OBJECTIVES:

To evaluate whether mild water-filtered near infrared whole-body hyperthermia (NI-WBH) produces an additional benefit when applied as an adjunct to a standard multimodal rehabilitation (MR) compared with MR only in patients with fibromyalgia (FM).

METHODS:

One hundred thirty-nine patients of a German inpatient rehabilitation hospital meeting the ACR 1990 criteria for FM were randomly allocated to NI-WBH (heating-up to 38.1 degrees C body core temperature followed by a 15 min heat retention period) and MR or MR only, twice a week over 3 weeks. Main outcome measures were affective and sensory pain assessed by a German version of the McGill Pain Questionnaire, measured at baseline, postintervention, 3 and 6 months postintervention and analyzed by intention to treat.

RESULTS:

Repeated measures analysis of covariance showed significant differences between groups for both primary outcome measures in favor of NI-WBH and MR compared with MR only (P<0.001 for affective pain, P=0.001 for sensory pain). Secondary analyses on pain intensity, FM-related quality of life and tender point assessment yielded similar results. Moderate effect sizes were observed for all outcome measures considered (range, 0.41 to 0.75). NI-WBH related side effects were observed in 14 of 69 participants (20%) but all disappeared in less than 30 minutes.

DISCUSSION:

The study indicates that NI-WBH is a worthwhile adjunct to MR in the treatment of FM.