All men receiving hospital orders (Section 60) in the UK in the year 1963–64 (excluding those receiving restriction orders (Section 60/65)) were followed up over 15 years with regard to (1) subsequent offences and convictions, (2) hospital admissions, and (3) death. Nine per cent of the patients involved could not be traced. Sixteen per cent had died by 1978, a quarter of them by suicide.

Of the mentally ill only 4 per cent subsequently committed serious offences (manslaughter, wounding, GBH, robbery, rape or arson), although a further 4 per cent committed assaults repeatedly. Sex crimes were uncommon. Among the mentally subnormal, 7 per cent committed serious sex crimes subsequent to committal. A further 9 per cent were considered to be persistent sex offenders and another 9 per cent were judged to be persistently violent. In general the mentally subnormal were much younger and were detained for much longer than the mentally ill. Since 1964 the use of hospital orders for the detention of such people has become much less frequent.

The best predictor of subsequent offences was found by multiple regression analysis to be the number of previous offences: this was especially true for acquisitive offences committed by the young. The mentally ill were less often reconvicted than the mentally subnormal.