Pain Trajectories in Hand Osteoarthritis Influenced by Pain at Baseline

Three pain trajectories that were influenced by baseline pain level and patient characteristics were identified among patients with hand osteoarthritis, according to the results of a study published in Rheumatology.

Data collected at the Leiden University Medical Center in The Netherlands between 2009 and 2015 for the Hand OSTeoArthritis in Secondary care (HOSTAS) cohort were analyzed in this study. Australian/Canadian Osteoarthritis Hand Index (AUSCAN) pain measurement scores collected at 2 or more visits were used to establish trajectories of pain associated with hand osteoarthritis, and predictors for different trajectories were evaluated.

The study population consisted of 538 patients with a mean age of 61.0 (standard deviation [SD], 8.6) years; 86% were women; average body mass index (BMI) was of 27.1 (SD, 4.8) kg/m²; and mean 100-point visual analogue pain scale (VAS) score was 33.6 (SD, 22.5) points for the left hand and 36.7 (SD, 21.8) points for the right hand.

At baseline, the mean AUSCAN pain score was 9.3 (SD, 4.6; range, 0-20).

The AUSCAN score at baseline was associated with gender (β, 1.19), number of comorbidities (β, 0.99), low education level (β, 0.97), erosive disease (β, 0.84), AUSCAN function score (β, 0.40), Hospital Anxiety and Depression scale (HADS) score for depression (β, 0.36), HADS score for anxiety (β, 0.31), tender joint count (β, 0.31), right hand VAS (β, 0.11), left hand VAS (b, 0.09), symptom duration (β, 0.07), Mental Component Scale (MCS) score (β, -0.11), Physical Component Scale (PCS) score (β, -0.26), and working status (β, -1.22), as well as the illness perceptions of identity (β, 0.69), consequences (β, 0.34), emotional representation (β, 0.21), and illness coherence (β, -0.17) and Coping with Rheumatic Stressors (CORS) scores for decreasing activity (β, 0.29), pacing (β, 0.16), accepting (β, 0.13), creative solutions (β, 0.12), and comforting cognition (β, -0.10).

In the quadratic model, the best-fit pain trajectories were low (n=101), middle (n=226), and high (n=157) pain.

Compared with the low-pain group, predictors for belonging to the middle-pain group included tender joint count (adjusted odds ratio [aOR], 1.12), BMI (aOR, 1.07), AUSCAN function score (aOR, 1.05), right hand VAS (aOR, 1.03), left hand VAS (aOR, 1.01), and PCS score (aOR, 0.94). For the high-pain trajectory, predictors were similar as with the comparison between middle-pain and low-pain groups with the additional predictors of depression (aOR, 1.19) and symptom duration (aOR, 1.07).

Compared with the low-pain group, no significant differences in illness perceptions or CORS coping styles were observed for the middle-pain and high-pain cohorts.

A limitation of this study is that it may not be generalizable to a population of patients with less severe hand osteoarthritis, as the patients in this study were recruited from secondary and tertiary care environments and likely had more severe disease.

This study identified 3 pain trajectories among patients with hand osteoarthritis. In general, patient pain trajectories depended on baseline pain level, as well as psychological and social characteristics. Illness perceptions or coping strategies had little impact on the trajectories. According to the study authors, “These data can be used to inform patients of their prospects, as in our clinical experience patients often expect the disease to get worse with time; these results show that this need not be the case.”

Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.