Several studies have examined correlations between service characteristics and placement outcomes. For example, Yuan et al. (1990) found that placement was more likely among families who received less intensive family preservation services. Nelson et al. (1988) reported that placement rates were lower in programs that offered more focused, shorter-term, office-based services to families with fewer risk factors (versus more comprehensive, in- home services for families with more risk factors). Nelson and Landsman (1992) found that placement was less likely when caretakers participated in most or all treatment sessions. In addition, the provision of paraprofessional services was correlated with reduced placement rates among child neglect cases, while reduced placement rates were related to the receipt of marital counseling in cases of physical abuse (Nelson and Landsman 1992).
Associations between characteristics of services and outcomes in these studies do not provide convincing evidence for the effects of these service characteristics. Characteristics of cases (such as family problems and their severity) determine the kinds of services provided and these characteristics are also likely to be related to outcomes, so that case characteristics become an alternative explanation for associations between services and outcomes. Again, the best way to determine the effects of service characteristics is to randomly assign cases to varying treatments, thereby eliminating the association between case characteristics and services provided. A weaker alternative approach is to model the relationship between case characteristics and service provision, using such models to control for the effects of case characteristics.
In the Illinois experiment, relationships between service characteristics and placement outcomes were analyzed using statistical controls for the effects of case characteristics on features of service provision and case outcomes (see Schuerman, Rzepnicki, and Littell 1994). There were no overall relationships between the duration of family preservation services, amounts of contact with caseworkers or parent aides in the first 90 days of services, or the number of concrete services provided and the likelihood of placement once the effects of case characteristics were taken into account. In a related study, separate analyses of relationships between service characteristics and outcomes were examined for specific subgroups of cases (Littell, Schuerman, and Chak 1994). The subgroups were: families with cocaine problems, families with inadequate housing problems, cases in which a parent had a serious emotional problem, and families with serious child care skill deficits. Once the effects of other case characteristics on service provision and case outcomes were controlled, it appeared that the duration, amount of contact with workers, number of concrete services, and specific types of services provided were not related to the risk of placement.31
31 This study examined the effects on placement of the following types of services for specific subgroups: provision of substance abuse treatment in cocaine cases, assistance in moving to new housing for families with housing problems, individual counseling in cases with serious emotional problems, and parent education and homemaking services in cases with serious child care skill deficits.