Development of a bedside pain assessment kit for the classification of patients with osteoarthritis

Abstract

There are no standardized bedside assessments for subtyping patients with osteoarthritis (OA) based on pain mechanisms. Thus, we developed a bedside sensory testing kit (BSTK) to classify OA patients based on sensory profiles potentially indicative of pain mechanism. After usability and informal reliability testing (n = 22), the kit was tested in a formal reliability study (n = 20). Patients completed questionnaires and sensory testing: pressure algometry to detect hyperalgesia; repeat algometry after heterotopic noxious conditioning stimulation to measure diffuse noxious inhibitory control (DNIC); light touch using Von Frey filaments; and cold allodynia using a brass rod. The procedure was brief and well tolerated. Algometry and filament testing were highly reliable [intra-class correlation coefficients (ICCs) 0.71-0.91]; DNIC was acceptably reliable (ICCs 0.53-0.91); brass rod reliability was inconclusive. Patients were classified empirically into four groups: "All abnormal findings" (primary and secondary hyperalgesia and dysfunctional DNIC); "all normal findings"; and two intermediate groups. The "all abnormal findings" group had more neuropathic pain symptoms, and lower WOMAC total, stiffness, and activity scores than the "all normal findings" group. Simple BSTK procedures, consolidated in a kit, reliably classified OA patients into subgroups based on sensory profile, suggesting that OA patients differ in underlying pain mechanisms. Further research is needed to confirm these subgroups and determine their validity in predicting response to treatment.

Assessment of Chronic Pain: Domains, Methods, and Mechanisms

“…Pressure algometry can assess pressure pain sensitivity, and metal rods that are heated or cooled can assess thermal sensitivity. Some evidence supports the reliability and validity of this approach 62 ; therefore, bedside QST may provide an important next step in mechanism-based pain assessment. 27 …”

Association between osteoarthritis and cardiovascular disease: Systematic review and meta-analysis

“…1,2 Osteoarthritis of the knee has a prevalence of over 250 million people globally. 3 It is anticipated that this number will rise sharply in the future due to rapidly growing, ageing populations paralleled with the increasing prevalence of obesity.…”

Test Procedures to Assess Somatosensory Abnormalities in Individuals with Peripheral Joint Pain: A Systematic Review of Psychometric Properties

“…Evidence supports that pain perception differs among ethnic populations . In this review, only 5 studies reported the ethnicity of their participants . Of these studies, Lundlad et al .…”

“…The time intervals between successive sessions ranged from 2 minutes to 10 days for test‐retest reliability, 2 minutes to 10 days for intrarater reliability, and 5 to 30 minutes for interrater reliability. The number of trials ranged from 2 to 4 for PPT measurements, except for one study that conducted only 1 trial and one study that did not report the number of trials . For studies that conducted more than 1 trial, only 4 studies reported rest periods; these ranged from 20 seconds to 1 minute between trials …”

“…The order of testing procedures is important to consider when utilizing a battery of testing procedures, which may also influence the results of PMPs of testing procedures. While some of the included studies ( n = 11) used a battery of testing procedures, the order of test procedures was only reported in 3 studies, while other studies did not provide enough information regarding the sequence of testing . Standardized testing order is recommended, as thermal stimuli might lead to a sensitization to mechanical stimuli …”