The World Health Organization ageism towards older persons scale: preliminary validation of a novel measure of ageist stereotypes, prejudices, and discrimination in four different countries.

This study presents the preliminary validation of the WHO Ageism Towards Older Persons Scale (WHO-A-TOPS), a new measure designed to comprehensively assess ageism, whilst capturing its three dimensions (e.g. stereotypes, prejudices, and discrimination based on age). The study evaluated the structural validity, measurement invariance, internal consistency, and construct validity of the WHO-A-TOPS. Data were collected from four countries: Czech Republic, Germany, Israel, and the United Kingdom, with a total sample of 1778 participants aged 20-90 years. Through an iterative process, a 10-item one-factor model was identified, demonstrating acceptable partial scalar measurement invariance across the four countries and invariance across different age groups. Hence, indicating that the new measure can capture a common construct across the four investigated countries and the three age groups. The final 10-item scale captures all three dimensions of ageism: stereotypes, prejudices, and discrimination. The new tool represents an exceptional attempt to develop a measure of high psychometric properties following current state-of-the-art guidelines. The tool can be used across different countries and age groups. The study discusses the implications of these findings for ageism research and practise, highlighting the importance of cross-country validation and the complexities of measuring ageism's multifaceted nature.