Every person who is dissatisfied with a decision on a claim to a social welfare payment or with certain decisions made by health boards in regard to supplementary welfare allowances has a statutory right to appeal. When an appeal is received, the social welfare appeals office refers the case to the deciding officer for his or her comments on the arguments made by the appellant, including any new evidence submitted. As a result of this process, over one fifth of such cases are revised in the person's favour by deciding officers, usually because new evidence that warrants such a revision has become available.