ADL-Focused Occupation-Based Neurobehavioral Evaluation Software: Addition of a Rasch-Based Stroke Subscale to Measure Outcomes

Abstract

Background: Measurements are necessary in rehabilitation for evaluating service effectiveness. The ADL-focused Occupation-based Neurobehavioral Evaluation (A-ONE) is used for evaluating ADL performance and the impact of neurobehavioral impairments on the performance. Recently, Rasch-based software was constructed for the A-ONE ADL and neurobehavioral scales. It converts ordinal rating scale scores into measures, estimates missing data values and calculates the statistical significance of changes. Objectives: To expand the A-ONE software by developing a cerebrovascular accident (CVA) neurobehavioral subscale. Additionally, to pilot-test whether the ADL and CVA scales of the software can detect statistically significant improvements. Method: Rasch analysis was used for evaluating the item fit, PCA, person separation and reliability to establish the internal validity of the CVA subscale (n = 222). The external validity (n = 22) was obtained by comparing A-ONE software measures to Winsteps measures. Subsequently 21 pre-post-intervention comparisons were made of stroke patients using both the ADL and CVA scales. Results: All set criteria for internal and external validity were met. By using the software clinically after incorporating the CVA subscale, statistically significant changes were detected in 90.5% of comparisons using the ADL scale and 36.4% using the CVA scale. The intervention program used was determined to consist of 66.4% occupation-based activities. Conclusions: This study is the first to deliver a clinically deployable Rasch-based CVA subscale integrated into routine occupational therapy software. The A-ONE software offers considerable time saving for therapists and the potential to detect significant differences in performance and impairment impact. It contributes to the removal of clinical obstacles toward the use of the instrument as an outcome measure and encourages the use of measures in rehabilitation.

Keywords: ADL evaluation; CVA; Rasch analysis; instrument development; measurement; occupational therapy; outcome studies; rehabilitation; software development; stroke.

Figure 1

Item groups of the A-ONE CVA subscale. The items from the NBSIS are marked with capital letters referring to the five different domains. These are D = Dressing, G = Grooming and hygiene, T = Transfers and mobility, F = Feeding, and C = Communication. P refers to items from the NBPIP that remain dichotomous.

Figure 2

Key form for the CVA subscale and item hierarchy of the 49-item CVA scale. More frequently impacting items are listed at the bottom of the hierarchy on the right side of the figure. The rating scale for each of the tree groups of working categories range from 0 (no impact) to 3 (physical assistance needed to overcome the item’s impact). “:” represents the threshold between rating categories (50/50% chance of either score). Lower-impact ratings are located on the left side and more impacting ratings, reflecting a need for more assistance, on the right side. Background shades demonstrate the number of category ratings, based on the grouping for each of the items (yellow = dichotomous; green = three categories; blue = four categories). Circles indicate a rating sample for a patient diagnosed with LCVA. Black circles indicate detected ratings; red circles represent predicted missing scores. The red vertical line represents the person’s measure, with the blue lines on either side indicating the SE.

Figure 3

Time record for use by activity groups. * Time unit is minutes.

Figure 4

Software forms. The illustrated forms show the data entry form of the A-ONE software used to construct the evaluation reports and an example of a summary sheet from the digital report. Comparison of two different performance measures obtained at different times indicate statistically significant improvement in ADL performance but non-significant changes in the impact of impairments on the CVA scale in this particular report.

Figure 5

Manual conversion of rating scale scores into measures. (A) Documentation: performance of ADL tasks and detection of impacting impairments. (B) Manual combination of scoring categories: a combination of two categories on the ADL scale is required before conversion to measures, but two, three or four categories are required on the NBI scales depending on the item groups. (C) Sample from the A-ONE CVA scale conversion table. Reliable measures based on a score table require that no rating scale values are missing.

Figure 6

The software cycle of the A-ONE. The idea for the A-ONE software construction developed as result of clinical therapists being reluctant to use score tables for converting ordinal scale scores into measurements. This led to the construction of mathematical models based on Rasch key forms. The software is based on research on the internal and external scale validity for both the ADL and NBI scales. The software and the research studies behind it have been presented at international conferences. Benefits of the cycle that can flow back into clinical practice include access of A-ONE trained therapists to software measures and information on its use. (Adapted from Árnadóttir G. Measuring the impact of body functions on occupational performance: Validation of the ADL-focused Occupation-based Neurobehavioral Evaluation (A-ONE) p. 47. The Author, Reykjavík, Iceland, 2010 [6]).