Self-reported pain levels in patients with fibromyalgia may change according to weather conditions. Previous studies suggest that low barometric pressure (BMP) is significantly related to increased pain, but that the contribution of changes in BMP has limited clinical relevance. The present study examined whether BMP influenced variability in perceived stress, and if stress levels moderated or mediated the relationship between BMP and pain. Forty-eight patients with fibromyalgia enrolled in a randomized controlled trail (RCT) reported pain and emotional state three times daily with mobile phone messages for a 30-consecutive day period prior to the start of the treatment in the RCT. The patients were unaware that weather data were collected simultaneously with pain and emotional reports. The results showed that lower BMP and increased humidity were significantly associated with increased pain intensity and pain unpleasantness, but only BMP was associated with stress levels. Stress levels moderated the impact of lower BMP on pain intensity significantly, where higher stress was associated with higher pain. Significant individual differences were present shown by a sub-group of patients (n = 8) who reacted opposite compared to the majority of patients (n = 40) with increased pain reports to an increase in BMP. In sum, lower BMP was associated with increased pain and stress levels in the majority of the patients, and stress moderated the relationship between BMP and pain at the group-level. Significant individual differences in response to changes in BMP were present, and the relation between weather and pain may be of clinical relevance at the individual level.

Background: Instruments for monitoring the clinical status of adolescents with emotional problems are needed. The Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM) according to theory measures problems/ symptoms, well-being, functioning and risk. Documentation of whether the theoretical factor structure for CORE-OM is applicable for adolescents is lacking. Methods: This study examined the factor structure and psychometric properties of the CORE-OM based on two samples of adolescents (age 14-18): youths seeking treatment for emotional problems (N = 140) and high school students (N = 531). A split half approach was chosen. An exploratory factor analysis (EFA) was performed on the first half of the stratified samples to establish the suitability of the model. A Confirmatory Factor Analysis (CFA) with the chosen model from the EFA was performed on the second half. Internal consistency and clinical cutoff scores of the CORE-OM were investigated. Results: The best fitting model only partially confirmed the theoretical model for the CORE-OM. The model consisted of five factors: 1) General problems, 2) risk to self, 3) positive resources 4) risk to others and 5) problems with others. The clinical cutoff score based on the all-item total was higher than in an adult sample. Both the all-item total and general problems cutoff scores showed gender differences. Conclusion: The factor analysis on CORE-OM for adolescents resulted in a five-factor solution, and opens up for new subscales concerning positive resources and problems with others. A 17-item solution for the general problems/ symptoms scale is suggested. We advise developers of self-report instruments not to reverse items, if they do not intend to measure a separate factor, since these seem to affect the dimensionality of the scales. Comparing means for gender in non-clinical samples should not be done without modification of the general emotional problem and the positive resources scales. Slightly elevated CORE-OM scores (up to 1.3) in adolescents may be normal fluctuations.