Sensitivity of Sickness Impact Profile items to measure change over time in a low-back pain patient group.

The purpose of this study was to identify Sickness Impact Profile (SIP) items that are most sensitive to change in patients with low-back pain. Seventy-six patients with low-back pain were administered the SIP at their initial visit and after discharge from physiotherapy treatment. A formal item reduction was performed to identify the most sensitive items. An item was considered sensitive if it showed change in 20% of the patients and had an item-corrected total SIP score correlation greater than 0.30. Twenty items were identified. Seven of the 20 items identified in this study appear on the Roland-Morris disability questionnaire. Also, only 50% of the items identified are from the physical subscale of the SIP.