Bmc Med Res Methodol
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Bmc Med Res Methodol · Jan 2014
Thresholds for statistical and clinical significance in systematic reviews with meta-analytic methods.
Thresholds for statistical significance when assessing meta-analysis results are being insufficiently demonstrated by traditional 95% confidence intervals and P-values. Assessment of intervention effects in systematic reviews with meta-analysis deserves greater rigour. ⋯ If followed, the proposed eight-step procedure will increase the validity of assessments of intervention effects in systematic reviews of randomised clinical trials.
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Bmc Med Res Methodol · Jan 2014
A comparison of three clustering methods for finding subgroups in MRI, SMS or clinical data: SPSS TwoStep Cluster analysis, Latent Gold and SNOB.
There are various methodological approaches to identifying clinically important subgroups and one method is to identify clusters of characteristics that differentiate people in cross-sectional and/or longitudinal data using Cluster Analysis (CA) or Latent Class Analysis (LCA). There is a scarcity of head-to-head comparisons that can inform the choice of which clustering method might be suitable for particular clinical datasets and research questions. Therefore, the aim of this study was to perform a head-to-head comparison of three commonly available methods (SPSS TwoStep CA, Latent Gold LCA and SNOB LCA). ⋯ Our subjective judgement was that Latent Gold offered the best balance of sensitivity to subgroups, ease of use and presentation of results with these datasets but we recognise that different clustering methods may suit other types of data and clinical research questions.
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Bmc Med Res Methodol · Jan 2014
ReviewA critical analysis of test-retest reliability in instrument validation studies of cancer patients under palliative care: a systematic review.
Patient-reported outcome validation needs to achieve validity and reliability standards. Among reliability analysis parameters, test-retest reliability is an important psychometric property. Retested patients must be in a clinically stable condition. This is particularly problematic in palliative care (PC) settings because advanced cancer patients are prone to a faster rate of clinical deterioration. The aim of this study was to evaluate the methods by which multi-symptom and health-related qualities of life (HRQoL) based on patient-reported outcomes (PROs) have been validated in oncological PC settings with regards to test-retest reliability. ⋯ Test-retest reliability has been infrequently and poorly evaluated. The confirmation of clinical stability was an important factor in our analysis, and we suggest that special attention be focused on clinical stability when designing a PRO validation study that includes advanced cancer patients under PC.
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Bmc Med Res Methodol · Jan 2014
Multicenter StudyMeasuring health-related quality of life in chronic obstructive pulmonary disease: properties of the EQ-5D-5L and PROMIS-43 short form.
The Patient Reported Outcomes Measurement Information System 43-item short form (PROMIS-43) and the five-level EQ-5D (EQ-5D-5L) are recently developed measures of health-related quality of life (HRQL) that have potentially broad application in evaluating treatments and capturing burden of respiratory-related diseases. The aims of this study were: (1) to examine their psychometric properties in patients with chronic obstructive pulmonary disease (COPD), and (2) to identify dimensions of HRQL that differ and do not differ by lung function. ⋯ Results supported the validity of EQ-5D-5L and PROMIS-43 in COPD patients, and indicate that physical function and social activities decrease with level of lung function by GOLD grade, but not pain, mental health, sleep or fatigue as reported by patients.
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Bmc Med Res Methodol · Jan 2014
Bayesian designs of phase II oncology trials to select maximum effective dose assuming monotonic dose-response relationship.
For many molecularly targeted agents, the probability of response may be assumed to either increase or increase and then plateau in the tested dose range. Therefore, identifying the maximum effective dose, defined as the lowest dose that achieves a pre-specified target response and beyond which improvement in the response is unlikely, becomes increasingly important. Recently, a class of Bayesian designs for single-arm phase II clinical trials based on hypothesis tests and nonlocal alternative prior densities has been proposed and shown to outperform common Bayesian designs based on posterior credible intervals and common frequentist designs. We extend this and related approaches to the design of phase II oncology trials, with the goal of identifying the maximum effective dose among a small number of pre-specified doses. ⋯ The use of Bayesian hypothesis tests and nonlocal alternative priors under ordering constraints between dose groups results in a robust performance of the design, which is thus superior to other common designs.