Predictors of Pain for Patients With Early Inflammatory Polyarthritis

Objective To identify predictors of pain at 1 year in patients with early inflammatory polyarthritis (EIP). Methods Using a prospective design, patients were examined by a rheumatologist and completed questionnaires at baseline and at 1 year after symptom onset. Separate regression analyses were run for pain intensity, sensory pain, and affective pain. Age and sex were adjusted in cross-sectional and longitudinal analyses; baseline potential predictors consisted of measures for corresponding pain values and disease activity, depression, coping scores, medication use, rheumatoid arthritis criteria being met, and duration of symptoms. Results A total of 211 patients were enrolled in the study (mean ± SD age 58.8 ± 14.2 years, 63% women). There were significant improvements at 1 year for disease activity, instrumental coping, emotional coping, depression, and all 3 pain measures. At baseline, disease activity and depression were positively associated with all types of pain; in addition, instrumental coping was positively associated with sensory pain and palliative coping was positively associated with affective pain. At 1 year, pain intensity was predicted by baseline pain intensity, duration of symptoms, use of disease-modifying antirheumatic drugs (DMARDs), and emotional coping. Sensory pain was predicted by baseline sensory pain and DMARD use. Affective pain was predicted by baseline affective pain, DMARD use, and emotional coping. Conclusion The majority of treated EIP patients can expect improvements in clinical and psychosocial variables over the first year of their illness. Emotional coping at baseline may contribute to pain in the future, and therefore it may be useful for patients to learn other means of dealing with this chronic disease.