Pain assessment in clinical trials: a narrative review

Abstract

Pain is a symptom measured in many clinical trials. For pain as an outcome domain, trialists need to choose adequate outcome measure(s), as there are myriad outcome measures for pain to choose from. To ensure consistency and uniformity in clinical trials and systematic reviews, core outcome sets (COS) have been defined; COS includes a predefined minimal list of core outcomes that should be measured within a trial, to ensure their consistency and comparability. COS is defined via consensus procedure, which includes relevant stakeholders such as experts from a specific field and patients. Along with outcomes, outcome measures for each outcome need to be defined to make sure that the outcomes will be measured consistently and uniformly. Hereby we reviewed studies that have examined use of recommended core outcome domains and outcome measures in clinical trials that would be expected to measure pain. Despite the existence of COS and defined core outcome measures (COMs), multiple studies have shown that these are not necessarily used in clinical trials, or in the relevant systematic reviews, which further increases heterogeneity of existing evidence, hinders evidence synthesis and trial comparability, and assessment of comparative effectiveness of interventions. Trialists are encouraged to use COS and COMs when designing clinical trials. Research community is encouraged to design interventions that will help with identifying barriers for using COS and COMs and interventions to foster their uptake. Use of consistent pain outcomes and pain outcome measures is in the interest of patients, research community, healthcare workers and decision-makers. For clinical conditions for which there are no COS and COMs, efforts to design them would be beneficial.

Low Back Pain Assessment Based on Alpha Oscillation Changes in Spontaneous Electroencephalogram (EEG)

“…Pain, especially chronic pain, is one of the biggest public health problems in our society [ 1 ]. A survey by the National Center for Health Statistics found that low back pain (LBP), migraine or severe headache, and joint pain were the most common types of chronic pain in clinical practice [ 2 ].…”

“…Because pain is a subjective individual experience, self-reported pain intensity is considered the gold standard for evaluating pain in clinical situations [ 1 , 2 ]. However, the clinical pain measure always needs careful evaluation and a skillful clinician to guide [ 4 ].…”

“…Besides, self-reports of pain intensity are not available for some vulnerable populations, who have severe cognitive or communicative impairments and cannot provide self-reports [ 5 ]. Hence, an objective measure of pain intensity that is expected to be associated with standard measures, such as visual analog scale (VAS) [ 1 ], can complement self-reports that would be useful in clinical practice, such as to monitor the effect of an analgesic drug or track the recovery of the nociceptive system in noncommunicative patients [ 5 , 6 ].…”