-50 (whether the measure was taken, when and why no other possibility than solitary confinement was possible). From the examination of prison records it is possible to find out: • What is the average duration of the isolation measures? • Were consecutive disciplinary measures applied? • Were there meaningful social contacts? • Did isolated detainees have access to a doctor in line with international standards? • Did the records document the introduction of specific items in the isolation cells that could be an indication of a possible ill-treatment (e.g. delay in providing the prisoners with a blanket)? • Do medical records show the use of solitary confinement as a response to self-harm acts or suicide attempts? It is very important, however, to cross-check the accuracy of prison records, wherever it is possible to do so. 4.3.3. Interviews The monitoring of solitary confinement cannot be done without interviewing prisoners. In order to avoid the risk of reprisals, several NPMs interview all (or almost all) people in solitary confinement. To locate a person who has shared valuable information in the past but is no longer in solitary confinement, the Italian NPM has identified that it is good practice to ask the prison director for the list of all detainees held in prison and their location so there is no need to endanger a prisoner by asking his/her specific location. Interviews can take a significant amount of time. It is important not to rush the process. The interviewed NPMs have talked about an average of half an hour for each interview. In most cases interviews are conducted by two people, one taking notes and the other talking. They generally have the following structure: the delegation introduces itself, the work and the mission of the NPM and informs the person of the absolute confidentiality of the information exchanged during the interview. There is no questioning of the reasons why the person is detained, unless the detainee reveals it.