Objective: To determine the psychometric properties of a pre-existing orthodontic satisfaction questionnaire and to assess patient satisfaction of their orthodontic treatment.
Design: Psychometric assessment of a pre-existing orthodontic satisfaction questionnaire.
Setting: Two sites at King's College Hospital NHS Foundation Trust.
Participants: Individuals aged 12-15 years who had completed fixed orthodontic treatment.
Methods: An expert panel assessed a pre-existing orthodontic treatment satisfaction questionnaire for validity and readability. As a result, revisions were made to the questionnaire and it was distributed to 103 participants aged 12-15 years, on completion of their fixed orthodontic treatment (T1). Test-retest reliability of the questionnaire was assessed through completion of a second questionnaire by 17 participants, at a two-week interval (T2). The questionnaire was assessed for reliability using item-total correlations (I-TC) and Cronbach's alpha. Factor analysis allowed exploration of the underlying factor structure of the questionnaire. Test-retest reliability was assessed using Cohen's kappa coefficient. Multiple regression analysis was used to find out the significant demographic variables that predicts the satisfaction level of treatment.
Results: Following validity and readability assessment by the expert panel, the questionnaire was revised. Eleven items were removed following item analysis (with I-TC ⩽ 0.3). Factor analysis was deemed uninterpretable. The overall scale demonstrated greater reliability than the underlying sub-scales. Therefore, the sub-scales were removed, resulting in one scale which assessed overall orthodontic satisfaction, comprising 37 items, with a Cronbach alpha of 0.92. The test-retest reliability of the revised 37-item scale was deemed to be poor (kappa coefficient = 0.39). Multiple regression analysis identified ethnicity as a significant predictor of orthodontic treatment satisfaction (P = 0.01).
Conclusion: This study provides a valid measure to assess orthodontic treatment satisfaction for use in a UK population aged 12-15 years on completion of fixed orthodontic treatment.
Keywords: patient satisfaction; psychometric validation; satisfaction questionnaire.