Many clinical scores have been developed in research to measure rheumatoid arthritis (RA), spondyloarthritis (SpA) and psoriatic arthritis (PsA) activity. In routine care, they may be used as part of a treat to target (T2T) strategy consisting of a systematic evaluation of disease activity followed by an adaptation of the treatment in order to reach a predefined therapeutic target, generally remission. The benefits of this strategy have been showed in RA and its use is recommended for this condition. The added value of the T2T strategy for SpA and PsA remains debated, requiring further studies. Scores may be used for the follow-up of patients, but their limitations should be taken in consideration.