To evaluate the association between clinical, demographic, and psychological factors and the functional Health Assessment Questionnaire (HAQ) and psychological HAQ (PSHAQ) in patients with rheumatoid arthritis (RA).
After a mean followup time of 7 years after diagnosis, 112 patients with RA were asked to fill out the HAQ and the PSHAQ. Several clinical variables [erythrocyte sedimentation rate (ESR), visual analog scale (VAS) pain, VAS general well-being, Thompson joint score, and morning stiffness] had been assessed at diagnosis and at followup. In addition, the Impact of Rheumatic diseases on General health and Lifestyle questionnaire, comprising different domains of psychological distress, was assessed at diagnosis. Spearman correlations were calculated to determine associations between functional HAQ and clinical and psychological variables at baseline and to determine the associations between clinical variables and the HAQ and PSHAQ score at followup. Univariate logistic regression analyses were performed to identify possible predictors at diagnosis for a worse HAQ score and PSHAQ score (score > 1) at followup.
At followup the functional HAQ score was associated with all clinical variables, whereas the PSHAQ was only associated with more subjective patient related variables (VAS pain, VAS general well-being, and morning stiffness). The final model of the multivariate regression analyses to predict a worse HAQ score at followup only included worse functional ability [odds ratio (OR) 2.63, 95% confidence interval (CI) 1.30-5.32, p = 0.007]. Anxiety (OR 1.13, 95% CI 1.03-1.24, p = 0.007) and a lower ESR value (OR 0.98, 95% CI 0.96-1.00, p = 0.05) assessed at diagnosis were included into the final model as predictors for a high PSHAQ score.
Overall, the HAQ score, reflecting limitations of daily functioning, is a good representation of disease activity at diagnosis and after a mean disease duration of 7 years, whereas PSHAQ is not.