This scale is named after the St. Hans Hospital (Roskilde, Denmark) where one of the designers of the scale, Jes Gerlach, worked.
This scale is very suitable for clinical practice. The advantage is that this scale measures four drug-induced adverse events simultaneously: tardive dyskinesia, akathisia, parkinsonism and dystonia. The scale has been researched and appears to be valid and reliable. Training is required for high inter-rater reliability, but reliability is also reasonably high for the less experienced rater.