The latest available data on the number of people who previously qualified for Disability Living Allowance (DLA) but have been disallowed on reassessment to Personal Independence Payment (PIP) after an assessment by Independent Assessment Services in Liverpool Walton constituency can be found in the statistical tables released in December 2017 here: https://www.gov.uk/government/statistics/personal-independence-payment-april-2013-to-october-2017
Table 8G (DLA to PIP Reassessment outcomes by Parliamentary Constituency) shows the PIP reassessment outcome of claimants who have been reassessed from DLA to PIP by parliamentary constituency. It shows the number of people who have had their awards increased, unchanged and decreased and also those that were disallowed pre and post referral to the assessment. The latest date for which published data is available is 31st October 2017. Comparisons of DLA reassessment to PIP awards are published annually.