Background: Since 2008 there is a law stating that patients who do not require institutional forensic psychiatric care may be moved to non-institutional forensic care, with special conditions. RättspsyK is a national quality register where all of the 25 forensic care units in Sweden collect information about their patients and their care. Previous analysis showed that a considerable amount of patients continue to receive institutional forensic psychiatric care despite they are assessed and found ready to move onto non-institutional forensic care. Aim: The objective of this study was to identify factors affecting why patients were still in institutional forensic care despite assessed to be ready for non-institutional forensic care.Method: First, yearly assessment of each patient between 2009 and 2014 was drawn from the RättspsyK register. Answers to the specific question, Question 10, were analyzed with descriptive statistics and were planned to be used in regression analyses as dependent variable. Result: 1900 patients were included. During analyses the fact that answers to this question were not trustable was found, therefore no exact prevalence of inpatients kept in institutional forensic care despite assessed ready for non-institutional care could be determined. Other information revealed that lack of housing and lack of collaboration were the most frequent reasons for this phenomenon. Conclusion: The present study could not give answer to the original question, but pointed out avalidity problem in the Swedish Forensic Psychiatry Register. The result calls for caution and for the need of validation of RättspsyK register.