Effects of asthma on stability of Wisconsin card sorting test measures A twin study

BACKGROUND: The four measures used to assess the stability of the Wisconsin card sorting test (WCST), that is, the number of preservative errors, percentage of preservative errors, number of categories completed, and the number of trials to complete the first category, reflect the function of the frontal lobe. OBJECTIVE: This study was designed to investigate the effects of asthma on the stability of WCST measurements through the use of a twin study, and to analyze whether egg-type difference exists. DESIGN: A cohort study. SETTING: Mental Health Center, the First Affiliated Hospital of Chongqing Medical University. PARTICIPANTS: Fifty-nine pairs of twins, aged 6–16 years, were primarily selected from schools between August 2005 and February 2007 and the WCST and Zygosity identification test was applied. Twins with achromatopsia, severe upper limb diseases, somatic diseases, or mental disorders were excluded. According to disease history of asthmatic attack, children were assigned into asthma (n = 16) and non-asthma (n = 43) groups. METHODS: Four WCST measurements were determined in the 59 pairs of twins, and egg-type differences were identified in conjunction. RESULTS: All 59 pairs of twins were included in the final analysis. Among the pairs of twins, 28 (48.5 %) were monozygotic twins, and 31 (52%) were dizygotic twins. Among the monozygotic and dizygotic twins, the number of preservative errors and percentage of preservative errors were significantly higher in the asthma group than in the non-asthma group (P < 0.05). However, there was no significant difference of each corresponding measure between the monozygotic and dizygotic twins (P > 0.05). CONCLUSION: Asthma may affect the stability of WCST measures, but egg-type differences do not exist.