Table 2 Crude relative risks of whiplash among drivers involved in two-car collisions: Poisson regression models
French dataSpanish data
CharacteristicNoPercentage with whiplashRR (95% CI)CharacteristicNoPercentage with whiplashRR (95% CI)
Severity apart from whiplashSeverity apart from whiplash
    Ref*53147.8Referent    Ref*67359.1Referent
    MAIS 1246321.42.78 (2.41 to 3.16)    MAIS 165240.04.38 (3.89 to 4.94)
    MAIS 271615.51.99 (1.61 to 2.45)    MAIS ⩾215917.61.93 (1.37 to 2.72)
    MAIS ⩾32273.50.45 (0.22 to 0.91)
    Total8720    Total7546
Impact area†Type of crash†
    Front to front (head-on)281712.5Referent    Front to front (head-on)22513.8Referent
    Front to rear end12276.80.54 (0.43 to 0.69)    Front to rear end18824.30.31 (0.21 to 0.46)
    Front to side7828.60.68 (0.53 to 0.89)    Front to side294311.00.80 (0.57 to 1.13)
    Left side127614.41.15 (0.96 to 1.38)    Side‡5774.50.33 (0.20 to 0.54)
    Right side10599.90.79 (0.64 to 0.98)
    Rear end108620.31.62 (1.37 to 1.92)    Rear end139730.52.21 (1.58 to 3.01)
    Total8247    Total7024
Type of roadType of road
    Roads/motorways327312.31.02 (0.90 to 1.15)    Beltway/arterial230313.11.14 (1.01 to 1.30)
    Streets/other544712.1Referent    Streets/other525511.5Referent
    Total8720    Total7558
Location
    Not Urban206112.00.99 (0.85 to 1.14)
    Urban665912.2Referent
    Total8720
CrossingCrossing
    No413312.50.94 (0.84 to 1.07)    No326511.80.98 (0.86 to 1.10)
    Yes458711.8Referent    Yes429312.1Referent
    Total8720    Total7558
Time of dayTime of day
    Day525212.91.16 (1.03 to 1.32)    Day441213.01.24 (1.09 to 1.41)
    Night346811.1Referent    Night314610.5Referent
    Total8720    Total7558
WeekendWeekend
    No589713.31.38 (1.20 to 1.58)    No402912.81.19 (1.05 to 1.36)
    Yes28239.7Referent    Yes262910.7Referent
    Total8720    Total7558
Traffic density
    Fluid642111.4Referent
    Dense103214.81.30 (1.11 to 1.53)
    Traffic jam755818.11.59 (1.05 to 2.40)
    Total
Car mass (kg)
    500–80067317.8Referent
    800–1000268014.50.81 (0.66 to 0.99)
    1000–1200130910.70.60 (0.47 to 0.77)
    1200+9538.90.50 (0.38 to 0.66)
    Total5615
Seatbelt wearingSeatbelt wearing
    No/unknown25317.41.38 (1.02 to 1.86)    No/unknown53015.71.15 (0.93 to 1.42)
    Yes719712.6Referent    Yes411513.7Referent
    Total7450    Total4645
AgeAge
    16–24213311.40.83 (0.70 to 0.98)    16–24128415.41.38 (1.15 to 1.65)
    25–34238013.71.00 (0.85 to 1.16)    25–34216314.81.32 (1.13 to 1.56)
    35–49234213.7Referent    35–49194211.2Referent
    50–64131410.10.73 (0.60 to 0.89)    50–64119512.31.10 (0.90 to 1.34)
    ⩾654917.10.52 (0.37 to 0.73)    ⩾653017.30.65 (0.43 to 0.99)
    Total8660    Total6885
SexSex
    Male62358.2Referent    Male578111.3Referent
    Female248522.12.69 (2.39 to 3.03)    Female101124.72.19 (1.92 to 2.49)
    Total8720    Total6792
  • *This category includes non-injured drivers as well as drivers who have only sustained a whiplash injury.

  • †Main location of impact for the car driver: in cases of frontal impact, details are given for the impact location on the other car (front, rear, side).

  • ‡Distinction between left and right side is not recorded.

  • MAIS, maximum abbreviated injury score.