Ceiling effects of the Health Assessment Questionnaire and its modified version in some ambulatory rheumatoid arthritis patients.

OBJECTIVE To examine if the reduced number of items in the modified version of the Health Assessment Questionnaire (MHAQ) concerning difficulty of performing activities of daily living may lead to a reduced ability to detect clinical changes compared with the original HAQ. METHODS In 56 consecutive ambulatory patients with rheumatoid arthritis, we examined the mean change in clinical and laboratory parameters for those who recorded improved, unchanged, or worse MHAQ scores one year after a baseline assessment. RESULTS At baseline, about 50% of the patients had an MHAQ score < 0.3 and clustered at the normal end of the scale. Because of a ceiling effect, the MHAQ failed to detect clinical improvement in 18% of the patients. Changes in clinical and laboratory parameters were associated with improved, unchanged, or worse scores with the HAQ but not the MHAQ. CONCLUSION Although the format of the MHAQ has the advantage of eliciting a 'satisfaction' score, limitations in its sensitivity to detect clinical improvement in patients with relatively little difficulty in activities of daily living may not justify the use of this particular version of shorter questionnaire in certain clinical settings.