Assessing executive function in Parkinson disease: the alternating names test. Part I. Reliability, validity, and normative data.

ABSTRACT

OBJECTIVES: To evaluate psychometric properties (convergent and divergent validity; alternate forms reliability) and provide normative data for the Alternating Names Test (ANT), a new bedside test of set-switching, a component of executive function (EF). The test was specifically designed for use in persons with Parkinson disease (PD). DESIGN: Cross-sectional study. SETTING: Clinic-based PD Research Registry. PARTICIPANTS: Data were gathered from two samples 829 patients with idiopathic PD enrolled in our clinic registry and 253 caregivers and family members of patients. MEASUREMENTS In the ANT, patients are asked to produce the names of children, switching back and forth from boys' to girls' names. Outcome measures include the time to complete ten correct pairs and the number of errors made. RESULTS: Correlations between the ANT and similar constructs were high (mean Spearman rank-order correlation coefficient, rho=.67), indicating good convergent validity. Measures of divergent validity were low (mean Spearman's rho=.31), demonstrating good divergent validity. Alternate forms reliability was high for time (rho=.76), but low for errors (rho=.37). Normative data are presented in a look-up table. CONCLUSION: Our test is a valid and reliable measure of set-switching in PD. Its ease of administration and effectiveness in identifying executive deficits suggests that the test could be useful in clinical practice and warrants further study.