Mandatory Drug Testing rates do not reliably measure drug prevalence. The MoJ’s own admission that resource constraints limit its capacity for MDT testing and therefore its ability to produce robust, publishable data demonstrates the failure of the current approach. The suspension of regular testing makes it extremely difficult to accurately assess the current scale of drug use or measure any improvement. A return to consistent, high- volume testing across the prison estate is essential to restore accountability and gather the data needed to understand the true extent of drug use. (Conclusion, Paragraph 21)