STarT-Lower Extremity Screening Tool at Six-weeks Predicts Pain and Physical Function 12-months after Traumatic Lower Extremity Fracture

Abstract

Background: Patients with lower extremity fracture requiring surgical fixation often have poor long-term pain and disability outcomes. This indicates the need for a risk stratification tool that can inform patient prognosis early in recovery. The purpose of this study was to determine the predictive validity of the STarT-Lower Extremity Screening Tool (STarT-LE) in patients with lower extremity fracture requiring surgical fixation.

Materials and methods: One-hundred and twenty-two patients (41.7 ± 14.7 years, 54% male) with lower extremity fracture and no history of chronic pain were enrolled in this prospective cohort study. Patients completed the STarT-LE Screening Tool six-weeks after definitive fixation. Validated measures of chronic pain development, pain interference, and physical function were collected at 12-months. STarT-LE low, medium, and high risk subgroups were compared against each outcome measure with chi-square, one-way analysis of variance, and sensitivity and specificity analyses. Multivariable linear regression analyses determined if STarT-LE risk subgroups at six weeks were associated with each outcome at 12 months when controlling for important baseline demographics.

Results: Twelve-month follow-up was completed by 114 patients (93.4%). Increase in STarT-LE risk subgroup at six-weeks was associated with higher frequency of chronic pain (Low: 14.7%, Medium: 48.3%, High: 85.0%), worse pain interference (Low: 48.6 ± 8.88, Medium: 56.33 ± 8.79, High: 61.65 ± 7.74), and worse physical function (Low: 50.77 ± 9.89, Medium: 42.52 ± 6.47, High: 37.44 ± 7.46) at 12-months. The low risk subgroup had high sensitivity (range: 84.9%-93.9%) and the high risk subgroup had high specificity (range: 87.7%-95.2%) for dichotomized 12-month outcomes. The multivariable results showed that medium and high STarT-LE risk categories were associated with chronic pain development (Medium odds ratio: 3.90, 95%CI: 1.11 to 13.66; High odds ratio: 13.14, 95%CI: 2.25 to 76.86), worse pain interference (Medium: β:4.37, 95%CI: 0.17 to 8.58; High: β:7.01, 95%CI: 1.21 to 12.81), and worse physical function (Medium: β:-3.76, 95%CI: -7.41 to -0.11; β:-7.44, 95%CI:-12.47 to -2.41), respectively, when controlling for important baseline variables.

Conclusion: The STarT-LE has the potential to identify patients at-risk for poor pain and functional outcomes, and may help inform the post-surgical management of patients with traumatic LE injury.

Keywords: Chronic Pain; Disability; Lower Extremity Fracture; Risk; STarT-LE Screening Tool.