Regression-based, demographically adjusted norms for Victoria Stroop Test, Digit Span, and Verbal Fluency for Sri Lankan adults

Age-stratified norms for Raven's standard progressive matrices for Sri Lankan adults

OBJECTIVE

The aim of this study was to create age-stratified norms for the Raven's Standard Progressive Matrices (SPM) for Sri Lankan adults.

METHODS

A sample of 610 adults (age: 18-72 years; education: 1-19 years), underwent the 60-item version of the SPM under individual supervision of a test administrator. The sample was stratified into 5-year age bands, and the norms are presented as percentile tables and percentile curves.

RESULTS

The age-related changes were more accurately predicted by a curvilinear model (overall R2 = 0.961) than a linear regression model (R2 = 0.639). The SPM norms are presented as age-stratified percentile tables, as well as sex-, age- and education-adjusted multiple regression equations. The highest percentiles in the younger end of the age spectrum showed a ceiling effect. In the context of age-stratified US (1993) and British (1992) norms, older individuals in the Sri Lankan sample scored much lower than their Western counterparts. However, the difference narrowed in the younger age bands, showing no difference among the 18-to-22-year age bands in the three countries.

CONCLUSIONS

This age-by-country interaction can be partly explained by poorer education in the older individuals in the present sample compared to those in the US and UK standardization samples. SPM norms presented in this paper fill a hiatus in assessment of general intellectual ability in Sri Lankan adults. Given that Sri Lanka improves its educational, socioeconomic and health standards faster than the nations who have already reached higher standards, these norms would require re-standardization in the coming decades.

A Systematic Review of Normative Data for Verbal Fluency Test in Different Languages

Verbal fluency tests are easy and quick to use in neuropsychological assessments, so they have been counted among the most classical tools in this context. To date, several normative data for verbal fluency tests have been provided in different languages and countries. A systematic review was carried out with studies that provide normative data for verbal fluency tests. Studies were collected from Scopus, PubMed and Web of Science. 183 studies were retrieved from the database search, of which 73 finally met the inclusion criteria. An analysis of the risk of bias regarding samples selection/characterization and procedure/results reports is conducted for each article. Finally, a full description of the normative data characteristics, considering country and language, verbal fluency task characteristics (type of task) and sample characteristics (number of subjects, gender, age, education) is included. The current systematic review provides an overview and analysis of internationally published normative data that might help clinicians in their search for valid and useful norms on verbal fluency tasks, as well as updated information about qualitative aspects of the different options currently available.

Subclinical memory impairment in unaffected siblings of patients with dementia

Objective: Family history of dementia is a known risk factor for dementia. The cognitive performance of unaffected siblings of dementia patients has been poorly studied. We aimed to determine whether clinically unaffected siblings of dementia patients have significant cognitive impairment compared to individuals who do not have first-degree relatives with dementia. Methods: We compared the cognitive performance of 67 patients with dementia (24 males; mean age 69.5), 90 healthy siblings of those patients (34 males; mean age 61.56) and 92 healthy adults (35 males; mean age 60.96) who have no first-degree relatives with dementia. We assessed learning and memory (Rey Auditory Verbal Learning Test (RAVLT)), short-term/working memory (Digit Span) executive functions (Stroop Test) and general intelligence (Raven Progressive Matrices). Test scores were compared among three groups, with regression-based adjustments for age, sex, and education. Results: As expected, the patients with dementia were impaired in all cognitive domains. In the Sibling Group, RAVLT total learning was significantly lower compared to controls (B = -3.192, p = .005). In a subgroup analysis, compared to controls, RAVLT delayed recall was poorer in the siblings of patients with early-onset (<65 years) dementia. No significant differences were observed in other cognitive domains. Conclusion: Clinically unaffected siblings of dementia patients seem to have a selective subclinical impairment in memory encoding. This impairment seems to be more prominent in siblings of patients with early-onset dementia who also have deficits in delayed recall. Future studies are needed to determine if the observed cognitive impairment deteriorates to dementia.