LETTER: Drink-driving figures mislead

Sir: It was disappointing to see the nation's media fall so readily into the innumeracy trap prepared for it by the Association of Chief Police Officers (Acpo), in heralding the 18 per cent increase in recorded instances of positive breath tests as evidence of increased drink-driving (report, 3 January; letter, 4 January).

Acpo asserted that it was "unable to supply a figure for the total number of tests performed". It was widely known that testing would be increased this year. If one allows for the increased number of vehicles on the road this year compared with last, then if the number of tests increased by more than 10 per cent or so - which is likely - the incidence of drink- driving has declined again, in line with recent trends. Clearly this is not what Acpo wanted us to hear.