Polypharmacy and inappropriate medication use are very common in multimorbid older patients. This population has unfortunately been excluded from most large, randomized studies. In a recent multicenter randomized study (OPERAM), we included over 2000 multimorbid patients. We found that 86% of the patients aged 70 years and more had inappropriate medications and that these medications could be discontinued without negative impact on the health of these patients. This cohort of multimorbid patients will be followed for 10 years to evaluate their prognosis, life expectancy, treatments and quality of life, with numerous projects to better understand the inappropriate prescribing of individual drugs and their consequences on the health of this population.