Cultural Adaptation and Validity of the Sniffin’ Sticks Psychophysical Test for the UK Setting

Abstract

Introduction

Olfactory testing must be culturally adapted to be relevant to the target population. This study aimed to validate the Sniffin’ Sticks test for the UK setting.

Methods

A cohort study was conducted at a tertiary olfactory dysfunction clinic. Phase 1—healthy volunteers underwent the original German identification test followed by a UK adapted version. Phase 2—patients with olfactory dysfunction underwent the extended smell test (TDI) including the new descriptors. Outcome measures included differences in identification test (phase 1), retest reliability and differences in scores before and after treatment.

Results

A total of 31 healthy volunteers and 87 patients were recruited (6 and 31 males, respectively). Phase 1—mean identification scores showed a small improvement after descriptor adaptations (13.77 and 14.57, p = 0.0029). Phase 2—41 untreated participants had a mean identification score of 7.31 at both intervals (95% CI: − 1.15 to 1.15, p > 0.999). The mean change in treated participants was 1.88 (0.70 to 3.06, p = 0.0224). TDI score difference between treated and untreated groups was 6.63 (2.48 to 10.79, p = 0.0023). The intraclass correlation coefficient for untreated patients was high for both TDI score (ICC = 0.82, 95% CI 0.57 to 0.93) and identification score (ICC = 0.80, 0.52 to 0.93); CIs suggest the reliability is moderate to excellent.

Conclusions

This study confirms the validity of the descriptor adaptations of the identification component of the Sniffin’ Sticks test to distinguish between health and disease.

Implications

The Sniffin’ Sticks test can now reliably be used for clinical assessment of British patients, modifying only the descriptors.