Reliable Digit Span Scores Among Latin American Monolingual Spanish Speakers

The Reliable Digit Span (RDS) is an embedded measure used to assess performance validity. The purpose of this study was to determine whether the RDS can be used with Spanish speakers from Latin America.

The Digit Span subtest of the Wechsler Adult Intelligence Scale-IV was administered to 66 Spanish-speaking patients, 66 English-speaking patients, and 30 Spanish-speaking normal controls. The Spanish-speaking patients had a mean age of 65.82 (standard deviation [SD] = 12.44) and mean education of 6.62 years (SD = 4.91), whereas the controls had a mean age of 48.27 (SD = 10.97) and mean education of 8.33 (SD = 3.04). The English-speaking patients had a mean age of 56.44 (SD = 13.53) and mean education of 12.14 (SD = 2.37).

The average RDS among the Spanish-speaking patients was 5.36 (SD = 1.27) and the average RDS among the controls was 5.90 (SD = 1.06). The mean RDS of the English-speaking patients was 7.83 (SD = 1.72). The modal RDS among Spanish-speaking patients was 5. The modal RDS among Spanish-speaking controls was also 5, though the distribution was bimodal in nature with nearly as many 7 s as 5 s. The modal RDS among the English-speaking patients was 7. Among patients with ≥9 years of education and controlling for age, there remained a significant difference between both language patient groups on the RDS (F(1, 79) = 30.85, p < .0001).

These data suggest that the RDS may not be a valuable measure in assessing performance validity among monolingual Spanish speakers from Latin America, particularly among those with low levels of education.