Reducing the time needed to administer a sustained attention test in patients with stroke.

Administering a sustained attention test often takes a lengthy time, which can hamper routine assessments in clinical settings. Therefore, we first proposed a method to reduce the time needed for administering a sustained attention test (the Computerized Digit Vigilance Test, C-DVT). The method was to retrieve 5 segments from different trial positions of the original C-DVT testing. Then we compared the concurrent validity, convergent validity, and random measurement error of the examinees' performance on these segments to find the segment with better psychometric properties. The 5 segments were as follows: the first 50% of testing, the 21st~50th percentile of testing, the first 60% of testing, the 31st~60th percentile of testing, and the 36th~65th percentile of testing. Then we compared the validities and random measurement error of the examinees' performance on these segments. Ninety patients with stroke participated in the validity study, and 44 of them participated in the random measurement error study. The patients' scores on the 5 segments were highly correlated with those of the C-DVT (Pearson's r ≥ 0.98), indicating excellent concurrent validity. The patients' scores on the 5 segments were moderately correlated with those of the Tablet-based Symbol Digit Modalities Test (Pearson's r = -0.51~-0.48), indicating sufficient convergent validity. The amounts of random measurement error (percent standard error of measurement) were all limited: 5.1% for the C-DVT, 6.6% for the first 50% of testing, 6.0% for the 21st~50th percentile of testing, 6.1% for the first 60% of testing, 6.0% for the 31st~60th percentile of testing, and 6.1% for the 36th~65th percentile of testing. The patients needed on average 3~4 minutes to complete all the aforementioned testing. The patients' scores on the 5 segments showed excellent concurrent validity, sufficient convergent validity, and limited amounts of random measurement error in patients with stroke. We suggest the 31st~60th percentile of testing segment for users because it had the lowest amount of random measurement error and can reduce the time needed for formal testing by about 40%.