Reliability And Validity Of A WeChat-based Cognitive Function Assessment Tool

Background: Postoperative cognitive dysfunction(POCD)and other mild cognitive impairments(MCI)are identified by neuropsychological testing.We aimed to develop an internet-based cognitive function assessment tool for assessing POCD on smartphones.Methods: A We Chat-based tool was developed that comprised Digit Span,Digit Symbol and Visual Reproduction subtests,plus the Stroop Color and Word Test(SCWT)and the Color Trails Test(CTT).We included 197 participants who were divided into two groups and administered the tests through traditional and We Chat-based methods,with intervals of more than 2 months between assessments,and the order of testing differing between the two groups.Among of them,26 participants tested with the We Chat-based method were retested with the same method after 3 months.Results: The We Chat-based subscales had excellent internal consistencies,with Cronbach's alpha of 0.811 for Digit Span,Digit Symbol,Visual Reproduction and SCWT and 0.784 for the CTT.Test–retest reliabilities were fair to excellent(intraclass correlation coefficients [ICCs] = 0.550–0.890),except for the CTT(ICCs = 0.183–0.387).Although concurrent validities were low(ICCs = 0.144–0.328),finally,Bland–Altman plots indicated that agreement between the traditional and We Chat-based tests was good for Digit Span,Visual Reproduction and CTT,but that a consistent bias existed for Digit Symbols and SCWT.Conclusions: The We Chat-based tool,except for the CTT,can be recommended for use when assessing POCD,though further research is warranted.Of note,given the method for evaluating POCD(based on Z scores),we speculate the finding of systematic bias should not affect the identification of POCD.Whether we should correct the test results of the two versions of each scale to improve agreement,or whether we need to repeat the normality research for the We Chat version scales,it is clear that further research is needed.Further research is also needed on whether the software is suitable for the elderly.