The Qualification of Outcome after Cervical Spine Surgery by Patients Compared to the Neck Disability Index

Abstract

ObjectiveThe Neck Disability Index (NDI) is a patient self-assessed outcome measurement tool to assess disability, and that is frequently used to evaluate the effects of the treatment of neck-related problems. In individualized medicine it is mandatory that patients can interpret data in order to choose a treatment. A change of NDI or an absolute NDI is generally meaningless to a patient. Therefore, a correlation between the qualification of the clinical situation rated by the patient and the NDI score was evaluated.MethodsPatients who completed an NDI after anterior surgery because of symptomatic single level degenerative cervical disc disease were asked one month after completion of the NDI to qualify their clinical situation of a 5-item Likert scale varying from excellent to bad. Since a clear distinction between the categories was not possible based on the total NDI score, a ROC-curve was built, and the AUC computed in order to estimate best dichotomization in qualification of the clinical situation. The best corresponding cut-off point for the NDI total score was found by studying sensitivity and specificity for all possible cut-off points.Results102 patients were included. The highest AUC was obtained by dichotomizing the qualification into a group with good outcome and less-good outcome. The highest sensitivity and specificity for the dichotomized qualification as good outcome corresponded to a NDI ≤ 7. Sensitivity was 81.08% and specificity was 78.57%.ConclusionThis is the first study that correlated the qualification of the situation by the patients themselves and NDI. An NDI ≤ 7 corresponded to a good outcome according to the patients. This is valuable information to inform patients in their decision for any treatment.

Neck disability index, Visual analog scale, and Likert scale in patients receiving pharmacotherapy for neck pain: How good do they correlate?

“…[8,9] In this study disability of patients due to neck pain was assessed using NDI before and after treatment and a significant reduction in scores was observed posttreatment which represented reduction in disability. This goes in agreement with the findings of study done by Donk et al [10] Our study also showed that there is a correlation between NDI and qualitative Likert scale rating which confirmed that improvement in pain status is also associated with reduced disability of patients with neck pain. Donk et al compared the qualification of outcome by patients after cervical spine surgery to the NDI and found that there was a correlation between qualification of the situation by the patients themselves and NDI.…”

“…Previous studies also proved qualitative Likert scale as an effective tool to measure the improvement in clinical condition after treatment. [10,11] VAS showed significant reduction in scores following treatment with skeletal muscle relaxants and analgesics in the study population. In their study, Lee et al measured the change in VAS score associated with adequate pain control and a mean reduction in VAS of 30.0 mm was observed which represented a clinically important difference in pain severity with respect to patients' perception of adequate pain control.…”

Long-term Evaluation of Cervical Disc Arthroplasty with the Mobi-C© Cervical Disc: A Randomized, Prospective, Multicenter Clinical Trial with Seven-Year Follow-up

“…It will not help him/her in decision-making about any treatment for neckrelated problems." 32 Therefore, in this study, we have attempted to transform the outcome scores into expressions that can easily be understood by patients to help them in making a decision about their eventual treatment. Here we report that the vast majority of patients in both single and two level cohorts improved in neck disability after surgery (70.2%-80.8% of two-level surgeries and 84.6%-84.8% of single level surgeries) and neck pain (83.3%-87.5% of single level surgeries and 77.7%-86.0% of two-level surgeries).…”

Substantial clinical benefit for Neck Disability Index revisited: establishing the goal for treatment?

“…For data analysis the Student's t test was used. At dichotomisation of outcome, two groups of patients could be defined: those with a good to excellent outcome, and those with a less than good outcome [9]. To estimate the value of DNDI that corresponded best with the dichotomised outcome, the cut-off values with the highest sensitivity and specificity were chosen separately.…”