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The natural history of flare-ups: a daily diary study of patients with, or at high risk of, knee osteoarthritis

Parry, E.; Ogollah, R.; Peat, G.


R. Ogollah

G. Peat


Purpose: To determine, in a sample of community dwelling adults, the natural history of flare-ups in knee osteoarthritis (OA).

Methods: 330 adults aged 45 years and over with a recent primary care consultation for knee OA/arthralgia and no existing diagnosis of inflammatory disease were invited to complete a daily pen-and-paper diary for up to 3 months. Average knee pain intensity in the past 24 hours (0-10NRS) was rated daily, along with pain quality, other symptoms, and interference with usual activities. Informed by a systematic review of the literature, flare-ups were defined as an increase in pain intensity of a minimum of 2 points above participants’ rating of their usual pain intensity, sustained for a minimum of 2 consecutive days (i.e. excluding more transient episodes of pain). A flare-up was judged ‘resolved’ when pain intensity returned to usual levels for at least 5 consecutive days. We calculated the rate of flare-ups in the sample as an incidence density per 100 person-days at risk and used descriptive statistics and plots to summarise duration and nature of flare-ups.

Results: 67 participants (mean age 62.2 (SD 10.6); 55% female) completed at least one month of diaries. 30 participants experienced a total of 54 flare-ups (incidence density 1.09 flare-ups per 100 person-days). On average, flare-ups showed reductions in pain within 2 days followed by a longer, gradual return to ‘usual’ pain intensity (Fig. 1). The pattern differed between individuals with the median time to resolution = 8 days (range: 2-30). During a flare-up participants were more likely to report several additional features compared to days when they were not in a flare: swelling (50% vs 35%), limping (64% vs 42%), stiffness (60% vs 26%), night pain (34% vs 10%). On a third of flare-up days, patients increased their pain medication. Despite this, on 15% of flare-up days, pain stopped usual activities.

Conclusions: Our small study with intensive longitudinal data collection suggests acute flare-ups may be experienced by a substantial number of patients. These episodes often last a week or longer, interfere with sleep and daily activities, and lead to increased analgesic use.


Parry, E., Ogollah, R., & Peat, G. (2018, April). The natural history of flare-ups: a daily diary study of patients with, or at high risk of, knee osteoarthritis. Paper presented at 2018 OARSI World Congress on Osteoarthritis, ACC Congress Center Liverpool, United Kingdom

Presentation Conference Type Conference Paper (unpublished)
Conference Name 2018 OARSI World Congress on Osteoarthritis
Conference Location ACC Congress Center Liverpool, United Kingdom
Start Date Apr 26, 2018
End Date Apr 29, 2018
Publisher Elsevier
Series Title 2018 OASRI World Congress on Osteoarthritis
Publisher URL