Ability of Visual Analogue Scale to predict Oswestry Disability Index improvement and surgical treatment decision in patients with adult spinal deformity

Abstract

IntroductionThe effect of pain on HRQoL scores in ASD patients is not well studied. Disability is a major factor on decision and outcomes. On the other hand, little is known about the effect of perceived and reported pain on these parameters, especially in the elderly population. We hypothesized that baseline back and leg pain would not affect the treatment decision whereas may have a negative effect on outcomes. Research questionTo determine the correlation between preoperative ODI and VAS scores; and to identify the effect of baseline VAS score on treatment decision and ODI improvement following treatment. Material and methodsIn this retrospective study, patients with a follow-up duration of minimum 2 years were enrolled from a prospective multicentric ASD database. Pearson and Spearman correlation tests were used to evaluate the correlation between ODI and VAS scores; univariate binary logistic regression method was used to analyze the effect of VAS on treatment decision as well as the outcomes. Results1050 patients (mean age 48.2) were analyzed. Baseline ODI and back, leg pain VAS scores were significantly correlated (P ​< ​0.001). One unit increase in baseline back and leg pain VAS scores, increased the probability of improvement in ODI by 1.219 (P ​= ​0.016) and 1.182 times (P ​= ​0.029), respectively in surgically treated patients; and reduced it by 0.894 times (P ​= ​0.012) for conservatively treated patients. For patients >70 years old, one-unit increase in baseline leg pain VAS score increased the probability of deciding on surgical treatment by 1.121 times (p ​= ​0.016). Discussion and conclusionsPreoperative back and leg pain VAS scores were found to be significantly correlated with the preoperative ODI scores. Additionally, preoperative baseline back and leg pain VAS scores were useful in predicting the improvement in disability as assessed by ODI. Another important finding was that, higher baseline leg pain (but not back pain) VAS scores increased the rate of elderly patients preferring surgical treatment.