Impact of cognition on test–retest reliability and concurrent validity of n-back for Chinese stroke patients

Abstract

Objective

The objective of this study was the measurement of the test–retest reliability of n-back in Chinese stroke patients.

Methods

Seventy-five sub-acute stroke patients performed n-back twice in three days. The test–retest reliability of n-back was analyzed by correlation coefficient.

Results

The n-back had excellent test–retest reliability in stroke patients. Pearson or Spearman coefficients ranged from 0.81 to 0.88. The intra-class correlation coefficients ranged from 0.72 to 0.87. The Chinese version of Montreal Cognitive Assessment-Basic (MoCA-BC) score was significantly correlated with the performance of n-back. MoCA-BC and n-back accuracy were significantly related in the Mild Cognitive Impairment (MCI) group (r = 0.60 in 1-back, p = .002; r = 0.43 in 2-back, p = .040). However, MoCA-BC was correlated with reaction time (RT) in the Cognitively Normal (CN) group (r = –0.44 in 1-back, p = .003; r = –0.36 in 2-back, p = .018). The test–retest reliability of CN group was mostly higher than that of MCI group RT: 0.71–0.76 in MCI, 0.80–0.88 in CN; accuracy: 0.80–0.85 in MCI, 0.75–0.86 in CN). The practice effect was observed in the CN group instead of the MCI group.

Conclusions

This study indicated that the test–retest reliability of n-back was high in stroke patients. N-back was correlated with cognition. It was preferable to conduct subgroup analyses according to the level of cognitive assessment of patients with stroke.

Keywords:

• Cognitive impairment
• Montreal Cognitive Assessment-Basic
• n-back
• stroke
• test–retest reliability

Acknowledgments

The authors thank AiMi Academic Services (www.aimieditor.com) for the English language editing and review services.

Author contributions

X. Liu designed and performed the research and wrote the manuscript. F. Li analyzed data and edited the manuscript. W. Song provided critical feedback on the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).