Correlation Analysis of the In-clinic and Telephone Batteries from the AREDS Cognitive Function Ancillary Study. AREDS Report No. 15

Abstract

Purpose: To determine whether the AREDS Telephone Battery can be substituted for the In-Clinic Cognitive Function Battery to assess cognitive function, so that participants could still provide follow-up information without having to come to the clinic. Methods: Correlation analysis was performed on scores of the following in-clinic and telephone administrations: 1) Modified Mini-Mental State Examination (3MS), conducted in person vs. Telephone Interview Cognitive Status (TICS-M); 2) Wechsler Memory Scale-III (WMS-III), Logical Memory I and II; 3) Digits Backwards (a sub-test of the WMS-R); 4) Verbal Fluency; and 5) Letter Fluency (F,A,S). Results: A total of 1,738 AREDS participants completed an In-Clinic Battery and a Telephone Battery within twelve months. Significant positive correlations were found for all tests, ranging from Δ = 0.89 between the 3MS and TICS-M scores (95% CI; 0.88 – 0.90), to Δ = 0.71 for Letter Fluency (95% CI; 0.68 – 0.74). Conclusion: The linear relationships between the In-Clinic Battery and Telephone Battery scores support the hypothesis that the Telephone Battery is an appropriate substitute for participants who are unable to complete an in-clinic assessment of cognitive function.

KEYWORDS:

• Cognitive function
• correlation analysis
• AREDS Telephone Battery
• In-Clinic Cognitive Function Battery
• Age-Related Eye Disease Study
• age-related macular degeneration
• cataract