Defining acute flares in knee osteoarthritis: a systematic review

Abstract

ObjectiveTo identify and critically synthesise definitions of acute flares in knee osteoarthritis (OA) reported in the medical literature.DesignSystematic review and narrative synthesis. We searched Medline, EMBASE, Web of science and six other electronic databases (inception to July 2017) for original articles and conference abstracts reporting a definition of acute flare (or synonym) in humans with knee OA. There were no restrictions by language or study design (apart from iatrogenic-induced flare-ups, eg, injection-induced). Data extraction comprised: definition, pain scale used, flare duration or withdrawal period, associated symptoms, definition rationale, terminology (eg, exacerbation or flare), baseline OA severity, age, gender, sample size and study design.ResultsSixty-nine articles were included (46 flare design trials, 17 observational studies, 6 other designs; sample sizes: 15–6085). Domains used to define flares included: worsening of signs and symptoms (61 studies, 27 different measurement tools), specifically increased pain intensity; minimum pain threshold at baseline (44 studies); minimum duration (7 studies, range 8–48 hours); speed of onset (2 studies, defined as ‘sudden’ or ‘quick’); requirement for increased medication (2 studies). No definitions included activity interference.ConclusionsThe concept of OA flare appears in the medical literature but most often in the context of flare design trials (pain increases observed after stopping usual treatment). Key domains, used to define acute events in other chronic conditions, appear relevant to OA flare and could provide the basis for consensus on a single, agreed definition of ‘naturally occurring’ OA flares for research and clinical application.PROSPERO registration numberCRD42014010169.

Acute Flares of Knee Osteoarthritis (the ACT-FLARE Study): Protocol for a Web-Based Case-Crossover Study in Community-Dwelling Adults

“…Recognition of the potential importance of episodic flares in the natural history of OA is gaining momentum among the clinical research community [49,53,54]. In this 13-week Web-based case-crossover study, we will combine general practice–based recruitment with social media advertising across England to identify proximate causes ( triggers ) of acute flare-ups in knee OA, estimate their time course and consequences, and describe individuals most susceptible to flares.…”

“…It may impact on the ability to perform everyday activities and result in an increase in analgesic intake”. This definition was derived from our pilot study [30], which used a qualitative approach based on self-assessment, a previous literature review [49], group discussions with patients and members of the public, and findings from a previous survey and 3-month pen-and-paper daily diary study (unpublished data at time of submission).…”

Short‐Term Recovery Trajectories of Acute Flares in Knee Pain: A UK‐Netherlands Multicenter Prospective Cohort Analysis

“…13 (10,15) 11 (8,14) 13 (11,15) 9 (2,12) 13 (10,15) 14 (12,16) 16 (14,18) Function (0-170) to 5 days of oral nonsteroidal antiinflammatory drugs (NSAIDs), remained at high levels of pain. All other groups showed different rates of pain reduction, with 3 groups experiencing pain scores of <3 on a 0-10 NRS after 5 days of treatment.…”

“…unpredictable and distressing (1). The underlying nature of these episodes, including the role of inflammation, is still poorly understood, and while a common terminology has yet to be agreed on (2), patients often use the terms "flares" or "flare-ups" to describe these phenomena, and this is the term under which a new Outcome Measures in Rheumatology initiative has recently been launched (3).…”

Risk-stratified and stepped models of care for back pain and osteoarthritis: are we heading towards a common model?

“…Although musculoskeletal conditions are very often recurrent, 18 , 19 , 71 , 74 and many people with OA and LBP seek care repeatedly with periods of self-management in between, none of the existing models explicitly suggest how recurrence is handled. Episodic pain generally has less negative impact than persistent pain and recurrences do not necessarily indicate progression of the condition.…”