**6. Concluding remarks**

As the population is aging, people are more prone to chronic diseases. Pharmacotherapy is the best treatment to follow. Approximately, half of the elderly have at least three chronic diseases, which result in polypharmacy. Complicated drug delivery regimens cause the elderly to eventually give up treatment. Another reason for treatment discontinuation is the high prices of medicines. Failure to adhere to treatment has a negative impact not only on the patient's health, increasing the risk of morbidity and mortality, yet also on the sustainability of entire healthcare care systems, due to higher number of avoidable hospitalizations and emergency visits, and finally, on the economy.

Thus, it becomes mandatory to find a way to overcome this problem, and it is necessary to implement techniques that increase adherence. These changes start with patient education. Providing the patients with all the necessary information about their illness, treatment, prognosis, and the consequences of non-adherence is the prerequisite of the right decisions. However, this should be followed with the use of other adherence-targeting interventions, tailored to the individual needs.

Finally, more studies are needed in this area, as the impact of non-adherence to therapeutics by the elderly on the economy has not yet been fully unveiled.

## **Acknowledgments**

This work received financial support from the European Union (FEDER funds POCI/01/0145/ FEDER/007728) and National Funds (FCT/MEC, Fundação para a Ciência e Tecnologia and Ministério da Educação e Ciência) under the Partnership Agreement PT2020 UID/MULTI/ 04378/2013.
