Cross-cultural validation of the Dutch Vertigo Symptom Scale - Short Form: dimensionality, reliability and cultural differences in symptom reporting.

Abstract

Background: The Vertigo Symptom Scale - Short Form (VSS-SF) is a widely used questionnaire to measure vestibular symptoms such as dizziness and vertigo. Most cross-cultural validations focus only on translation and basic psychometrics, providing limited insight into cross-national comparability. This study aimed to (1) develop and validate a Dutch version of the VSS-SF, and (2) provide novel insights into cross-cultural differences in symptom reporting and the methodological robustness of the scale.

Methodology: Following international guidelines, we translated and linguistically validated the Dutch VSS-SF. We then compared its dimensional structure, reliability, and differential item functioning (DIF) with the original British version, using bifactor modeling to test essential unidimensionality. We used data from patients aged 50 years and older with chronic vestibular symptoms who participated in British (n = 296) and Dutch (n = 322) randomized controlled trials.

Results: The Dutch version was well understood. Psychometric evaluation supported essential unidimensionality in both versions (structural coefficient bias < 15%). Reliability was excellent (omega-total 0.920 Dutch; 0.956 British). DIF analysis revealed cultural differences: Dutch patients were less likely to report nausea/vomiting but more likely to report unsteadiness, even at the same symptom level. However, these differences had negligible impact on total scores.

Conclusions: The Dutch VSS-SF is valid and reliable, with scores directly comparable to the British version. Beyond translation, this study shows how advanced psychometric methods reveal both the robustness of the VSS-SF and subtle cultural differences in symptom perception, strengthening its use in multinational research and clinical practice.