The two main aims for the review were to assess evidence on whether parental imprisonment is a risk factor for undesirable child outcomes and to assess evidence on whether parental imprisonment is a causal risk factor. A third aim of the review was to investigate whether associations between parental imprisonment and child outcomes differ according to child, parent, and environmental characteristics.
Between June and September 2008, researchers searched for studies that met the eligibility criteria. Several strategies were used to conduct an exhaustive search for eligible studies. Researchers started with an existing set of documents collected by Joseph Murray during his previous research on the effects of parental imprisonment on children and then used three methods to search for additional studies. First, researchers searched 23 electronic databases for the years 1960-2008. The same keywords were used to search each database. Second, researchers examined bibliographies of previous reviews of studies on the effects of parental imprisonment on children. Third, researchers contacted experts in the field. Two groups of researchers and practitioners were emailed and asked to inform researchers of any studies they thought might be eligible for the review. The first group consisted of about 65 researchers and practitioners who researchers knew had a professional interest in children of prisoners. The second group consisted of about 30 directors of major longitudinal studies in criminology. From all of these sources, 10,727 references were retrieved for further screening.
The first set of seven eligibility criteria used to identify studies for the reviewed included:
- The study must include children of prisoners and at least one group of children without imprisoned parents.
- The study must include a measure of child antisocial behavior or mental health.
- The child outcome must have been measured after parental imprisonment first occurred.
- The study must use the same measure of child outcome for children of prisoners and the comparison group.
- Numerical information: At least one effect size must be reported, or there must be enough numerical information to calculate at least one effect size.
- Publication: Studies may be published or unpublished
- Location and language: Studies may be conducted in any country and may be reported in English, German, Dutch, French, Spanish, Portuguese, Swedish, Danish, or Norwegian.
After initial screening of studies using the seven eligibility criteria above, researchers determined that additional criteria were required to exclude other studies that were not relevant to the review's objectives. The following three criteria were added:
- Studies were excluded if all children were recruited from courts or mental health clinics.
- Studies were excluded if the only comparison group of children was separated from a parent (for reasons other than imprisonment), or were the best friends of children of prisoners.
- One adoption study was excluded from the review because its design could only be used to estimate the genetic association between maternal imprisonment and child outcomes, not the environmental effects of parental imprisonment on children
After eliminating studies that did not meet all 10 eligibility criteria, 16 studies (reported in 25 documents) were identified as eligible for the review.
All published and unpublished studies of children with imprisoned parents between 1960 and 2008.
Researchers examined the bibliographies of the following prior reviews:
- Dallaire, D.H. (2007). Children with incarcerated mothers: Developmental outcomes, special challenges and recommendations. Journal of Applied Developmental Psychology, 28(1), 15-24.
- Gabel, S. (2003). Behavioral problems in sons of incarcerated or otherwise absent fathers: The issue of separation. In O. Harris and R.R. Miller (Eds.), Impacts of Incarceration on the African American Family (pp. 105-119). New Brunswick, NJ: Transaction.
- Hagan, J., and Dinovitzer, R. (1999). Collateral consequences of imprisonment for children, communities and prisoners. In M. Tonry and J. Petersilia (Eds.), Crime and Justice: A Review of Research (Vol. 26, Prisons, pp.121-162). Chicago, IL: University of Chicago Press.
- Johnston, D. (1995). Effects of parental incarceration. In K. Gabel and D. Johnston (Eds.), Children of Incarcerated Parents (pp.59-88). New York: Lexington Books.
- Murray, J. (2005). The effects of imprisonment on families and children of prisoners. In A. Liebling and S. Maruna (Eds.), The Effects of Imprisonment (pp.442-492). Cullompton, England: Willan.
- Murray, J., and Farrington, D.P. (2008). The effects of parental imprisonment on children. In M. Tonry (Ed.), Crime and Justice: A Review of Research (Vol. 37, pp.133-206). Chicago, IL: University of Chicago Press.
- Myers, B.J., Smarsh, T.M., Amlund-Hangen, K., and Kennon, S. (1999). Children of incarcerated mothers. Journal of Child and Family Studies, 8(1), 11-25.
- Nijnatten, C. (1998). Detention and Development; Perspectives of Children of Prisoners, Monchengladbach, Germany: Forum Verlag Godesberg.
The following 23 electronic databases were searched for the years 1960-2008 (numbers in parentheses show the number of non-duplicated hits retrieved from each database):
- Bibliograph of Nordic Criminology (16)
- Blackwell/Wiley (0)
- C2-SPECTR (The Campbell Collaboration Social, Psychological, Educational and Criminological Trials Register) (3)
- Cochrane (13)
- Criminal Justice Abstracts (1,689)
- Dissertation Abstracts (728)
- Education-Line (2)
- Embase (409)
- ERIC (Education Resources Information Center) (357)
- Google (26)
- Google Schlar (9,140, of which the first 1,000 could be examined)
- Ingenta (217)
- JSTOR (779)
- Medline (408)
- National Institute of Corrections Information Centre (73)
- National Criminal Justice Reference Service (NCJRS) (1,079)
- Newton: University of Cambridge Library (99)
- PsychInfo (1,517)
- Science Direct (658)
- System for Information on Grey Literature in Europe (17)
- Sociological Abstracts (571)
- Springer (0)
- Web of Science (1,003)
The following keywords were used to search the electronic databases: prison* OR jail* OR penitentiary OR imprison* OR incarcerat* OR detention AND child* OR son* OR daughter* OR parent* OR mother* OR father* AND antisocial* OR delinquen* OR crim* OR offend* OR violen* OR aggressi* OR mental health OR mental illness OR internailz* OR depress* OR anxiety OR anxious OR psychological*
Studies included in the review were coded for the following key features:
- Reference information (title, authors, publication year, etc.)
- Sample characteristics (age, gender, ethnicity, response rates, etc.)
- Details about the measure of parental imprisonment
- Details of subsamples, and multiple comparisons made in the study
- Details of the comparison group(s) used to derive effect sizes
- Types of outcome measured and measurement details
- Methods used to control for confounding variables to estimate causal effects
- Methodological quality of the study for drawing conclusions about risk factors and causal risk factors
- Statistical information used to derive an effect size
- Bivariate effect sizes for the associations between parental imprisonment and children's antisocial behavior and mental health
- Covariate adjusted effect sizes for the associations between parental imprisonment and children's antisocial behavior and mental health