pretest-posttest control group designs

[ASKurz]

Please leave suggestions for studies using a pretest-posttest control group design. This could also include variants, such as with two active conditions versus a non-treatment control, or designs substituting treatment-as-usual (TAU) for a non-treatment control.

[ASKurz]

Consider Nelson et al (2007; https://doi.org/10.1126/science.1143921), Cognitive recovery in socially deprived young children: The Bucharest early intervention project. Here's the abstract:

In a randomized controlled trial, we compared abandoned children reared in institutions to abandoned children placed in institutions but then moved to foster care. Young children living in institutions were randomly assigned to continued institutional care or to placement in foster care, and their cognitive development was tracked through 54 months of age. The cognitive outcome of children who remained in the institution was markedly below that of never-institutionalized children and children taken out of the institution and placed into foster care. The improved cognitive outcomes we observed at 42 and 54 months were most marked for the youngest children placed in foster care. These results point to the negative sequelae of early institutionalization, suggest a possible sensitive period in cognitive development, and underscore the advantages of family placements for young abandoned children. (emphasis added)

[ASKurz]

Consider Dawson et al (2010; https://doi.org/10.1542/peds.2009-0958), Randomized, controlled trial of an intervention for toddlers with autism: The Early Start Denver model. Here's the abstract:

OBJECTIVE: To conduct a randomized, controlled trial to evaluate the efficacy of the Early Start Denver Model (ESDM), a comprehensive developmental behavioral intervention, for improving outcomes of toddlers diagnosed with autism spectrum disorder (ASD). METHODS: Forty-eight children diagnosed with ASD between 18 and 30 months of age were randomly assigned to 1 of 2 groups: (1) ESDM intervention, which is based on developmental and applied behavioral analytic principles and delivered by trained therapists and parents for 2 years; or (2) referral to community providers for intervention commonly available in the community. RESULTS: Compared with children who received community-intervention, children who received ESDM showed significant improvements in IQ, adaptive behavior, and autism diagnosis. Two years after entering intervention, the ESDM group on average improved 17.6 standard score points (1 SD: 15 points) compared with 7.0 points in the comparison group relative to base- line scores. The ESDM group maintained its rate of growth in adaptive behavior compared with a normative sample of typically developing children. In contrast, over the 2-year span, the comparison group showed greater delays in adaptive behavior. Children who received ESDM also were more likely to experience a change in diagnosis from autism to pervasive developmental disorder, not otherwise specified, than the comparison group. CONCLUSIONS: This is the first randomized, controlled trial to demonstrate the efficacy of a comprehensive developmental behavioral intervention for toddlers with ASD for improving cognitive and adaptive behavior and reducing severity of ASD diagnosis. Results of this study underscore the importance of early detection of and intervention in autism. (emphasis in the original)

The primary outcome measures scale like IQ scores, which means they provide a nice discussion of how to standardize a Cohen's d.

[ASKurz]

Consider Horan & Johnson (1971; https://doi.org/10.1016/0005-7916(71)90040-1), Coverant conditioning through a self-management application of the Premack principle: Its effect on weight reduction. Here's the abstract:

To evaluate Homme's contention that coverants (cognitive behaviors) incompatible with overeating can be reinforced through a self-management application of the Premack principle, 96 women students between 20 per cent and 30 per cent overweight were randomly assigned to one of four individual counseling programs. After 8 weeks the mean weight differences for Treatment 1 (delayed control), Treatment 2 (information and encouragement), Treatment 3 (scheduled coverants), and Treatment 4 (reinforced coverants) were 0.02, -3.13, -2.72 and -5.66 pounds respectively. Analysis of covariance with pretreatment weight as the covariate revealed that Treatment 4 produced more weight loss than Treatment 1, (p < 0.03). No other paired comparisons were significant. The efficacy of the Premack principle in a self-management situation was supported but not established.

The primary outcome is weight, which might make for a good gamma regression model. The paper is nice in that the authors presented their entire pre/post N = 96 data set in their Table 2 (p. 246).