An effect size measure and Bayesian analysis of single-case designs.

This article describes a linear modeling approach for the analysis of single-case designs (SCDs). Effect size measures in SCDs have been defined and studied for the situation where there is a level change without a time trend. However, when there are level and trend changes, effect size measures are either defined in terms of changes in R(2) or defined separately for changes in slopes and intercept coefficients. We propose an alternate effect size measure that takes into account changes in slopes and intercepts in the presence of serial dependence and provides an integrated procedure for the analysis of SCDs through estimation and inference based directly on the effect size measure. A Bayesian procedure is described to analyze the data and draw inferences in SCDs. A multilevel model that is appropriate when several subjects are available is integrated into the Bayesian procedure to provide a standardized effect size measure comparable to effect size measures in a between-subjects design. The applicability of the Bayesian approach for the analysis of SCDs is demonstrated through an example.

Regression models and effect size measures for single case designs.

A regression modelling approach for the analysis of single case designs (SCDs) is described in this paper. The approach presented addresses two key issues in the analysis of SCDs. The first issue is that of serial dependence among the observations in SCDs. The second issue is that of an effect size measure appropriate for SCDs. As with traditional between-subjects experimental designs, effect size measures are critical in assessing the impact of interventions in SCDs. Although effect size measures when there is level change without trend are straightforward to obtain and have been well studied, the situation is different when there are changes in both level and trend. An effect size measure that combines changes in levels and slopes and that is comparable to the d-type effect size measure obtained in between-subjects designs is presented. Finally, an inferential procedure for assessing the effect of the intervention based on the effect size measure is provided and illustrated.

The Cancer Message Literacy Tests: psychometric analyses and validity studies.

OBJECTIVE: To examine the psychometric properties of two new health literacy tests, and to evaluate score validity. METHODS: Adults aged 40-71 completed the Cancer Message Literacy Test-Listening (CMLT-Listening), the Cancer Message Literacy Test-Reading (CMLT-Reading), the REALM, the Lipkus numeracy test, a brief knowledge test (developed for this study) and five brief cognitive tests. Participants also self-reported educational achievement, current health, reading ability, ability to understand spoken information, and language spoken at home. RESULTS: Score reliabilities were good (CMLT-Listening: alpha=.84) to adequate (CMLT-Reading: alpha=.75). Scores on both CMLT tests were positively and significantly correlated with scores on the REALM, numeracy, cancer knowledge and the cognitive tests. Mean CMLT scores varied as predicted according to educational level, language spoken at home, self-rated health, self-reported reading, and self-rated ability to comprehend spoken information. CONCLUSION: The psychometric findings for both tests are promising. Scores appear to be valid indicators of comprehension of spoken and written health messages about cancer prevention and screening. PRACTICE IMPLICATIONS: The CMLT-Listening will facilitate research into comprehension of spoken health messages, and together with the CMLT-Reading will allow researchers to examine the unique contributions of listening and reading comprehension to health-related decisions and behaviors.

Factors influencing preceptors' responses to medical errors: a factorial survey.

BACKGROUND: Preceptors must respond to trainees' medical errors, but little is known about what factors influence their responses. METHOD: A total of 115 primary care preceptors from 16 medical schools responded to two medical error vignettes involving a trainee. Nine trainee-related factors were randomly varied. Preceptors indicated whether they would discuss what led to the error, provide reassurance, share responsibility, express disappointment, and adjust their written evaluation of the trainee. RESULTS: Almost all preceptors would discuss what led to the error; relatively few would express disappointment. The trainee's prior history of errors, knowledge level relative to peers, receptivity to feedback, training level, emotional reaction, offering to apologize, and offering an excuse were predictive of preceptors' responses; gender and time-in-office were not. CONCLUSION: This study identified seven trainee-related factors as predictive of preceptors' responses to medical errors. More research is needed to identify other influential factors, and to improve teaching from medical errors.

The relationship between checklist scores on a communication OSCE and analogue patients' perceptions of communication.

Many efforts to teach and evaluate physician-patient communication are based on two assumptions: first, that communication can be conceptualized as consisting of specific observable behaviors, and second, that physicians who exhibit certain behaviors are more effective in communicating with patients. These assumptions are usually implicit, and are seldom tested. The purpose of this study was to investigate whether specific communication behaviors are positively related to patients' perceptions of effective communication. Trained raters used a checklist to record the presence or absence of specific communication behaviors in 100 encounters in a communication Objective Structured Clinical Examination (OSCE). Lay volunteers served as analogue patients and rated communication during each encounter. Correlations between checklist scores and analogue patients' ratings were not significantly different from zero for four of five OSCE cases studied. Within each case, certain communication behaviors did appear to be related to patients' ratings, but the critical behaviors were not consistent across cases. We conclude that scores from OSCE communication checklists may not predict patients' perceptions of communication. Determinants of patient perceptions of physician communication may be more subtle, more complex, and more case-specific than we were able to capture with the current checklist.

Development and testing of a new instrument for measuring concerns about dying in health care providers.

A new measure of concerns about dying was investigated in this psychometric study. The Concerns About Dying instrument (CAD) was administered to medical students, nursing students, hospice nurses, and life sciences graduate students (N = 207) on two occasions; on one occasion they also completed three related measures. Analyses included descriptive statistics, factor analysis, Cronbach's alpha, test-retest correlations, t tests, and correlations with other measures. Results suggest the CAD measures three distinct but related areas: general concern about death, spirituality, and patient-related concern about death. Reliability estimates were good, and correlations with related measures were strong. Between-group differences suggest scores are related to actual differences in level of concern and beliefs about death and dying. The CAD has the advantage of being very brief and of explicitly assessing concerns about working with patients who are dying.