Design: Pragmatic cluster randomized clinical trial with 18 months follow-up.
Unit of randomization: general practitioner.
Unit of analysis: patient.
Setting: Primary Health Care Centres in three different Spanish Autonomous Communities (Aragón, Madrid and Andalucía).
Population: Patients 65-74 years of age with multimorbidity (3 or more chronic diseases) and polypharmacy (5 or more drugs taken for at least three months). N=1234 patients (617 in each arm, 8 patients per physician) will be recruited by general practitioners before randomization.
Intervention: Complex intervention incorporating previous MultiPAP intervention (based on the ARIADNE principles with two main components: 1) Training of general practitioners and 2) Patient-centered clinical interview) And it adds a clinical-decision support system to help structured treatment-plan review.
Control group: usual care.
Variables: First level (Patient): a) Main: hospitalizations and/or mortality; b) Secondary: health services use, quality of life (Euroqol 5D-5L), disability (WHODAS), fractures, pharmacotherapy and adherence to treatment (Morisky-Green), clinical and socio-demographic. Second level (Physician): a) Socio-demographic. b) CDSS use: acceptance and satisfaction of health care provider use c) Professional background: time in the position, center characteristics and medical education involvement.
Analysis: All analyses will be carried out adhering to the intention-to-treat principle. Description of baseline characteristics. Basal comparison between groups. Analysis of primary outcome: difference in percentages in the final combined variable from 0 (T0) to 18 months (T3), with its corresponding 95% CI. Adjustement by main confounding and prognostic factors will be performed through a multilevel analysis.