Validity of the Telephone Interview for Cognitive Status (TICS) in post-stroke subjects

Background: Cognitive impairment and dementia are very common after stroke. Telephone screening has potential advantages for clinical follow-up and population-based research in this group. We wished to test the validity of the Telephone Interview for Cognitive Status (TICS) for cognitive testing in post-stroke subjects.

Methods: Cognitive function in stroke outpatients was assessed using the R-CAMCOG (a modification of the cognitive part of the Cambridge Examination for Mental Disorders of the Elderly, for use in stroke subjects) along with the TICS and a modified version, the TICSm. The tests were administered in random order. A cut-off point of 33 on the R-CAMCOG was used to define post-stroke dementia.

Results: Sixty-four patients with a median age of 72 years were assessed. The Pearson correlation coefficients between the R-CAMCOG and the TICS and TICSm were 0.833 and 0.855 (both p <0.001) respectively. Twenty-four (38%) patients met R-CAMCOG criteria for post-stroke dementia. The area under the ROC curve for both the TICS and TICSm was 0.94. Using a cut-off of 28 or less on the TICS produced a sensitivity of 88% and a specificity of 85% for the diagnosis of post-stroke dementia. For the TICSm a cut-off of 20 or lower produced a sensitivity of 92% and a specificity of 80%.

Conclusions: The TICS and TICSm telephone questionnaires are practicable and valid methods of assessing cognitive function in community outpatients following stroke. Scores of < or =28 and < or =20 respectively carry good sensitivity and specificity for the diagnosis of post-stroke dementia.