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Risk factors of poor prognosis after whiplash injury
S Suissa
Whiplash,
a common injury following motor vehicle crashes, is
associated with high costs and a prognosis that is variable
and difficult to predict. In this paper, we review findings
from the Quebec cohort epidemiological study on predictive
factors of recovery from whiplash injury after a motor
vehicle crash.
We formed a population-based incident cohort of all
4,759 individuals who sustained a whiplash injury resulting
from a motor vehicle crash in the province of Québec,
Canada, in 1987, and followed these patients for up
to seven years. The data were obtained from the universal
automobile insurance plan (SAAQ) that covers all seven
million residents of the Province for all vehicular-related
injuries. From this cohort, we formed the cohort of
3,014 for whom a police report was completed. For this
cohort, we obtained data on crash-related factors directly
from the police report. We also formed the cohort of
2,627 subjects who had strictly a whiplash injury, without
associated injuries. For this cohort, the data on signs
and symptoms were obtained from the medical charts kept
by the SAAQ. For both cohorts, data on the outcome,
the recovery time from whiplash, was obtained from the
SAAQ databases.
The crash-related cohort study found that socio-demographic
factors associated with a longer recovery from whiplash
include older age, female sex, having dependents and
not being employed full time and that each decreases
the rate of recovery by 14 to 16 per cent. Factors related
to the crash conditions indicate that being in a truck
or bus, with
a decrease of 52% in the rate of recovery, being a passenger
in the vehicle (15%), colliding with a moving vehicle
(16%), and a side or frontal collision (15%) all decrease
the rate of recovery. We introduce a combined risk score
that predicts longer recovery.
In the cohort of subjects with signs and symptoms, the
median recovery time was 32 days and 12% of subjects
had still not recovered after 6 months. The signs and
symptoms that were found to be independently associated
with a slower recovery from whiplash, besides female
gender and older age, were neck pain on palpation; muscle
pain; pain or numbness radiating from neck to arms,
hands or shoulders; and headache. Together, the presence
of all these factors in females aged 60 predicted a
median recovery time of 262 days, compared with 17 days
for younger males aged 20 who do not have any of these
factors. In contrast, using the Quebec classification
of signs and symptoms, the median recovery time varied
from 17 to 123 days.
We conclude that several socio-demographic and crash-related
factors, as well as several signs and symptoms, including
a combination of specific musculoskeletal and neurological
ones that whiplash patients present with, are predictive
of a longer recovery period. These patients should be
targeted for an early intervention programme aimed at
managing whiplash patients with a poor prognosis.
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