Clinically Meaningful Change Estimates for the Six-Minute Walk Test and Daily Activity in Individuals With Chronic Heart Failure

Purpose

The purpose of the present pilot study was to provide a preliminary estimate of the minimum detectable difference (MDD) and minimum clinically important difference (MCID) of the six-minute walk test (6MWT) and daily activity in outpatients with chronic heart failure (CHF).

Methods

A convenience sample of 22 adults with stable New York Heart Association Functional Class II and III CHF performed two baseline 6MWTs separated by 30 minutes of rest. Subjects then wore a triaxial accelerometer for 7 days to monitor daily activity. After 7 weeks of usual care, subjects again wore the accelerometer for 7 days and then returned to the clinic to complete the Global Rating of Change Scale (GRS) with regard to their heart disease and perform another set of 6MWTs. For the 6MWT, the MDD was calculated using the two baseline 6MWT distances. For daily activity, the MDD was calculated using two methods: (1) day-to-day test-retest reliability during baseline monitoring, and (2) baseline to follow-up test-retest reliability in those who reported no change on the GRS. The MCID for the 6MWT and daily activity was calculated using the mean and 95% confidence interval (CI_95%) for those subjects who reported ‘improvement’ on the GRS.

Results

The MDD at the CI_95% for the 6MWT was 32.4 meters. The MCID for the 6MWT was 30.1 (CI_95% 20.8, 39.4) meters. The MDD for daily activity was 5,909 vector magnitude units (VMU·hr.⁻¹) The MCID for daily activity was 1,337 VMU·hr.⁻¹ There was good alignment of the MDD and MCID for the 6MWT, suggesting that clinically meaningful change is approximately 32 meters. However, the calculated MCID was substantially less than measurement error as represented by the MDD, indicating that the MCID was underestimated in this sample or that daily activity may be robust to change in overall disease status.Key Words: six-minute walk test, daily activity, heart failure, clinically meaningful change     

Motivational control of goal-directed action

The control of goal-directed, instrumental actions by primary motivational states, such as hunger and thirst, is mediated by two processes. The first is engaged by the Pavlovian association between contextual or discriminative stimuli and the outcome or reinforcer presented during instrumental training. Such stimuli exert a motivational influence on instrumental performance that depends upon the relevance of the associated outcome to the current motivational state of the agent. Moreover, the motivational effects of these stimuli operate in the absence of prior experience with the outcome under the relevant motivational state. The second, instrumental, process is mediated by knowledge of the contingency between the action and its outcome and controls the value assigned to this outcome. In contrast to the Pavlovian process, motivational states do not influence the instrumental process directly; rather, the agent has to learn about the value of an outcome in a given motivational state by exposure to it while in that state. This incentive learning is similar in certain respects to the acquisition of “cathexes” envisaged by Tolman (1949a, 1949b).     

Story comprehension and recall in dyslexic students

This article is an extension of work reported earlier in this journal (Weaver 1978). In that paper, we echoed the commonly suggested need for examining reading difficulties in relation to higher-order language processes and offered a schema-theoretical framework for guiding such an examination. In this article we report the findings and implications of an empirical investigation into the characteristics of story recall abilities in students with dyslexia or severe reading disabilities.     

Relationships Among Teachers’ Use of Mental State Verbs and Children’s Vocabulary Growth

Research Findings: Mental state verbs (MSV), a component of literate and academic language, may facilitate vocabulary growth, as they relate to metacognitive and metalinguistic awareness as well as decontextualized talk, all of which have been associated with vocabulary growth. In this study, we examined teacher MSV use in group content instruction and book reading in Head Start classrooms (N = 49) to determine the prevalence of teachers’ use of MSV. We sought to determine whether there was an association between teachers’ MSV use and children’s (N = 402) receptive and expressive vocabulary scores across 1 year of preschool. Results from hierarchical linear modeling revealed that teachers’ use of MSV in group content instruction was positively associated with children’s end-of-year receptive, but not expressive, vocabulary scores. No significant relations emerged for book reading. Positive associations between MSV in which the child was the referent of the verb and children’s receptive vocabulary were found, which indicates a potential scaffolding effect. Practice or Policy: Results indicate that teachers should consider including MSV in their content-rich instruction and provide support by placing the child as the referent of the verb. Additional instructional implications are addressed.     

Producing Video‐based Resource Material for Teacher Training in Zimbabwe

The Zimbabwe Science Teacher Training project (ZeSTT) has, since 1979, been running at the Science Education Centre of the University of Zimbabwe, producing learning resource materials for teacher‐trainers in Zimbabwean Colleges of Education. Multi‐media packages, video programmes and printed materials have been produced, not only in science but in an increasing number of other subject areas. The paper describes the evolution of techniques of recording videotaped material of teachers in action during typical lessons in local schools, for editing into complete programmes or as study excerpts.     

An examination of male-female performance in a programmed achievement learning center

College students operated under different classroom contingencies. The Programmed Achievement (PA) condition required students to evidence criterion performance (100% mastery) on weekly quizzes. Failure to show mastery performance on any of the weekly quizzes resulted in course failure. The Standard Control (S-C) condition involved a more traditional college classroom structure where students took weekly quizzes with no requirement to evidence mastery. Male and female performances were analyzed to determine if different course structures interacted with sex of student. The results indicated that PA students demonstrated higher performance than controls on weekly quizzes and a major exam. It was also shown that PA females increased at a more rapid rate than PA males, while S-C males and females were not significantly different. Theoretical implications of the results are discussed.