ABSTRACT
Purpose: The Nijmegen questionnaire is a screening tool for detecting hyperventilation syndrome. The present study aimed to cross-culturally adapt the questionnaire to Thai language and test its psychometric properties for screening hyperventilation syndrome, in which the prevalence is increasing due to the impacts of the COVID-19 pandemic.Design/methodology/approach: The Thai version of the Nijmegen questionnaire (NQ-TH) was generated following a cross-cultural adaptation guideline including initial translation, synthesis of forward translation, back translation, expert committee review, and prefinal testing. Fifty control participants and one-hundred patients with symptoms related to hyperventilation syndrome were enrolled in this study for the determination of psychometric properties. Content validity, construct validity, internal consistency reliability, and test-retest reliability of the NQ-TH were assessed. Its discriminant ability and cutoff point for screening hyperventilation syndrome were also revealed. Findings: The obtained IOC and disappeared floor and ceiling effects indicated excellent content validity of the questionnaire. There were significant correlations between the total scores of the NQ-TH and other questionnaires and recorded respiratory measurements obtained from the patients, i.e., SF-36-TH (r = -0.257), HADS-TH (r = 0.331), RR (r = 0.377), and BHT (r = -0.444). This supported the construct validity of the NQ-TH. An acceptable internal consistency was also observed (Cronbach's alpha = 0.789). Test-retest repeatability of the questionnaire was high (ICC = 0.90). Moreover, the NQ-TH reliability was also ensured by calculated MDC (2.68). The cutoff point of the NQ-TH was at 20 with 98% sensitivity and 94% specificity.Originality/value: The NQ-TH established by the present study is a valid and reliable tool for screening hyperventilation syndrome among Thais.
ABSTRACT
OBJECTIVE: To translate and evaluate psychometric properties of Thai version of the Dizziness Handicap Inventory (DHI-TH). STUDY DESIGN: A cross-sectional study. SETTING: Ambulatory. PATIENTS: Fifty patients with dizziness at a vestibular clinic. MAIN OUTCOME MEASURES: Translation and cross-cultural adaptation of the original English version of the DHI was performed according to published guidelines. Psychometric evaluation included internal consistency, content validity, test-retest reliability, convergent validity, discriminant ability, and responsiveness. Responsiveness was examined in 28 patients with vestibular dysfunction who received vestibular rehabilitation for 6 to 8âweeks. RESULTS: There were no floor and ceiling effects. The Cronbach's alpha was good for the total score (0.87) and subscale scores (0.70 physical, 0.73 emotional, and 0.71 functional). Excellent test-retest reliability was demonstrated for the total and subscales (ICC ranged from 0.91 to 0.97, pâ<â0.001). The SEM was 3.50 and the MDC was 9.68. The total and subscales of DHI-TH were moderately correlated with the SF-36-TH scores (r ranged from -0.40 to -0.63). An optimal cut-off point for detection of dizziness was 21 points (98% sensitivity, 94% specificity). Responsiveness of the DHI-TH was excellent. The ES and SRM were large (1.25 and 1.59, respectively). The DHI-TH discriminated well between patients with self-perceived improved dizziness versus unchanged dizziness (AUCâ=â0.87). The MCID was 17 points (82.0% sensitivity, 82.0% specificity). CONCLUSION: The DHI-TH demonstrated good psychometric properties for patients with dizziness. The DHI-TH is a valid and reliable instrument recommended as a measure of disability and quality of life in Thai patients with dizziness.
