Visual/emotional stimuli and treatment with antidepressants alter Numerical Rating Scale score in patients with chronic pain.
OBJECTIVE
To examine the impact of visual stimulation (exciting red and tranquilizing green) on the score of the Numerical Rating Scale (NRS) questionnaire in patients with chronic pain.


METHODS
Prospective randomized study.


METHODS
Outpatient pain clinic of a university hospital.


METHODS
Two hundred outpatients with chronic pain.


METHODS
Patients were randomly assigned to receive the NRS questionnaire printed on either red paper (red group) or green paper (green group).


METHODS
The questionnaire included 5 questions consisting of the NRS in the worst, in the least, and in the average pain during last week and the NRS at rest and on movement at present. Calculation of the sample size was based on power of 0.8 and α=.01.


RESULTS
The NRS scores were not different between the 2 groups. In patients on antidepressants (n=76) and with depression (n=49), the NRS scores, except the NRS in the worst pain during last week score in patients on antidepressants, were significantly higher in the red group than in the green group (all P≤.040). In the red group, the NRS scores were significantly higher in patients with than without depression (all P≤.003), whereas there was no difference in the scores between patients of the green group with and without depression.


CONCLUSIONS
Our findings suggest that visual/emotional stimuli and treatment with antidepressants alter the NRS score in patients with chronic pain.
Department of Research and Development Center for New Medical Frontiers, Kitasato University School of Medicine, Sagamihara, Japan. Electronic address: kanaiakifumi@aol.com.
Akifumi
A
Kanai
Anesthesiology, Kitasato University School of Medicine, Sagamihara, Japan.
Shigehiro
S
Matsumoto
Anesthesiology, Kitasato University School of Medicine, Sagamihara, Japan.
Norihito
N
Hayashi
Anesthesiology, Kitasato University School of Medicine, Sagamihara, Japan.
Junko
J
Shimao
Anesthesiology, Kitasato University School of Medicine, Sagamihara, Japan.
Yuki
Y
Nagahara
D000368:Aged; D000928:Antidepressive Agents / Q000627:therapeutic use*; D059350:Chronic Pain / Q000175:diagnosis* / Q000523:psychology; D003116:Color; D003863:Depression / Q000188:drug therapy / Q000523:psychology; D004644:Emotions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018710:Pain Clinics; D059408:Pain Management / Q000379:methods; D010147:Pain Measurement / Q000379:methods* / Q000523:psychology; D010775:Photic Stimulation / Q000379:methods*; D011446:Prospective Studies; D016037:Single-Blind Method; D011795:Surveys and Questionnaires
D000928:Antidepressive Agents
Analog Pain Scale; Antidepressants; Chronic pain; Visual perception