Revisiting Risk-stratified Whiplash-exposed Patients 12 to 14 Years After Injury

Objective: The objective of this study was to evaluate the long-term predictive value of the Danish Whiplash Group Risk Assessment Score (DWGRAS) with 7 risk strata. Design: E-questionnaire-based follow-up study (n=927) combining 2 cohorts of whiplash-injured patients, 1 observational (n=187) and 1 interventional randomized controlled trial (n=740). Methods: Nine hundred twenty-seven previously healthy persons exposed to acute whiplash injury during motor vehicle collision were sent letter by postal service asking the addressee if they would respond to an E-questionnaire. Outcome measures were: whiplash-related disability, pain, use of medication/nonmedical treatment, work capacity. Results: The response rate was 37%. Fifty-five percent reported whiplash-related disability. Fourteen percent reported daily symptoms. A strong relationship was found between risk strata and impact of event and between risk strata and disabling symptoms. Conclusions: Internal and long-term validation of DWGRAS was performed, but a low response rate indicates that results should be interpreted with caution. Furthermore, external validation needs to be done in long-term studies. An receiver operating characteristics curve of 0.73 (95% confidence interval 0.67; 0.79) predicting daily or weekly whiplash-related disability after 12 to 14 years was found using the DWGRAS risk score.