The presence of Waddell signs depends on age and gender, not diagnosis

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.

A pilot study in the association between Waddell Non-organic Signs and Central Sensitization

STUDY DESIGN

A cross-sectional observational multicenter pilot-study was performed within care as usual in three rehabilitation centers in the Netherlands.

OBJECTIVE

To explore the relationship between Waddell Non-organic Signs (NOS) and Central Sensitization (CS) in patients with chronic back pain.

SUMMARY OF BACKGROUND DATA

A possible relationship between NOS and CS is theoretically plausible, but it has never been tested.

METHODS

A cross-sectional observational multicenter pilot-study was performed in three rehabilitation centers in the Netherlands. Patients with chronic back pain were included. Main measures were Waddell's NOS, a battery of eight clinical tests performed during a physical examination, and Central Sensitization Inventory (CSI), a questionnaire measuring symptoms originating from CS. Analyses included Spearman correlation and univariate multiple regression analysis with NOS as dependent variable, CSI as independent, and controlled for confounders (psychosocial variables).

RESULTS

Data of n = 56 patients (59% female, mean age 42.6 years) were obtained. Correlation between NOS and CSI was rs = 0.34 (p = 0.01). After controlling for confounders, CSI did not independently predict NOS.

CONCLUSION

In this pilot study, CS was moderately related to NOS, but CS did not independently contribute to NOS after controlling for confounders. The results suggest that NOS may not exclusively be non-organic tests, although questions remain. The results of this pilot study can help to develop larger studies to allow replication and more detailed analyses.

You'd Better Believe It: The Conceptual and Practical Challenges of Assessing Malingering in Patients With Chronic Pain

Chronic pain is a prevalent and costly condition, with many patients receiving income support and funded treatment. Given that pain cannot be assessed objectively, patients may be suspected of exaggerating their pain and disability to receive additional funding. Although numerous methods of detecting malingering have been suggested, it is unclear whether clinicians can reliably identify malingering in patients with chronic pain. The present focus article was developed to assess the theoretical basis and empirical support for proposed methods of detecting malingering in patients with chronic pain. Five approaches were identified: the evaluation of behavioral signs, effort testing, pen and paper measures, symptom validity tests, and combined methods. An examination of the literature revealed that proposed assessment tools have little theoretical basis or empirical support in patients with chronic pain. Additionally, assessment tools are inconsistent with advances in pain science and scores or observations are likely to be influenced by the typical features of chronic pain, including fear-avoidance and central sensitization. Clinicians should be aware that as yet neither subjective clinical opinions nor clinical detection methods can reliably identify malingering in patients with chronic pain. Perspective: There is interest in the development of assessment tools to detect malingering in patients with chronic pain. An evaluation of methods reveals theoretical and empirical limitations that undermine the usefulness of these approaches. As yet, there is no reliable way for clinicians to identify malingering in patients with chronic pain.