The impact of comorbidity on medication adherence and therapeutic goals

Introduction

Prescribing medications is often challenging in older people with multiple chronic diseases. Non-adherence to prescribed medications is among the most important problems, so that many people are not benefiting properly from the drugs they are prescribed. Additionally, this also represents a costly waste for health services [1].

Comorbidity and medication adherence

Poor adherence to the prescribed therapy is highly prevalent in older patients. Prevailing evidence suggests that age per se should not be considered as a risk factor for poor adherence [2]. Lower educational level, less affluent economic status, cognitive/physical impairment, being assisted by foreign caregivers, and some chronic diseases, such as chronic renal failure, are commonly reported poorly modifiable correlates of non-adherence. Regimen complexity represents a to some extent modifiable correlate [2]. Vision impairment, reduced manual dexterity, and patients’ perception of medication importance may contribute to determine the relationship between regimen complexity and non-adherence. There is minimal evidence to support interventions that improve medication adherence, and the effects of psychosocial interventions are largely unknown [1].

Therapeutic goals in patients with multiple chronic conditions

Patients with multiple chronic conditions may vary in regard to their opinion about health outcomes such as longer survival, prevention of disease-specific events, physical and cognitive function, and tolerable risk of adverse drug reactions. A paradigmatic example of how challenging this issue can be in clinical practice is the difficulty in rational prescribing for older patients with multiple chronic conditions and reduced life expectancy, when the likelihood of benefit and goals of care must also be considered in addition to satisfying the basic principles of optimal medication use in the elderly [3].