Reliability And Validity Of Loewenstein Occupational Therapy Cognitive Assessment(LOTCA) In Chinese Patients With TBI

BackgroundTraumatic brain injury (TBI) is among the most common causes of neurologic disabilities in young adults. Although physical impairment may prominent early, particularly after severe TBI, cognitive impairments are more persistent and make a greater contribution to long-term handicap. So cognition rehabilitation plays a critical role in treatment of TBI. Cognition assessment is the main issue of cognition rehabilitation, but it is difficult to assess exactly for there has no golden standard. Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) is one of the best instruments in occupational therapy that is primarily used to evaluate whether the patients' cognitive function fits for the task. It assesses the basic cognitive skills, defined as those intellectual functions thought to be prerequisites for managing everyday encounters with the environment. LOTCA is a standardized battery that derived from clinical experience, neuropsychologic theories, developmental theories and evaluation procedures. Together with its administrating easily and high reliability and validity, LOTCA is widely used in healthy children and elder and persons with TBI or stroke in developed countries. Now LOTCA has developed to 2nd edition according to feedback from Occupational therapists all over the world. To be a world universal instrument, LOTCA is not consummate without used in People's Republic of China, the most populated country with more than 7% of handicapped. China needs LOTCA too, but its reliability and validity should be retested. AlthoughLOTCA 1st edition has used in Chinese clinic separately since 1999, and some researchers revealed that LOTCA 2nd edition was a better instruments in cognition disorder, but Traumatic brain injury had its own characters against other brain injury and the LOTCA was initially used to assess brain-wounded soldiers, furthermore, the authors of LOTCA analyze the reliability and validity in the group of TBI and other brain injury separately, so it is necessary to reveal the reliability and validity in Chinese patients with TBI. ObjectiveTo Introduce in Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) 2nd Edition and to test its reliability and validity in Chinese patients with TBI. Methods1. Chinese LOTCA: Agreed and supported by Noomi Katz, the principal researcher of LOTCA, we bought the instrument from Maddak inc. Two professionals in our research term firstly translated the Administration and Scoring into Chinese independently. Then through exchanging their views where they differed from each other and perfecting the contents several times, we integrated their Chinese versions into the 1st manuscript. Secondly, we used 1st manuscript to assess a few normal Chinese. According their feedback, we revised those misunderstood or those not conforming to Chinese accustomed expression and the 2nd manuscript came into being. Finally, two persons who were well up in English and Chinese but LOTCA translated 2n manuscript back. The final manuscript was formed if this manuscript showed more than 95 % of consistency with the initial version according actual meaning. We called the final manuscript as Chinese LOTCA.2. Subject: The exclusion criteria and the inclusion criteria for clients group and control group were defined firstly, and sample size were estimated according to the datum for pre-experiment. There were 34 cases in clients group and 64 cases in control group were included. Difference of gender, age and years of education between the two groups were analyzed.3. Procedures: Both groups were assessed with Chinese LOTCA. Usingblindness, two experienced assessors gave scores individually. 2 weeks later, all subjects would be evaluated by Chinese LOTCA for the second time in the same assessment room.4. Data analysis: Reliability (and internal consistency) and validity (the content validity, the construct validity and the discriminant validity) were examined in this study. Spearman's correlation coefficient and Wilcoxon singed rank test were used in the test-retest reliability and the reliability between different assessors. Cronbach's alpha coefficient was applied as a measure of internal consistency. Content validity was examined by the correlation of the items with its own area. Factor analysis was used for construct validity analysis. Discriminant validity was measured by statistic difference between the two groups through Mann-Whitney U test. SPSS 10.0? processed all data. Subjects who lost follow-up interview were excluded in test-retest reliability. Results1. Reliability between different assessors: The correlation coefficients between two assessors of most items were more than 0.8 (P<0.001), except lower coefficients of 0.716, 0.737, 0.797 in the items of P3, PS1, PS2(P<0.001). Wilcoxon singed rank test revealed that no significant difference between two assessors (P>0.05).2. Test-retest reliability: The correlation coefficients between retest and initial of all items were more than 0.8 (PO.001), with a lower coefficient of 0.827(P<0.001) in the item of CA. Wilcoxon singed rank test showed that no significant difference between test and retest (P>0.05).3. Internal consistency: Cronbach's alpha coefficient for the complete 36-item was 0.977 in clients group and 0.873 in control group, and the coefficients for every area were more than 0.8 in clients group, demonstrating high internal consistency.4. Content validity: Most items had significant correlation to each other. And all items demonstrated high correlation with its areas in clients group (r=0.697~0.975? P<0.05) , with the lowest coefficients of 0.697 in the correlation of CA to Thinking Operations, which meant that LOTCA had good content validity.5. Construct validity: Factor analysis showed LOTCA had bad construct validityin control group. But it had good construct validity in clients group because the 6-factor solution showed that 6 factors corresponded with the hypothesized areas. And this solution explained 88.4% of variance.6. Discriminant validity: Mann-Whitney U test showed that the scores in every item were significant difference between clients group and control group (P<0.0001).7. Scores in LOTCA: the score of complete LOTCA is 108.66±5.52(mean±SD) in control group and 67.88±21.97 in clients group, which confirmed Katz's reports.Conclusion1. Since the reliability and validity were high in all items of LOTCA when used in Chinese patients with TBI, it was worth carrying forward to the clinic.2. To keep the reliability and validity at a higher level, such items as Categorization may be perfected according to Chinese culture.3. Some intensive research should be done for the sample was limited in the area of south China.