When we asked what criteria it used to decide on investment in one area against another, NHSE explained the consultative approach it took to prioritise services but could 13 NHS Long Term Workforce Plan, Overview, Chapter 1, paragraph 26, and Table 5 14 Qq 147–148 15 Qq 31,102, 105, 108, 111 16 House of Commons Committee of Public Accounts report, Improving access to mental health services, Sixteenth report of session 2016–17 17 Q 17; C&AG’s Report, paras 7, 15 18 Q 102 19 Qq 101, 109–110; C&AG’s Report, paras 7, 3.12. 20 Qq 34, 61, 98–105, 117; C&AG’s Report, paras 15, 2.25 Progress in improving NHS mental health services 11 not explain to us the cost effectiveness of its chosen interventions. It agreed with us that it is important to understand the impact of its initiatives, highlighting the opportunity that its current evaluation of mental health support teams in schools provides to understand the impact of earlier interventions on preventing later problems.21