Research Review by Dr. Michael Haneline©

Date:

Jan. 2008

Study Title:

Early aggressive care and delayed recovery from whiplash: Isolated finding or reproducible result?

Authors:

Côté P et al.
Authors’ Affiliations: Institute for Work & Health, the University of Toronto, and the Toronto Western Research Institute and Rehabilitations Solutions, Toronto, Ontario, Canada.

Publication Information:

Arthritis & Rheumatism, 2007; 57(5):861-68.

Summary:

Whiplash is the most common traffic injury affecting about 83% of those involved in motor vehicle crashes. The reported incidence is 834 per 100,000 persons in the general population of Canada.

Whiplash typically results in neck pain and headache which may lead to long-term disability. It can also increase of the risk for future neck pain and other health problems.

Based on previous work by Côté and his colleagues, as well as a recent randomized clinical trial by Scholten-Peeters et al. (see below), there appears to be a growing body of evidence suggesting that when intensive health care is delivered soon after whiplash injury, iatrogenic disability result.

The objective of the current study was to determine whether the authors’ previously reported findings that early intensive health care following whiplash leads to poor recovery in a cohort of whiplash patients compensated under no-fault insurance, would be reproducible in a cohort of whiplash patients compensated under tort insurance. The authors thought that their previous results would be strengthened if similar findings were present in a different population.

Data sources for this study:
  1. Saskatchewan Government Insurance data were used to collect potential confounders and outcome measures.
  2. Saskatchewan Health administrative health services data were used to collect potential confounders and information needed to measure initial patterns of care.
The records of a cohort of 1,693 patients who experienced a whiplash injury between July 1, 1994 and December 31, 1994 were reviewed. Patients were stratified according to the pattern of care they received. Eight patterns of care were identified based on the type and intensity of care received in the first 30 days following a traffic collision:
  1. General practitioner—Low utilization (1-2 visits)
  2. General practitioner—High utilization (>2 visits)
  3. Chiropractic—Low utilization (1-6 visits)
  4. Chiropractic—High utilization (>6 visits)
  5. Combined general practitioner plus chiropractic—Low utilization (Any number of visits to a general practitioners and 1-6 visits to a chiropractor)
  6. Combined general practitioner plus chiropractic—High utilization (Any number of visits to a general practitioner and >6 visits to a chiropractor)
  7. Combined general practitioner plus specialist (Any number of visits to a general practitioner and any number of visits to a specialist)
  8. General medical group (Any number of visits to medical doctors, but the submitted diagnosis was not whiplash)
The primary outcome measure was the length of time to recovery, defined as the number of days between the date of injury and the date the insurance claim was closed.

The authors attempted to control for a number of potential confounders, such as injury severity, comorbidity, pre-crash health status, and previous health care utilization. More than 20 other variables were factored into the analysis including body mass index, age, gender, education level, etc.

Pertinent Results:

Patients in the general medical group had the fastest rate of recovery (median time to recovery 323 days; [95% CI: 270–357]).

The slowest rates of recovery were found in patients in the:
  • high-utilization general practitioner group (median time to recovery 517 days),
  • low-utilization general practitioner plus chiropractic group (median time to recovery 516 days), and
  • high-utilization general practitioner plus chiropractic group (median time to recovery 689 days).
Interestingly, the rate of recovery was actually slower in the low-utilization chiropractic group (median time to recovery 375 days) than in the high-utilization chiropractic group (median time to recovery 363 days).

Overall, the intensity of care patients received during the first 30 days after the collision was negatively associated with their rate of recovery. That is, the more care they received, the more delayed their recovery and vice versa. Based on multivariable analysis, the authors thought very little confounding of their results occurred in relation to injury severity and other variables.

Patients in the high-utilization general practitioner group, as well as those in the high-utilization general practitioner plus chiropractic group had more serious whiplash injuries than those in the low-utilization general practitioner group. (See comment below.)

Hazard rate ratios (HRRs) were used in the statistical analysis to describe the strength and direction of associations, with ratios <1 pointing to slower recovery. The general practitioner plus chiropractic groups exhibited the largest recovery delays; HRR = 0.74 for the low-utilization general practitioner plus chiropractic group (representing a 26% slower rate of recovery) and HRR = 0.64 for the high-utilization general practitioner plus chiropractic group (representing a 36% slower rate of recovery) as compared with patients in the low-utilization general practitioner group 1 year post-crash.

The authors offered the following opinions as to the reasons recovery was delayed in patients who received early aggressive care: “Because patient pressure is a known predictor of physician behavior, doctors may use treatments, schedule follow-up visits, and refer patients when not medically needed. This in turn may lead to adverse outcomes and even prolong recovery by legitimizing patients’ fears and creating unnecessary anxiety.” Another reason provided was that early aggressive clinical care delays recovery by promoting the use of passive coping strategies which reinforces the patients’ beliefs that whiplash injuries often lead to disability.

Conclusions & Practical Application:

The authors suggested that their findings support the concept that excessive early health care following whiplash injuries negatively influences the patient’s prognosis, and that when chiropractic and general practitioner care were combined, it did not appear to confer any benefit to patients.

Comment: These conclusions fly in the face of the experience of many practitioners who manage whiplash patients, especially general practitioners who refer their whiplash patients to chiropractors for treatment. Consequently, this study and its 2005 predecessor have been criticized by practitioners and researchers from various health care disciplines. The clearest was a letter to the editor by Freeman et al. that was written in response to the 2005 Côté et al study on this topic.

Under the leadership of Michael Freeman, PhD, DC, MPH, the letter was authored by the editors of the Journal of Whiplash and Related Disorders, the Journal of Pain Research and Management, as well as a professor in the Department of Public Health at Oregon State University. Freeman et al. pointed out numerous study limitations, but their bottom line was that “…patients with more severe injuries tend to both treat more frequently initially and take longer to recover from their injuries.

The authors' conclusion that treatment for a painful injury prolongs the duration of the injury is unsupported...” Thus, it seems Côté et al may have failed to apply common sense in this case, missing the most obvious conclusion.

Additional References:

  1. Côté P, et al. Initial patterns of clinical care and recovery from whiplash injuries: a population-based cohort study. Arch Intern Med, 2005;165(19):2257-63.
  2. Scholten-Peeters GG, Neeleman-van der Steen CW, van der Windt DA, Hendriks EJ, Verhagen AP, Oostendorp RA. Education by general practitioners or education and exercises by physiotherapists for patients with whiplash-associated disorders? A randomized clinical trial. Spine 2006;31:723–31.
  3. Freeman MD, et al. Greater injury leads to more treatment for whiplash: no surprises here. Arch Int Med 2006;166(11):1238-9.