The aim of this study was to determine the PASS for both the Japanese version of the NDI (NDI-J) and the Visual Analogue Scale (VAS) for cervical pain at six months post-surgery for cervical degenerative diseases.
This was a retrospective cohort study. Subjects were patients who were six months post-surgery and had undergone decompression or fusion surgery for cervical degenerative diseases. Exclusion criteria were traumatic injuries, postoperative paralysis, cerebrovascular diseases, neuromuscular diseases, and dementia. The evaluation items included basic attributes (age, gender, BMI, number of intervertebral lesions, and presence of fixation), the NDI-J, VAS for neck pain and the Japanese version of the Core Outcome Measures Index (COMI). The COMI is a questionnaire that uses a five points Likert scale, “Very satisfied,” “Somewhat satisfied,” “Neither satisfied nor dissatisfied,” “Somewhat dissatisfied,” and “Very dissatisfied,” to answer the question, "If your current symptoms were to continue for the rest of your life, how would you feel about them?" COMI was used as the external anchor in the anchor-based method to calculate PASS. Responses of "very satisfied" or "somewhat satisfied" were considered to have achieved PASS. ROC curve analysis was performed to calculate the cutoff value, sensitivity, specificity, and Area Under the Curve (AUC) for achieving PASS in the NDI-J and VAS for neck pain at six months postoperatively.
The study included 80 subjects (26 women). The mean age was 69 years, and the mean BMI was 25 kg/m2. The median number of affected vertebral segments was 3, and 47 patients underwent fusion surgery. 22 patients (27.5%) achieved PASS. For VAS for neck pain, the cutoff for achieving PASS was 5 mm, with a sensitivity of 0.72, specificity of 0.83, and Area Under the Curve (AUC) of 0.81. For NDI, the cutoff was 10%, with a sensitivity of 0.67, specificity of 0.83, and AUC of 0.72.
In this study of Japanese patients six months after surgery for cervical degenerative diseases, the PASS threshold was 10% for the NDI-J and 5 mm for the VAS of neck pain.
These findings may be useful in determining treatment efficacy and setting goals for patients who have undergone surgery for cervical degenerative diseases. Further studies are needed to assess the external validity of these results for broader generalization.
Patient acceptable symptom state
Postoperative cervical degenerative disease
