Maximum pain on visual analog scales in spinal disorders

Abstract

Background context: Determining pain intensity is largely dependent on the patient's report.

Purpose: The objective of this study was to test the hypothesis that patients initially reporting a pain score of 10 out of 10 on the visual analog scale (VAS) would experience symptom improvement to a degree similar to patients reporting milder pain.

Study design: This study is a retrospective chart review.

Patient sample: A total of 6,779 patients seeking care for spinal disorders were included in the study.

Outcome measures: The outcome measures used in the study were pain scores on the VAS pain scale, smoking status, morbid depression, gender, and the presence of known secondary gain.

Materials and methods: Patients with lumbar degenerative disk disease with or without spinal stenosis who reported a VAS pain score of 10 out of 10 were identified. Changes in reported VAS pain, patient age, smoking status, morbid depression, gender, and the presence of known secondary gain were examined.

Results: A total of 160 individuals (2.9%) reported a maximum pain score of 10 out of 10 on a VAS at their initial presentation. The patients had a median improvement of 3 points in reported VAS pain between the first visit and the last follow-up appointment. The odds to improve by at least 40% on the VAS were 1.500 (95% confidence interval 1.090-2.065) compared with patients reporting submaximal pain. The proportion of patients with identifiable secondary gain was higher (p=.001) than that of patients with submaximal pain. Patients whose pain scores improved dramatically (ie, at least 4 points on the VAS) tended to be older (p=.001), to less often have secondary gain from their disease (p=.007), and to have a negative current smoking status (p=.002). Patients whose pain remained 10 out of 10 during the course of treatment smoked more frequently (p=.016).

Conclusions: Our analysis supports the need to consider the influence of secondary gain on the patients' reported VAS pain scores. Maximum pain seems to be a more acute phenomenon with some likelihood to significantly improve.

Keywords: Maximal pain; Pain; Secondary gain; Smoking; Spine; Visual analog scale.