Evaluating the effectiveness of Smoke-Free Home SafeCare, an integrated intervention, among families at risk for secondhand smoke exposure and child maltreatment in the United States: a study protocol for a hybrid type 1 trial

Background: Secondhand smoke exposure (SHS) and child maltreatment (CM) are preventable yet have negative lifelong impacts on health. When considered together, the risk for negative health outcomes may be compounded, especially for people living in low-resource settings. Evidence-based interventions exist for preventing CM and reducing SHS among families with low resources; however, no programs jointly target SHS exposure and maltreatment risk.

Methods: This study is a hybrid type 1 trial to examine the effectiveness of a systematically braided intervention to target CM risk and SHS in the home. Fifty SafeCare Providers will be randomized to deliver either standard SafeCare (i.e., the SafeCare model alone; active treatment control; n = 25) or Smoke-Free Home SafeCare (SFHSC; treatment condition; n = 25), the braided intervention that includes both SafeCare and the Smoke-Free Homes: Some Things are Better Outside intervention to N = 500 families. Aim 2 is to assess family-level outcomes. The primary outcome is a full home smoking ban, validated by air nicotine monitors; secondary outcomes include parenting and smoking outcomes. Aim 3 is to evaluate process and implementation outcomes, including cost-benefit. We will use multilevel models and ROC analyses to evaluate and validate the primary outcome. We will use tests of non-inferiority to evaluate secondary outcomes. Cost-effectiveness analyses will be used to assess cost-benefit of SFHSC.

Discussion: This study will be the first to document the outcomes of a multi-component intervention to address cumulative risk factors that impact cancer risk among children whose parents are at risk or involved in child-protective services. Integrating an evidence-based intervention that targets SHS exposure in the home with a broadly disseminated CM prevention intervention may be a sustainable way to help reduce the compounded effects of SHS in the home and CM.

Trial registration: Clinicaltrials.gov, NCT05000632. Registered on August 11, 2021.