# The Dutch Version of the Orthognathic Quality of Life Questionnaire (OQLQ-NL): Validation for Cleft Patients

## TL;DR

This study validates a Dutch version of a questionnaire to measure quality of life after orthognathic surgery in cleft patients.

## Contribution

The OQLQ-NL is validated for use in cleft patients in the Netherlands, showing strong reliability and validity.

## Key findings

- The OQLQ-NL showed excellent internal and test-retest reliability.
- Correlations between OQLQ-NL and CLEFT-Q domains were mostly as expected.
- The OQLQ-NL is confirmed as a valid and reliable tool for cleft patients in the Netherlands.

## Abstract

The aim of this study is to validate the Dutch version of the Orthognathic Quality of Life Questionnaire (OQLQ-NL) for cleft patients who received orthognathic surgery.

To compare the OQLQ-NL with the CLEFT-Q, we used a convenience sample of thirty-two cleft patients. Using the Cronbach's alpha coefficient for multiple item scales, internal reliabilities of the OQLQ-NL were evaluated. The OQLQ-NL was repeated at a two-week interval and the intraclass correlation coefficient was calculated, to establish of the test-retest reliability. The construct validity of the OQLQ-NL was evaluated by using Spearman's correlation to test its correlation with the CLEFT-Q.

Thirty-two patients filled in the OQLQ-NL and CLEFT-Q. The OQLQ-NL had excellent results in internal reliability and test-retest reliability. The vast majority of the correlations between the domains and scales of the questionnaires were as expected. Data from this study and previous studies confirm the construct validity of the OQLQ-NL.

Our results suggest the OQLQ-NL is a valid and reliable instrument for measuring quality of life in cleft patients who have received orthognathic surgery in the Netherlands.