Feasibility of advanced composite endpoint analysis: Post-hoc insights from the vitamin intervention for stroke prevention randomized control trial.

BACKGROUND AND AIMS: Stroke is a major cause of mortality and disability, highlighting the importance of prevention. Clinical trials play an important role in evaluating interventions that can maximize stroke prevention. Traditional composite endpoints (TCE) used in clinical trials have limitations, as they pool together events of varying clinical importance. Weighted composite endpoints (WCE) have emerged as a solution to address these limitations and provide more accurate assessments of outcomes. In this study, we investigate the use of WCE in a previously reported negative clinical trial for stroke prevention. METHODS AND RESULTS: We analyzed data from the Vitamin Intervention for Stroke Prevention (VISP) trial, which compared high dose and low dose multivitamin therapy. We utilized weighted methods to analyze time-to-event outcomes with censoring. The primary outcomes of interest were time to nonfatal stroke, nonfatal coronary events, and death. We calculated modified Kaplan-Meier (KM) curves for each intervention group. We also performed a modified log-rank test to assess significant differences based on the weighted KM curves. The analysis included 3668 VISP trial participants, and most remained event-free throughout the study period. The TCE KM curve showed no significant difference in outcomes between high dose and low dose groups. Similarly, the WCE KM curves, with different weights assigned to each outcome, did not reveal significant differences in outcomes between the studied groups. CONCLUSION: This post-hoc analysis confirms the negative trial results of VISP and demonstrates the feasibility of using WCE in assessing nutrition-based interventions for stroke prevention.

Clinical experience and categorical perception of children's speech.

BACKGROUND: Accurate and detailed records of children's speech are a critical component of competent service delivery in speech-language pathology/speech and language therapy (SLP/SLT). Previous research has shown that during speech-sound acquisition, children gradually learn to produce sounds in adult-like manners. Continuous rating scales are a way to track this gradual learning. AIMS: To examine whether clinical experience affects the ability and willingness to rate children's speech production using continuous rating scales. METHODS & PROCEDURES: An online survey was administered to 81 US-based SLPs/SLTs, binned into more- and less-experienced groups, and 20 non-SLPs/SLTs. The survey included a speech-sound rating task in which participants rated the production of place of articulation in children's productions of word-initial /θ/, /s/, /ʃ/, /d/, /ɡ/, /t/ and /k/ on a nine-point equally appearing interval scale. We examined the extent to which these were accurate (i.e., the extent to which they matched laboratory measures of production characteristics) and the extent to which the ratings were gradual (i.e., they used the entire rating scales, rather than just the endpoints). MAIN CONTRIBUTION: There were no consistent differences between non-SLPs/SLTs, less-experienced SLPs/SLTs and more-experienced SLPs/SLTs in a measure of the accuracy of responses. More consistent differences were found in the extent to which listeners used the endpoints of the scale: greater experience was associated with greater use of the endpoint values. CONCLUSIONS & IMPLICATIONS: More-experienced SLPs/SLTs are less likely to use the entire range of continuous rating scales to rate children's speech accuracy than less-experienced SLPs/SLTs or clinically untrained listeners. Implications for service delivery are discussed. What this paper adds What is already known on the subject Children's productions of individual sounds, like /k/, become gradually more adult-like over the course of development. For a child who has a [t] for /k/ error, this gradual development means that children's productions become progressively less like /t/ and more like /k/ over development. Phonetic transcription does not capture this gradual development. In contrast, studies have shown that continuous ratings of children's speech (such as rating productions on a scale anchored by the text "the 't' sound" at one end and "the 'k' sound" at the other end) can capture this gradual development. What this paper adds to existing knowledge To determine continuous ratings are clinically feasible, we must first determine whether clinical experience affects people's use of continuous rating scales to rate children's speech. We conducted an on-line speech perception experiment in which 81 speech-language pathologists/speech and language therapists (SLPs/SLTs) and 20 non-SLPs/SLTs rated 60 productions by children on continuous rating scales. The 60 stimuli included many sounds that had been independently verified to be intermediate productions (i.e., a target /k/ that was neither completely /k/-like nor completely /t/-like). Non-SLPs/SLTs and less-experienced SLPs/SLTs rated those intermediate sounds with intermediate ratings (i.e., somewhere on the midpoint of a continuous scale). In contrast, more-experienced SLPs/SLTs were more likely to rate those sounds as instances of endpoints (i.e., as either /k/ or /t/). What are the potential or actual clinical implications of this work? This finding suggests that clinical experience is paradoxically associated with a reduced tendency to use the entire range of responses on continuous rating scales. This finding suggests that we must better understand the cause of this reduced tendency, so that clinicians at all levels can use continuous rating scales equally effectively.

Deconstructing phonetic transcription: covert contrast, perceptual bias, and an extraterrestrial view of Vox Humana.

This article honours Adele Miccio's life work by reflecting on the utility of phonetic transcription. The first section reviews the literature on cases where children whose speech appears to neutralize a contrast in the adult language are found on closer examination to produce a contrast (covert contrast). This study presents evidence from a new series of perception studies that covert contrast may be far more prevalent in children's speech than existing studies would suggest. The second section presents the results of a new study designed to examine whether naïve listeners' perception of children's /s/ and /theta/ productions can be changed experimentally when they are led to believe that the children who produced the sounds were older or younger. Here, it is shown that, under the right circumstances, adults report more tokens of /theta/ to be accurate productions of /s/ when they believe a talker to be an older child than when they believe the talker to be younger. This finding suggests that auditory information alone cannot be the sole basis for judging the accuracy of a sound. The final section presents recommendations for supplementing phonetic transcription with other measures, to gain a fuller picture of children's production abilities.