Pain assessment in patients with fibromyalgia syndrome: a consideration of methods for clinical trials.
OBJECTIVE
This study was designed to compare 3 commonly used methodologies for assessing clinical pain during trials involving patients diagnosed with fibromyalgia syndrome. Baseline characteristics, characteristics over time, and compliance were evaluated for each of the methods.


METHODS
Fourteen patients diagnosed with fibromyalgia syndrome were asked to monitor their symptoms of pain using 3 different strategies over a 12-week period: 1) real-time pain reports were collected on an electronic diary using randomly-scheduled audible prompts; 2) end-of-week reports asked patients to rate their mean pain over the past week on the electronic diary; and 3) monthly in-clinic reports asked patients to rate their mean pain for the week using a traditional paper and pencil diary.


RESULTS
Significantly different baseline values were obtained for the 3 methods. Paper and pencil produced the highest values, and real-time pain reports produced the lowest baseline values. Pain ratings were more likely to reflect decreases in the 2 methods relying on recall than the real-time strategy. The average adherence with pain monitoring using the electronic diary was 85%, which was superior to the adherence for the recall measures completed during the clinic visits.


CONCLUSIONS
Pain assessment methods relying on recall might contribute to an apparent improvement in clinical trials in the absence of an intervention; such an effect has been considered a "placebo response." Future clinical trials might consider using a real-time approach to pain assessment, which in this study appeared to mitigate against seeing improvement in the absence of an intervention and demonstrated higher levels of patient adherence.
Williams
David A
DA
Department of Medicine, Division of Rheumatology, University of Michigan, Ann Arbor 48106, USA. daveawms@umich.edu
Gendreau
Michael
M
Hufford
Michael R
MR
Groner
Kimberly
K
Gracely
Richard H
RH
Clauw
Daniel J
DJ
D000328:Adult; D000368:Aged; D002986:Clinical Trials as Topic; D018592:Cross-Over Studies; D003625:Data Collection; D005260:Female; D005356:Fibromyalgia / Q000150:complications*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008499:Medical Records; D016347:Medical Records Systems, Computerized; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis* / Q000209:etiology; D010147:Pain Measurement / Q000379:methods*; D015203:Reproducibility of Results; D013997:Time Factors