OBJECTIVE: The aim of this study was to develop a patient-based measure of the process and outcome of combined orthodontic and orthognathic care in the National Health Service in the UK. DESIGN: Identification of relevant dimensions through qualitative methods, design of form, determination of psychometric properties of the scale, specific readability, reliability and validity. SETTING: NHS hospitals in the South West Region. SUBJECTS: The sample comprised patients who had received combined orthodontic and orthognathic treatment between 01 January 1998 and 31 December 2000. Twenty-six participants (a 25% response rate) took part in four focus group meetings. Thirty subjects (65% response rate) took part in a pilot study to test the properties of the questionnaire. MAIN OUTCOME MEASURES: Six broad themes emerged from the focus groups. These formed the basis of the sections in the questionnaire. RESULTS: The questionnaire developed had a Flesch reading ease score of 72.9 or US grade level 4 equivalent to aged 9-10 years. Test-retest reliability gave kappa values for most questions that exceeded 0.4. Criterion validity of the measure was established by comparing responses to the questionnaire over two periods with a telephone interview on a sample of 30 patients. Criterion related validity was poor for nine of the 16 items. By contrast the construct validity of the questionnaire was satisfactory. CONCLUSION: A patient-based measure of the process and outcome of combined orthodontic and orthognathic treatment has been developed. This has sufficient validity and reliability for use in inter-center audit projects.
OBJECTIVE: The aim of this study was to develop a patient-based measure of the process and outcome of combined orthodontic and orthognathic care in the National Health Service in the UK. DESIGN: Identification of relevant dimensions through qualitative methods, design of form, determination of psychometric properties of the scale, specific readability, reliability and validity. SETTING: NHS hospitals in the South West Region. SUBJECTS: The sample comprised patients who had received combined orthodontic and orthognathic treatment between 01 January 1998 and 31 December 2000. Twenty-six participants (a 25% response rate) took part in four focus group meetings. Thirty subjects (65% response rate) took part in a pilot study to test the properties of the questionnaire. MAIN OUTCOME MEASURES: Six broad themes emerged from the focus groups. These formed the basis of the sections in the questionnaire. RESULTS: The questionnaire developed had a Flesch reading ease score of 72.9 or US grade level 4 equivalent to aged 9-10 years. Test-retest reliability gave kappa values for most questions that exceeded 0.4. Criterion validity of the measure was established by comparing responses to the questionnaire over two periods with a telephone interview on a sample of 30 patients. Criterion related validity was poor for nine of the 16 items. By contrast the construct validity of the questionnaire was satisfactory. CONCLUSION: A patient-based measure of the process and outcome of combined orthodontic and orthognathic treatment has been developed. This has sufficient validity and reliability for use in inter-center audit projects.