Predictors of Pain Control Following Treatment for Zoster-Associated Pain

Postintervention pain control among patients with zoster-associated pain was found to depend on patient characteristics, according to results of a study published in Pain Theory.

This single-center, retrospective study evaluated pain control among 429 patients with zoster-associated pain who underwent treatment with gabapentin or pregabalin, antiviral drugs, and nonsteroidal anti-inflammatory drugs plus nerve block with corticosteroids, lidocaine, and vitamin B₁₂ at Capital Medical University in China between 2012 and 2022. Risk factors for poor pain control, as defined by a numerical rating scale (NRS) pain score greater than 3 at discharge, were evaluated.

Patients were divided in 2 cohorts based on having good (n=334) or poor (n=95) pain control; the mean age of the 2 cohorts was 64.4 and 68.2 years, 54.8% and 41.0% were in the acute phase of disease (<1 month), and mean NRS score at baseline was 6.0 and 6.8 points, respectively.

Poor pain control was associated with albumin, age, baseline NRS score, cancer, diabetes, disease course, and red blood cell count (all P ≤.014).

In the multivariate analysis, risk for poor pain control was associated with cancer (OR, 4.173; 95% CI, 1.342-12.970; P =.014), baseline NRS score (OR, 1.929; 95% CI, 1.528-2.434; P <.001), and red blood cell count (OR, 0.560; 95% CI, 0.328-0.954; P =.033).

These factors were able to predict poor pain control with an area under the curve (AUC) of 0.730 (95% CI, 0.670-0.790; P <.001), sensitivity of 54%, specificity of 82%, and a Youden index of 36%. These values indicated the model has some diagnostic value and was a reliable predictor (Hosmer-Lemeshow goodness-of-fit statistic, 0.874).

Limitations of this study include its small sample size and the fact that some relevant clinical markers may not have been considered.

Study authors concluded, “This study identified three independent risk factors for poor pain control in patients with herpes zoster neuropathic pain treated with drugs plus nerve block therapy. To a certain extent, it can guide clinicians to make the most appropriate pain treatment decisions.”