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1.
Exact tests of equivalence and efficacy with a non-zero lower bound based on two independent binomial proportions for comparative trials are proposed. These exact tests are desirable for studies with small sample sizes. They generalize classical methods to include testing of null hypotheses of prespecified differences and can be used to demonstrate a new treatment's efficacy or its equivalence to a standard treatment. The proposed exact tests use unconditional distributions of the test statistics. Variances of test statistics are estimated via a constrained maximum likelihood method (Farrington and Manning). Data from oncology and vaccine clinical trials are used to illustrate the exact tests.  相似文献   

2.
We are seeing evidence of more studies investigating the effectiveness of psychosocial interventions of cancer patients, predominantly within groups. As roles within cancer and palliative care diversify, specially trained nurses and other health care workers are taking a more active role within psychosocial intervention studies. Frequently, these studies are randomised controlled trials (RCTs). Often, the results of these psychosocial RCTs have been laid open to general criticisms of design, implementation and reporting. The following paper focuses specifically on the general and experimenter problems in conducting RCTs within psychosocial interventions. It highlights the limitations and inherent problems seen with RCTs of psychosocial interventions so that health care workers are aware of these before considering undertaking psychosocial RCTs with cancer patients.  相似文献   

3.
We systematically reviewed randomized controlled trials (RCTs) of pharmacological therapy in knee osteoarthritis (OA), published between 1966 and August 1994. RCTs were identified by MEDLINE, supplemented by a manual search of reference lists. Qualitative assessment of RCTs was performed using Gotzsche's method; design and analysis features were rated on a scale of 0 (worst) to 8 (best). Heller et al's method was used to compare efficacy of nonsteroidal antiinflammatory drugs (NSAIDs) in comparative trials. A total of 80 RCTs were analyzed (45 involved NSAIDs, 3 analgesics, 5 intraarticular [IA] steroids, 9 biological agents, including IA hyaluronic acid, and 18 mixed modalities, including topical capsaicin). The median design and analysis scores for all 80 RCTs were 2 and 5, respectively. NSAIDs were superior to placebo in all short-term trials, but in the 32 comparative NSAID trials, only five (16%) found significant differences in efficacy. Heller et al's method identified differences in 14 NSAID comparisons; etodolac (600 mg/day) was superior in five of its nine comparisons. Indomethacin and aspirin were the most toxic NSAIDs. IA steroids were superior to placebo in short-term efficacy (< 1 month). Biological agents were superior to placebo and generally well tolerated over a mean follow-up of 48 weeks. Acetaminophen was superior to placebo and was comparably efficacious to low-dose naproxen and ibuprofen (< 2,400 mg/day). The data support the use of acetaminophen, topical capsaicin, IA steroids, IA hyaluronic acid, and NSAIDs in the treatment of patients with knee OA.  相似文献   

4.
OBJECTIVES: To determine whether antibiotic prophylaxis reduces respiratory tract infections (RTI) and overall mortality in an unselected adults intensive care population. SEARCH STRATEGY: Systematic literature search in peer-reviewed journals indexed in MEDLINE, examination of relevant proceedings of scientific meetings and personal contact with trialists. SELECTION CRITERIA: All randomised clinical trials (RCTs), published and unpublished, comparing different forms of antibiotic prophylaxis used to reduce RTIs and mortality in unselected adult intensive care units (ICUs) populations. DATA COLLECTION AND ANALYSIS: Out of the 32 RCTs eligible for this review data have been extracted from published reports and then complemented with information provided by study investigators for 29 trials. Data were available only from published reports in the remaining three RCTs. For each trial the following information has been sought: a) method of randomisation; b) use of blinding techniques; c) number of randomised patients; d) number of patients with RTIs; e) number of deaths; f) number of patients excluded from the published analysis; g) number of RTIs and number of deaths among excluded patients. Pooled estimates of treatment effects across trials have been calculated after grouping RCTs in two main, mutually exclusive, categories: a) 15 trials testing the effect of a combination of a topical and a systemic antibiotic against no prophylactic treatment; b) 17 trials where the experimental treatment was a topical antimicrobial preparation. Crude proportions of RTIs and mortality were used to calculate the overall treatment effect. We also computed the number of ICU patients who need to be treated in order to prevent one infection and one death. MAIN RESULTS: Overall 32 RCTs including 5639 patients were identified. Pooled estimates of the 15 RCTs (including 3273 patients) testing the effect of the topical and systemic antibiotic combination indicate a strong significant reduction of both RTIs (OR = 0.36, 95% CI = 0.30-0.43) and total mortality (OR = 0.80, 95% CI = 0.68-0.93). Five and 23 patients need to be treated to prevent one infection and one death, respectively, using this treatment. When data on the effect of the combination based on topical antimicrobials were pooled from the 17 available trials (including 2366 patients) a marked reduction on RTIs (OR = 0.57, 95% CI = 0.46-0.69) also emerged but no corresponding effect on overall mortality (OR = 1.01; 95% CI = 0.84-1.22) was found. CONCLUSIONS: After 15 years of clinical research this meta-analysis of 32 RCTs shows that a regimen of antibiotic prophylaxis based on a combination of a systemic and topical antibiotic can reduce both RTIs and overall mortality in ICU patients in a way that is both statistically significant and humanly worthwhile. Over and above their personal opinions intensivists should take this evidence into account when defining their policies.  相似文献   

5.
Context: Evaluating the efficacy of pediatric weight loss treatments is critical. Objective: This is the first meta-analysis of the efficacy of RCTs comparing pediatric lifestyle interventions to no-treatment or information/education-only controls. Data Sources: Medline, PsycINFO, and Cochrane Controlled Trials Register. Study Selection: Fourteen RCTs targetting change in weight status were eligible, yielding 19 effect sizes. Data Extraction: Standardized coding was used to extract information on design, participant characteristics, interventions, and results. Data Synthesis: For trials with no-treatment controls, the mean effect size was 0.75 (κ = 9, 95% confidence interval [CI] = 0.52-0.98) at end of treatment and 0.60 (κ = 4, CI = 0.27-0.94) at follow-up. For trials with information/education-only controls, the mean ES was 0.48 (κ = 4, CI = 0.13-0.82) at end of treatment and 0.91 (κ = 2, CI = 0.32-1.50) at follow-up. No moderator effects were identified. Conclusions: Lifestyle interventions for pediatric overweight are efficacious in the short term with some evidence for extended persistence. Future research is required to identify moderators and mediators and to determine the optimal length and intensity of treatment required to produce enduring changes in weight status. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

6.
The randomized controlled trial (RCT) may have considerable limitations in clinical research. Lacking the possibility of blinding impairs the internal validity of the trials. The external validity is often impaired, as results of RCTs obtained in an ideal situation, may be difficult to generalize to a clinical routine situation. Pragmatic randomized trials move from ideal situations towards routine situations, and by modifying the design it is possible to reduce selection bias due to patient and physician preferences. Quasi-experimental studies have varying degrees of problems with internal validity but are necessary contributions to our knowledge of the effect of treatment in clinical routine situations. Limitations of the usefulness of RCTs as well as pragmatic and quasi-experimental studies in clinical research make it necessary to recognise that different methods complement one another. Research in development of RCTs and new methods in clinical research should be encouraged.  相似文献   

7.
Study Design: Systematic review. Objective: To examine the evidence supporting the effectiveness of cognitive behavioral therapy (CBT) for improving psychosocial outcomes in individuals with spinal cord injury (SCI). Method: Electronic databases (MEDLINE, CINAHL, EMBASE, and PsycINFO) were searched for studies published between 1990 and October 2010. Randomized control trials (RCTs) and nonrandomized control trials (non-RCTs) utilizing a CBT intervention to improve psychosocial outcomes (depressive symptomatology, anxiety, coping, and adjustment to disability) in outpatient persons with SCI were included for review. Levels of evidence were assigned to each study using a modified Sackett scale. Effect size calculations for the interventions were provided where possible. Results: Nine studies met the inclusion criteria. The studies reviewed included two RCTs, six prospective controlled trials (PCTs) and one cohort study. All studies examined at least two groups. There is Level 1 and Level 2 evidence supporting the use of specialized CBT protocols in persons with SCI for improving outcomes related to depression, anxiety, adjustment, and coping. Conclusions: CBT holds promise as an effective approach for persons with SCI experiencing depression, anxiety, adjustment, and coping problems. As CBT may involve many different components, it is important in the future to determine which of these elements alone or in combination is most effective in treating the emotional consequences of SCI. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

8.
BACKGROUND: With the expansion of academic departments, the National Research and Development initiative, and the Culyer report, United Kingdom (UK) general practice research is undergoing a period of investment and change. AIM: To examine the content and methodological quality of UK-published general practice research, and in particular to focus on the quantity and proportion of studies that were of high methodological quality, namely randomized controlled trials (RCTs). METHOD: We manually searched three UK-published journals over a five-year period: the British Journal of General Practice (BJGP), Family Practice, and the British Medical Journal (BMJ), which has a section devoted to general practice research. Studies were classified according to the International Classification of Health Problems of Primary Health Care (ICHPPC-2). RESULTS: Nearly half of published studies in UK primary care journals were concerned with either organization and administration issues in primary care or social problems (509 studies, 48%). Just over half were either qualitative studies or surveys of opinion or attitudes (528 studies, 50%). The overall number of RCTs was low (67 studies, 6%), and the proportion published has not changed over time (chi 2 for trend = 3.79, df = 1, P = 0.051). In contrast to surgical journals, nearly one-fifth of studies in general practice followed a longitudinal design (186 studies, 18%). CONCLUSIONS: The content and design of published general practice research in the UK is varied and broad. The most robust methodological design should be the aim of all prospective researchers in general practice.  相似文献   

9.
Randomised controlled trials (RCTs), with their prospective definition of methods and outcome measures, double-blind assessment of outcomes and unbiased selection of subjects and controls, provide the best possible evidence for deciding the value of a medical or surgical intervention. Few surgical studies are designed as RCTs, and those that are should be of a higher quality. The lack of good surgical RCTs may be a result of surgeons lacking the necessary training, expertise and desire to perform RCTs, inadequate funding from granting agencies, difficulties in securing patient consent or a lack of sufficient patient numbers. If an RCT is not feasible for a particular study, then alternative research designs, such as prospective matched-pair trials, may need to be better developed and used. If RCTs can be performed, other strategies to increase the number and quality of RCTs may be needed: Education of surgeons in clinical research methods Improved funding of surgical RCTs Compulsory evaluation of new techniques and technology before their general adoption is permitted.  相似文献   

10.
PURPOSE: To review the current status of multimodality treatment and lymphadenectomy in the management of esophageal cancer. DATA SOURCES: Literature review. STUDY SELECTION: Multimodality treatment and lymphadenectomy in esophageal cancer. DATA EXTRACTION: Results in research papers published selected by literature search. RESULTS: Numerous studies have been carried out attempting to define the roles of various neoadjuvant or adjuvant regimens in the treatment of esophageal cancer. These included the use of radiotherapy or chemotherapy alone or in different combinations, with or without surgical resection. Randomized trials have failed to show significant improvement compared with surgical resection alone, although downstaging of disease and benefits on subgroups of patients could be demonstrated. Whether the extent of resection can influence outcome was tested by varying the surgical approach, and by increasing the extent of lymphadenectomy. Although indirect evidence exists suggesting more extensive resection may improve long term prognosis, definitive proof is lacking. CONCLUSIONS: More well organized randomized controlled trials are needed to further elucidate the roles of these approaches in the treatment of esophageal cancer.  相似文献   

11.
OBJECTIVE: The study aimed to determine the effectiveness of prophylactic medical intervention in reducing the incidence of cystoid macular edema (CME) and the effectiveness of medical treatment for chronic CME after cataract surgery. DESIGN: The study design was a systematic review and meta-analysis of published reports of randomized clinical trials (RCTs). PARTICIPANTS: Sixteen RCTs involving 2898 eyes examining the effectiveness of medical prophylaxis of CME and 4 RCTs involving 187 eyes testing the effectiveness of medical treatment of chronic CME were used in the study. INTERVENTIONS: Medical prophylaxis of treatment (cyclo-oxygenase inhibitors or corticosteroids) versus control (placebo or active treatment) was performed. MAIN OUTCOME MEASURES: Incidence of angiographically diagnosed CME, incidence of clinically significant CME, and vision were measured. RESULTS: Thirty-six articles reported testing a prophylactic medical intervention for CME after cataract surgery. The incidence of CME varied extensively across studies and was related to the study design used. Summary odds ratios (OR) indicated that prophylactic intervention was effective in reducing the incidence of both angiographic CME (OR = 0.36; 95% confidence interval [CI] = 0.28-0.45) and clinically relevant CME (OR = 0.49; 95% CI = 0.33-0.73). There also was a statistically significant positive effect on improving vision (OR = 1.97; 95% CI = 1.14-3.41). A combination of the results of the four RCTs testing medical therapy for chronic CME indicated a treatment benefit in terms of improving final visual acuity by two or more Snellen lines (OR = 2.67; 95% CI = 1.35-5.30). Assessment of the quality of the 20 RCTs included in the meta-analyses indicated problems in the design, execution, and reporting of a number of trials. CONCLUSION: A combination of the results from RCTs indicates that medical prophylaxis for aphakic and pseudophakic CME and medical treatment for chronic CME are beneficial. Because most of the RCTs performed to date have problems related to quality, a well-designed RCT is needed to confirm this result, using clinical CME and vision as outcomes.  相似文献   

12.
Comments on P. W. Cheng's (see record 1985-29947-001) hypothesis concerning categorization as an explanation of improved task performance that was presented as an alternative to the automatization hypothesis of the present authors (see PA, Vol 58:305; see also Shiffrin and Schneider, PA, Vol 57:4785). The present authors note that they carried out several critical studies showing that the categorization hypothesis was correct but also showing conclusively that it and several related hypotheses were insufficient to explain a number of key findings. The authors reiterate evidence providing a definitive demonstration of automatization. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

13.
This lecture bring a big interest to every practitioner of the Dental Art. Implantology combined with lingual orthodontics give to the patient esthetic solutions, and also, a new approach in the building of the treatment's plan of the team. Some questions must be settled: orthodontics indications: anatomic, physiologic, periodontal considerations; what is an implant treatment? When must be place the implant? The clinical's possible results! A careful conception of end's treatment previsualization allow to each specialist to have a clear vision of his role and timing. Time treatment's management will enjoy the patient.  相似文献   

14.
This paper details the challenges encountered by authors summarizing evidence from a primary study to describe a treatment's effectiveness using an effect size (ES) estimate. Dilemmas that are encountered, including how to calculate and interpret the pertinent standardized mean difference ES for results from studies of various research designs, are described. Recommendations are offered to authors of primary studies and to those conducting summaries of primary studies. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

15.
Tested the hypotheses that goal acceptance moderates the relationship of goal difficulty to task performance as follows: (a) The relationship is positive and linear for accepted goals; (b) it is negative and linear if the goal is rejected; and thus, (c) slope reversal from positively to negatively linear relationships is associated with transition from positive to negative values of goal acceptance. The experiment was a within-S design, allowing for high variance in acceptance, with technicians and engineers (21–50 yrs of age) divided at random into a 2-phase experimental condition (n?=?104) with specific goal difficulty gradually increasing from Trial 1 to 7 and a control group (n?=?36) with the general instructions to "do your best." Instructions for Phase 2 differed from Phase 1 in that Ss were instructed to reassess their acceptance of difficult goals. The task consisted of determining, within 2-min trials, how many digits or letters in a row were the same as the circled one to the left of each row. Results support the hypotheses. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

16.
Cognitive control enables flexible interaction with a dynamic environment. In 2 experiments, the authors investigated control adjustments in the stop-signal paradigm, a procedure that requires balancing speed (going) and caution (stopping) in a dual-task environment. Focusing on the slowing of go reaction times after stop signals, the authors tested 5 competing hypotheses for post-stop-signal adjustments: goal priority, error detection, conflict monitoring, surprise, and memory. Reaction times increased after both successful and failed inhibition, consistent with the goal priority hypothesis and inconsistent with the error detection and conflict hypotheses. Post-stop-signal slowing was greater if the go task stimulus repeated on consecutive trials, suggesting a contribution of memory. We also found evidence for slowing based on more than the immediately preceding stop signal. Post-stop-signal slowing was greater when stop signals occurred more frequently (Experiment 1), inconsistent with the surprise hypothesis, and when inhibition failed more frequently (Experiment 2). This suggests that more global manipulations encompassing many trials affect post-stop-signal adjustments. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

17.
BACKGROUND: Few meta-analyses of randomised trials assess the quality of the studies included. Yet there is increasing evidence that trial quality can affect estimates of intervention efficacy. We investigated whether different methods of quality assessment provide different estimates of intervention efficacy evaluated in randomised controlled trials (RCTs). METHODS: We randomly selected 11 meta-analyses that involved 127 RCTs on the efficacy of interventions used for circulatory and digestive diseases, mental health, and pregnancy and childbirth. We replicated all the meta-analyses using published data from the primary studies. The quality of reporting of all 127 clinical trials was assessed by means of component and scale approaches. To explore the effects of quality on the quantitative results, we examined the effects of different methods of incorporating quality scores (sensitivity analysis and quality weights) on the results of the meta-analyses. FINDINGS: The quality of trials was low. Masked assessments provided significantly higher scores than unmasked assessments (mean 2.74 [SD 1.10] vs 2.55 [1.20]). Low-quality trials (score < or = 2), compared with high-quality trials (score > 2), were associated with an increased estimate of benefit of 34% (ratio of odds ratios [ROR] 0.66 [95% CI 0.52-0.83]). Trials that used inadequate allocation concealment, compared with those that used adequate methods, were also associated with an increased estimate of benefit (37%; ROR=0.63 [0.45-0.88]). The average treatment benefit was 39% (odds ratio [OR] 0.61 [0.57-0.65]) for all trials, 52% (OR 0.48 [0.43-0.54]) for low-quality trials, and 29% (OR 0.71 [0.65-0.77]) for high-quality trials. Use of all the trial scores as quality weights reduced the effects to 35% (OR 0.65 [0.59-0.71]) and resulted in the least statistical heterogeneity. INTERPRETATION: Studies of low methodological quality in which the estimate of quality is incorporated into the meta-analyses can alter the interpretation of the benefit of intervention, whether a scale or component approach is used in the assessment of trial quality.  相似文献   

18.
Defining empirically supported therapies.   总被引:1,自引:0,他引:1  
A scheme is proposed for determining when a psychological treatment for a specific problem or disorder may be considered to be established in efficacy or to be possibly efficacious. The importance of independent replication before a treatment is established in efficacy is emphasized, and a number of factors are elaborated that should be weighed in evaluating whether studies supporting a treatment's efficacy are sound. It is suggested that, in evaluating the benefits of a given treatment, the greatest weight should be given to efficacy trials but that these trials should be followed by research on effectiveness in clinical settings and with various populations and by cost-effectiveness research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

19.
To determine the extent to which published randomized controlled trials (RCTs) of psychotherapy can be generalized to a sample of outpatients, the authors matched information obtained from charts of patients who had been screened out of RCTs to inclusion and exclusion criteria from published RCT studies. Most of the patients in the sample who had primary diagnoses represented in the RCT literature were judged eligible for at least 1 RCT. However, many patients in the sample with substance use disorders or social anxiety disorder were not eligible for at least 2 RCTs. Common reasons that patients did not match with at least 2 published RCTs for psychotherapy included (a) patients were in partial remission, (b) patients failed to meet minimum severity or duration criteria, (c) patients were being treated with antidepressant medication, and (d) the disorder being studied was not primary (mostly for social anxiety patients). The implications of these findings for future research and clinical practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

20.
Lack of uniformity in the classification of oral diseases, and variability of study designs, measurements, methods, and statistical formats, hamper the interpretation, comparison and review of the evidence linking smoking and oral diseases. However, there have been a significant number of controlled studies, allowing definitive conclusions to be drawn. This review of 22 controlled scientific studies from 1983-1992, considers the role of smoking as an aetiological agent in: gingival problems (impaired gingival bleeding, ANUG), periodontal problems (periodontitis, bone loss, tooth loss), and caries.  相似文献   

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