Pos1352 comparison of validated questionnaires with clinical items for the measurement of change in pain

Background Hand pain is a common symptom in hand osteoarthritis (OA). Questionnaires are used to measure and to monitor this pain over time. However, it is unknown whether these measurements reliably reflect patients’ experience. Objectives This study aimed to compare pain development scored by a validated questionnaire with pain development scored by a direct question to the patient. Methods Data from the first four years of the ongoing HOSTAS (Hand OSTeoArthritis in Secondary care) cohort were used. HOSTAS consists of patients with primary hand OA diagnosed by a rheumatologist. Pain was measured with the Australian/Canadian hand Osteoarthritis index (AUSCAN) pain subscale (range 0-20) at baseline and annually afterwards. Partway through the study, an annual anchor question was added asking participants whether pain had worsened, improved, remained stable or if they had never had pain, compared with the year before. Patients were included in the current analysis when change in AUSCAN pain and the anchor question were available for at least one year. Change in pain measured with AUSCAN was categorized according to the minimal clinical important difference (MCID) of 1.49 between the yearly visits. Changes between annual visits on AUSCAN and the anchor questions were described and Cohen’s kappa was calculated for each category (increase, stable and decrease). Annual results were comparable between years, and so the years were pooled. Results In 307 patients, the mean age was 61.0 (SD 8.2), with 82% women and a mean BMI of 27.3 (SD 4.8). The baseline AUSCAN pain was 9.1 (SD 4.2). Over 4 years, 708 annual intervals with both change in AUSCAN and anchor questions were available. Of the 309 patients, 95 provided one interval, 74 provided two intervals, 87 provided three and 51 provided four. Results are described in Table 1. In 203 intervals 172 patients reported an increase in AUSCAN pain (of which in 151 intervals patients (74%) indicated their pain had worsened on anchor questions), in 293 intervals 199 patients reported a stable level of pain (of which in 96 intervals (33%) indicated their pain had not changed) and in 212 intervals 176 patients reported a decrease in pain (of which 39 (19%) indicated their pain had improved) (Table 1). The most frequent answer was a worsening of pain, regardless of AUSCAN change. In total, in 286 out of 704 (40%) of the intervals, the anchor question was in accordance with the AUSCAN pain, with a Cohen’s kappa of 0.12. Conclusion There are large differences between changes in AUSCAN pain and experienced changes in pain when reported by the patient. The patient experiences worsened pain more often than is reflected in the AUSCAN pain. Although recall bias may play a role in the answers to the anchor questions, they are close to the real-world clinical practice, in which patients are often asked how the symptoms compare to last visit. This indicates a difference between change in pain perceived in the clinical setting and in research setting, which should be addressed in order to improve research on pain development. Table 1. Change in AUSCAN pain vs anchor questions. Data presented as number (%), with the % calculated over the vertical columns. Change in AUSCAN pain horizontally, anchor questions vertically. The number and % of concordant answers in bold. Change in AUSCAN pain Worsening Stable Improvement Total Anchor question Worse – more pain 151 (74 ) 173 (59) 98 (46) 422 (60) No change 41 (20) 96 (33 ) 74 (35) 211 (30) Better – less pain 11 (5) 20 (7) 39 (19 ) 70 (10) Never had this symptom 0 (0) 4 (1) 1 (0) 5 (1) Total 203 (100) 293 (100) 212 (100) 708 (100) REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests Coen van der Meulen Grant/research support from: The HOSTAS study is supported by a grant from the Dutch Arthritis Society, paid to the institution, Lotte van de Stadt: None declared, Frits Rosendaal: None declared, Margreet Kloppenburg Grant/research support from: The HOSTAS study is supported by a grant from the Dutch Arthritis Society, paid to the institution.