Early Aggressive Care and Delayed Recovery From Whiplash: Isolated Finding or Reproducible Result? PIERRE CO ˆ TE ´ , 1 SHEILAH HOGG-JOHNSON, 2 J. DAVID CASSIDY, 3 LINDA CARROLL, 4 JOHN W. FRANK, 5 AND CLAIRE BOMBARDIER 6 Objective. To test the reproducibility of the finding that early intensive care for whiplash injuries is associated with delayed recovery. Methods. We analyzed data from a cohort study of 1,693 Saskatchewan adults who sustained whiplash injuries between July 1, 1994 and December 31, 1994. We investigated 8 initial patterns of care that integrated type of provider (general practitioners, chiropractors, and specialists) and number of visits (low versus high utilization). Cox models were used to estimate the association between patterns of care and time to recovery while controlling for injury severity and other confounders. Results. Patients in the low-utilization general practitioner group and those in the general medical group had the fastest recovery even after controlling for important prognostic factors. Compared with the low-utilization general practitioner group, the 1-year rate of recovery in the high-utilization chiropractic group was 25% slower (adjusted hazard rate ratio [HRR] 0.75, 95% confidence interval [95% CI] 0.54 –1.04), in the low-utilization general practitioner plus chiropractic group the rate was 26% slower (HRR 0.74, 95% CI 0.60 – 0.93), and in the high-utilization general practitioner plus chiropractic combined group the rate was 36% slower (HRR 0.64, 95% CI 0.50 – 0.83). Conclusion. The observation that intensive health care utilization early after a whiplash injury is associated with slower recovery was reproduced in an independent cohort of patients. The results add to the body of evidence suggesting that early aggressive treatment of whiplash injuries does not promote faster recovery. In particular, the combination of chiropractic and general practitioner care significantly reduces the rate of recovery. KEY WORDS. Whiplash injuries; Neck pain; Health services research; Episode of care; Primary health care; Prognosis; Recovery of function. INTRODUCTION Whiplash is the most common traffic injury, affecting 83% of individuals involved in motor vehicle collisions (1,2). It leads to neck pain, headache, and other symptoms such as dizziness (1). Whiplash injuries result in a significant bur- den of disability and health care utilization. In 1994, in Saskatchewan, Canada, the incidence of whiplash was 834 This study is based in part on nonidentifiable data pro- vided by the Saskatchewan Department of Health. The in- terpretations and conclusions contained herein do not nec- essarily represent those of the Government of Saskatchewan or the Saskatchewan Department of Health. Supported by Health Canada through the National Health Research and Development Program (grant 6606-6599-004) and the Canadian Institutes for Health Research. Dr. Co ˆte ´’s work was supported by a Doctoral Fellowship Training award from the National Health Research and Development Program, a New Investigator award from the Canadian In- stitutes of Health Research, and by the Workplace Safety and Insurance Board of Ontario through the Institute for Work & Health. Dr. Carroll’s work was supported by a Health Scholar award from the Alberta Heritage Foundation for Medical Research. 1 Pierre Co ˆte ´, DC, PhD: Institute for Work & Health, the University of Toronto, and the Toronto Western Research Institute and Rehabilitations Solutions, Toronto, Ontario, Canada; 2 Sheilah Hogg-Johnson, PhD: Institute for Work & Health, the University of Toronto, and Mt. Sinai Hospital, Toronto, Ontario, Canada; 3 J. David Cassidy, PhD, Dr Med Sc: the University of Toronto, and the Toronto Western Research Institute and Rehabilitations Solutions, Toronto, Ontario, Canada; 4 Linda Carroll, PhD: Alberta Centre for Injury Control and Research, Edmonton, Canada; 5 John W. Frank, MD, MSc: Institute for Work & Health, the University of Toronto, and the Institute of Population and Public Health, Toronto, Ontario, Canada; 6 Claire Bombardier, MD: Institute for Work & Health, the University of Toronto, the Toronto General Hospital Research Institute, and Mt. Sinai Hospital, Toronto, Ontario, Canada. Dr. Cassidy has received consulting fees (less than $10,000) from the Insurance Bureau of Canada. Address correspondence to Pierre Co ˆte ´, DC, PhD, Toronto Western Hospital, Fell Pavilion 4-124, 399 Bathurst Street, Toronto, Ontario, Canada M5T 2S8. E-mail: pierre.cote@ uhnresearch.ca. Submitted for publication June 29, 2006; accepted in re- vised form October 31, 2006. Arthritis & Rheumatism (Arthritis Care & Research) Vol. 57, No. 5, June 15, 2007, pp 861– 868 DOI 10.1002/art.22775 © 2007, American College of Rheumatology ORIGINAL ARTICLE 861