Minimal Clinically Important Difference (MCID) of the EOSQ-24 Questionnaire

Area of Science:

• Orthopaedic surgery
• Paediatric spine deformity
• Health-related quality of life (HRQoL) assessment

Background:

• Orthopaedic management of early onset scoliosis (EOS) often focuses on radiographic correction, but patient-reported outcomes like HRQoL are crucial.
• The Early Onset Scoliosis Questionnaire (EOSQ-24) measures HRQoL in EOS patients, but a definitive minimal clinically important difference (MCID) was lacking.
• Previous assumptions suggested a 10% score difference indicated clinical significance, necessitating evidence-based MCID determination for the EOSQ-24.

Purpose of the Study:

• To determine the MCID for the EOSQ-24 questionnaire in patients diagnosed with early onset scoliosis (EOS).
• To establish a clinically relevant threshold for assessing meaningful changes in patient HRQoL using the EOSQ-24.

Main Methods:

• A prospective, multicenter study involving 85 EOS patients who completed the EOSQ-24 pre- and post-treatment.
• Anchor-based MCID determination using receiver operating characteristic curves on global assessment survey data.
• Secondary calculation of a distribution-based MCID using 1 standard error of measurement (1 SEM) and prior reliability data.

Main Results:

• The mean change in EOSQ-24 scores across all patients was 8.5 points (SD = 8.1).
• The anchor-based MCID was calculated as 5.2 points, with an area under the curve (AUC) of 0.600.
• The distribution-based MCID, representing change beyond measurement error, was 4.6 points.

Conclusions:

• A 5-point change in EOSQ-24 scores is established as the minimal clinically important difference (MCID) for early onset scoliosis (EOS) patients.
• The consistency between anchor-based and distribution-based methods supports the robustness of this 5-point threshold for meaningful HRQoL changes.
• Accurate clinician recognition of important HRQoL shifts, guided by this MCID, is vital for enhancing clinical care in EOS management.