those in other solitary confinement units. Given that expert opinion22 and the Mandela Rule 45(2) explicitly prohibit the placement of prisoners with physical or mental disabilities in solitary confinement, it could be argued that these units, as they operated at the time of the visits, breached international standards by their very nature. The deprivation of social interaction which is inherent in all solitary confinement practices, was often made worse by the deprivation of other provisions which could have helped to mitigate the harmful effects of seclusion, including restrictions on family visits, in-room provisions such as books, hobby and craft materials or a TV set, and the generally very limited regimes. Review processes were not always robust, and some stays in restrictive conditions were far too long.23 a. The prevalence of the use of seclusion and restraint in New Zealand The prevalence of segregation and forms of restraint in Corrections Segregation The use of segregation in prisons across the country, according to data provided by the Department of Corrections, was high. In the year to 30 Nov 2016, there were 16,370 recorded instances of segregation in New Zealand. With an average prison population of 9,798 people, this equals 167.1 instances of segregation per 100 prisoners. To put these numbers in context, in England and Wales the rate was 36.9 segregation instances per 100 prisoners,24 meaning that, on average, New Zealand segregated prisoners over four times more often than England and Wales. This was a surprising finding, especially considering that the use of segregation in England and Wales itself was found to be high.25 22 Including, inter alia, the UN Special Rapporteur on Torture (2011) and the Istanbul Statement on the Use and Effects of Solitary Confinement (2007). 23 It is worthwhile noting that many of the concerns raised in this report have been previously raised by, among others, the UN Subcommittee on the Prevention of Torture following their 2013 visit (see SPT report of 28 July 2014, UN DOC CAT/OP/NZL/1), and successive reports by New Zealand's NPM bodies, indicating slow progress. 24 Using the same definitions and measurements, in England and Wales, between 1/1-31/3/2014, there were 7,889 segregation events with an average total prison population of 85,509 (National Offenders Management data, cited in Shalev, S. and Edgar, K. (2015) Deep Custody: segregation units and close supervision centres in England and Wales, London: Prison Reform Trust p148). Note that, as with the New Zealand data, these segregation events included stays of less than 24 hours, usually while the prisoner was waiting for their adjudication hearing. 25 See discussion in Shalev & Edgar, Deep Custody (2015). 25