Validity and reliability of the Niigata PPPD Questionnaire in a Western population

Abstract

Purpose To analyze the psychometric properties of the Niigata Questionnaire (NPQ) for use in a European population with persistent postural-perceptual dizziness (PPPD). Methods Observational study included 140 patients with different vestibular conditions. Construct validity, internal consistency and concurrent validity were analyzed. Intra-class correlation coefficient (ICC), standard error of measurement (SEM) and minimal detectable change (MDC) were calculated. Receiver operating characteristic (ROC) curve was used to test diagnostic values. Results Of the 140 patients, 47 had a diagnosis of PPPD. Factorial analysis showed a single-factor structure and concurrent validity analysis showed strong correlations with other instruments. Cronbach alpha coefficients of 0.938 for the total score, 0.869 for the standing and gait subscale, 0.803 for the subscale of movements and 0.852 for the visual stimulation subscale were obtained. The reproducibility was substantial except for the standing subscale, which could be considered moderate. For the standing, movement and visual stimulation subscales and for the total score, the SEM was 3.27, 2.41, 2.50 and 6.63, respectively, and the MDC was 6.40, 4.72, 4.91 and 12.99, respectively. The NPQ total score showed an area under the curve (AUC) of 0.661, a sensitivity of 72.34 and a specificity of 55.91 for discriminating between PPPD and other vestibular disorders. Conclusions The NPQ is feasible for use in a Western population and presents a uni-factorial structure, high internal consistency and strong correlation with other instruments. The reliability can be considered substantial. The NPQ has low accuracy in discriminating between subjects with or without PPPD.

French adaptation and validation of the Niigata PPPD Questionnaire: measure of severity of persistent postural perceptual dizziness and its association with psychiatric comorbidities and perceived handicap

“…The results strongly confirmed our predictions with the highest NPQ scores for the PPPD group, the second highest for the vestibular group, and the control group having the lowest NPQ scores, similarly to Yagi et al [31]. Our ROC curve analysis showed that NPQ was a significant but poor predictor of PPPD, similar to a ROC curve analysis by Castillejos-Carrasco-Muñoz et al [6], but poorer than the original analysis by Yagi et al [31].…”

“…Our study aimed to better understand the symptoms of patients with PPPD and to validate the NPQ in a Western French speaking population. Our participant pool aligned perfectly with previous literature suggesting a higher percentage of women than men suffering from PPPD and an age range of 30−50 years [6,26,28].…”

“…A recent study by Yagi et al [32] suggested that there might be three subtypes of PPPD following the factors of NPQ: a visual-dominant type, an active motion-dominant type, and a mixed type. However, Castillejos-Carrasco-Muñoz et al [6] failed to replicate this finding in a Western (Spanish) population. Behrendt et al To the best of our knowledge, our study is the first to provide such a holistic analysis and overview of the PPPD symptomatology and include a healthy control group in addition to the group of vestibular patients for comparison.…”

“…Despite its prevalence and impact on daily life, PPPD remains underdiagnosed and undertreated. PPPD is more prevalent in individuals around 30 to 50 years old, and females [6,28]. The lack of specific biomarkers and the subjective nature of symptoms contribute to the complexity of accurate diagnosis [14,15,28].…”

“…The NPQ has been used to assess subjective symptoms of patients with PPPD and other vestibular disorders [17], and as a predictor of development of PPPD [14,29]. The NPQ has already been translated and culturally adapted to Spanish [6] and German [2]. However, there is no French version of the NPQ available, even though around 30% of the French-speaking population, i.e.…”