Table 3

Secondary outcomes estimated from linear mixed effects model from 1 to 24 months after combat injury

β95% CIP value
Neuropathic Pain Scale*
 Pain intensity
  Intercept3.372.92 to 3.81<0.001
  Month since initial injury−0.04−0.06 to −0.03<0.001
  Regional anesthesia−0.23−0.66 to 0.200.297
 Overall pain quality
  Intercept2.780.00 to 2.360.207
  Month since initial injury−0.200.00 to −0.250.157
  Regional anesthesia−0.120.56 to −0.510.277
 Total pain score
  Intercept2.552.22 to 2.88<0.001
  Month since initial injury−0.03−0.04 to −0.02<0.001
  Regional anesthesia−0.04−0.36 to 0.280.810
Treatment Outcomes of Pain Survey†
 Fear avoidance
  Intercept49.8344.18 to 55.49<0.001
  Month since initial injury−0.58−0.78 to −0.38<0.001
  Regional anesthesia1.73−3.62 to 7.090.525
 Healthcare satisfaction
  Intercept61.5956.77 to 66.40<0.001
  Month since initial injury−0.34−0.55 to −0.140.001
  Regional anesthesia3.83−0.70 to 8.350.097
 Life control
  Intercept75.4370.05 to 80.81<0.001
  Month since initial injury−0.06−0.27 to 0.160.604
  Regional anesthesia4.12−0.91 to 9.150.108
 Objective family social disability
  Intercept48.2642.63 to 53.89<0.001
  Month since initial injury−0.20−0.42 to 0.020.075
  Regional anesthesia−1.20−6.54 to 4.140.659
 Patient satisfaction with outcomes
  Intercept64.4559.70 to 69.19<0.001
  Month since initial injury0.18−0.01 to 0.360.065
  Regional anesthesia2.36−2.13 to 6.850.301
Pain symptom
 Intercept40.1835.02 to 45.34<0.001
 Month since initial injury−0.35−0.53 to −0.17<0.001
 Regional anesthesia−1.45−6.34 to 3.440.560
Solicitous response
 Intercept55.3247.45 to 63.19<0.001
 Month since initial injury−1.12−1.45 to −0.80<0.001
 Regional anesthesia3.22−4.13 to 10.580.389
Mental component summary‡
 Intercept54.9552.30 to 57.59<0.001
 Month since initial injury−0.26−0.36 to −0.17<0.001
 Regional anesthesia0.73−1.75 to 3.210.564
Physical component summary‡
 Intercept38.3635.78 to 40.94<0.001
 Month since initial injury0.520.43 to 0.61<0.001
 Regional anesthesia−0.07−2.51 to 2.360.954
Patient Health Questionnaire 9-Item§
 Intercept4.323.40 to 5.25<0.001
 Month since initial injury0.00−0.03 to 0.040.997
 Regional anesthesia0.40−0.47 to 1.260.364
PTSD Check List (continuous)¶
 Intercept28.3925.71 to 31.07<0.001
 Month since initial injury0.07−0.02 to 0.160.126
 Regional anesthesia0.35−2.19 to 2.890.788
  • All models included a covariate for ISS and length of hospitalization. See online supplementary table for more detail.

  • *Neuropathic Pain Scale outcomes measure sensations of neuropathic pain from 0, no pain, to 10, the wrost pain imaginable.

  • †Treatment Outcomes of Pain Survey outcomes fear avoidance, objective family social disability, pain symptom, and solicitous response are measured from 100, the greatest possible amount of that concept (worst score), to 0, none of that concept (best score). For outcomes of patient satisfaction with care, patient satisfaction with outcomes, and life control, a score of 100 indicates the best health or greatest satisfaction (best score) and 0 indicates worst health or worst satisfaction (worst score).

  • ‡Embedded in the Treatment Outcomes of Pain Survey for this study, the Short Form Health Survey 36-Item component summary scores are aggregates of individual domains measured from 1, poor health, to 5, very good health that have been transformed to weighted z-scores, multiplied by 10 and added to 50 to linearly transform the summary scores on the T-score metric, which has a mean of 50 and a SD of 10 for the US general population. Higher T-scores indicate a positive improvement in a domain.

  • §Patient Health Questionnaire scores are a sum of the nine depression-specific questions scores from 0, no depressive symptoms at all, to 3, with depressive symptoms experienced nearly every day, allowing for scores to range from 0 to 27.

  • ¶PTSD Check List measures the frequency of 17 symptoms of PTSD in the past month on a scale of 1, not at all, to 5, extremely, for a summary score ranging from 17 to 85. Previously, a score of 30 has been suggested as a cut-point for estimating PTSD in active duty military personnel serving in OEF/OIF (https://www.ptsd.va.gov/professional/assessment/documents/PCL_handoutDSM4.pdf).

  • **Non-linear mixed effects model fit.

  • 95% CI, 95% CI of fixed effect beta coefficient; ISS, Injury Severity Scores; OEF, Operation Enduring Freedom; OIF, Operation Iraqi Freedom; PTSD, post-traumatic stress disorder.