Validation of 5-item and 2-item questionnaires in Chinese version of Dizziness Handicap Inventory for screening objective benign paroxysmal positional vertigo.

As possible candidate screening instruments for benign paroxysmal positional vertigo (BPPV), studies to validate the Dizziness Handicap Inventory (DHI) sub-scale (5-item and 2-item) and total scores are rare in China. From May 2014 to December 2014, 108(55 with and 53 without BPPV) patients complaining of episodic vertigo in the past week from a vertigo outpatient clinic were enrolled for DHI evaluation, as well as demographic and other clinical data. Objective BPPV was subsequently determined by positional evoking maneuvers under the record of optical Frenzel glasses. Cronbach's coefficient α was used to evaluate the reliability of psychometric scales. The validity of DHI total, 5-item and 2-item questionnaires to screen for BPPV was assessed by receiver operating characteristic (ROC) curves. It revealed that the DHI 5-item questionnaire had good internal consistency (Cronbach's coefficient α = 0.72). Area under the curve of total DHI, 5-item and 2-item scores for discriminating BPPV from those without was 0.678 (95 % CI 0.578-0.778), 0.873(95 % CI 0.807-0.940) and 0.895(95 % CI 0.836-0.953), respectively. It revealed 74.5 % sensitivity and 88.7 % specificity in separating BPPV and those without, with a cutoff value of 12 in the 5-item questionnaire. The corresponding rate of sensitivity and specificity was 78.2 and 88.7 %, respectively, with a cutoff value of 6 in 2-item questionnaire. The present study indicated that both 5-item and 2-item questionnaires in the Chinese version of DHI may be more valid than DHI total score for screening objective BPPV and merit further application in clinical practice in China.