Occupational Therapy Adult Perceptual Screening Test (OT-APST)

Overview

We conducted a literature search to identify all relevant publications on the psychometric properties of the OT-APST. To our knowledge, the creators of the OT-APST have personally gathered the majority of psychometric data that are currently published on the scale.

Reliability

Internal consistency:
Cooke, McKenna, Fleming, Darnell (2006a) examined the internal consistency of the OT-APST subscales Agnosia, Body scheme, Neglect, and Constructional skills in 208 participants with stroke. The internal consistency alpha coefficients for these subscales ranged between 0.71 and 0.83, indicating adequate to excellent levels of internal consistency.

Test-retest:
Cooke, McKenna, Fleming, and Darnell (2005b) examined the test-retest reliability of the OT-APST by having one rater administer and score the OT-APST to 15 patients with stroke and videotape their performance. The same rater then assessed the same patients at the same time of day, 2 weeks later. On 14 of the 25 items, there was 100% agreement between the first and second assessments. For the 11 remaining items, the percentage agreement ranged between 70% and 90%, with the exception of one item, Two-dimensional Constructional skills, which had only 20% agreement. Intraclass correlation coefficients (ICCs) were calculated for 6 of the 13 items, where the percentage agreement was less than 100% and the scale of the item was appropriate for this form of correlation calculation. The ICCs were considered excellent, ranging from 0.76 to 0.95.

Intra-rater:
Cooke, McKenna, Fleming, and Darnell (2005b) examined the intra-rater reliability of the OT-APST by having 9 occupational therapy raters each score 5 patients with stroke from video recordings. Following a time delay of 2 weeks, all of the raters viewed the videos again and scored the same five participants in a different randomized order. On 12 of the 25 items, there was 100% agreement between the scores for the first and second video scoring sessions. On the other 13 items, the percentage agreement for raters between the first and second scoring sessions ranged from 83% to 98%. ICCs ranged from adequate (ICC = 0.64) to excellent (ICC = 1.0).

Inter-rater:
Cooke, McKenna, Fleming, and Darnell (2005b) examined the inter-rater reliability of the OT-APST by having one rater administer and score the OT-APST to 15 patients with stroke and videotape their performance. Nine raters were then allocated to score 5 patients. Each video was scored by three separate raters and presented in random order to each rater. Intraclass correlation coefficients (ICCs) ranged from adequate (ICC = 0.66 for the Clock item) to excellent (ICC = 1.00 for the items Wave left hand-command and copy, and Two-dimensional Constructional skills). On 12 of the 25 items, there was 100% agreement between all raters and the original ratings given by one rater on 15 patients. On the other 13 items, the proportion of agreement between all raters and the original rater ranged between 83% and 99%.

Validity

Criterion:
Concurrent:
Cooke, McKenna, Fleming, Darnell (2006b) examined the concurrent validity of the OT-APST in 208 patients with stroke by comparing patient performance on the OT-APST with their performance on the Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) and the LOTCA-Geriatric version (LOTCA-G). Somer’s d was used to calculate correlations between the measures. The OT-APST was found to have a poor to excellent correlation with the LOTCA (0.27-0.64) and with the LOTCA-G (0.25-0.80).

Construct:
Convergent:
Cooke, McKenna, Fleming, Darnell (2006a) examined the convergent validity of the OT-APST by comparing the subscales of the OT-APST to the corresponding subscale of the Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) or the LOTCA-Geriatric version (LOTCA-G) using Spearman’s rho correlations. Statistically significant correlations were found between each subscale of the OT-APST and the corresponding subscale of the LOTCA or LOTCA-G. The highest correlations occurred for the subscales of Constructional skills and Neglect, with more moderate correlations occurring for subscales assessing Agnosia, Body scheme, and Apraxia. Correlations ranged from poor (0.33 for Apraxia) to excellent (0.80 for Constructional skills).

Similar to the study by Cooke et al. (2006a), Itzkovich, Elazar, Averbuch and Katz (2000) examined the convergent validity of the OT-APST with the Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) in 208 people with stroke who were younger than 70 years of age. Adequate to excellent correlations were found between the OT-APST and on five of the related subscales of the reference tool of the LOTCA (r = 0.36 to r = 0.70).

Elazar, Itzkovich , and Katz (1996) examined the convergent validity of the OT-APST with the Loewenstein Occupational Therapy Cognitive Assessment-Geriatric (LOTCA-G) version for those 70 years and over and found adequate to excellent correlations between the performance of elderly patients with stroke on the OT-APST and on the LOTCA-G (r = 0.33 to r = 0.80).

Cooke, McKenna, Fleming, Darnell (2006a) examined whether the OT-APST correlated with the Functional Independence Measure (FIM). Significant correlations were observed between six of the seven OT-APST subscales and FIM motor scores. Spearman’s correlations ranged from poor to adequate (r = 0.26 to r = 0.41). Significant correlations were found between all seven OT-APST subscales and the FIM cognitive scores. Spearman’s correlations were adequate (r = 0.36 to r = 0.50). Significant negative correlations were also observed between the time taken by participants to complete the OT-APST and both FIM scores, indicating that more severe functional disability was associated with greater length of time to complete the OT-APST. Body scheme was the only OT-APST subscale score not significantly correlated with FIM motor scores.

Known groups:
Cooke, McKenna, Fleming, Darnell (2006a) examined whether the OT-APST was able to discriminate between patients with stroke and healthy control participants. The patients with stroke performed significantly worse than the healthy participants on all 7 subscales of the OT-APST, and took significantly longer to complete the test. All t-tests and Mann-Whitney U tests comparing the two groups were significant at p < 0.001. The OT-APST was found to correctly predict membership of the healthy group for 94.1% of the healthy participants, and correctly predicted membership of the stroke participant group for 56.7% of participants with stroke. The inverse figures for these comparisons are that 5.9% of the healthy participants were predicted to be members of the stroke group (predicted to have perceptual impairments), and 43.3% of participants following stroke were predicted to be members of the healthy group (no perceptual impairments).

Responsiveness

Not applicable.

References
  • Cooke, D. (1993). Development and standardization of an apraxia assessment and perceptual screening test for the elderly. In: Australian Association of Occupational Therapists 17th National Conference Proceedings, 1993.
  • Cooke, D. M., McKenna, K., Fleming, J. (2005a). Development of a standardized occupational therapy screening tool for visual perception in adults. Scandinavian Journal of Occupational Therapy, 12, 59-71.
  • Cooke, D. M., McKenna, K., Fleming, J., Darnell, R. (2005b). The reliability of the Occupational Therapy Adult Perceptual Screening Test (OT-APST). British Journal of Occupational Therapy, 68(11), 509-517.
  • Cooke, D. M., McKenna, K., Fleming, J., Darnell, R. (2006a). Construct and ecological validity of the Occupational Therapy Adult Perceptual Screening Test (OT-APST). Scandinavian Journal of Occupational Therapy. 13, 49- 61.
  • Cooke, D. M., McKenna, K., Fleming, J., Darnell, R. (2006b). Criterion validity of the Occupational Therapy Adult Perceptual Screening Test (OT-APST). Scandinavian Journal of Occupational Therapy. 13, 38-48.
  • Cooke, D. M., McKenna, K., Fleming, J., Darnell, R. (2006c). Australian normative data for the Occupational Therapy Adult Perceptual Screening Test. Australian Occupational Therapy, 53, 325-336.
  • Itzkovich, M., Elazar, B., Averbuch, S., Katz, N.(2000). LOTCA manual (2nd ed.). Pequannock, NJ: Maddak Inc.
  • Elazar, B., Itzkovich, M., Katz, N. (1996).Geriatric version: Loewenstein Occupational Therapy Cognitive Assessment (LOTCA-G) battery. Pequannock, NJ: Maddak Inc.