Pain
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Although many individuals with chronic pain use analgesics, the methods used in many randomized controlled trials (RCTs) do not sufficiently account for confounding by differential post-randomization analgesic use. This may lead to underestimation of average treatment effects and diminished power. We introduce (1) a new measure-the Numeric Rating Scale of Underlying Pain without concurrent Analgesic use (NRS-UP(A))-which can shift the estimand of interest in an RCT to target effects of a treatment on pain intensity in the hypothetical situation where analgesic use was not occurring at the time of outcome assessment; and (2) a new pain construct-an individuals' perceived effect of analgesic use on pain intensity (EA). ⋯ More negative values of EA (ie, greater perceived benefit) were associated with a greater number of analgesics used but not with pain intensity, analgesic type, or opioid dose. The NRS-UP(A) and EA were significantly associated with future analgesic use 6 months later, but the conventional pain NRS was not. Future research is needed to determine whether the NRS-UP(A), used as a secondary outcome may allow pain RCTs to target alternative estimands with clinical relevance.
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Abdominal pain is a common symptom of several debilitating conditions (eg, inflammatory bowel disease, irritable bowel syndrome, and endometriosis) and affects individuals throughout their lifespan. Quantitative sensory testing (QST) reference values exist for many body sites but not the abdomen. ⋯ Evaluating the sensory functioning of the abdomen and characterizing ranges of QST measures is an essential first step in understanding and monitoring the clinical course of sensory abnormalities in patients with underlying diseases affecting the abdomen and pelvis. The impact of age and development on sensory functioning is necessary, given age-related changes in pain perception and modulation.
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Meta Analysis
Placebo and nocebo responses in painful diabetic neuropathy: systematic review and meta-analysis.
This preregistered (CRD42021223379) systematic review and meta-analysis aimed to characterize the placebo and nocebo responses in placebo-controlled randomized clinical trials (RCTs) on painful diabetic neuropathy (PDN), updating the previous literature by a decade. Four databases were searched for PDN trials published in the past 20 years, testing oral medications, adopting a parallel-group design. Magnitude of placebo or nocebo responses, Cochrane risk of bias, heterogeneity, and moderators were evaluated. ⋯ The year of study initiation was the only significant moderator of placebo response (regression coefficient = -0.06, [95% CI: -0.10, -0.02, P = 0.007]). More recent RCTs tended to be longer, bigger, and to include older patients (N = 21, rs = 0.455, P = 0.038, rs = 0.600, P = 0.004, rs = 0.472, P = 0.031, respectively). Our findings confirm the magnitude of placebo and nocebo responses, identify the year of study initiation as the only significant moderator of placebo response, draw attention to contextual factors such as confidence in PDN treatments, patients' previous negative experiences, intervention duration, and information provided to patients before enrollment.
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Neuropathic pain is associated with substantial healthcare costs. However, cost-of-illness studies of small fiber neuropathy (SFN) are scarce. Our aim was to estimate the healthcare, patient and family, and productivity costs of patients with SFN in the Netherlands from a healthcare and societal perspective. ⋯ At the patient level, the average annual SFN healthcare and societal cost of SFN was €3614 (95% confidence interval [CI] €3171-€4072) and €17,871 (95% CI €14,395-€21,480). At the SFN population level, the average healthcare costs were €29.8 (CI €26.4-€34.2) million, and on a societal level, these were €147.7 (CI 120.5-176.3) million. Severe pain was associated with significant lower Qol and higher depression scores, higher healthcare, patient and family, and productivity costs ( P < 0.001).