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Rick Scott, Governor
Florida Department of Corrections, Secretary Michael D. Crews

Florida Department of Corrections
Timothy H. Cannon, Interim Secretary

Methodology

All inmates released from Florida prisons from January 1, 2005 to December 31, 2012 are included in the study with the following exceptions:

  • Inmates who died or were executed have been omitted from the calculation of recidivism rates.
  • Inmates who are missing information on the factors of interest are omitted from the analysis of factor influences.
  • Inmates with more than one release in a calendar year have only the first such release included.
  • Inmates with detainers in place at the time of release are omitted.

This methodology follows the definition of recidivism stated by the Association of State Correctional Administrators (ASCA) Performance-Based Measures System Counting Rules.4 For this study, survival analysis techniques are used to compute recidivism rates and to define the statistical models that determine which factors significantly influence recidivism rates.  The basic rates for tables and graphs are computed from Kaplan-Meier estimates of the survival curve using right-censored data.  The analyses of factor significance are conducted using Cox models (proportional hazards regression) of the same data.  The analysis used a 5% level of significance to determine the factors to include, and a stepwise selection routine for determining the order of importance.  The correlations between factors were considered during the stepwise routine to eliminate highly correlated variables from both being selected for inclusion in the model. 
The following variables were considered for inclusion in the model:

Inmate Background Information

  • Gender is male – Yes/No
  • Number of prior prison commitments
  • Age at release
  • Age at first offense
  • Race is black – Yes/No
  • Ethnicity is hispanic – Yes/No
  • Confirmed or suspected gang member – Yes/No

Inmate Incarceration Information

  • Time served in prison (current incarceration in months)
  • Custody level– Low or High
  • Number of disciplinary reports during current incarceration
  • Number of violent disciplinary reports during current incarceration
  • Internal classification score
  • Substance abuse severity score
  • Diagnosed mental illness – Yes/No
  • Supervision to follow – Yes/No

Inmate Education Information

  • Has inmate obtained a GED/HS certificate – Yes/No
  • Has inmate received a vocational certificate – Yes/No
  • Most recent Tests of Adult Basic Education (TABE) score (education level in grade equivalents)

Inmate Criminal History

  • Worst violent offense in criminal history (Categories for murder/manslaughter, sex offense, robbery, other violent offense (like assault or kidnapping) – Yes/No)
  • Worst violent offense within 15 years prior to admission (Categories for murder/manslaughter, sex offense, robbery, and other violent offense – Yes/No)
  • Offense counts in criminal history (Categories for murder/manslaughter, sex offense, robbery, other violent offense, burglary, theft, drugs, weapons, and other non-violent offense)
  • Offense counts in criminal history (Categories for violent, property, drugs, and other non-violent offense)
  • Non-violent offense counts within 5 years prior to admission (Categories for burglary, theft, drugs, weapons, and other non-violent offense)

Inmate Social Relations

  • Inmate’s level of concern about child’s welfare
  • Does inmate have enemies – Yes/No
  • Inmate’s family is in crisis – Yes/No
  • Influence of family on the inmate – Positive/ Negative
  • Influence of friends on the inmate – Positive/ Negative
  • Influence of spouse on the inmate – Positive/ Negative
  • Does inmate have spouse – Yes/No
  • Inmate’s relationship with his/her attorney – Positive/Negative
  • Does inmate have any other influences in his/her life – Positive/Negative

Note that for the "worst" offense factors the hierarchy is: murder/manslaughter > sex offense > robbery > other violent offense.  Each inmate can only be designated in at most one of the categories.  For example, if he has committed both sex offenses and robbery, he will be considered in the "worst offense is sex offense" category, not in the "worst offense is robbery" category.

Also, for the criminal history factors, only those offenses for which the inmate received either a Florida prison sentence or Florida community supervision sentence are considered.  Crimes in Florida that resulted in other sanctions, such as fines or county jail or federal sentences, are not considered.  Arrests, supervision, or prison sentences outside of Florida are not considered unless they are part of the inmate's Florida sentence.

4“ASCA Performance-Based Measures System Counting Rules” (April 2013 Web) http://www.asca.net/system/assets/attachments/5685/PBMS%20KeyIndicators%204_3_13.pdf?1365012031