27 AUGUST 1988, Page 16

. . . and statistics'

'DRINKING and driving: discretionary or random testing? Some facts arid figures: Great Britain, 1986 No. of roadside breath tests 320,000 (20 per cent more than 1985) Positive results 28 per cent (32 per cent in 1985) No. of convictions 120,000 (no change) (British Medical Journal, 13 August) THE number of convictions cannot relate to the number of positive breath- test results, which by the BMJ's own percentage figures must be 89,600 in 1986 and 85,333 out of 266,667 tested in 1985. And from the context the `no change' in parentheses would seem to refer to the percentage change since 1985, but that would entail a different figure from 120,000. Or does 'no change' refer to a figure of 120,000 convictions for 1985?

£20 goes to Professor Bryan Brooke, of Balham.

Send examples (with date) to '. . • and statistics': £20 for the best pub- lished; £10 for every other published.