HL Deb 20 March 1997 vol 579 cc109-10WA
Lord Astor of Hever

asked Her Majesty's Government:

If he will make a statement on the present position on the availability of information from the Prison Service mandatory drug testing programme.

Baroness Blatch

As part of the programme of mandatory drug testing in prison establishments the Prison Service collect a range of statistical information, including information about the percentage of prisoners who test positive for drugs in the tests which are carried out at random. Since April 1996 the number of random tests that prove positive, expressed as a percentage of the total number of random tests carried out, has been one of the Prison Service's key performance indicators.

As a result of internal checking, a number of errors have been found in the information held centrally. The main problems are thought to relate to the recording of results of confirmation tests (carried out where a prisoner pleads not guilty at adjudication in response to an initial positive result) and to cases where an initial positive result should subsequently have been discounted because the prisoner concerned was on a course of prescribed medication.

The Prison Service have commissioned the National Addiction Centre to carry out an independent validation of a sample of the available statistical information on mandatory drug testing covering the period April 1996 to June 1996. This involves a detailed scrutiny of the information held in prison establishments and comparison with the information held centrally. The validation exercise should provide a measure of the extent of the errors, the possible implications for performance against the key indicator, and more generally, of the reliability of data on mandatory drug testing held by the Prison Service. There is no reason to suppose, from the work completed so far, that the statistical information for the period from April 1996 is other than broadly accurate.

Once the exercise is complete, the Prison Service expect to be in a position to provide reliable information on performance against the key indicator for the period April 1996. However, until such information is available, all previously published figures relating to the percentage of prisoners who test positive for drugs should be regarded as provisional.

In addition, no firm conclusions, including conclusions on any apparent trends on the use of drugs in prison, should be drawn from data relating to the first phase of the mandatory drugs testing programme (February 1995 to March 1996), since not all establishments were involved and some differences in testing protocols were in place. We are not yet in a position to say whether the use of cannabis has declined since mandatory drug testing was introduced. It remains the case that there is no clear evidence of switching from cannabis to opiates or vice versa.

This Answer should be taken as correcting any inadvertently misleading statements which may have been made in relation to mandatory drug testing statistics.