Validity of the Health Assessment Questionnaire Predicting All-Cause Mortality in Early Rheumatoid Arthritis: Reply to three letters to the editor

We appreciate the interest in our manuscript concerning the Health Assessment Questionnaire disability index (HAQ) in an early rheumatoid arthritis incident cohort (the CATCH cohort) which predicted all-cause mortality (1). We will clarify queries raised in letters to the editor (2-4).