Validation study of the "Sniffin' Sticks" olfactory test in a British population: a preliminary communication

Objective: The 'Sniffin' Sticks' olfactory test contains pen-like odour dispensing devices which are used to assess olfactory threshold, discrimination and identification. Odour identification is strongly dependent on familiarity with the odours and has an important cultural component which has limited the usefulness of other validated tests. The ` Sniffin' Sticks' test was developed in Germany and is validated in other countries but not in the UK. This study aims to validate the applicability of ` Sniffin' Sticks' in a local population. Design: Prospective controlled study. Setting: Rhinology or olfactory disorder clinic. Participants: About 82 subjects, 33 healthy volunteers with a reported normal sense of smell, and 49 patients with an impaired sense of smell presenting either at a rhinology or an olfactory disorder clinic. Each subject's olfactory function was assessed using the 'Sniffin' Sticks' test with a maximum score of 48. Main outcome measures: Threshold, discrimination and identification scores along with the combined olfactory score. Results: The mean age of the subjects tested was 46.7 years; 46 female and 36 male. In the patient group 36 were hyposmic and 13 anosmic. In the healthy volunteers group all subjects were normosmic. In the control group the mean combined olfactory score was 34.5 (+/- 2.5). The mean combined score in the patients group was 20.8 (+/- 7.4). Odour threshold scores were 3.7(+/- 2.8) for patients (hyposmics and anomics) and 8.3(+/- 1.8) for controls. In the identification test the controls mean score was 13.6 (+/- 1.2) for while the patients' mean score was 8.6 (+/- 3.5). Conclusions: In our sample of the local population the combined olfactory and odour identification scores for healthy volunteers and patients with olfactory disorders are comparable with the normative data published on large samples of European populations. However, modification of a few of the distracters is recommended for British patients based on our findings.