Risk factors for chronic disability in a cohort of patients with acute whiplash associated disorders seeking physiotherapy treatment for persisting symptoms.

OBJECTIVES

(1) To identify risk factors for chronic disability in people with acute whiplash associated disorders (WAD). (2) To estimate the impact of the numbers of risk factors present.

DESIGN

Prospective cohort study. Data were collected, on average, 32 days after injury (SD=10.9) and 12 months later. Baseline measures of pain, disability, neck movement, psychological and behavioural factors were independent variables and chronic disability at 12 months was the dependent variable in a multivariable logistic regression analysis.

SETTING

National Health Service physiotherapy departments.

PARTICIPANTS

Participants (n=599) with symptoms 3 weeks after injury, self-referred to physiotherapy as part of a randomised controlled trial. 430 (72%) participants provided complete data for this analysis.

MAIN OUTCOME MEASURES

Chronic disability based on Neck Disability Index scores.

RESULTS

136 (30%) participants developed chronic disability. High baseline disability (OR 3.3, 95% CI 1.97 to 5.55), longer predicted recovery time (OR 2.4, 95% CI 1.45 to 3.87), psychological distress (OR 1.9, 95%CI 1.05 to 3.51), passive coping (OR 1.8, 95% CI 1.07 to 2.97) and greater number of symptoms (OR 1.7, 95% CI 1.07 to 2.78) were associated with chronic disability. One risk factor resulted in 3.5 times the risk (95% CI 1.04 to 11.45) of chronic disability but this risk increased to 16 times (95%CI 5.36 to 49.27) in those with four or five risk factors.

CONCLUSION

Baseline disability had the strongest association with chronic disability but psychological and behavioural factors were also important. Treatment strategies should reflect this which may require a change to current physiotherapy approaches for acute WAD. The number of risk factors present should be considered when evaluating potential for poor outcome.