PRODUCT MODIFICATION

For more than 20 years there has been a coherent programme of product modification in the UK, involving the introduction of low tar brands o f cigarettes and the gradual reduction in average tar yields over the whole range of manufactured cigarettes. The sales-weighted average tar yield has declined from 20.8 mg/ cigarette in 1972 to 11.0 mg/cigaret te in 1993. To some extent potential benefits to established smokers h ave been offset by their tendency to 'compensate' for reduced nicotine yields. Investigating such aspects has Formed one part of a wide-rang ing research programme to monitor effects of modified products on heal th. Collectively the studies show benefits in terms of smoke intake an d health outcome related to reduced tar cigarettes, but the success ac hieved in reducing average tar yields and narrowing the range has limi ted opportunities to detect differential effects.