Age as an Independent Predictor of MCID Achievement and Patient Satisfaction Following Elective Cervical Spine Surgery

Study DesignRetrospective Cohort Study.ObjectivesTo determine whether age independently predicts minimal clinically important difference (MCID) achievement in physical function (PF) and pain interference (PI) following elective cervical spine surgery, and to examine how age-related expectation-achievement discordance influences postoperative satisfaction.MethodsAdult patients undergoing elective cervical spine surgery at a single academic center (2022-2025) were included if they completed preoperative and 12-month Patient-Reported Outcomes Measurement Information System (PROMIS) PF and PI computerized adaptive tests (CATs) and a preoperative expected outcome assessment. MCID was defined as an 8-point PROMIS T-score change. Patients were stratified into five age groups (<45, 45-54, 55-64, 65-74, ≥75). Multivariable logistic regression modeled age continuously, adjusting for BMI, levels fused, sex, smoking, revision status, and pathology.ResultsAmong 129 patients, MCID achievement declined significantly with age for both domains (trend p<0.001). Each additional year of age independently reduced odds of achieving MCID (PF: OR 0.95, p=0.007; PI: OR 0.96, p=0.02). Adjusted MCID probability fell below 50% at 45.9 years for PF and 49.1 years for PI. The expectation-achievement gap was widest in middle-aged patients (45-64), who held expectations comparable to younger patients yet achieved outcomes consistent with older cohorts. Among non-achievers, satisfaction increased with advancing age (trend p=0.05 for PF).ConclusionsAfter adjusting for the covariates assessed, age continuously and independently predicts failure to achieve MCID after cervical spine surgery, with probability falling to 50% by the late forties. Despite this, older non-achievers report high satisfaction, suggesting MCID is not a universal prerequisite for surgical success and underscoring the need for age-specific preoperative counseling.