A cross-sectional study to validate an administrative back pain severity classification tool based on the graded chronic pain scale.

Treatment of chronic lower back pain (CLBP) should be stratified for best medical and economic outcome. To improve the targeting of potential participants for exclusive therapy offers from payers, Freytag et al. developed a tool to classify back pain chronicity classes (CC) based on claim data. The aim of this study was to evaluate the criterion validity of the model. Administrative claim data and self-reported patient information from 3,506 participants (2014-2021) in a private health insurance health management programme in Germany were used to validate the tool. Sensitivity, specificity, and Matthews' correlation coefficient (MCC) were calculated comparing the prediction with actual grades based on von Korff's graded chronic pain scale (GCPS). The secondary outcome was an updated view on direct health care costs (€) of patients with back pain (BP) grouped by GCPS. Results showed a fair correlation between predicted CC and actual GCPS grades. A total of 69.7% of all cases were correctly classified. Sensitivity and specificity rates of 54.6 and 76.4% underlined precision. Correlation between CC and GCPS with an MCC of 0.304 also indicated a fair relationship between prediction and observation. Cost data could be clearly grouped by GCPS: the higher the grade, the higher the costs and the use of health care. This was the first study to compare the predicted severity of BP using claim data with the actual severity of BP by GCPS. Based on the results, the usage of CC as a single tool to determine who receives CLBP treatment cannot be recommended. CC is a good tool to segment candidates for specific types of intervention in BP. However, it cannot replace a medical screening at the beginning of an intervention, as the rate of false negatives is too high. Trial registration The study was conducted using routinely collected data from an intervention, which was previously evaluated and registered retrospectively in the German Registry of Clinical Trials under DRKS00015463 (04/09/2018). Informed consent and the self-reported questionnaire have remained unchanged since the study and, therefore, are still valid according to the ethics proposal.

Association between chronic low back pain and regular exercise, sedentary behaviour and mental health before and during COVID-19 pandemic: insights from a large-scale cross-sectional study in Germany.

BACKGROUND: Nonspecific chronic low back pain (CLBP) is a complex symptom with numerous possible causes and influencing factors. Understanding how modifiable factors affect the course of CLBP is important for preventing progression. As the COVID-19 pandemic has changed the lifestyle of many people, this study paper assessed whether it also changed the influence of modifiable lifestyle factors (regular exercise and sedentary behaviour) and mental health factors (anxiety and depression) on CLBP pain intensity and disability by comparing the strength of these associations before and during the pandemic. We hypothesised that the importance of regular physical activity and good mental health for CLBP patients would increase during the pandemic. METHODS: These questions were investigated in a cross-sectional study of insurance claims data and self-reported data from various questionnaires from 3,478 participants in a German CLBP health intervention (2014-2021) by calculating pre- and intra-pandemic odds ratios (OR) and 95% confidence intervals (CI) for each variable of interest and outcome. Potential confounders were also considered. Pandemic status was treated as an effect modifier. Based on the date of enrolment, participants were classified as "pre-pandemic" or "pandemic". RESULTS: Regularly exercising ≥ 4 h/week significantly reduced the odds of high disability for men (OR 0.49, 95% CI 0.31 - 0.79, p = 0.003) and women (OR 0.30, 95% CI 0.14 - 0.563, p = 0.002) and reduced the probability of severe pain in women (OR 0.37, 95% CI 0.21 - 0.65, p < 0.001). Each one-point increase in PHQ-4 score for anxiety and depression increased the OR of high pain intensity by 1.25 points (95% CI 1.18 - 1.34, p < 0.001). A clear impact of COVID-19 lockdowns was observed. In individuals who exercised ≥ 4 h/week the OR of high disability was 0.57 (95% CI 0.36 - 0.92, p = 0.021) in the pre-pandemic group compared to 0.29 (95% CI 0.12 - 0.56, p = 0.002) in the pandemic group. The probability of high disability increased from an OR of 1.42 (95% CI 1.33 - 1.52, p < 0.001) per marginal increase in the PHQ-4 scale before the pandemic, to an OR of 1.73 (95% CI 1.58 - 1.89, p < 0.001) during the pandemic. CONCLUSIONS: The magnitude of association of the factors that influenced high pain intensity and disability increased during the pandemic. On the one hand, the protective effect of regular exercising was greater in participants surveyed during lockdown. On the other hand, a higher risk through anxiety or depression during the lockdown was identified. An additional study with objective measures of sedentary behaviour and physical activity is needed to validate these results. More in-depth investigation of lockdown-induced associations between reduced daily physical activity, increased levels of anxiety and depression, and their effects on CLPB could also be worthwhile. TRIAL REGISTRATION: This study used routinely collected data from a CLBP intervention that was previously evaluated and registered in the German Registry of Clinical Trials under DRKS00015463 (04/09/2018). The original ethics approval, informed consent and self-reported questionnaire have remained unchanged and are still valid.

Cost-effectiveness analysis of a chronic back pain multidisciplinary biopsychosocial rehabilitation (MBR) compared to standard care for privately insured in Germany.

BACKGROUND: Multidisciplinary biopsychosocial rehabilitation (MBR) is highly recommended for chronic lower back pain (CLBP) treatment, but its economic benefit remains to be clearly demonstrated. The purpose of this study is to analyse the effect of a 12-month MBR programme of behavioural change coaching and device-supported exercise on direct medical costs, sick leave and health-related quality of life (HRQOL) at 24 months. METHODS: An incremental cost-effectiveness analysis was conducted in Germany from a private health insurance perspective using data from a multi-centre, two-arm randomised controlled trial with parallel-group Zelen's randomisation and 24-month follow-up. After removing dissimilarities in characteristics between MBR and usual care (control) via propensity score matching, treatment effects were calculated using a difference-in-difference approach. RESULTS: Base-case analysis of the MBR (n=112) and usual care group (n=111) showed an incremental cost-effectiveness ratio (ICER) of €8,296 per quality-adjusted life year (QALY) gained, indicating that the intervention was cost-effective. Compared to the controls, MBR reduced economically unaccounted sick leave due to back pain in the last six months by 17.5 days (p = 0.001) and had a positive effect on health-related quality of life (HRQOL) (0.046, p=0.026). Subgroup analysis of participants with major impairment demonstrated that a dominant intervention was possible, as reflected by an ICER of - €7,302 per QALY. Savings were driven by a - €1,824 reduction in back pain-specific costs. Moreover, sick leave was 27 days (p = 0.006) less in the MBR group. CONCLUSIONS: This first cost-effectiveness study with combined data from a private health insurer and a controlled trial in Germany demonstrated that long term MBR for the treatment of CLBP is cost-effective. Subgroups with major impairment from back pain benefitted more from the intervention than those with minor impairment. MBR significantly reduced sick leave in all participants. Hence, it is a profitable intervention from a societal point of view. TRIAL REGISTRATION: The trial of the evaluation study was retrospectively registered in the German Clinical Trials Register under trial number DRKS00015463 retrospectively (dated 4 Sept 2018).

Feasibility and long-term efficacy of a proactive health program in the treatment of chronic back pain: a randomized controlled trial.

BACKGROUND: To facilitate access to evidence-based care for back pain, a German private medical insurance offered a health program proactively to their members. Feasibility and long-term efficacy of this approach were evaluated. METHODS: Using Zelen's design, adult members of the health insurance with chronic back pain according to billing data were randomized to the intervention (IG) or the control group (CG). Participants allocated to the IG were invited to participate in the comprehensive health program comprising medical exercise therapy and life style coaching, and those allocated to the CG to a longitudinal back pain survey. Primary outcomes were back pain severity (Korff's Chronic Pain Grade Questionnaire) as well as health-related quality of life (SF-12) assessed by identical online questionnaires at baseline and 2-year follow-up in both study arms. In addition to analyses of covariance, a subgroup analysis explored the heterogeneity of treatment effects among different risks of back pain chronification (STarT Back Tool). RESULTS: Out of 3462 persons selected, randomized and thereafter contacted, 552 agreed to participate. At the 24-month follow-up, data on 189 of 258 (73.3%) of the IG were available, in the CG on 255 of 294 (86.7%). Significant, small beneficial effects were seen in primary outcomes: Compared to the CG, the IG reported less disability (1.6 vs 2.0; p = 0.025; d = 0.24) and scored better at the SF-12 physical health scale (43.3 vs 41.0; p < 0.007; d = 0.26). No effect was seen in back pain intensity and in the SF-12 mental health scale. Persons with medium or high risk of back pain chronification at baseline responded better to the health program in all primary outcomes than the subgroup with low risk at baseline. CONCLUSIONS: After 2 years, the proactive health program resulted in small positive long-term improvements. Using risk screening prior to inclusion in the health program might increase the percentage of participants deriving benefits from it. TRIAL REGISTRATION: The trial was registered at the German Clinical Trials Register under DRKS00015463 retrospectively (dated 4 Sept 2018).

Surface induced vibrational modes in the fluorescence spectra of PTCDA adsorbed on the KCl(100) and NaCl(100) surfaces.

We report a combined experiment-theory study on low energy vibrational modes in fluorescence spectra of perylene-3,4,9,10-tetracarboxylic acid dianhydride (PTCDA) molecules. Using very low coverages, isolated molecules were adsorbed on terrace sites or at sites located at residual steps on (100) oriented alkali halide films (KCl and NaCl). The low energy modes couple to the optical transition only because the PTCDA molecule is geometrically distorted (C2v) upon adsorption on the surface; they would be absent for the parent planar (D2h) PTCDA molecule. The modes differ in number and energy for molecules adsorbed on regular terrace sites and molecules adsorbed at step edge sites. Modes appearing for step edge sites have the character of frustrated rotations. Their coupling to the optical transition is a consequence of the further reduced symmetry of the step edge sites. We find a larger number of vibrational modes on NaCl than on KCl. We explain this by the stronger electrostatic bonding of the PTCDA on NaCl compared to KCl. It causes the optical transition to induce stronger changes in the molecular coordinates, thus leading to larger Franck-Condon factors and thus stronger coupling. Our results demonstrate how optical spectroscopy can be used to gain information on adsorption sites of molecules at low surface concentrations.