One-year outcomes of early-crossover patients in a cohort receiving nonoperative care for lumbar disc herniation

Abstract

OBJECTIVE The authors comprehensively studied the recovery course and 1-year outcomes of early-crossover patients who were randomized to the nonoperative care arm of the Leiden-The Hague Spine Intervention Prognostic Study. The primary goal was to gain insight into the differences in the recovery patterns of early-crossover patients and those treated nonoperatively; secondary goals were to identify predictors of good 1-year outcomes, and to understand when and why patients were likely to cross over. METHODS Individual EuroQol-5D scores were obtained at baseline and at 2, 4, 8, 12, 26, 38, and 52 weeks for 142 patients. Early-crossover patients were defined as those electing to undergo surgery during the first 12 weeks of treatment. Crossover and noncrossover groups were compared using Kruskal-Wallis, Wilcoxon-Mann-Whitney, and chi-square tests. Linear mixed-effects models were used to examine the growth trajectories of crossover and noncrossover groups. Recursive partitioning trees were used to model crossover events and the timing of crossover decisions. Multivariable logistic regression models were used to identify predictors of good 1-year outcomes. RESULTS Of the 142 patients randomized to receive prolonged nonoperative care, 136 were selected for the study. In this cohort, 43/136 (32%) opted for surgery, and 31/43 (72%) of crossover events occurred before the 12-week time point. Early-crossover patients had significantly greater functional impairment at Week 2 than noncrossover patients (p = 0.031), but experienced greater recovery by 26 weeks and better 1-year outcomes (p = 0.045). Patients who did not experience an improvement in their symptoms between 2 and 8 weeks were more likely to cross over (OR 3.5, 95% CI 1.2-10.1; p = 0.01). Recursive partitioning trees were able to identify crossover patients with 76% accuracy. Regression models suggested that better recovery at 26 weeks (p < 0.01) was predictive of good 1-year outcome; declining health status between Weeks 4 and 8 was negatively predictive of good outcome (p < 0.01). CONCLUSIONS This study is the first to comprehensively analyze the recovery and outcomes of crossover patients, and compare them to nonoperatively treated patients. The results suggest that patients who have a low EuroQol-5D score during the early weeks of treatment and who do not respond to nonoperative care during the first few weeks of treatment are most likely to cross over. Early-crossover patients experience a greater rate of recovery and more frequently have a good 1-year outcome when compared with nonoperatively treated patients. The current results motivate a broader investigation into the timing of surgery and the identification of patient populations that will be most benefited by early surgical treatment for lumbar disc herniation.