Neck Pain Driving Index: Appropriateness of the Rating Scale and Unidimensionality of the Strategic, Tactical, and Operational Levels

This study established the 9-item NPDI, and its 3 subsections (strategic, tactical, and operational levels) are unidimensional. The magnitude of self-reported driving difficulty at each of the 3 subsections can be assessed with the use of a 0 to 3 scale and Rasch scores.