Treatment Effect Size (treatment + effect_size)

Distribution by Scientific Domains

Selected Abstracts

The effectiveness of psychological treatments for treatment-resistant depression: a systematic review

S. McPherson
Objective:, A systematic review of all studies (controlled and uncontrolled) to evaluate psychological interventions with treatment-resistant depression. Method:, A systematic search to identify studies evaluating a psychological intervention with adults with a diagnosis of major depressive disorder who had not responded to at least one course of antidepressant medication. Results:, Twelve studies met inclusion criteria, of which four were controlled and eight uncontrolled. Treatment effect sizes were computable for four studies and ranged from 1.23 to 3.10 with a number of better quality studies demonstrating some improvements in patients following a psychological intervention. Conclusion:, Psychological treatments for depression are commonly delivered and often recommended following the failure of medication. The paucity of evidence for their effectiveness in these situations is a significant problem. There is a need for studies with a strong controlled design investigating the effectiveness of psychological treatments for patients with treatment-resistant depression. [source]

Adaptive patient enrichment designs in therapeutic trials

Sue-Jane Wang
Abstract The utility of clinical trial designs with adaptive patient enrichment is investigated in an adequate and well-controlled trial setting. The overall treatment effect is the weighted average of the treatment effects in the mutually exclusive subsets of the originally intended entire study population. The adaptive enrichment approaches permit assessment of treatment effect that may be applicable to specific nested patient (sub)sets due to heterogeneous patient characteristics and/or differential response to treatment, e.g. a responsive patient subset versus a lack of beneficial patient subset, in all patient (sub)sets studied. The adaptive enrichment approaches considered include three adaptive design scenarios: (i) total sample size fixed and with futility stopping, (ii) sample size adaptation and futility stopping, and (iii) sample size adaptation without futility stopping. We show that regardless of whether the treatment effect eventually assessed is applicable to the originally studied patient population or only to the nested patient subsets; it is possible to devise an adaptive enrichment approach that statistically outperforms one-size-fits-all fixed design approach and the fixed design with a pre-specified multiple test procedure. We emphasize the need of additional studies to replicate the finding of a treatment effect in an enriched patient subset. The replication studies are likely to need fewer number of patients because of an identified treatment effect size that is larger than the diluted overall effect size. The adaptive designs, when applicable, are along the line of efficiency consideration in a drug development program. [source]

Meta-Analysis of Studies with Missing Data

BIOMETRICS, Issue 2 2009
Ying Yuan
Summary Consider a meta-analysis of studies with varying proportions of patient-level missing data, and assume that each primary study has made certain missing data adjustments so that the reported estimates of treatment effect size and variance are valid. These estimates of treatment effects can be combined across studies by standard meta-analytic methods, employing a random-effects model to account for heterogeneity across studies. However, we note that a meta-analysis based on the standard random-effects model will lead to biased estimates when the attrition rates of primary studies depend on the size of the underlying study-level treatment effect. Perhaps ignorable within each study, these types of missing data are in fact not ignorable in a meta-analysis. We propose three methods to correct the bias resulting from such missing data in a meta-analysis: reweighting the DerSimonian,Laird estimate by the completion rate; incorporating the completion rate into a Bayesian random-effects model; and inference based on a Bayesian shared-parameter model that includes the completion rate. We illustrate these methods through a meta-analysis of 16 published randomized trials that examined combined pharmacotherapy and psychological treatment for depression. [source]

Effectiveness of Multilevel (Tongue and Palate) Radiofrequency Tissue Ablation for Patients with Obstructive Sleep Apnea Syndrome,

David L. Steward MD
Abstract Objectives: The primary objective is to determine the effectiveness of multilevel (tongue base and palate) temperature controlled radiofrequency tissue ablation (TCRFTA) for patients with obstructive sleep apnea syndrome (OSAS). The secondary objective is to compare multilevel TCRFTA to nasal continuous positive airway pressure (CPAP). Study Design and Methods: The study is a controlled case series of one investigator's experience with multilevel TCRFTA for patients with OSAS. Twenty-two subjects with mild to severe OSAS, without tonsil hypertrophy, completed multilevel TCRFTA (mean 4.8 tongue base and 1.8 palate treatment sessions) and had both pre- and posttreatment polysomnography. Primary outcomes included change from baseline in apnea/hypopnea index (AHI), daytime somnolence, and reaction time testing measured 2 to 3 months after TCRFTA. Secondary outcomes included change in other respiratory parameters, OSAS related quality of life, and upper airway size. Comparison of 18 patients treated with TCRFTA for mild to moderate OSAS (AHI > 5 and , 40) is made with 11 matched patients treated with nasal CPAP for mild to moderate OSAS. Results: Multilevel TCRFTA significantly improved AHI (P = .001), apnea index (P = .02), as well as respiratory and total arousal indices (P = .0002 and P = .01). Significant improvement with moderate or large treatment effect sizes were noted for OSAS related quality of life (P = .01) and daytime somnolence (P = .0001), with a trend toward significant improvement in reaction time testing (P = .06), with mean posttreatment normalization of all three outcome measures. Fifty-nine percent of subjects demonstrated at least a 50% reduction in AHI to less than 20. The targeted upper airway, measured in the supine position, demonstrated a trend toward significant improvement in mean cross sectional area (P = .05) and volume (P = .10). Side effects of TCRFTA were infrequent, mild, and self-limited. No significant correlation between pretreatment parameters and outcome improvement was noted. Nasal CPAP resulted in significant improvement in AHI (P = .0004) to near normal levels, with an associated improvement in OSAS related quality of life (P = .02) and a trend toward significant improvement in daytime somnolence (P = .06). Reaction time testing demonstrated no significant improvement (P = .75). No significant differences were seen for change in AHI, OSAS related quality of life, daytime somnolence, or reaction time testing between multilevel TCRFTA and CPAP. Conclusion: Multilevel (tongue base and palate) TCRFTA is a low-morbidity, office-based procedure performed with local anesthesia and is an effective treatment option for patients with OSAS. On average, abnormalities in daytime somnolence, quality of life, and reaction time testing demonstrated improvement from baseline and were normalized after treatment. Polysomnographic respiratory parameters also demonstrated significant improvement with multilevel TCRFTA. [source]

Who's afraid of the big bad wolf?

Making sense of results from randomised controlled trials
Background:, Reading and interpreting results from research can be challenging. Many therapists read the abstract and discussion but confess to bypassing the results section of journal articles. Methods:, This paper discusses necessary steps to reading the results section of a published randomised controlled trial. Recent clinical trials are used as examples. Results:, An ability to read and interpret the results section of a paper requires the therapist to consider whether the tests conducted are appropriate, the results reported are accurate and the conclusions drawn by the authors are appropriate. Estimates of treatment effect sizes can be calculated by the therapist and used to determine if the effect of treatment is likely to be large enough to be "clinically worthwhile". Conclusions:, The ability to extract meaningful statistical information from clinical trials is a fundamental skill that will enhance therapists' knowledge and understanding of evidence-based practice. [source]