Department of Psychiatry, University of Illinois College of Medicine, Chicago, IL, USA.
Department of Psychology, Illinois Institute of Technology, Chicago, IL, USA.
Arch Clin Neuropsychol. 2023 May 22;38(4):619-632. doi: 10.1093/arclin/acac082.
Reliable Digit Span (RDS), RDS-Revised (RDS-R), and age-corrected scaled score (ACSS) have been previously validated as embedded performance validity tests (PVTs) from the Wechsler Adult Intelligence Scale-IV Digit Span subtest (WAIS-IV DS). However, few studies have directly compared the relative utility of these and other proposed WAIS-IV DS validity indicators within a single sample.
This study compared classification accuracies of 10 WAIS-IV DS indices in a mixed neuropsychiatric sample of 227 outpatients who completed a standardized neuropsychological battery. Participants with ≤1 PVT failures of the four, freestanding criterion PVTs constituted the valid group (n = 181), whereas those with ≥2 PVT failures formed the invalid group (n = 46). Among the valid group, 113 met criteria for mild cognitive impairment (MCI).
Classification accuracies for all DS indicators were statistically significant across the overall sample and subsamples with and without MCI, apart from indices derived from the Forward trial in the MCI sample. DS Sequencing ACSS, working memory RDS (wmRDS), and DS ACSS emerged as the most effective predictors of validity status, with acceptable to excellent classification accuracy for the overall sample (AUCs = 0.792-0.816; 35%-50% sensitivity/88%-96% specificity).
Although most DS indices demonstrated clinical utility as embedded PVTs, DS Sequencing ACSS, wmRDS, and DS ACSS may be particularly robust to cognitive impairment, minimizing risk of false positive errors while identifying noncredible performance. Moreover, DS indices incorporating data from multiple trials (i.e., wmRDS, DS ACSS) also generally yielded greater classification accuracy than those derived from a single trial.
可靠的数字跨度（RDS）、RDS 修订版（RDS-R）和年龄校正的量表分数（ACSS）已在韦氏成人智力量表-IV 数字跨度子测验（WAIS-IV DS）中被验证为嵌入式的绩效有效性测试（PVT）。然而，很少有研究在单个样本中直接比较这些和其他提议的 WAIS-IV DS 有效性指标的相对效用。
本研究比较了 227 名接受标准化神经心理测验的混合神经精神病门诊患者中 10 个 WAIS-IV DS 指数的分类准确性。符合以下标准的患者构成有效组（n=181）：四个独立的标准 PVT 中≤1 次 PVT 失败，而 PVT 失败≥2 次的患者构成无效组（n=46）。在有效组中，113 名患者符合轻度认知障碍（MCI）的标准。
除了 MCI 样本中的正向试验衍生的指数外，所有 DS 指标在整个样本以及有无 MCI 的亚组中的分类准确性均具有统计学意义。DS 序列 ACSS、工作记忆 RDS（wmRDS）和 DS ACSS 是最有效的有效性预测指标，对于整个样本具有可接受至优秀的分类准确性（AUCs=0.792-0.816；35%-50%敏感性/88%-96%特异性）。
尽管大多数 DS 指标作为嵌入式 PVT 具有临床效用，但 DS 序列 ACSS、wmRDS 和 DS ACSS 可能对认知障碍更为稳健，在识别不可信表现的同时最小化假阳性错误的风险。此外，包含多个试验数据的 DS 指数（即 wmRDS、DS ACSS）通常比源自单个试验的指数具有更高的分类准确性。
