Table 3

Comparison of clinical outcomes between groups at different time intervals (n = 103).

Early (n = 42)Late (n = 61)
MeanSDMeanSD P Valuea
6-mo VAS NP b 0.023
6-mo VAS AP b 0.027
6-mo JOA15.21.914.12.6 0.022
6-mo NS b 14.915.124.924.1 0.044
6-mo NPD b 10.112.917.115.5 0.042
6-mo NDI b 8.412.015.813.20.074
6-mo PCS51.38.545.710.80.059
6-mo MCS51.710.650.611.7 0.015
2-y VAS NP b
2-y VAS AP b
2-y JOA15.31.514.72.3 0.007
2-y NS b 13.514.322.020.6 0.046
2-y NPD b 6.910.013.013.7 0.042
2-y NDI b 6.810.211.713.8 0.036
2-y PCS52.16.949.49.8 0.008
2-y MCS53.19.848.713.50.057
  • Boldface indicates statistical significance.

  • aUsing multivariate regression to control for age, gender, body mass index, comorbidities and baseline JOA and NDI scores.

  • bA lower score is better.

  • JOA, Japanese Orthopaedic Association; MCS, Mental Component Summary; NDI, Neck Disability Index; NPD, neck pain and disability; NS, neurogenic symptoms; PCS, Physical Component Summary; RTW, return to work; VAS AM, visual analog scale arm pain; VAS NP, visual analog scale neck pain.