Psychometric Properties of Two Tasks in the Allen Cognitive Level Screen-Sixth Edition for Community-Dwelling People Living With Schizophrenia.

IMPORTANCE: Empirical evidence is needed on the psychometric properties of the Allen Cognitive Level Screen-Sixth Edition (ACLS-6), an instrument that assesses cognitive functions and is commonly used for people living with schizophrenia. OBJECTIVE: To examine the convergent validity, discriminative validity, and test-retest reliability of two tasks, stitching and copying, in the ACLS-6 for community-dwelling people living with schizophrenia. DESIGN: Prospective observational study. SETTING: Psychiatric center. PARTICIPANTS: 110 people living with schizophrenia. OUTCOMES AND MEASURES: To examine convergent validity, we calculated correlations (Pearson's r) between the two tasks and between these two tasks and three cognitive measures. We checked for floor and ceiling effects and conducted independent t tests to evaluate discriminative validity. We calculated intraclass correlation coefficients (ICCs) to investigate test-retest reliability. RESULTS: We found a strong correlation (r = .88) between the two tasks and moderate correlations (rs = .32-.52) between the two tasks and the three cognitive measures. No floor or ceiling effects were observed for the two tasks, and t tests showed significant differences between two participant groups with marginal and mild clinical symptoms (p < .001). The ICC values for the two tasks were .71-.74. CONCLUSION AND RELEVANCE: The stitching and copying tasks of the ACLS-6 have good convergent validity, discriminative validity, and test-retest reliability for community-dwelling people living with schizophrenia. The copying task showed a strong correlation with the stitching task and a similar score range, so practitioners can consider using the copying task as a substitute for the stitching task. What This Article Adds: The stitching and copying tasks of the ACLS-6 have sound psychometric properties for measuring cognitive functions in community-dwelling people living with schizophrenia.

A Cycling Movement Based System for Real-Time Muscle Fatigue and Cardiac Stress Monitoring and Analysis.

In this study, we defined a new parameter, referred to as the cardiac stress index (CSI), using a nonlinear detrended fluctuation analysis (DFA) of heart rate (HR). Our study aimed to incorporate the CSI into a cycling based fatigue monitoring system developed in our previous work so the muscle fatigue and cardiac stress can be both continuously and quantitatively assessed for subjects undergoing the cycling exercise. By collecting electrocardiogram (ECG) signals, the DFA scaling exponent α was evaluated on the RR time series extracted from a windowed ECG segment. We then obtained the running estimate of α by shifting a one-minute window by a step of 20 seconds so the CSI, defined as the percentage of all the less-than-one α values, can be synchronously updated every 20 seconds. Since the rating of perceived exertion (RPE) scale is considered as a convenient index which is commonly used to monitor subjective perceived exercise intensity, we then related the Borg RPE scale value to the CSI in order to investigate and quantitatively characterize the relationship between exercise-induced fatigue and cardiac stress. Twenty-two young healthy participants were recruited in our study. Each participant was asked to maintain a fixed pedaling speed at a constant load during the cycling exercise. Experimental results showed that a decrease in DFA scaling exponent α or an increase in CSI was observed during the exercise. In addition, the Borg RPE scale and CSI were positively correlated, suggesting that the factors due to cardiac stress might also contribute to fatigue state during physical exercise. Since the CSI can effectively quantify the cardiac stress status during physical exercise, our system may be used in sports medicine, or used by cardiologists who carried out stress tests for monitoring heart condition in patients with heart diseases.