The review included 12 studies. These were all observational studies reporting outcomes before and after the 1998 regulations.
Liver unit referrals (3 studies): all 3 studies reported reductions in referrals to liver units following the introduction of regulations. One study also reported a decrease in liver transplants.
Severity of poisoning (8 studies): 3 studies reported reductions in the severity of paracetamol poisoning, while 5 studies reported no change in severity.
Hospital admissions (6 studies): 5 studies reported a decrease in hospital admissions for paracetamol poisoning; one study reported no change in cases presenting to hospitals in Belfast.
Mortality (3 studies): one study looking at data for England and Wales reported a decrease in deaths due to paracetamol alone in the first year after the regulations were introduced. Data from Scotland, reported by 2 studies, showed no change in mortality in the 2 years following the introduction of the regulations.
OTC sales (2 studies): both studies reported the same data covering 97% of OTC paracetamol sales to manufacturers and wholesalers in the UK in different ways. They found an increase in sales of packets of less than 100 tablets, but an overall decrease in the total mass of paracetamol sold.