BackgroundHypovitaminosis D has previously been reported in both the general population, in people with chronic musculoskeletal pain, and in people with low back pain (LBP). Myopathy-related symptoms such as diffuse bone and muscle pain, weakness and paresthesia in the legs, have also been observed in people with non-specific LBP and associations with low levels of Vitamin D have been suggested. The objectives of this study were to investigate (1) Vitamin D levels in patients seeking care for LBP in a Danish out-patient secondary care setting, and (2) their possible relationship with myopathy-related symptoms, Body Mass Index (BMI), and Modic changes.MethodsA total of 152 consecutive patients with non-specific LBP participated in a cross-sectional study. Participants were recruited at The Spine Centre of Southern Denmark during springtime 2011. Individual serum levels of 25-Hydroxyvitamin-D were determined using Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS). Information about symptoms, height, and weight were collected from electronic questionnaires completed by the participants. All patients had an MRI from which Modic changes were identified. Correlations between Vitamin D level and pain, paresthesia, weakness in the legs, BMI or Modic changes were described using correlation coefficients and odds ratios obtained from logistic regression.ResultsTwo-thirds of the included patients with LBP had normal Vitamin D levels of >50 nmol/L. No correlations were seen between Vitamin D deficiency and gender, age, back pain intensity, leg pain intensity, and duration of pain. Statistically significant, but low, correlation coefficients were found between Vitamin D levels and BMI as well as Modic changes. Low Vitamin D levels and Modic changes were statistically significantly associated with an odds ratio of 0.30 (95% CI 0.12; 0.75) while weakness, paresthesia and widespread pain were not.ConclusionsIn patients seeking care for low back pain in a Danish outpatient clinic, Vitamin D deficiency was not common. Whether patients who are overweight or who have Modic changes might represent subgroups of people for whom their LBP may be associated with Vitamin D levels, needs further investigation.

Standardized difference scores are intuitive indexes which measure the effect size between two groups. Compared to a t-test or Wilcoxon rank-sum test, they are independent of sample size. Thus, their use can be recommended for comparing baseline covariates in clinical trials as well as propensity-score matched studies. In this paper, we show how to calculate sample standardized differences for continuous and categorical variables and how to interpret results. We also provide a SAS macro which performs the calculation without using the IML procedure.

Objective Chronic low back pain (cLBP) is the leading cause of disability. Interdisciplinary pain management is recommended for patients with severe cLBP. Such programs are expensive, not easily accessible, and have limited effect and therefore new cost-effective strategies are warranted. Cognitive Functional Therapy (CFT) has shown promising results, but has not been compared with an interdisciplinary pain management approach. The primary aim of this randomized controlled trial (RCT) is to investigate if a pathway starting with CFT including psychologist support (CFT+) with the option of additional usual care (if needed), is superior in improving disability and more cost-effective at 12 months compared with an interdisciplinary pain management pathway (usual care). Methods This pragmatic, two-arm, parallel-group RCT will randomly allocate patients (n = 176) aged 18 to 75 referred to an interdisciplinary pain center due to severe cLBP to one of two groups (1:1 ratio). Patients randomized to CFT+ will participate in a 3-month functional rehabilitation pathway with the option of additional usual care (if needed) while patients randomized to the interdisciplinary pain management pathway will participate in an individualized program of longer duration designed to best suit the individual patient's situation, needs and resources. The primary outcome is the proportion of patients with an 8-point improvement in the Oswestry Disability Index (ODI) score at 12 months. Exploratory outcomes is change in ODI scores over time, and an economic analysis of quality-adjusted life years using the 3-level version of the EuroQol EQ-5D. Impact The study evaluates the cost-effectiveness of CFT+ with the option of additional usual care (if needed) for patients with severe cLBP. Findings can potentially improve future care pathways and reduce cost for the health care system.