Methodology
Median Length of Stay

Notes on Source Data

IMPORTANT NOTE: The following methodology may include references to report features not available on the public site version. On the public site, masking is performed to protect the privacy of individuals served by CDSS and comply with CDSS data de-identification guidelines. Values of 1 to 10 and calculations based on values of 1 to 10 are masked ('M' or '*'). In stratified views of the data, additional values (the lowest available) are masked to prevent calculation of values 1 to 10.

These reports use the Kaplan-Meier method to compute the median length of stay in foster care for children entering a placement episode lasting 8 days or more. This method allows for median, first quartile, and third quartile durations in care to be estimated even though not all children who entered foster care will have exited the system. This method avoids the problems in interpretation that result from using exit or point-in-time caseloads to measure length of stay.

Length of stay is presented in days. The median is the estimated time for half (50%) of the children who entered out-of-home care during the specified time period to exit. First and third quartiles have also been provided which are estimates of the time in days for one-fourth (25%) and three-fourths (75%) of the children to exit, respectively. For inclusion, a child must have been in care for 8 days or more. In addition, tables are presented for children aged 0-17 years old at entry, children aged 0-17 years old at entry (aged out), and for children aged 0-20 years old at entry. Children aged 0-17 years old at entry (aged out) include those who "aged out" / turned 18 while in care; for these children, time in care was calculated from the placement episode start date until the 18th birthday. Per Assembly Bill 12, children aged 0-20 years old at entry includes children entering care from age 18 until their 21st birthday. Only children with non-missing ethnic and gender codes are considered in this analysis. Estimates which could not be calculated since the corresponding proportion of entries had not yet exited care are represented by a “**”.

Reports may be viewed as either the estimated length of stay in days (“Estimates”) or as the underlying samples used to the compute the estimates (“Sample Sizes”). If the sample size for a particular group is very small (as may be the case in counties with few children entering care) results should be interpreted with caution. Unlike the point-in-time analyses, this report does not adjust for children in an open episode but not an open placement for more than 6 months; all children are counted as being in care until the episode is closed in CWS/CMS. Therefore, the length of stay may be inflated depending on the quality of county data.

Users may specify whether reports consist of only episodes that are first entry placements (“First Entry”) or episodes that are re-entry placements (“Other Entry”). “First Entry” provides an unduplicated count of children entering care for the first time, since that event can occur only once. When “Other Entry” is selected, all entries to a second or greater spell during the specified time period are considered; thus, multiple entries for one child can be returned.

Cells containing a period (".") represent a value of zero. In cells representing quotients, a period may also indicate the indeterminate form 0/0.

Please note that counties for which there are no data available for a specified time period are not included in the resulting output table.

Length of stay reports may be stratified by predominant placement type, age, ethnicity, or gender.

Predominant Placement Type

Age Group

Ethnic Group

Sex at Birth