This study examines the effectiveness and the costs of a complex multiple risk behavior intervention to promote healthy behaviors in people aged between 45 and 75 years attended in Primary Health Care services. This intervention aims to reduce tobacco use, to enhance adherence to the Mediterranean dietary pattern and to increase physical activity. The study also seeks to provide evidence on the strategies to integrate health promotion into the usual clinical practice of primary care providers.

Health promotion interventions are complex and need in-depth understanding of the context which is part of its effect. In this respect, the methodology proposed by the Medical Research Council offers a unique opportunity. This methodology proposes a development in five sequential phases in which both quantitative and qualitative methods are used, which include: a) definition of the theoretical basis (preclinical phase), b) modeling (phase I), c) exploratory trial (phase II), d) definitive randomized controlled trial (phase III) and e) long-term implementation (phase IV). This methodology promotes the participation of citizens and professionals in research and increases the acceptability and the feasibility of intervention. It is also an ideal tool to achieve the sustainability of interventions and the transfer of research to practice. Research on complex interventions marks a turning point in the conventional way of conducting experimental studies in which the most important thing is finding value and understanding the context of practice rather than trying to control its influence. Hybrid trials represent the ideal design because they allow a joint assessment of clinical effectiveness and implementation, thanks to their dual approach.

In this connection, the researchers started in 2012 the EIRA study and carried out the first three phases (preclinical phase, phase I and phase II). Currently, researchers are pursuing the phase III whose purpose is to assess the cost-effectiveness and the implementation of a health promotion intervention through a hybrid design.

This cluster randomized controlled trial aims to assess the effectiveness and the implementation of a complex multiple risk behavior intervention with two parallel groups (intervention and usual care). It is based on:

• The "Consolidated Framework for Implementation Research" (CFIR) which identifies five constructs: 1) intervention characteristics (intervention source, evidence strength and quality, relative advantage, adaptability, trialability, complexity, design quality and packaging; and cost); 2) outer setting (patient needs and resources, cosmopolitanism, peer pressure, and external policy and incentives); 3) inner setting (structural characteristics, networks and communications, culture, implementation climate and readiness for implementation); 4) characteristics of individuals (knowledge and beliefs about the intervention, self-efficacy, individual state of change, individual identification with the organization, and other personal attributes); and 5) the implementation process itself.
• A set of discrete implementation strategies which includes: plan strategies (gather information, adapt and pilot material and processes, build buy-in, initiate leadership and develop relationships); educate strategies (develop materials, educate, educate through peers, inform and influence stakeholders); finance strategies (modify incentives and facilitate financial support); restructure strategies (revise professional roles and create community and group interventions committees) and quality management strategies (develop and organize implementation monitoring systems, conduct continuous assessment and feedback, establish a system of reminders, obtain and use patient opinion, centralize technical assistance focused on implementation issues).
• An evaluation framework to determine the success of implementation.

The study will be carried out in three stages:

STAGE 1: PRE-IMPLEMENTATION. During this stage, the researchers will assess local needs and resources to develop specific implementation strategies. Likewise, the scientific literature will be reviewed and the perspectives of clinicians on the internal resources will be measured by the "Survey of Organizational Attributes for Primary Care". All the support material for the intervention will be drawn up, besides the facilitator (member of the research team) and the leader (member of the primary care team) of the implementation will be designated. Mechanisms for the effective communication and the case report form (CRF) will be defined and piloted. Formal compromises will be made with the managers (at the macro, meso and micro levels) and with the professionals involved. Training activities will be carried out in which training in motivational interview will have a central role. In addition, a checklist (on-line database) will be developed and piloted to monitor the progress of implementation in each primary care center.

STAGE 2: IMPLEMENTATION. In this stage the implementation plan will be carried out. The facilitator and the leader of implementation will monitor the implementation processes, identify opportunities for improvement and optimize implementation. Likewise, positive feedback techniques will be used towards the main stakeholders in order to keep the agreed compromise and the motivation. Besides, health professionals will receive continuous training in motivational interview.

STAGE 3: POST-IMPLEMENTATION.

The evaluation of the implementation will be carried out through qualitative and quantitative research. It will be evaluated in terms of:

A) OUTCOMES (see section "Outcome Measures"). B) DETERMINANTS. Three focus groups (one of health professionals and two of participants) will be conducted in each health center. Sampling will be theoretical (discursive plurality). Sessions will be transcribed in an anonymous fashion. A thematic content analysis will be done. The CFIR constructs will be scored following standard criteria that they will reflect the influence of the construct on the implementation (positive or negative) and its magnitude (between 1 and 2).

C) LEVEL OF DEVELOPMENT. The level of development of each of the implementation strategies will be determined from the online database. Updating of this database will be carried out by the facilitator of implementation. Likewise, logistic regression models will be developed in which the dependent variable will be the effectiveness of the intervention, considered as a positive change in any of the three behaviors studied. In one of the models the independent variables will be the quantitative measures of the results of the implementation and in the other, the degree of implementation of the different strategies. The purpose of these analyzes is to model the relationship between the implementation variables and those of effectiveness. On the other hand, the influence and the magnitude of the determinants of the implementation and the results will be established through multivariate models.

SAMPLE SIZE It will be necessary to study a minimum of 3640 people (1820 for each of the two groups). This sample size will allow to detect an increase of 8% in the proportion of people who show a positive change in one or more of the three behaviors in the intervention group over control group. The proportion of losses during follow-up estimated was of 30%. The sample size was decided taking into account the effect of design (intraclass correlation coefficient of 0.01).The power was 80% and alpha risk 5%.

Inclusion Criteria:

• People who carry out 2 or more of the following unhealthy behaviors: tobacco consumption, low adherence to the Mediterranean dietary pattern or insufficient physical activity. In addition, they must have a professional provider of the health center assigned and voluntarily agree to participate.

Exclusion Criteria:

• Advanced serious illnesses
• Cognitive impairment
• Dependence in basic everyday activities
• Severe mental illness
• People included in a long term home health care program
• People in treatment for cancer
• People in end-of-life care