Influence of biased clinician statements on patient report of referred pain.
OBJECTIVE
The purpose of this study was to examine the influence of clinician bias on patients' reports of referred pain. Diagnosis of temporomandibular disorders is dependent on subjective reports of pain and referred pain upon manual muscle palpation. The influence of biased clinician statements in such subjective reports has not been previously investigated.


METHODS
Forty subjects with pain and who met specific inclusion criteria were randomly assigned to 1 of 2 experimental groups. One group was subjected to a standardized biasing statement, while the other group was not. Tender points in the masseter muscle were then stimulated with a pressure algometer to the pressure-pain threshold. Subjects then recorded the presence or absence, location, intensity, and unpleasantness of any referred pain. State-trait anxiety and social desirability were also assessed to explore the possibility that anxiety levels or subjects' desires to please the experimenter influenced results.


RESULTS
The biased group reported increased presence (P < 0.01), intensity (P < 0.001), and unpleasantness (P < 0.003) of referred pain as compared to the non-biased group. There were no differences between groups on state-trait anxiety or social desirability (P > 0.05).


CONCLUSIONS
These data suggest that patient reports of pain referral may be subject to clinician bias, and recommendations to control this bias are offered.
Branch
M A
MA
Department Head TMD/Orofacial Pain, Naval Dental Center, 2310 Craven Street, San Diego, CA 92136, USA. mbranch@sciti.com
Carlson
C R
CR
Okeson
J P
JP
D000293:Adolescent; D000328:Adult; D001007:Anxiety / Q000523:psychology; D001291:Attitude of Health Personnel; D016009:Chi-Square Distribution; D015331:Cohort Studies; D005157:Facial Pain / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008406:Masseter Muscle / Q000503:physiopathology; D008875:Middle Aged; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology; D010173:Palpation; D011287:Prejudice; D011312:Pressure; D011369:Professional-Patient Relations; D012684:Sensory Thresholds / Q000502:physiology; D012928:Social Desirability; D013223:Statistics as Topic; D013705:Temporomandibular Joint Disorders / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology*