To compare the level of morning stiffness in a cohort of patients with early rheumatoid arthritis (RA), assessed on a self-report questionnaire, to levels of patient self-report scores and clinical and laboratory variables.
A total of 337 patients with recent onset RA since 1998 were assessed for tender and swollen joint counts, erythrocyte sedimentation rate (ESR), physician global assessment, and radiographs of the hands and feet, as well as Multidimensional Health Assessment Questionnaire (MDHAQ) scores for functional disability, pain, fatigue, global status, morning stiffness, and number of symptoms. Regression models were used to estimate possible associations between these variables and morning stiffness.
At study entry, 70 patients (21%) reported no morning stiffness, 52 (15%) reported morning stiffness < 15 minutes, 52 (15%) for 16-59 minutes, and 163 (49%) for >/= 1 one hour. At baseline and in longitudinal analyses, morning stiffness was significantly associated with functional disability scores on the MDHAQ and with other patient self-report data, and was associated at lower levels with swollen and tender joint counts and erythrocyte sedimentation rate (ESR).
The degree of morning stiffness appears to reflect functional disability and pain more than traditional markers of inflammation such as joint counts and ESR in patients with early RA. Inclusion of morning stiffness as a marker of inflammatory activity in classification criteria for RA, inclusion criteria for most clinical trials in RA, and RA remission criteria, may be open to reassessment.