4.—(1) For the purposes of Part XIIA of the Social Security Contributions and Benefits Act 1992 (incapacity for work) a determination under the all work test made before 3rd April 2000 shall from that date be treated as if it were a determination under the personal capability assessment.
(2) For the purposes of regulation 28, where before 3rd April 2000 the all work test was treated as satisfied in relation to a person under that regulation, from that date regulation 28 shall apply in relation to that person as if he had been treated as incapable of work in accordance with the personal capability assessment.