Graduate School of Human Health Science, Tokyo Metropolitan University, Tokyo, Japan.
Spine (Phila Pa 1976). 2012 Oct 1;37(21):E1343-7. doi: 10.1097/BRS.0b013e318267f7f5.
Translation and psychometric testing.
To translate and culturally adapt the Neck Disability Index (NDI) and to assess the reliability and validity of the Japanese version of the NDI (NDI-J) in Japanese outpatients with neck pain.
To date, no previous report exists on the translation process and psychometric testing of the NDI-J.
The NDI was translated and culturally adapted into Japanese in accordance with published guidelines. A total of 110 outpatients with neck pain participated in the study. Psychometric testing included reliability by internal consistency (Cronbach α) and test-retest reliability (intraclass correlation coefficient), factor analysis, convergent validity by comparing the NDI-J with the short-form health survey (Pearson correlation) and responsiveness (unpaired t tests, standard error of measurement, and minimal detectable change).
The Cronbach α of the NDI-J was 0.88 and the intraclass correlation coefficient for test-retest reliability was 0.91 (95% confidence interval, 0.82-0.95). Factor analysis demonstrated a 2-factor structure, explaining 61.8% of the total variance. The correlation between the NDI-J and the short-form health survey, version 36, subscales ranged from good to fair (-0.25 to -0.51). The analysis of responsiveness was calculated with an unpaired t test after 3 weeks of treatment demonstrating a statistically significant difference between the stable and improved patients (P ≤ 0.05). The standard error of measurement and minimal detectable change were calculated as 2.9 and 6.8, respectively.
The NDI-J is a valid, reliable, and responsive tool that can be used to assess neck pain in Japanese outpatients.
翻译和心理计量学测试。
将颈痛疾患指数量表（NDI）翻译并文化调适为日文版本，并评估日文版 NDI（NDI-J）在日本门诊颈痛患者中的信度和效度。
迄今为止，尚无关于 NDI-J 的翻译过程和心理计量学测试的先前报告。
根据已发表的指南，将 NDI 翻译并文化调适为日文。共有 110 名颈痛门诊患者参与了这项研究。心理计量学测试包括信度，采用内部一致性（Cronbach α）和重测信度（组内相关系数）；因子分析；效标关联效度，通过比较 NDI-J 与简明健康调查问卷（Pearson 相关）和反应度（独立样本 t 检验、测量误差标准和最小可检测变化）；收敛效度。
NDI-J 的 Cronbach α 为 0.88，重测信度的组内相关系数为 0.91（95%置信区间，0.82-0.95）。因子分析显示出 2 因素结构，可解释总方差的 61.8%。NDI-J 与简明健康调查问卷 36 条版本各子量表的相关性为良好至中等（-0.25 至-0.51）。在 3 周治疗后，通过独立样本 t 检验分析反应度，稳定和改善患者之间存在统计学显著差异（P ≤ 0.05）。测量误差标准和最小可检测变化分别计算为 2.9 和 6.8。
NDI-J 是一种有效、可靠且敏感的工具，可用于评估日本门诊颈痛患者的颈痛。
