BACKGROUND: Clinicians and researchers use brief instruments, such as the Mini Mental State Examination (MMSE) and the Telephone Interview for Cognitive Status (TICS), to measure cognitive functioning in patients with cerebral aneurysms. MMSE and TICS scores are often dichotomized to classify patients as cognitively impaired or not. Frequently, after an initial MMSE face-to-face evaluation, the TICS is used for follow-up assessments by telephone.
METHODS: A cross-sectional cohort of patients with cerebral aneurysms completed the MMSE at baseline and the MMSE or TICS at the 12-month follow-up examination. Multivariate logistic regression adjusting for demographics was used to model cognitive impairment. MMSE and TICS results were compared using the MMSE as the gold standard.
RESULTS: Eleven out of 171 (6%) patients had baseline MMSE scores less than 24, indicating cognitive impairment. Multivariate analysis showed that a history of subarachnoid hemorrhage was associated with cognitive impairment measured with the MMSE (odds ratio, 13.9; P = 0.021; C statistic = 0.87); there was no relationship between subarachnoid hemorrhage or treatment and TICS cognitive impairment (i.e., score < 27). In patients without recent or interim invasive interventions that might affect cognition (n = 65), raw baseline MMSE and 12-month TICS scores had fair correlations (r = 0.30, P = 0.015); however, dichotomized scores had poor agreement, and TICS sensitivity and positive predictive value was 0% compared with the MMSE.
CONCLUSION: The MMSE may be more sensitive than the TICS to the effects of subarachnoid hemorrhage on cognitive functioning. Raw MMSE and TICS scores are well correlated, but dichotomized MMSE and TICS scores are probably not interchangeable in this patient population.