Acupuncture for the Treatment of Chronic Pain in the Military Population: Factors Associated With Treatment Outcomes.

OBJECTIVES: Acupuncture is characterized as an alternative or complementary medicine with a low complication rate and minimal side effects. There is a lack of robust evidence that shows acupuncture is an effective treatment for chronic pain. The purpose of this study was to determine which (if any) characteristics can predict successful response to acupuncture in chronic pain patients treated at military treatment facilities. METHODS: Data from 222 patients who received treatment for a chronic pain condition were collected from 2 medical centers. The patients underwent at least 4 acupuncture treatments and had an average pain score of 4 or higher on a 0- to 10-point numerical rating scale or visual analog scale in the week before treatment initiation. A successful outcome was defined to be a 2-point or greater reduction on the numerical rating scale or visual analog scale 12 weeks postinitial treatment. RESULTS: The overall treatment success rate was 42.3%. Multivariate logistic regression found a higher baseline pain rating and the use of stimulation needles to be associated with a positive outcome (odds ratio [OR]=1.26; 95% confidence interval [CI], 1.03-1.55; P=0.02 and OR=2.73; 95% CI, 1.39-5.32; P=0.03, respectively). Only the presence of one or more psychological comorbidities was found to be associated with treatment failure (OR=0.67; 95% CI, 0.49-0.92; P=0.01). DISCUSSION: The use of electrical stimulation and higher baseline pain score were associated with a positive treatment outcome, while the presence of a psychological comorbidity diminished the likelihood of treatment success. Practitioners should consider using electrical stimulation more frequently, and addressing psychopathology before or concurrent to treatment, when initiating acupuncture.

Occipital nerve pulsed radiofrequency treatment: a multi-center study evaluating predictors of outcome.

OBJECTIVE: Occipital neuralgia (ON) is a challenging condition for which there is no reference standard for treatment. The purpose of this study was to provide outcome data on the largest study to date evaluating pulsed radiofrequency (PRF) for ON and to determine whether any demographic, clinical, or treatment characteristics are associated with success. DESIGN: Retrospective data analysis was conducted in 102 subjects evaluating the effect of myriad factors on treatment success. SETTING: This study was conducted in academic civilian and military pain treatment centers. PATIENTS: One hundred and two consecutive patients with a primary diagnosis of ON were treated with PRF of the greater and/or lesser occipital nerve. OUTCOME MEASURES: A positive primary outcome was predefined as ≥50% pain relief lasting at least 3 months. The secondary outcome measure was procedural satisfaction. RESULTS: Fifty-two (51%) patients experienced ≥50% pain relief and satisfaction with treatment lasting at least 3 months. Variables associated with a positive outcome included a traumatic inciting event (65.7% success rate; P=0.03), lower diagnostic block volumes (odds ratio [OR]: 0.72; 95% confidence interval [CI]: 0.62-0.82; P<0.0001), and employment of multiple rounds of PRF (OR: 2.95; 95% CI: 1.77-4.92; P<0.0001). Factors correlating with treatment failure included extension of pain anterior to the scalp apex (OR: 0.32; 95% CI: 0.14-0.73; P=0.006) and ongoing secondary gain issues (OR: 0.19; 95% CI: 0.11-0.33; P<0.0001). CONCLUSION: PRF may provide intermediate-term benefit in ON to a significant proportion of refractory cases. Careful attention to selection criteria and treatment parameters may further improve treatment outcomes.

A multi-center analysis evaluating factors associated with spinal cord stimulation outcome in chronic pain patients.

BACKGROUND: In addition to its conventional use as a treatment for refractory neuropathic extremity pain, spinal cord stimulation (SCS) has recently emerged as a possible treatment for visceral and arthritic pain. But concurrent with the expansion of possible conditions amenable to SCS, other studies have questioned the long-term efficacy of SCS for traditional indications. These disparate findings argue strongly for the refinement of selection criteria. The purpose of this study is to identify correlates of outcome for SCS. METHODS: Data were retrospectively collected on 244 patients who underwent a SCS trial at two academic medical centers. Success was predefined as ≥50% pain relief sustained for ≥6 months. Variables analyzed for their association with outcome included demographics, location of pain, diagnosis, presence of coexisting diseases, pain descriptors, opioid and adjuvant medication use, duration and pain relief during trial, and complications. RESULTS: The presence of allodynia and/or hyperalgesia correlated with both a positive SCS trial (P = 0.01) and long-term implantation outcome (P = 0.05). History of substance abuse was associated with a negative permanent SCS outcome (P = 0.05) but bore no relationship to trial results. The variable most strongly associated with an SCS outcome was experiencing <50% pain relief during the trial, which strongly presaged a negative result (P < 0.001). CONCLUSIONS: Although weak associations with outcome were noted for several clinical variables, none was strongly associated with trial and permanent implantation results. The strongest predictor of a negative SCS outcome was obtaining <50% pain relief during the trial period.