Prognostic value of hypersensitivity reactions on epidural steroid injection outcomes: a phenotypic signature? A prospective cohort study

Association between chronic pain and risk of cardiometabolic multimorbidity: a prospective cohort study

BACKGROUND

Although chronic pain was deleteriously related to single cardiometabolic diseases, the relationship between chronic pain and cardiometabolic multimorbidity remains unclear. The purpose of this study was to investigate the association between chronic pain with the risk of cardiometabolic multimorbidity.

METHODS

A prospective cohort study included 452 818 participants who were free of cardiometabolic multimorbidity at baseline. Chronic pain was assessed in diverse anatomical sites including the head, face, neck/shoulder, stomach/abdominal area, back, hip and knee or 'all over the body'. Participants were classified into six groups according to the amount of chronic pain sites: no chronic pain, chronic pain at one, two, three and four or more sites, and those reporting pain 'all over the body'. Cardiometabolic multimorbidity was defined as the occurrence of at least two cardiometabolic diseases, involving type 2 diabetes, ischaemic heart disease and stroke.

RESULTS

After a median follow-up of 13.7 years, 4445 participants developed cardiometabolic multimorbidity. Compared with individuals without chronic pain, those experiencing chronic pain in four or more sites were associated with a 1.82-fold (HR: 1.82, 95% CI: 1.61, 2.06) higher risk of cardiometabolic multimorbidity. Pain distributed 'all over the body' was associated with a 59% (HR: 1.59, 95% CI: 1.30, 1.93) increased risk of cardiometabolic multimorbidity Additionally, individuals who had chronic pain in both the head and stomach/abdomen showed the highest risk with cardiometabolic multimorbidity (HR: 1.88, 95% CI: 1.60, 2.20).

CONCLUSIONS

Our findings suggested that there was an elevated risk of cardiometabolic multimorbidity associated with an increased amount of chronic pain sites.

Multicenter study evaluating factors associated with treatment outcome for low back pain injections

BACKGROUND

There has been a worldwide surge in interventional procedures for low back pain (LBP), with studies yielding mixed results. These data support the need for identifying outcome predictors based on unique characteristics in a pragmatic setting.

METHODS

We prospectively evaluated the association between over two dozen demographic, clinical and technical factors on treatment outcomes for three procedures: epidural steroid injections (ESIs) for sciatica, and sacroiliac joint (SIJ) injections and facet interventions for axial LBP. The primary outcome was change in patient-reported average pain intensity on a numerical rating scale (average NRS-PI) using linear regression. For SIJ injections and facet radiofrequency ablation, this was average LBP score at 1 and 3 months postprocedure, respectively. For ESI, it was average leg pain 1- month postinjection. Secondary outcomes included a binary indicator of treatment response (success).

RESULTS

346 patients were enrolled at seven hospitals. All groups experienced a decrease in average NRS-PI (p<0.0001; mean 1.8±2.6). There were no differences in change in average NRS-PI among procedural groups (p=0.50). Lower baseline pain score (adjusted coefficient -0.32, 95% CI -0.48 to -0.16, p<0.0001), depressive symptomatology (adjusted coefficient 0.076, 95% CI 0.039 to 0.113, p<0.0001) and obesity (adjusted coefficient 0.62, 95% CI 0.038 to 1.21, p=0.037) were associated with smaller pain reductions. For procedural outcome, depression (adjusted OR 0.94, 95% CI 0.91, 0.97, p<0.0001) and poorer baseline function (adjusted OR 0.59, 95% CI 0.36, 0.96, p=0.034) were associated with failure. Smoking, sleep dysfunction and non-organic signs were associated with negative outcomes in univariate but not multivariate analyses.

CONCLUSIONS

Identifying treatment responders is a critical endeavor for the viability of procedures in LBP. Patients with greater disease burden, depression and obesity are more likely to fail interventions. Steps to address these should be considered before or concurrent with procedures as considerations dictate.

TRIAL REGISTRATION NUMBER

NCT02329951.

Waddell (Nonorganic) Signs and Their Association With Interventional Treatment Outcomes for Low Back Pain

BACKGROUND

The rising use of injections to treat low back pain (LBP) has led to efforts to improve selection. Nonorganic (Waddell) signs have been shown to portend treatment failure for surgery and other therapies but have not been studied for minimally invasive interventions.

METHODS

We prospectively evaluated the association between Waddell signs and treatment outcome in 3 cohorts: epidural steroid injections (ESI) for leg pain and sacroiliac joint (SIJ) injections and facet interventions for LBP. Categories of Waddell signs included nonanatomic tenderness, pain during sham stimulation, discrepancy in physical examination, overreaction, and regional disturbances divulging from neuroanatomy. The primary outcome was change in patient-reported "average" numerical rating scale for pain intensity (average NRS-PI), modeled as a function of the number of Waddell signs using simple linear regression. Secondary outcomes included a binary indicator of treatment response. We conducted secondary and sensitivity analyses to account for potential confounders.

RESULTS

We enrolled 318 patients: 152 in the ESI cohort, 102 in the facet cohort, and 64 in the SIJ cohort, having sufficient data for primary analysis on 308 patients. Among these, 62% (n = 192) had no Waddell signs, 18% (n = 54) had 1 sign, 11% (n = 33) had 2, 5% (n = 16) had 3, 2% (n = 7) had 4, and about 2% (n = 6) had all 5 signs. The mean change in average NRS-PI in each of these 6 groups was -1.6 ± 2.6, -1.1 ± 2.7, -1.5 ± 2.5, -1.6 ± 2.6, -1 ± 1.5, and 0.7 ± 2.1, respectively, and their corresponding treatment failure rates were 54% (102 of 192), 67% (36 of 54), 70% (23 of 33), 75% (12 of 16), 71% (5 of 7), and 83% (5 of 6). In the primary analysis, an increasing number of Waddell signs were not associated with a significant decrease in average NRS-PI (coefficient [Coef] = 0.19; 95% confidence interval [CI], -0.43 to 0.05; P = .12). A higher number of Waddell signs were associated with treatment failure, with a 1.35 increased odds of treatment failure per cumulative number of signs (P = .008).

CONCLUSIONS

Whereas this study found no consistent relationship between Waddell signs and decreased mean pain scores, a significant relationship between the number of Waddell signs and treatment failure was observed.