OBJECTIVES

To explore the content and face validity of existing PRO measures (PROs) (6 VAS items and SNOT-22) in a nasal polyp (NP) population.

METHODS

This study consisted of 27 semi-structured concept elicitation (CE) and cognitive interviews (CI conducted by telephone. During the CI , participants completed the PROs on paper using a ‘think aloud’ process and were asked about their experience of completing the measures. Participants were also asked about the level of change in symptoms they considered meaningful.

RESULTS

Participants demonstrated a clear understanding of the SNOT-22 with 20 of the 22 items understood by more than 80% of participants. Items assessing nasal blockage, dizziness, decreased sense of smell/taste, difficulty falling asleep and waking up at night, were understood by all participants. The post-nasal discharge item was the least well understood (n=23/27, 85.0%). All participants demonstrated an understanding of each SNOT-22 response option and the two-week recall with the majority of items relevant to participants. The most relevant item in the SNOT-22 assessed nasal blockage (n=23/24, 96.0%) while the least relevant items were dizziness (n=15/25, 60.0%) and feeling sad (n=15/26, 57.7%); potential redundancy was noted for some items. Exploration of meaningful change highlighted that definitions of meaningful change, relevant to this population, may differ to that of other populations but typically across all SNOT-22 items achieving a state of ‘very mild problem’ or ‘no problem at all’ would be considered meaningful change.Overall participant understanding of each VAS assessment and response was good and their measurement concepts deemed relevant to the experience of NP.

CONCLUSIONS

Findings support the content validity of the PROs in NP patients. The items and instructions in the PROs were well understood and interpreted consistently. Further research is required to establish the psychometric validity of the SNOT-22 in a NP population.

Funding: GSK [206325/HO-16-17264]