Annotated Abstracts of Journal Articles
2015, 4th Quarter
Annotations by Elie Isenberg-Grzeda, MD and Sean Heffernan, MD
January 2016
Also of interest:
Scott EL, Kroenke K, Wu J, Yu Z
J Pain 2015 Nov 2 [Epub ahead of print]
ANNOTATION (Isenberg-Grzeda & Heffernan)
The Finding: By treating three psychological factors commonly associated with pain (depression, pain catastrophizing, and anxiety), pain was reduced in a sample of 250 primary care patients with chronic musculoskeletal pain.
Strength and Weaknesses: Strengths include the prospective design, large sample size, use of validated measurement tools, and blinding of symptom-raters to the study arm. Limitations include the potential lack of generalizability owing to the study sample demographics, which consisted of a VA sample made up of mostly white men who were suffering from chronic musculoskeletal pain. Additionally, the treatment of psychological factors (depression, pain catastrophizing, and anxiety) was not done in a controlled way. Still, the findings suggest that even without a controlled treatment approach, patients’ pain can still improve if they receive any treatment of these psychological factors.
Relevance: We often hear about the association between depression and pain, and that patients with depression may experience greater pain than those not depressed. This study builds on that notion by showing that treatment of depression, pain catastrophizing, and anxiety can improve pain outcomes. Among C-L psychiatrists who treat patients with chronic pain, the benefit of screening for and treating depression, anxiety, and pain catastrophizing extends beyond just improving the psychological well-being of patients, but seems to also improve pain outcomes.
Depression, pain catastrophizing, and anxiety commonly co-occur with chronic pain. However, the degree to which improvement in these psychological comorbidities predicts subsequent pain outcomes and, in particular, the relative effects of these 3 psychological factors with respect to each other is only partially known. Longitudinal analysis of 250 primary care patients with chronic musculoskeletal pain enrolled in the Stepped Care to Optimize Pain care Effectiveness (SCOPE) trial was examined, using data gathered at baseline, and at 3 and 12 months. Mixed effects model repeated measures analyses were used to determine if changes in depression, pain catastrophizing, and anxiety predicted a subsequent reduction in pain intensity or interference and pain-related disability. Defining a clinically significant change as twice the standard error of measurement for each predictor, we found that a 2-standard error of measurement improvement in depression, pain catastrophizing, and anxiety resulted in, respectively, an effect size decrease in pain intensity or interference of .45, .33, and .12; a 14%, 12%, and 6% reduction in the number of pain-specific disability days; and a 43%, 30%, and 28% decreased likelihood of high disability (defined as ≥10 pain-specific disability days in the past 4 weeks). In summary, improvements in 3 common psychological comorbidities predicted better pain outcomes.
Perspective: Because depression, pain catastrophizing, and anxiety commonly accompany chronic pain and might adversely affect pain outcomes, treatment of these modifiable psychological factors is warranted to optimize the effectiveness of pain-specific therapies.
ANNOTATION (Isenberg-Grzeda & Heffernan)
The Finding: The GAD-7 and GAD-2 are reliable and valid self-report screening tools for identifying generalized anxiety disorder in patients with migraines.
Strength and Weaknesses: Strengths of the study include a clearly defined cohort of patients with migraine headaches. Along with the GAD-7 and GAD-2, the patients received a full diagnostic assessment using standard measures, including a standardized diagnostic interview with a neuropsychologist. A limitation of the study is its small sample size of 146 patients, 86% of which were female. Also, the GAD-7 and GAD-2 are self-report questionnaires that focus only on generalized anxiety symptoms occurring over the previous two weeks; this observation period does not align with that of the clinical diagnosis of GAD. Positive-predictive value for the GAD-7 and GAD-2 were limited. Lastly, the instrument was administered in Korean to native-speakers, so its diagnostic properties may differ when applied in different countries, cultures, and languages.
Relevance: Self-rating symptom scales are a quick and inexpensive means of identifying patients more likely to have a clinical diagnosis. These screening tools are valid for detecting GAD symptoms in patients with co-occurring migraine, which may aid both research and clinical treatment efforts.
Background: Psychiatric problems have been commonly reported in patients with migraine. This study investigated the reliability and validity of the Generalized Anxiety Disorder-7 (GAD-7) and Generalized Anxiety Disorder-2 (GAD-2) in patients with migraine.
Methods: Subjects were recruited from a headache clinic and a neuropsychologist examined their GAD using the Mini International Neuropsychiatric Interview-Plus Version 5.0.0 (MINI). Subjects completed several instruments, including the GAD-7, the Beck Anxiety Inventory (BAI), the Migraine Disability Assessment Scale (MIDAS), the Headache Impact Test-6 (HIT-6), and the Migraine-Specific Quality of Life (MSQoL).
Results: Among 146 participants, 32 patients (21.9 %) had GAD as determined by the MINI. Cronbach’s α for the GAD-7 and GAD-2 were 0.915 and 0.820, respectively. At a cutoff score of 5, the GAD-7 had a sensitivity of 78.1 %, a specificity of 74.6 %, a positive predictive value (PPV) of 46.3 %, and a negative predictive value (NPV) of 92.4 %. At a cutoff score of 1, the GAD-2 had a sensitivity of 84.4 %, a specificity of 72.8 %, a PPV of 46.6 %, and a NPV of 94.3 %. The scores of the GAD-7 and GAD-2 well correlated with the BAI score, the MIDAS score, the HIT-6 score, and the MSQoL score.
Conclusions: The GAD-7 and GAD-2 are both reliable and valid screening instruments for GAD in patients with migraine.
ANNOTATION (Isenberg-Grzeda & Heffernan)
The Finding: High psychiatric comorbidity including depression and anxiety (termed, by the authors, as high “negative affect” or NA) is a presentation among patients with chronic low back pain, which may predict worse outcomes. Patients with high NA experienced less response to analgesia (despite higher doses), higher rates of opioid misuse, and higher rates of adverse effects. While patients with high NA did report some improvements in mood, the degree of improvement was often well below what is considered acceptable for the treatment of depression. As such, the authors found that opiates are not a suitable treatment for either pain or mood symptoms among patients with high NA. Among patients with low NA, the authors found higher rates of improvement in pain from opiate use, supporting the use of opiates for treating low back pain in these patients.
Strength and Weaknesses: This was a well-designed, prospective study, with a follow-up period longer than many (6 months). Its sample size of 250 is large but may not allow for this study to be absolutely definitive.
Relevance: C-L psychiatrists who treat patients with chronic pain should identify patients with high NA since opiates do not appear to be effective in treating chronic pain among these patients. Rather than refusing to prescribe opiates for the treatment of chronic low back pain among patients with high NA, the authors suggest identifying and treating these patients early, before their symptoms develop into chronic pain.
Background: Opioids are frequently prescribed for chronic low back pain (CLBP), but there are little prospective data on which patient subgroups may benefit. Psychiatric comorbidity, such as high levels of depression and anxiety symptoms (termed comorbid negative affect [NA]), is a common presentation and may predict diminished opioid analgesia and/or increased opioid misuse.
Methods: The authors conducted a 6½-month prospective cohort study of oral opioid therapy, with an active drug/placebo run-in period, in 81 CLBP patients with low, moderate, and high levels of NA. Treatment included an opioid titration phase with a prescribing physician blinded to NA group assignment and a 4-month continuation phase, during which subjects recorded daily pain levels using an electronic diary. The primary outcome was the percent improvement in average daily pain, summarized weekly.
Results: There was an overall 25% dropout rate. Despite the high NA group being prescribed a higher average daily dose of morphine equivalents, linear mixed model analysis revealed that the 24 study completers in each of the high NA and low NA groups had an average 21 versus 39% improvement in pain, respectively (P < 0.01). The high NA group also had a significantly greater rate of opioid misuse (39 vs. 8%, P < 0.05) and significantly more and intense opioid side effects (P < 0.01).
Conclusions: These results indicate that the benefit and risk considerations in CLBP patients with high NA versus low NA are distinctly different. Thus, NA is an important phenotypic variable to characterize at baseline, before deciding whether to prescribe opioids for CLBP.
