Peter Tugwell

The role of before-after studies of therapeutic impact in the evaluation of diagnostic technologies.

Studies in which clinicians therapeutic plans are determined before and after application of a new test offer an attractive alternative to randomized trials as a strategy for establishing the usefulness of diagnostic technologies. To maximize scientific credibility such studies should include a number of design features: specific clinical questions should be addressed; consecutive patients presenting with a clinical problem should be entered; the tests accuracy should be assessed; and changes in therapy should be described in sufficient detail to allow an estimate of the impact on patient outcome. Even with attention to these issues, the validity of before-after studies of therapeutic impact is limited by possible discrepancies between clinicians stated plans and actual behavior, and by the often tenuous link between change in therapy and patient benefit. Before-after designs will be most useful in primary investigations which, if positive, should be followed by more rigorous studies to establish patient benefit.

Gold induced thrombocytopenia: 12 cases and a review of the literature

Gold induced thrombocytopenia is immune mediated, with the production of platelet associated IgG leading to peripheral platelet destruction. An association with HLA-DR3 has been demonstrated. Corticosteroid therapy is effective in treatment, although other modes of therapy may be as efficacious.

Aspirin and gastrointestinal haemorrhage: a methodologic assessment.

The literature on the association between Aspirin (ASA) use and gastrointestinal haemorrhage (GIH) has been reviewed. Thirteen control-studies were selected and examined for (i) the type of design (ii) the choice of outcome measures, and (iii) the adequacy of satisfying defined causation criteria and the influence of sampling strategies on one of these criteria--strength of association. Of the 13 studies seven were large scale randomized control trials (RCTs) and six were case-control studies. Among the outcome measures utilized in these studies and currently available for the assessment of GIH, we found none were uniquely satisfactory for use as a gold standard. Furthermore, in none of these studies was the particular chosen outcome measure sufficiently satisfactory to allow firm conclusions on the issue of causation. None of the studies adequately met all the defined causation criteria or adequately eliminated the potential biases in the chosen sampling strategies. Thus the evidence that aspirin causes GIH fails to stand up to critical evaluation. This, of course, does not mean that ASA does not cause GIH. However, it is common practice for physicians to advise their patients with a prior history of GIH and or gastrointestinal symptoms to refrain from ASA use. This is probably sound advice in the setting where ASA is being used as a casual or short term analgesic or anti-inflammatory agent. But in the context of severe inflammatory joint disease when the use of ASA is clinically indicated, it should not be withheld on the basis of the risk of GIH. There is a widespread belief in medicine that by implication aspirin and other nonsteroidal anti inflammatory drugs are a common cause of bleeding from the gastrointestinal tract, yet it has been pointed out frequently [1-3] that the evidence to support the belief is weak and circumstantial. Despite this the perceived association of aspirin with gastrointestinal bleeding influences both pharmaceutical and clinical practice and often hinders or prevents the prescription of anti-inflammatory medication to patients with severe inflammatory joint disease. It was felt that a proper critical appraisal of the evidence was essential. It is unfortunate that the evidence most frequently cited implicating ASA as a cause of GIH is almost entirely related to the casual use of the drug. Thus our conclusions must be viewed with some caution in the patient group where this knowledge would be of most importance, that is in patients with inflammatory joint disease.

A controlled comparison of piroxicam and diclofenac in patients with osteoarthritis

SummaryEighty patients with osteoarthritis were randomly assigned to either piroxicam (20 mg daily) or diclofenac (75–150 mg daily) in a 12-week double-blind, parallel groups study. In the 70 patients who completed the study, both medications were effective; statistically significant improvement was observed on all assessments of efficacy. However, no statistically significant differences between the two drugs were seen on any of the efficacy parameters measured. There was a trend towards better tolerance in the piroxicam treated patients, although this was not statistically significant; 3 of the 40 piroxicam treated patients versus 6 of the 40 patients on diclofenac were discontinued from the trial due to intolerable adverse events.

A province-wide survey on self-reported language proficiency and its influence in global health education

OBJECTIVE nLiterature has reported that language is the most common barrier in a health care setting and a risk factor associated with negative outcomes. The present study reports the differences between nursing students who speak one language and nursing students who speak two or more languages (self-reported language proficiency) and their skills and learning needs in global health.nnnMETHOD nAn observational cross-sectional study was performed among nursing students from five Ontario universities. A survey was designed to measure knowledge, skills and learning needs in global health.nnnRESULTS nStudents who speak more than two languages are more likely to have more interest in learning global health issues, such as health risks and their association with travel and migration (p=0.44), and social determinants of health (p=0.042).nnnCONCLUSION nLanguage training is needed for nursing students to be able to face language barriers in health care settings and improve global health, locally and internationally.