Validity and internal consistency of a whiplash-specific disability measure.

Study Design: Cross-sectional study of patients with whiplash-associated disorders investigating the internal consistency, factor structure, response rates, and presence of floor and ceiling effects of the Whiplash Disability Questionnaire (WDQ).

Objectives: The aim of this study was to confirm the appropriateness of the proposed WDQ items.

Summary Of Background Data: Whiplash injuries are a common cause of pain and disability after motor vehicle accidents.

Validity of the neck disability index, Northwick Park neck pain questionnaire, and problem elicitation technique for measuring disability associated with whiplash-associated disorders.

The Neck Disability Index (NDI) and Northwick Park Neck Pain Questionnaire (NPQ) were developed to measure self-perceived disability from neck pain, including that which may arise from whiplash injury. However, there is little data specifically concerning their validity for whiplash-associated disorders (WAD). The aim of this study was to assess the validity of the NDI and NPQ as measures of outcome in WAD by comparing them to a patient preference questionnaire, the problem elicitation technique (PET), which identifies problems that are of most importance to the individual patient.