria, the subjective criteria were associated with more variable enrolment decisions (p = 0.07 for the "eligible" scenario and p = 0.0001 for the "ineligible" and "uncertain" scenarios), and investigators were less sure about the decisions they made (p = 0.0001 for all scenarios). Demographic characteristics of the investigators failed to explain the observed differences. CONCLUSIONS: Subjective eligibility criteria may interfere with the conduct and interpretation of RCTs and, therefore, their use ought to be justified explicitly in the study protocol. RCT designers, funding agencies and research ethics boards have an important role in reviewing eligibility criteria for their necessity.

Age Factors↗
PubMed1997

Bioethics for clinicians: 10. Research ethics.

Medical research involving human subjects raises complex ethical, legal and social issues. Investigators sometimes find that their obligations with respect to a research project come into conflict with their obligations to individual patients. The ethical conduct of research rests on 3 guiding principles: respect for persons, beneficience, and justice. Respect for persons underlies the duty to obtain informed consent from study participants. Beneficence demands a favourable balance between the potential benefits and harms of participation. Justice requires that vulnerable people not be exploited and that eligible candidates who may benefit from participation not be excluded without good cause. Studies must be designed in a way that ensures the validity of findings and must address questions of sufficient importance to justify the risks of participation. In any clinical trial there must be genuine uncertainty as to which treatment arm offers the most benefit, and placebo controls should not be used if effective standard therapies exist. Researchers have a responsibility to inform themselves about the ethical, legal and policy standards that govern their activities. When difficulties arise, they should consult the existing literature and seek the advice of experts in research ethics.

Beneficence↗
PubMed1997

Twisted scroll waves organize Dictyostelium mucoroides slugs.

Cellular slime moulds (Dictyosteloids) are characterised by at least two different modes of slug migration. Most species, e.g. Dictyostelium mucoroides, produce a stalk continuously during slug migration, while a few species, e.g. Dictyostelium discoideum are characterised by stalk-less slug migration and only produce a stalk upon culmination. Experiments on D. discoideum and theoretical model calculations have shown that D. discoideum slugs are organized by a cAMP scroll wave in the tip which produces planar waves in the back. These waves guide cell movement in slugs: spiralling in the tip and forward movement parallel to the slug axis in the back. Simple changes in model parameters can lead to the formation of a twisted scroll wave which extends throughout the slug. In order to investigate whether such twisted scroll waves occur naturally we have analysed the movement of fluorescently labelled single cells in migrating D. mucoroides slugs. The results show that cells in the prespore zone of D. mucoroides slugs move in a spiral path. Although the velocity of single cells in D. mucoroides is faster than in D. discoideum, the net forward component of their movement is less due to their spiral trajectories. As a result D. mucoroides slugs move more slowly than D. discoideum slugs. The entire D. mucoroides slug also describes a spiralling path leaving corkscrew shaped stalks behind. Based on these observations we propose that cell movement in D. mucoroides slugs is controlled by a propagating twisted scroll wave of cAMP which extends throughout the length of the slug.

Animals↗
PubMed1997

Do patients with breast cancer participating in clinical trials receive better nursing care?

PURPOSE/OBJECTIVES: To examine differences in nursing care received by patients with breast cancer enrolled in clinical trials and those not enrolled in clinical trials. DESIGN: Retrospective review of clinic charts. SETTING: Oncology outpatient department of a tertiary-care hospital. SAMPLE: 90 women with early stage breast cancer. The mean age of the women was 53 years. More than half of the women (51 of 90) were treated in a clinical trial. METHODS: Retrospective chart review of all the nurse-patient clinic encounters for a six-month period from date of cancer diagnosis. The content of each encounter was coded using a modified version of the Nursing Action Classification System. MAIN RESEARCH VARIABLES: Nursing interventions (i.e., assessment, medical scheduling, psychosocial scheduling, reassurance, and teaching) and phone calls. FINDINGS: Women enrolled in clinical trials had more phone interactions with nursing staff (p = 0.003) and received teaching (p < 0.001) and reassurance (p = 0.005) from nursing staff more often than women not enrolled in clinical trials. Controlling for age and stage of disease, teaching (p < 0.001), and reassurance (p = 0.10) were the primary differences in nursing care between the patients enrolled in clinical trials and those not enrolled. CONCLUSION: Differences in nursing care received exist between patients with breast cancer enrolled in clinical trials and those not enrolled. IMPLICATIONS FOR NURSING PRACTICE: Both teaching and reassurance are important components of caring for patients with cancer and are associated with treatment compliance. If the results of this study are confirmed, measures must be employed to ensure that all patients receive optimal care.

Adult↗
PubMed1996

What difference does it make to be treated in a clinical trial? A pilot study.

OBJECTIVE: Pilot study to characterize treatment differences between patients treated in clinical trials and those treated in a clinical setting. Previous studies have shown higher survival rates for participants in trials of cancer therapy. This difference is observed even after rates are adjusted for important covariates such as age and stage of disease. DESIGN: Retrospective chart review. SETTING: Oncology outpatient department in a tertiary care hospital. PATIENTS: Ninety women 18 to 70 years of age with early-stage breast cancer who were diagnosed in 1990. Fifty-one of the women were treated through clinical trials and 39 were treated outside of clinical trials. OUTCOME MEASURES: Number of blood tests, telephone calls, clinic visits and imaging procedures as well as intensity of chemotherapy and use of radiation therapy. The age of the patient and the stage of disease were important covariates. RESULTS: After the analysis was controlled for patient age and stage of disease, patients treated through a clinical trial were more likely to receive standard-dose chemotherapy (p = 0.020, 95% confidence interval 1.20 to 200.73) and more frequent blood tests (p < 0.001, 95% confidence interval 1.02 to 1.13) than other patients treated in the clinic. CONCLUSIONS: Our results provide a plausible mechanism for the observed survival advantage for participants in clinical trials in oncology. Further study is called for. If these results are confirmed, they have important implications for informed consent to participate in clinical trials and for clinical practice.

Adolescent↗
PubMed1995

Monitoring clinical research: an obligation unfulfilled.

The revelation that data obtained for the US-based National Surgical Adjuvant Breast and Bowel Project (NSABP) from subjects enrolled at Hôpital Saint-Luc in Montreal was falsified has eroded public trust in research. Institutions can educate researchers and help prevent unethical research practices by establishing procedures to monitor research involving human subjects. Research monitoring encompasses four categories of activity: annual reviews of continuing research, monitoring of informed consent, monitoring of adherence to approved protocols and monitoring of the integrity of data. The authors describe characteristics of research projects that may call for monitoring procedures in each category. The form taken by such monitoring depends on the nature of the protocol. Although appropriate research monitoring requires substantial investment of personnel and financial resources, it is required under guidelines regulating research involving human subjects in Canada. Research monitoring is a step forward in re-establishing public confidence in medical research.

Canada↗