Journal of clinical epidemiology
-
We sought to determine whether producers or users of systematic reviews using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach or a close variation give the same meanings to terms intended to convey uncertainty about treatment effects when interpreting grades for the quality or strength of evidence. ⋯ GRADE is, in general, a suitable method to convey uncertainties for systematic review producers to users. The wide ranges of likelihoods associated with GRADE terms suggest that current definitions of levels of QOE that rely exclusively on qualitative certainty expressions should be augmented by numerical predictions once such data are available.
-
Multi-item questionnaires are frequently used to measure outcomes in randomized controlled trials (RCTs) in patients with sciatica. Knowing the minimaly important change (MIC) values for these instruments will facilitate interpretation of change scores. MIC values have been shown to be dependent on baseline values. The question is whether they also depend on the type of intervention. To estimate the MIC of the Roland Morris Disability Questionnaire (modified 23 item version) (RMDQ) and of intensity of leg pain measured by a Visual Analogue Scale (VAS) in patients with sciatica and to assess to what extent MIC values depend on type of intervention and on baseline values. ⋯ The MIC values of the RMDQ-23 and VAS leg pain were found to be highly dependent on their baseline values, although the type of intervention appeared to influence the MIC value only slightly.
-
To provide a reliable, validated, and culturally adapted instrument that may be used in monitoring dry eye in Brazilian patients and to discuss the strategies for the enhancement of the cross-cultural adaptation and validation process of a self-report measure for dry eye. ⋯ Although most of the reviewed guidelines on CCAP involve well-defined steps (translation, synthesis/reconciliation, back translation, expert committee review, pretesting), the proposed methodological steps have not been applied in a uniform way. The translation and adaptation process requires skill, knowledge, experience, and a considerable investment of time to maximize the attainment of semantic, idiomatic, experiential, and conceptual equivalence between the source and target questionnaires. A well-established guideline resulted in a culturally adapted Brazilian-Portuguese version of the OSDI, tested and validated on a sample of Brazilian population, and proved to be a valid and reliable instrument for assessing patients with dry eye syndrome in Brazil.
-
The objective was to evaluate time-trend bias in the context of a series of studies reporting that a national hepatitis B virus vaccination program (launched in mid-1980s) substantially reduced childhood hepatocellular carcinoma (HCC) incidence. ⋯ Time trend may play a more important role than the universal vaccination program in interpretation of the observed early decreasing trend in HCC in children, especially among boys.
-
We aimed to compare nonlinear modeling methods for handling continuous predictors for reproducibility and transportability of prediction models. ⋯ Flexible nonlinear modeling methods led to better model performance at internal validation. However, when application of the model is intended across a wide range of settings, less flexible functions may be more appropriate to maximize external validity.