Outcomes After Injection-Based Therapy: A Pain Outcomes Questionnaire for Veterans Univariate Analysis
Background: The Pain Outcomes Questionnaire-For Veterans (POQ-VA) was developed within the Veterans Health Administration (VHA) as a brief but psychometrically sound pain outcomes instrument that assesses key domains. In routine clinical practice, it is valid and reliable for evaluating effectiveness of treatment of chronic noncancer pain in veterans. We hypothesized that POQ-VA scores would improve across multiple domains in the veteran population following injection-based interventional treatment for chronic pain.
Methods: We aggregated all available POQ-VA reports from veterans who underwent ≥ 1 interventional pain procedures between April 1, 2009 and April 1, 2019. Patients were included who had pre- and posttreatment POQ-VA results separated by ≤ 6 months (N = 112). A paired-samples t test was used to compare means, standard deviations, and ranges for each POQ-VA domain. Individual question responses were analyzed using a nonparametric Wilcoxon matched-pairs signed-rank test.
Results: All POQ-VA domains showed a statistically significant decrease posttreatment (P ≤ .03). Directionally, the responses to 17 of 20 individual POQ-VA questions reflect a small but statistically significant positive treatment response (P < .04).
Conclusions: Most veterans undergoing injection therapy for chronic pain had statistically significant improvements in POQ-VA measures within a 6-month period. To conduct more rigorous, multivariate studies, continued and widespread use of the POQ-VA instrument is warranted.
Recent literature suggests interdisciplinary chronic pain management represents the best outcomes for patients’ physical, emotional, and social health, though these kinds of focused outpatient programs have not been studied on a large scale.16 The evolution of pain management in recent years to incorporating a biopsychosocial model has revolutionized how pain is treated and assessed, with multiple studies suggesting the greatest benefits lie in a multipronged approach.16,17 Past studies assessing individual interventions for chronic pain tend not to show strongly positive results, further reinforcing the idea that the answer does not lie in a specific treatment. Many veterans who were included in this study possibly had received or were receiving adjunct therapies such as physical therapy, cognitive behavioral therapy, and acupuncture for pain management, as well as oral and topical medications. Unfortunately, due to the selected methodology, it was not possible for us to gather those data. In turn, we were unable to determine how much these additional factors played a role in changing patient scores, alongside injection therapy. This inability to control variables in this type of research continues to present a challenge to data interpretation, even in the highest quality of research, as acknowledged by Staal and colleagues.8
Future research may be best focused by expanding our knowledge of outpatient interdisciplinary pain management programs. Some interventions may be more relevant for a particular group within a program, and this information can be useful to direct resources.18 Future prospects will require an appropriate multidimensional assessment tool, and the POQ-VA is an example of a valid and reliable option for monitoring progress in pain management in the veteran population.
Conclusions
The POQ-VA is the only instrument to date that has been validated to detect change following treatment of chronic pain in an exclusively veteran population. Our study is the first univariate analysis since the instrument’s validation in 2003. Our descriptive and inferential statistics suggest that the majority of veterans undergoing injection therapy for chronic pain had statistically significant improvements in POQ-VA measures within a 6-month period following treatment. In order to conduct more rigorous, multivariate studies, continued and more widespread use of the POQ-VA instrument is warranted.
