Dr Keith Hawton and colleagues from the United Kingdom assessed the long term effect of United Kingdom legislation introduced in 1998 to restrict pack sizes of paracetamol on deaths from paracetamol poisoning and liver unit activity.
Interrupted time series analyses to assess mean quarterly changes from 1998 to the end of 2009 relative to projected deaths without the legislation based on pre-legislation trends.
The team evaluated mortality (1993-2009) and liver unit activity (1995-2009) in England and Wales, using information from the Office for National Statistics and NHS Blood and Transplant, respectively.
The team's main outcome measures included suicide, deaths of undetermined intent, and accidental poisoning deaths involving single drug ingestion of paracetamol and paracetamol compounds in people aged 10 years and over, and liver unit registrations and transplantations for paracetamol induced hepatotoxicity.
Compared with the pre-legislation level, following the legislation there was an estimated average reduction of 17 deaths per quarter in England and Wales involving paracetamol alone that received suicide or undetermined verdicts.
|There was 61% reduction in liver transplant registrations for paracetamol induced hepatotoxicity|
|British Medical Journal|
This decrease represented a 43% reduction or an estimated 765 fewer deaths over the 11 years after the legislation.
The researchers found a similar effect when accidental poisoning deaths were included, and when a conservative method of analysis was used.
The team observed that the decrease was largely unaltered after controlling for a non-significant reduction in deaths involving other methods of poisoning and also suicides by all methods.
The research team found a 61% reduction in registrations for liver transplantation for paracetamol induced hepatotoxicity.
However, the team noted no reduction was seen in actual transplantations, nor in registrations after a conservative method of analysis was used.
Dr Hawton's team concludes, "UK legislation to reduce pack sizes of paracetamol was followed by significant reductions in deaths due to paracetamol overdose, with some indication of fewer registrations for transplantation at liver units during the 11 years after the legislation."
"The continuing toll of deaths suggests, however, that further preventive measures should be sought."