Medication Non-Adherence in Geriatric Patients With Multimorbidity

Introduction

Medication adherence is defined as the patient’s behavior agree with the physician’s plan regarding the agreed treatment plan. Compliance and adherence are usually used interchangeably despite the subtle difference in the meaning. Compliance is the degree of patient’s behavior corresponding with the health care provider’s plan whereas adherence is the mutual work between the patient and the physician to achieve the desired outcome of the treatment plan. There are three common types of non-adherence in practice. First, the primary non-fulfillment adherence when the therapy is prescribed but has not been used by the patient. Second, the non-persistence non-adherence occurs when the patient stops the therapy in the midway of the treatment journey without consulting the physician. This type of non-adherence could be intentional or unintentional. Unintentional could be due to lack of access to therapy, poor memory, and financial burden while Intentional non-adherence is attributed to the patient’s beliefs, attitudes, motivation, and expectation. Third, the non-conforming in which the medication is utilized by the patient in incorrect time, dose, or frequency. The rate of adherence is measured in literatures as a percentage of the actual consumed doses divided on the supposed doses to be utilized during a treatment period. The rate is estimated to be approximately 50% in developed countries and half of the non-adherence is intentional (Jimmy & Jose, 2011).

Medication non-adherence is linked to poor disease outcome and prognosis, increase of healthcare cost, increase hospital admission rates and death. In USA, medication non-adherence is accounted for 33 to 69% of hospital admissions linked to medication issues with a yearly cost of $100 billion (Osterberg & Blaschke, 2005). Of all hospital admissions, medication non-adherence consisted of 10% of the total hospitalizations. Non-adherence increases the yearly cost by $2000 due to increase in medical visits by 3 visits annually. The adjusted cost of medication non-adherence is the highest in cancer patients followed by osteoporosis, cardiovascular, mental health, and diabetes mellitus with adjusted costs of $144,101, $43,240, $16,124, $16,110, and $7,077, respectively (Cutler et al., 2018).

There are indirect and direct methods to detect non-adherence with advantages and disadvantages for each methos. Direct observed therapy, drug level in bodily fluids and measurement of biological markers in blood are examples for the direct methos. Direct observed therapy is the most accurate method, but patients may hide pills in the mouth cavity to throw them away later on. Measurement of drug or its metabolites in blood is objective method, despite that, metabolism may vary greatly among patients due to genetic differences. Also, Measurement of biological markers may differ due to variation of response from an individual to another. Indirect methos such as pill counts and prescription refills are often used in practice, however, they may not assess the actual received medication due to pill dumping and stocking pills without using them (Osterberg & Blaschke, 2005).

In many cases the prescription medications are not taken as prescribed because failure to adhere to the medication regimen. The reason for not adhering to drug treatment include unpleasant or inconvenient side effects of the medications like dry mouth, change in taste, fatigue or frequent urination are various reasons of stopping a mediation. Older adults are at higher risk for medication nonadherence due to prevalence of multiple comorbidities including cognitive deficit and polypharmacy. Medication adherence can be enhanced by considering geriatric's vision, hearing, swallowing, cognition, motor impairment and health literacy while providing counselling and education. On the positive side, a study found that increased medication adherence was associated with fewer hospitalizations and decreased cost in patients with certain chronic medical conditions (e.g., diabetes, hypertension).

The WHO suggests clinicians consider five dimensions when assessing medication adherence: social/economic factors (e.g., cultural), provider–patient/healthcare system factors (e.g., provider–patient relationship), condition-related factors (e.g., chronic conditions), therapy-related factors (e.g., regimen complexity), and patient-related factors (e.g., visual or hearing impairment). Clinicians can improve the likelihood of adherence by considering the use of adhering aids like special packaging, a medication record, a drug calendar, medication boxes, magnification for insulin syringes, dose-measuring devices, and spacer devices for metered-dose inhalers.