The "Som la Pera" intervention: sustainability capacity evaluation of a peer-led social-marketing intervention to encourage healthy lifestyles among adolescents.

Sustainability capacity, always considered a challenge, is the ability to maintain effective long-term intervention in a community. The aim of the study was to improve the sustainability capacity of effective "Som la Pera," a school-based, peer-led, social-marketing intervention that encourages healthy diet and physical activity, in low socioeconomic adolescents from Spain. The sustainability capacity was analyzed by a "programme sustainability assessment tool (PSAT)" comprising eight domains: political support, funding stability, partnerships, organizational capacity, programme evaluation, programme adaptation, communications, and strategic planning. Each domain was evaluated from 1 (no or to a small extent) to 7 points (to a great extent). The final score for sustainability capacity was the mean of the eight domain scores. The PSAT was assessed by nine professionals (researchers, staff members, and stakeholders) at two periods during intervention implementation: end of the first year (January 2015) and end of the second year (September 2015). At the end of the first year, strategic planning (4.43 ± 1.98) and funding stability (4.38 ± 1) were considered deficient domains, and at the end of the second year, these domains had improved by 1.67 points (p =.043) and 0.59 points (p = .159), respectively. The funding stability increase was not significant because only one of the five specific items, "policies implemented to ensure sustained funding," improved by 1.08 points (p = .036). The sustainability capacity final score was 5.93 ± 1.13. The sustainability capacity assessment during the intervention allows its improvement before the programme expires, ensuring the long-term implementation of the "Som la Pera" intervention programme to encourage healthy lifestyles in adolescents.