A new stratified risk assessment tool for whiplash injuries developed from a prospective observational study

OBJECTIVES An initial stratification of acute whiplash patients into seven risk-strata in relation to 1-year work disability as primary outcome is presented. DESIGN The design was an observational prospective study of risk factors embedded in a randomised controlled study. SETTING Acute whiplash patients from units, general practitioners in four Danish counties were referred to two research centres. PARTICIPANTS During a 2-year inclusion period, acute consecutive whiplash-injured (age 18-70 years, rear-end or frontal-end car accident and WAD (whiplash-associated disorders) grades I-III, symptoms within 72 h, examination prior to 10 days postinjury, capable of written/spoken Danish, without other injuries/fractures, pre-existing significant somatic/psychiatric disorder, drug/alcohol abuse and previous significant pain/headache). 688 (438 women and 250 men) participants were interviewed and examined by a study nurse after 5 days; 605 were completed after 1 year. A risk score which included items of initial neck pain/headache intensity, a number of non-painful complaints and active neck mobility was applied. The primary outcome parameter was 1-year work disability. RESULTS The risk score and number of sick-listing days were related (Kruskal-Wallis, p<0.0001). In stratum 1, less than 4%, but in stratum 7, 68% were work-disabled after 1 year. Early work assessment (p<0.0001), impact of the event questionnaire (p<0.0006), psychophysical pain measures being McGill pain questionnaire parameters (p<0.0001), pressure pain algometry (p<0.0001) and palpation (p<0.0001) showed a significant relationship with risk stratification. ANALYSIS Findings confirm previous studies reporting intense neck pain/headache and distress as predictors for work disability after whiplash. Neck-mobility was a strong predictor in this study; however, it was a more inconsistent predictor in other studies. CONCLUSIONS Application of the risk assessment score and use of the risk strata system may be beneficial in future studies and may be considered as a valuable tool to assess return-to-work following injuries; however, further studies are needed.