PubMed Health⌕ Search

Biomedical subjects

Sharon E Straus

Publications and source records attributed to Sharon E Straus.

9 recordsLinked to original sources
PubMed2003

Analysis and reporting of factorial trials: a systematic review.

CONTEXT: Although factorial trials have become common, standards for the analysis and reporting of such trials have not been established and, despite concerns about the possibility of unrecognized interactions between therapies in factorial trials, the magnitude of this potential problem is unknown. OBJECTIVE: To examine the rationale, methods, and analysis of randomized factorial trials. DATA SOURCES AND STUDY SELECTION: We searched MEDLINE, EMBASE, and the Cochrane Controlled Trials Register using the terms factorial, interaction, 2 x 2, 2 by 2, and incremental to identify factorial randomized trials published from January 2000 to July 2002. To identify trials missed by the electronic search, we performed a hand search of English-language trials in a defined topic area (using the term myocardial ischemia [exp]) listed in MEDLINE (1966-2002), EMBASE (1980-2002), and the Cochrane Controlled Trials Register, as well as all trials in any topic area published in December 2000, excluding trials reporting only continuous surrogate end points. The final set of 33 eligible publications described 29 unique trials. DATA EXTRACTION: Two investigators independently identified factorial trials, generated a list of items affecting validity of results, and abstracted these items from each trial. DATA SYNTHESIS: The sensitivity of electronic searching for identifying factorial trials was 76%. Our 3-pronged search strategy identified 44 factorial trials with clinically important binary outcomes: 36 (82%) were done for reasons of efficiency (testing 2 interventions in the same patient population), and 8 (18%) were done to assess the incremental benefits of combining the 2 treatments. All but 1 of the trials reported treatment effects by comparing all patients who received treatment A (ie, those receiving either A alone or both A and B) vs all those not receiving treatment A (ie, those receiving either B alone or neither A nor B). Twenty-nine of the 44 trials (66%) reported the data from each of the treatment groups separately; 26 trials (59%) reported testing for interactions between the treatments. Only 2 of 31 (6%) comparisons demonstrated a statistically significant interaction between the 2 treatments. CONCLUSIONS: Accurate interpretation of factorial trials depends on the transparent reporting of data for each treatment cell. Despite concerns about unrecognized interactions, our findings suggest that investigators are appropriately restricting their use of the factorial design to those situations in which 2 (or more) treatments do not have the potential for substantive interaction.

Data Interpretation, Statistical↗
PubMed2002

Accuracy of the preoperative assessment in predicting pulmonary risk after nonthoracic surgery.

We examined the accuracy of preoperative assessment in predicting postoperative pulmonary risk in a prospective cohort of 272 consecutive patients referred for evaluation before nonthoracic surgery. Outcomes were assessed by an independent investigator who was blinded to the preoperative data. There were 22 (8%) postoperative pulmonary complications. Statistically significant predictors of pulmonary complications (all p < or = 0.005) were as follows: hypercapnea of 45 mm Hg or more (odds ratio, 61.0), a FVC of less than 1.5 L/minute (odds ratio, 11.1), a maximal laryngeal height of 4 cm or less (odds ratio, 6.9), a forced expiratory time of 9 seconds or more (odds ratio, 5.7), smoking of 40 pack-years or more (odds ratio, 5.7), and a body mass index of 30 or more (odds ratio, 4.1). Multiple regression analyses revealed three preoperative clinical factors that are independently associated with pulmonary complications: an age of 65 years or more (odds ratio, 1.8; p = 0.02), smoking of 40 pack-years or more (odds ratio, 1.9; p = 0.02), and maximum laryngeal height of 4 cm or less (odds ratio, 2.0; p = 0.007). Thus, preoperative factors can identify those patients referred to pulmonologists or internists who are at increased risk for pulmonary complications after nonthoracic surgery.

Age Factors↗
PubMed2002

New evidence for stroke prevention: scientific review.

CONTEXT: Stroke is a major cause of morbidity and mortality, and the application of evidence for stroke prevention varies considerably. OBJECTIVE: To review the most recent, high-quality evidence for primary and secondary stroke prevention. DATA SOURCES AND STUDY SELECTION: Searches of MEDLINE, The Cochrane Library, and the ACP Journal Club were performed to identify English-language articles published from 1998 to 2001 that focused on primary and secondary stroke prevention. The references of each retrieved article were scanned, and experts in the field were contacted to identify additional relevant articles. DATA EXTRACTION: Each of the articles was appraised, and its quality was graded with levels of evidence based on specific scientific methods that affect a study's validity. DATA SYNTHESIS: For primary prevention of stroke, adequate blood pressure reduction, and treatment of hyperlipidemia, use of antithrombotic therapy in patients with atrial fibrillation and of antiplatelet therapy in patients with myocardial infarction are effective and supported by evidence from several randomized trials. Effective strategies for the secondary prevention of stroke include treatment of hypertension and hyperlipidemia, antithrombotic therapy for patients with atrial fibrillation, antiplatelet therapy, and carotid endarterectomy in patients with severe carotid artery stenosis. CONCLUSIONS: Stroke is a major public health concern, and a significant body of evidence supports many primary and secondary prevention strategies.

Aged↗
PubMed2002

New evidence for stroke prevention: clinical applications.

Stroke is a leading cause of morbidity and mortality in most developed nations. There is a significant body of evidence supporting strategies that target primary and secondary stroke prevention. This evidence cannot be broadly applied to all patients, and each patient's situation and values must be considered with regard to shared evidence-based decision making. Several models can be used to apply evidence to individual patients, including formal clinical decision analysis, decision aids, or simpler tools such as the likelihood of being helped vs harmed. Various programmatic models of providing patient care in stroke prevention may also be useful; these include specialized clinics or disease-management programs, anticoagulation management services, and self-testing and management of anticoagulation by patients.

Aged↗
PubMed2002

Accuracy of history, wheezing, and forced expiratory time in the diagnosis of chronic obstructive pulmonary disease.

OBJECTIVE: To determine the accuracy of the history and selected elements of the physical examination in the diagnosis of chronic obstructive pulmonary disease (COPD). DESIGN: Independent blind comparison of the standard clinical examination (evaluating the accuracy of history, wheezing, and forced expiratory time [FET]) with spirometry. The gold standard for diagnosis of COPD was a forced expiratory volume at 1 second (FEV1) below the fifth percentile (adjusted for patient height and age). SETTING: Seven sites in 6 countries, including investigators from primary care and secondary care settings. PARTICIPANTS: One hundred sixty-one consecutive patients with varying severity of disease (known COPD, suspected COPD, or no COPD) participated in the study. MAIN RESULTS: One hundred sixty-one patients (mean age 65 years, 39% female, 41% with known COPD, 27% with suspected COPD, and 32% normal) were recruited. Mean (+/-SD) FEV1 and forced vital capacity were 1,720 (+/-830) mL and 2,520 (+/-970) mL. The likelihood ratios (LR) for the tested elements of the clinical examination (and their P values on chi2 testing) were: self-reported history of COPD, 5.6 (P <.001); FET greater than 9 seconds, 6.7 (P < 0.01); smoked longer than 40 pack years, 3.3 (P =.001); wheezing, 4.0 (P <.001); male gender, 1.6 (P <.001); and age over 65 years, 1.6 (P =.025). The accuracy of these elements was not appreciably different when reference standards other than FEV1 below the 5th percentile were applied. Only 3 elements of the clinical examination were significantly associated with the diagnosis of COPD on multivariate analysis: self-reported history of COPD (adjusted LR 4.4), wheezing (adjusted LR 2.9), and FET greater than 9 seconds (adjusted LR 4.6). Area under the receiver operating characteristic curve for the model incorporating these 3 factors was 0.86. CONCLUSIONS: Less emphasis should be placed on the presence of isolated symptoms or signs in the diagnosis of COPD. While numerous elements of the clinical examination are associated with the diagnosis of COPD, only 3 are significant on multivariate analysis. Patients having all 3 of these findings have an LR of 33 (ruling in COPD); those with none have an LR of 0.18 (ruling out COPD).

Female↗
PubMed2002

Individualizing treatment decisions. The likelihood of being helped or harmed.

Clinical decision making cannot rely on evidence alone. Although significant advances have occurred in the development of high-quality evidence, similar efforts must be made to develop and evaluate tools that can be used at the bedside to individualize treatment decisions and to facilitate the incorporation of our patients' unique values and circumstances into the decision-making process. These tools should express the helpful and harmful effects of treatment, and it must be possible to modify these statements using patients' values. Finally, this process should be accomplished in real time in a busy clinical practice. In this article, the author outlines some of these decision support tools, describes an attempt to meet some of the challenges inherent in the goal of achieving effective shared decision making, and proposes a patient-centered measure of the likelihood of being helped and harmed by an intervention and discusses its derivation and an evaluation of its usefulness.

Anticoagulants↗