Wagner, Cameto, and Gerlach–Downie (1996) assessed the impact of Parents as Teachers (PAT) on parent and child outcomes using a randomized control design where a group of teen parents were randomly assigned to one of three intervention groups (PAT; comprehensive case management; PAT plus case management) or the control group. The control group received no direct services through the demonstration, though they did receive assessments of the children’s development and regular mailings of children’s toys.
Equivalence of groups was achieved by random assignment, with three exceptions. First, the control group had a smaller proportion of members who were dropouts at the time of assignment (25 percent) than other groups, significantly so when compared with the PAT group (35 percent; p<.05). Control teens who were not pregnant at enrollment were more likely to be using contraceptives at least some of the time than were teens in some intervention groups. PAT group members had more frequent experience with infants than any other group, even though they were not significantly more likely than other groups to rate their knowledge of infants as “high.”
Four agencies in Southern California participated in the study, recruiting a total of 717 clients. The average age of the participants was 16.7 years; 56.3 percent of the participants were Latina, 20.8 percent were white, 20.3 percent were African American, and 2.6 percent were “other.” Most (68.2 percent) were enrolled in high school programs, 30.3 percent were dropouts, and 1.5 percent had graduated or had achieved a GED.
Data came from a variety of sources, including enrollment interviews by agency staff, agency records maintained by staff, participant interviews, Children’s Protective Services data on opened cases of child abuse/neglect, comparison data from California’s Adolescent Family Life Program state database, and focus groups with service providers and with teen parents in intervention groups.
Attrition was significant: 402 teens dropped out of the demonstration between enrollment and the child’s second birthday, for an overall dropout rate of 56 percent. The rate at which teens dropped out was fairly evenly distributed among the four groups (PAT dropout rate was 58 percent; PAT plus case management 63 percent; combined intervention 53 percent, and the control group 54 percent). There were no significant differences between participants and dropouts, except that 35 percent who dropped out of the study had also dropped out of school, while only 24 percent of intervention participants had dropped out of school.
Measurement instruments included the Knowledge of Infant Development Inventory, the Parents’ Sense of Competence Scale, and the Home Observation for Measurement of the Environment scale. Descriptive statistics were used to compare the characteristics of the groups and their outcomes; ordinary least squares regression analysis and logit analysis were used to identify independent relationships.Study 2
Wagner and colleagues (1999) assessed the effectiveness of PAT as implemented by a consortium of school districts in the Salinas Valley of California from 1992 to 1996. Families with infants up to 6 months were recruited and randomly assigned either to the PAT group or to a control group. The control received services as usual. Both groups received annual child assessments around the child’s birthday until children were 3 years old.
Four hundred ninety-five mothers were recruited; 400 were Latina and 95 non-Latina. Most fathers (77 percent) also were Latino. The sample of Latinas included approximately equal numbers of English-speaking or bilingual mothers and primarily Spanish-speaking mothers. The sample ranged from 14 to 44 years old at enrollment, with the average age being 25. Fathers were 3 years older, on average. Fifty-six percent of the families had two married parents living with the child at enrollment; 16 percent had two unmarried parents living with the child.
The control and treatment groups did not differ significantly from each other in any measure at the start of the study, though the evaluators note a pattern of small difference that might favor positive outcomes for the control group (e.g., compared with PAT parents, control group parents were somewhat better educated). Group equivalence was largely maintained through the project, although the difference in the rate of Latina enrollment in the treatment and control groups reached statistical significance at the first assessment (PAT group was 84 percent Latina, the control group was 74 percent at the first assessment).
In-home assessments were conducted by trained field evaluators. Measurement instruments included the Knowledge of Infant Development Inventory, the Parents’ Sense of Competence Scale, Developmental Profile 2, the Home Observation for Measurement of the Environment scale, the Bayley Scales of Infant Development, and the Peabody Picture Vocabulary Test. Sixty-four percent of control parents participated in all three assessments, compared with 58 percent of PAT parents. Eleven percent of control parents participated in none of the assessments, compared with 17 percent of PAT parents. Forty-three percent of PAT participants dropped out of the study.
Descriptive statistics were used to compare the characteristics of the groups and their outcomes; multivariate analysis was used to identify independent relationships.
Wagner and colleagues (2001) employed an experimental design to assess the impact of PAT across three sites, including an Eastern Seaboard urban community, a mid-size Southern city, and a large Western city. A total of 667 families with infants up to 8 months of age were recruited from the communities and randomly assigned to a participant group or a control group. The participant group was offered monthly home visits and other PAT services. Families in the control group received services as usual in the community. Both groups received annual child assessments around the children’s birthdays.
Of the mothers recruited, 29 percent were Caucasian/white, 58 percent were African-American, and 12 percent were Hispanic/Asian/Other. The average age of mothers was 24 years old at enrollment. Overall, 28 percent of recruited families included teen mothers, but the majority of mothers were in their 20s. Fifty-four percent of the families had a father living in the household, 29 percent had two married parents, and 31 percent had three generations living in the household.
The control and treatment groups did not differ significantly in any measure at the start of the study or by the children’s first or second birthdays for families as a whole. The groups were virtually identical on all factors, although there were some differences between participant and control groups on a handful of factors in specific communities (for instance, at Site 1, the ethnic distribution differed between participant and control group mothers).
Attrition over the course of the study reached 56 percent. More than 20 percent of the families who responded positively to the initial enrollment invitation did not begin home visits when they were assigned to the participant group. Almost 35 percent of families began home visits, but discontinued them before their children were 2 years old. The dropout rate was almost twice as high between children’s first and second birthdays (23 percent) as before first birthdays (12 percent). About 44 percent of families were still participating as of their children’s second birthdays.
In-home assessments were conducted by trained field evaluators. Measurement instruments included the Knowledge of Infant Development Inventory, the Parents’ Sense of Competence Scale, the Child Maltreatment Precursor Scale (CMPS) from the Adult-Adolescent Parenting Inventory, Parent Observation Scale, the Developmental Profile II (DPII), a subscale of eight items from the Home Observation for Measurement of the Environment (HOME) scale, and the Nursing Child Assessment Satellite Training (NCAST) teaching scale.