Medication Adherence in Older Adults: 
An Overview 



Adherence to medication is a key determinant of successful treatment. For older people with underlying chronic conditions as well as those living alone, medication adherence becomes crucial for their health. Non-adherence leads to worsening of health conditions, an increase in healthcare expenditure and a burden on the healthcare system. This paper gives an overview of medication adherence in older adults. Various factors that lead to failure in adherence are described such as patient, physician, healthcare system related, and socioeconomic conditions. Various interventions that could be implemented to improve compliance are also addressed. Lastly, this paper also highlights various methods such as direct and indirect which can be used as a means to assess the level of adherence to the described interventions.




Adherence to medication has always been a crucial aspect of patient care. WHO defines Medication adherence as “ the extent to which a person’s behaviour which includes taking medications, following proper diet and lifestyle is in line with the recommendations from healthcare provider”. It consists of initiation, implementation, and discontinuation of the treatment regimen. (Lam, 2015) Medication adherence is of prime importance in older patients. As the elderly are susceptible to various comorbidities and polypharmacy, there is a higher risk of nonadherence which results in poor therapeutic benefit, increased healthcare costs, and deterioration of medical condition. (Yap, 2016) Although adherence and compliance are synonymous, compliance refers to the patient being obedient of the physician’s recommendations, however, adherence is a collaborative process that integrates the physician’s knowledge and patient’s values and opinions. (Jimmy, 2011) Nonadherence is a diverse concept. It includes the hesitation to start a treatment or not taking doses at proper time intervals, skipping doses, self-adjusting the regimen, or even continuing medicine without physician’s advice. (Dr Angel George, 2020)Consequences of not following the proper medication are applicable not only to the patient but also the healthcare provider and hence nonadherence is a serious public health concern. (Jimmy, 2011)

The following table describes the types of Nonadherence. (Jimmy, 2011)




Nonadherence or poor adherence to medication in the elderly is generally due to a number of causes that need to be understood before implementing measures or interventions to improve it. Reasons for nonadherence are typically classified into the following categories:


1.Patient Related Factors :

Adherence to medicines is mostly dependent on the individual. Therefore, adherence to medicines varies from person to person based on a number of factors. Health literacy is found to be one of the most important factors in determining adherence. It has been reported in a few studies that poor the health literacy, poor is the adherence. Lack of knowledge about disease, medication and misunderstanding of instructions contribute to health literacy. (Yap, 2016) Other patient related factors associated with poor adherence include cognitive ability, socio-demographics, past medical history, physical wellbeing, and behaviour, attitude, and beliefs. (Gellad WF, 2011)


2.Medication Related Factors:

Many articles have stated that complex medicine regimens and polypharmacy are important drivers for adherence. Elderly people with impaired cognitive ability or living alone would face difficulties in understanding the medicine regimen when a number of medicines have been prescribed. The cost of medicines plays a pivotal role for the elderly and especially those with low income. Formulation, packaging, proper labelling of instructions and adverse drug reactions and drug  interactions also need to be considered. (Yap, 2016) (Gellad WF, 2011) (Lee, 2018)


3.Healthcare provider Factors:

An ideal patient healthcare provider relation is required to establish the patient’s trust which leads to adherence to medication. Most of the time lack of communication, lack of patient’s involvement, trust, and confidence in the physician’s diagnosis and treatment cause poor adherence. (Yap, 2016) (Lee, 2018)One study reported that 60% of patients who were interviewed after a visit to physician misinterpreted the prescribing instructions. (Jimmy, 2011)


4.Healthcare system Factors:

Lack of patient education, follow-up, medication schedule may lead to poor adherence. Access to healthcare remains an important factor. Lack of patient education is risky for elderly with chronic conditions as they do not understand what the disease is, how will the medicine work, etc. In such cases, it is the responsibility of health systems to impart education among the population regarding diseases and how medicines should be taken as well as managing the cost effectiveness of medicines. (Yap, 2016)


5.Socioeconomic Factors:

Lack of caregiver, income level, and financial hardship also contribute to nonadherence. In one of the studies, it was reported that women and elderly patients faced a crisis to afford the high cost of medicines and hospital care. (Yap, 2016) (Lee, 2018)




For a treatment to be successful not only the effectiveness of the medicine plays a role but proper adherence to the regimen is of vital importance. A combination of various interventions is implemented to ensure proper adherence. Patient counselling is one of the strategies for medication adherence. Simplifying the drug regimen is a crucial aspect for the elderly. Healthcare providers can encourage patients by discussing their beliefs, reluctancy, and opinions about the treatment, informing key points of the medication regimen, explaining how and when to take medicines, also the common side effects and how to treat if they occur. Involving the patient in decision making process to ensure that the patient proactively follows the treatment and can implement the regimen in their daily life with ease are important points to be considered while patient counselling. (Jimmy, 2011)Considering the fact that a lot of elderly patients discontinue medicines due to their high cost, prescribing cost effective medications can increase patient adherence as it will reduce the economic burden. (Dr Angel George, 2020) Medication adherence improving aids can remind the patients to take medicines or to schedule a visit to the doctor for follow-up and screenings. Various kinds of reminders are used such as text messages, phone reminders, personalized blister packs and medication boxes, interactive voice response systems, pagers, etc. (Costa, 2015) One study which tried to assess the impact of reminder packaging on medication adherence found out that patients with reminder packaging were more diligent and adherent towards the treatment as compared to the ones without reminder packaging. (Dupclay, 2012) Another study tried to compare elderly patients who were given daily dose blister packaging(pill calendar) with the ones who were given a bottle of loose tablets. It was found that patients with Pill Calendar used to refill their prescription more on time as compared to the others. (Schneider, 2008) Medication aids have proved that they have a positive effect on adherence. A number of interventions are described in various studies and papers to improve medication adherence. However, which intervention to implement depends on the clinical condition, patient’s behavioural aspect, and integrated action between the health system and healthcare provider. (Costa, 2015)





Once the nature of adherence and the factors causing them is known, proper interventions can be designed uniquely to each patient. Measuring adherence therefore becomes important for researchers and clinicians to assess the effectiveness of interventions. Wrong assessment can result in effective treatments being labelled as ineffective and expensive. Accurate assessment can help outline the risk factors, consequences of therapy, etc. Measuring adherence can be challenging because the methods used should give accurate, reliable, and feasible results. A single method cannot prove to be accurate; every method will have flaws. Thus, a using combination of various methods, wherein each method’s advantages could compensate other method’s flaws can provide accurate results. Hence, there is no standard method for assessing adherence, a combination of various methods is used. (Lam, 2015)  Methods for measuring adherence are classified into direct and indirect measures.




Direct measures include direct observation of therapy that is observing patient’s medication taking behaviour, measuring the concentration of a drug or its metabolite in blood, urine, and body fluids, measuring the biological marker attached to the drug, etc. Direct methods are the most accurate but expensive method. Direct methods have certain drawbacks to be considered.  First, drug metabolism needs to be taken into account. Metabolism rate as well as the drug plasma levels differ in patients taking the same dose of medication. Also, drug-drug and drug-food interactions can increase or decrease the rate of metabolism. Some drugs leave trace amounts of metabolites in the blood even after stopping the medication. These factors need to considered when measuring the drug/metabolite concentration as a measure of adherence. Second, a phenomenon known as ‘white coat adherence’.  It means improved patient adherence around clinic visits. Patients may not adhere to the regimen daily, but around visits to clinicians they might take medications on time to give a false impression of adherence. Thus, while using direct measures these points need to be assessed. (Lam, 2015) (Jimmy, 2011)




Indirect measures include patient self-reports, questionnaires, pill count, assessment of patient’s responses, electronic medication monitors, rate of prescription refills, etc.

(1) Patient interviews, self-reports, questionnaires:

Subjective methods have gained popularity due to low cost, simplicity, practicality, flexibility, and real time feedback. Clinicians can understand patient’s concerns and queries clearly and provide as well as assess the tailored interventions. However, the drawbacks of this method should not be underestimated. Patient’s psychological state, false data input, purposely or accidently can hamper the authenticity of such subjective methods. (Lam, 2015)Questionnaires are used to minimize the shortcomings of self- reports. For each specific medication regimen, there is a standardized measurement of adherence. Questionnaire and scales like Brief Medication Questionnaire, 8 item Morisky Medication Adherence Scale, Hill Bone Compliance Scale, do not have a predefined cut-off range for adherence, instead they have rankings or levels/scores to describe the degree of adherence. (Jimmy, 2011) (Lam, 2015).

(2) Pill Count:

Pill count is basically measuring the number of pills/doses taken by the patient between two clinic visits. The number of pills taken is compared to the total number of pills given by the physician during the clinic visit to calculate the adherence ratio. The simplicity and low-cost of this method contributes to its popularity. Though the method is simple, it may have disadvantages like patients can switch medicines in the bottle or even discard them before a visit to clinic in order to appear that they are adherent of the regimen. This method only considers whether pills have been taken or not, it does not consider what time the medicine has been taken, drug holidays, etc. Hence, it is not an ideal measure of adherence. (Jimmy, 2011)

(3) Electronic Medication Monitors:

Such devices are incorporated in the packaging of medicines. They record the time of opening of bottles which corresponds to the dosing time. There can also be audio-visual reminders to take medicines. Medication Event Monitoring System is the most commonly used electronic medication monitor. The only disadvantage with this method is that it may not be accurate, for example the patient may open the bottle but take wrong dose, multiple dose, or no dose at all. (Jimmy, 2011)


An ideal adherence assessment should be low cost, user friendly, give accurate and reliable results. There is no single measure which can be considered as a standard for determining adherence since each measure has its own shortcomings. Hence a multi-measure approach is suggested by researchers and clinicians. (Lam, 2015) A study which used a multi-measure approach showed that the rate of adherence using combination of measures was higher than the rate of single measures. Having said that,  multi-measure approach increases the complexity of analyses. (Modi, 2006)






Medication adherence has always been a critical issue amongst the elderly. Poor medication adherence is an obstacle to ensure successful pharmacotherapy. With a rising trend of population aging and increasing healthcare costs as well as adverse events amongst elderly,  there is a need to ensure there are customized interventions for the elderly for successful treatment. Factors such as patient related, healthcare system, and physician related as well as socioeconomic factors should be considered while implementing interventions specifically for the elderly with chronic conditions and those living alone. Patient education is key for improving compliance. Use of various assessments that gives estimate of the degree of adherence is also essential to ensure interventions that are implemented actually work. Thus, while designing medication regimens and adherence for the elderly, a multidisciplinary approach must be considered keeping in mind each patient has a different set of needs and factors which lead to poor compliance, hence they require customized interventions.



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Dupclay, L. E. (2012). Real-world impact of reminder packaging on antihypertensive treatment adherence and persistence. Patient preference and adherence.

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