ESCRS - PP11.12 - Rasch Validated German Standardised Keratoconus Questionnaire (Korq)

Rasch Validated German Standardised Keratoconus Questionnaire (Korq)

Published 2023 - 41st Congress of the ESCRS

Reference: PP11.12 | Type: Free paper | DOI: 10.82333/eadv-bn61

Authors: Leon Pomberger* 1 , Mats Lundström 2 , Klemens Waser 1 , Haidar Khalil 1 , Marina Casazza 1 , Andreas Honeder 1 , Matthias Bolz 1 , Nino Hirnschall 1

1Ophthalmology,Kepler University Clinic,Linz,Austria, 2Ophthalmology,Lund University,Lund,Sweden

Purpose

Validation of the keratoconus questionnaire (KORQ) in German as a patient reported outcome measures (PROM) tool.

Setting

Kepler University Clinic, Ophthalmology department, Linz, Austria

Methods

The Keratoconus Outcomes Research Questionnaire (KORQ) was specifically developed for keratoconus patients and consists of 18 items concerning visual ability and 11 items concerning keratoconus associated symptoms. Within this study the English version of the KORQ was translated to German and 100 patients with different stages of keratoconus were included and asked to complete the German version of the KORQ.  Several psychometric statistical analyses were then performed to evaluate the questionnaire and to delete unnecessary items.

Results

The mean age of the study participants was 35 years (range: 18-74; SD: 11.5), and the mean visual acuity in the better eye was 0.15 logMAR. Contact lens use was reported by 54% of patients, and 44% had undergone corneal cross-linking prior to the study. To validate the KORQ, we conducted several psychometric statistical analyses. The Cronbach's alpha coefficient for the total KORQ was 0.93, indicating very good consistency reliability. Additionally, all Guttman scores were above 0.9. Results of the Rasch analysis and the shortened questionnaire will be presented at the ESCRS meeting.

Conclusions

The results of the study suggest that the KORQ questionnaire is a useful tool to collect patient reported outcome measures (PROM) in patients with keratoconus.