Human Studies

Background and aims Women with chronic pelvic pain represent a heterogeneous group, and it is suggested that the existence of sub-groups can explain varying results and inconclusiveness in clinical trials. Some predictors of treatment outcome are suggested, but the evidence is limited. The primary aim of this study was to explore if selected pre-treatment characteristics of the participants in a recently conducted randomized controlled trial were associated with treatment outcome. Methods In this study secondary analysis of data collected in a randomized trial were conducted. The participants were women with chronic pelvic pain randomized to two different physical therapy treatments. Analyses in this study were performed for the whole group as a cohort. The primary outcome measure was change in pain intensity from baseline to 12 months, measured with the numeric rating scale (0-10). The women were asked to rate their mean pelvic pain intensity during the last 7 days. Based on previous research and on available variables from the randomized controlled trial four potential predictive factors were derived from the baseline data and assessed one by one in a linear regression model, adjusted for age and treatment group. The variables with strongest association (p < 0.10) with the primary outcome were further included in a multivariable linear regression model with backward selection, adjusted for age and treatment group. Results Fifty women (mean age 38.1, SD = 12.2) were included in the analysis. For these women the mean change in pain intensity was -1.2 points (95% CI -1.8 to -0.7) from baseline to 12 months. The multivariable regression model showed that pelvic pain duration of 6 years or more was associated with less decrease in pain intensity with a regression coefficient of 1.3 (95% CI 0.3-2.4). Baseline pain intensity was associated with higher pain reduction after PT treatment with a regression coefficient per SD increase in baseline pain of -0.6 (95% CI -1.1 to -0.1). None of the women with main pain site other places than in the pelvis reported any pain reduction after physical therapy treatment, but due to the small numbers the predictor was not included in the regression analysis. Conclusions We identified that pelvic pain duration of 6 years or more was associated with less pain reduction, and that higher baseline pain intensity was associated with higher pain reduction after physical therapy treatment in this sample of women with chronic pelvic pain. For the variable main pain site other places than the pelvis the results are unsure due to small numbers. Implications Based on our finding of long pain duration as a negative predictor for pain reduction, we emphasize that early intervention is important. Many of the participants in our RCT reported pelvic surgeries or other treatments prior to referral for PT, and we suggest that referral to a non-invasive intervention such as PT should be considered at an earlier stage. In order to tailor interventions to the individual women's needs, thorough baseline assessments, preferably in a multidisciplinary setting, should be performed.

Background and aims The ACR1990 criteria of fibromyalgia (FM) have been criticized due to poor reliability of tender points counting (TPC), inconsistent definitions of the widespread pain, and by not considering other symptoms than pain in the FM phenotype. Therefore, several newer self-report measures for FM criteria have emerged. The aim of this study was to translate the fibromyalgia survey questionnaire (FSQ) to Norwegian and validate both the 2011 and the 2016 fibromyalgia survey diagnostic criteria (FSDC) against the ACR1990 criteria. Methods One hundred and twenty chronic pain patients formerly diagnosed with fibromyalgia according to the ACR1990 criteria, and 62 controls not diagnosed or where fibromyalgia was not suspected, were enrolled in this study. All responded to a Norwegian version of the FSQ. Also, they had a clinical examination according to ACR1990 fibromyalgia criteria including a counting of significant tender points with an algometer (TPC). The FSQ with the Widespread Pain Index (WPI) and Symptom Severity scale (SSS) subscales, Fibromyalgia Severity (FS) sum score, was examined for correlations with the fibromyalgia impact questionnaire (FIQ) and TPCs. Face-validity, internal consistence, test-retest reliability and construct validity with convergent and divergent approaches were examined and a Receiver Operating Characteristics (ROC) analysis was performed. Results The internal consistency of FS measured by Cronbach's alfa was good (=0.904). The test-retest reliability measures using intra class correlation were respectable for the FS, including WPI and SSS subscales (0.86, 0.84 and 0.87). FS, WPI and SSS correlated significantly with FIQ (0.74, 0.59 and 0.85) and TPC indicating an adequate construct, convergent validity. The medians of FS, WPI and SSS in the fibromyalgia-group were significantly different from the non-fibromyalgia-group indicating good construct, divergent validity. Using the 2011 and 2016 FSDC vs. ACR 1990 as a reference, sensitivity, specificity, positive likelihood ratio (LR +) and negative likelihood ratio (LR-) were identified. The accuracy rate for both 2011 and 2016 FSDC were respectable (84%). ROC analysis using FS revealed a very good Area Under the Curve (AUC) = 0.860. Conclusion The current study revealed that the Norwegian versions of FSQ is a valid tool for assessment of fibromyalgia according to the 2011 and 2016 (FSDC).

Female C57BL6 mice exhibit less severe chondropathy compared with male mice. We tests the robustness of this observation and explore underlying mechanisms.

Spinal cord stimulation (SCS) is an established treatment of chronic neuropathic pain. Although a temporary SCS screening trial is widely used to determine whether a patient should receive permanent SCS implant, its evidence base is limited. We aimed to establish the clinical utility, diagnostic accuracy, and cost-effectiveness of an SCS screening trial. A multicentre single-blind, parallel two-group randomised controlled superiority trial was undertaken at three centres in United Kingdom. Patients were randomised 1:1 to either SCS screening trial strategy (TG) or no trial screening strategy (NTG). Treatment was open label, but outcome assessors were masked. The primary outcome measure was numerical rating scale (NRS) pain at six-months follow-up. Between June 2017 and September 2018, 105 participants were enrolled and randomised (TG=54, NTG=51). Mean NRS pain decreased from 7.47 at baseline (before SCS implantation) to 4.28 at 6-months in TG and from 7.54 to 4.49 in NTG (mean group difference: 0.2, 95% CI: -1.2 to 0.9, p=0.89). We found no difference between TG and NTG in the proportion of pain responders or other secondary outcomes. SCS screening trial had a sensitivity of 100% (95% CI: 78 to 100) and specificity of 8% (95% CI: 1 to 25). The mean incremental cost-effectiveness ratio of TG versus NTG was £78,895 per additional quality-adjusted life-year (QALY) gained. In conclusion, although the SCS screening trial may have some diagnostic utility, there was no evidence that an SCS screening trial strategy provides superior patient outcomes or is cost-effective compared to a no trial screening approach.