WALS: Workplace Activity Limitations Scale; WLQ-25: Work Limitations Questionnaire. Rating criteria (based on overall appraisal of all available evidence in arthritis or musculoskeletal conditions). For construct validity, reliability, and responsiveness: ++: Evidence of this measurement property from 2 or more studies, in the absence of conflicting evidence; +: Evidence of this measurement property from at least 1 study, and overall body of evidence supporting > refuting; +/−: Conflicting evidence available, current evidence does not meet ++ or +; −: Only negative evidence available; ?: No evidence available. For RCT: ++: 2 or more RCT providing evidence of discrimination (required for OMERACT endorsement); +: 1 RCT providing evidence of discrimination; (+): Ongoing RCT using worker productivity outcome measure (protocol available); −: Only evidence of lack of discrimination available; ?: No RCT available. Note: Discrimination includes between-group differences of within-group change, or between-group differences of final state. For score interpretability: ++: Estimates available from 2 or more studies; +: Estimates available from 1 study; (+): Estimates expected from an ongoing study; ?: Not yet available. RCT: randomized controlled trials.