BACKGROUND-AIM:
About 70% of Spanish adults who smoke permit smoking in their homes, exposing household members to second-hand smoke (SHS). This pilot study aimed to assess the feasibility of implementing an adapted evidence-based smoke-free homes (SFH) intervention and to test its short-term effectiveness in promoting SFHs among Spanish households with minors.

METHODS:
In 2023–2024, we conducted a pilot study using a mixed-methods sequential explanatory design in the Barcelona Metropolitan Area. We recruited 45 participants through associations of school students’ families, living in households with minors and with at least one person who smokes. A pre–post intervention study to create SFHs was carried out. The intervention was adapted from the “Some Things Are Better Outside” program developed by Emory University (USA). It was delivered over six weeks and consisted of three mailings of printed materials (a guide to creating a SFH, challenges and solutions, an information sheet on third-hand smoke, etc.) and one coaching call. Then, a two-week follow-up was carried out (quantitative component), followed by eleven semi-structured interviews (qualitative component). Quantitative outcomes included recruitment strategy appropriateness, use and perceived usefulness of materials, and the intervention’s impact on SFH adoption and other home smoking characteristics. Qualitative research explored motivations, challenges, and facilitators of SFH adoption.

RESULTS:
Among the 45 participants recruited, 28 were people who smoke and 17 were people who do not smoke. At baseline, 3 participants had no smoking rules in place and 42 reported having some form of smoking restriction in their homes (28 allowed smoking only in outdoor household areas (e.g., balconies), 11 allowed smoking both indoors and outdoors, and 3 allowed smoking in specific indoor areas). Almost all participants with follow-up data (40 out of 41) perceived the recruitment strategy appropriate and rated the intervention materials as useful. At follow-up, 28 participants reported attempts to adopt SFH, and 7 succeeded. Number of days smoking occurred at home and cigarettes smoked per day decreased significantly at follow-up. Qualitative research showed that the main motivation to participate was protecting the health of household members, particularly children. The intervention components considered most useful were its core elements: the coaching call and the guide to adopting a SFH. The primary challenges to adopting SFHs were resistance from smoking family members and a low perceived risk associated with smoking in outdoor areas of the home.

CONCLUSIONS:
Implementing the adapted intervention through associations of students’ families is feasible in an urban Spanish school setting. The intervention showed promising short-term effectiveness in promoting the adoption of SFHs. These findings support the need for a rigorous implementation-effectiveness trial.