Objective To develop an observational assessment of the use of joint protection (JP) methods by people with rheumatoid arthritis (RA). Methods Subjects with and without RA were videotaped performing a kitchen activity to identify the range of JP and non-JP methods used. Behavior codes were developed for these. Seven rheumatology occupational therapists reviewed and scored behaviors as correct, partially correct, or incorrect JP methods. Test–retest and interrater agreement studies were conducted. Results The Joint Protection Behavior Assessment (JPBA) demonstrated good content validity (κ = 0.46 to 1.00), test–retest reliability (P < 0.0001), and interobserver agreement (κ = 0.68 to 0.88). Construct validity was supported by sign...