Validation of the RUDAS in Patients With a Middle-Level Education in Lima, Peru

Abstract

Objectives: To assess the psychometric properties of the Peruvian version of the Rowland Universal Dementia Assessment Scale (RUDAS-PE) to discriminate controls from patients with mild cognitive impairment (MCI) and early dementia (ED) in a population with a mid-level education. Methods: A total of 133 patients from a memory clinic were administered the RUDAS-PE, INECO Frontal Screening, Addenbrooke’s Cognitive Examination, and Mini-Mental State Examination. Results were compared against a neuropsychological evaluation (gold standard). Validity measures, internal consistency, and concurrent validity were calculated. Results: Cronbach’s α was 0.68; Pearson’s ratio was 0.79 ( P < .01). The area under the receiver–operating characteristics curve of the RUDAS to discriminate between ED and MCI was 89.0% (optimal cutoff at <21), whereas between MCI and controls, it was 99.0% (optimal cutoff at <24). Conclusions: The RUDAS-PE has acceptable psychometric properties performing well in its ability to discriminate controls from patients with MCI and ED.

Validation of the RUDAS for the Identification of Dementia in Illiterate and Low-Educated Older Adults in Lima, Peru

“…Based on the Youden index, the optimal cut-off point for the RUDAS-PE to discriminate patients with MCI and controls was 23, with better sensitivity (89%) and specificity (93%), percentage of correctly classified (91%) and LR+ (13) with LR-(0.18) as compared to the MMSE therefore supporting the diagnostic accuracy of the RUDAS-PE over the MMSE in discriminating controls from patients with MCI. These findings are similar to published studies comparing controls and patients with dementia (13- 15,21,23,25).…”

“…The internal consistency of the RUDAS-PE (Cronbach's alpha = 0.65) is in line with previous findings ranging from 0.54 to 0.80 (23,24). The Spearman's correlation values highlight the usefulness of the RUDAS-PE as a significant predictor of cognitive and functional status confirming our initial findings in a population with a mid-level of education (15). We found a much higher value for the correlation between RUDAS-PE/MMSE (ρ = 0.86) with respect to those reported in previous literature indicating the RUDAS and MMSE correlation to fluctuate between 40 and 80% (25)(26)(27)(28)(29)(30).…”

“…It is worth mentioning that the optimal cut-off scores for both the RUDAS-PE and MMSE in patients with illiteracy and low-levels of education vary from the scores found in literate populations with a mid-level of education (Table 4) (15). Taken together, these results would seem to suggest that the performance of the RUDAS-PE is influenced by level of education, but less so than the MMSE.…”

“…The adaptation process corresponded to the standards and methodology of the RUDAS-PE set by Custodio et al (15) and based on the Spanish translated version of the RUDAS by Ramos-Ríos et al (14). Suggestions made by clinical experts (neurologists SC and DL, and neuropsychologists JC and MS) were used to make improvements to the existing RUDAS-PE.…”

“…It has been proposed that the RUDAS has reasonable psychometric characteristics and is particularly useful in patients of various languages and cultures, thereby being preferable in populations with low-levels of educational attainment. While it is true that the RUDAS is validated in an urban Peruvian population with a middle-level of education (15), it has yet to be adapted for and evaluated in an illiterate elderly population with low-levels of education.…”