Worldwide, the population is aging and by 2050, there will be 2.1 billion individuals older than 60 years of age, accounting for 1 out of every 5 people.[1] The increased life expectancy is resulting in an increased prevalence of chronic disease comorbidities, functional impairment and concomitant multiple medications use.[2–6] The use of multiple medications introduces new challenges such as adverse effects, drug interactions, drug-induced diseases, complex drug dosing regimens, with resulting negative impact on medication non-adherence and an increase in medication errors.[6–9] Adherence is defined as “the degree to which the person’s behavior corresponds with the agreed recommendations of a healthcare provider.”[9] Medication non-adherence is of particular importance in management of chronic conditions. Non-adherence leads to less than optimal control of chronic health conditions and significant additional costs for the Canadian healthcare system estimated at $4 billion CAD per year.[10–14] There are numerous reasons why patients do not adhere to a medication regimen. Of the five different types of factors identified,[15,16] patient and therapy related factors are of particular importance among older adults. For example, increasing use of multiple medications to treat an increasing number of multi-morbidities results in complex therapeutic regimens which directly impact medication adherence negatively.[8,16,17] Older adults, especially those who may have mild cognitive impairment, may become more forgetful which decreases medication adherence.[17] Outside of forgetfulness and short-term memory impairment, a decline in executive function may reduce the ability of cognitively impaired individuals to organize and plan medication taking activities. [18,19] In addition, older adults may also accumulate physical limitations which impact medication taking resulting in medication non-adherence. Vision impairment increases the risk of medication errors.[20] Age-related conditions such as arthritis and Parkinson’s disease impacts the ability to open vials and punch blister packs. [21] According to the World Health Organization, the rate of medication non-adherence in developed countries nears 50%.[10]

The well recognized problem of medication non-adherence has spurred the development of numerous medication adherence technologies. A recent literature review identified 78 devices capable of providing real-time monitoring of medication intake.[22] Among these devices are vials, blister packaging, pill boxes, storage boxes and injectable and inhaler devices embedded with sensors or other technology that permits real-time tracking of medication taking through opening of vials or pill box compartments, puncturing of blisters or actuation or injection.[22] These devices offer a sizeable array of features which may impact the usability of the devices by older adults based on the physical or cognitive limitations they are facing. Usability is defined as the “extent to which a system, product or service can be used by specified users to achieve a specified goal with effectiveness, efficiency and satisfaction in a specified context of use.”[23] In their examination of key usability barriers associated with the use health technolog among older adults, Wildenbos et al. proposed a framework of four key categories: cognitive, physical, perception and motivational barriers as relevant for effective and safe use of technology.[24] Within this framework, cognitive barriers such as declining working memory, spatial cognition, attention, verbal fluency and reasoning may impact errors in the use of the technology, decrease efficiency, learnability, memorability and satisfaction.[24] Physical ability barriers such as declining speed of performance, grip strength, hand-eye coordination and flexibility of joints impact errors and efficiency of use.[24] Similarly, vision acuity, contrast detection, color vision, computer literacy, self confidence also affects learnability, efficiency, errors and satisfaction with use of technology.[24] Therefore, it is imperative that usability of medication adherence technology is assessed with older adults prior to utilizing these devices to address medication non-adherence.

Unfortunately, very few studies have examined the usability of medication adherence technology in older adults. In one study, where the usability of 21 electronic medication adherence products was investigated in older adults, caregivers and healthcare professionals, usability varied widely, with mean usability scores, as measured with System Usability Scale (SUS) per product ranging from 0 to 100.[25] However, the products tested in this study included electronic blister cards, pillboxes, and prescription vials with electronic caps with a variety of features. None of these electronic medication adherence devices automatically dispensed medications.

In one of the earliest studies examining the perceived usefulness and satisfaction of an automated medication dispensing device, 96 frail older adults receiving home care used one such device, the MD.2 dispenser, for one year after which they reported on the ease of use, reliability, acceptability, routine task performance and medication management assistance.[27] The MD.2 medication dispenser was 13” by 12” by 14” machine which held 42 medication cups and could dispense 1 to 6 cups per day. The front of the machine had a delivery ramp, an alert light, an LCD message screen and a dispensing button. The dispenser dispensed the allocated medications in a cup when dispensing button was pressed. In this study, 94% of participants found the device very easy to use and 84% indicated they would use it in the future. However, the results are not reflective of initial usability, i.e. immediately after the implementation of the device The study did not address the usability concerns that frail older adults may have faced in the first days or weeks of use. Furthermore, pre-filled cups with unit doses of patient’s medications were refilled in the MD.2 every two weeks by nurses and not the participants. This further limited a true test of usability of the device by participants by limiting the interaction with the machine to one of just dispensing. Finally, participants were receiving home care and had frequent interactions with healthcare providers who assisted with the automated dispensing device.

In their study examining the impact of cognitive impairment on the usability of an electronic medication delivery device, Ligons et al., demonstrated a significant relationship between cognitive impairment, measured with Mini Mental Status Examination (MMSE) scores and percentage of task success. For example, individuals with MMSE scores of 24 and above (no cognitive impairment) were able to successfully complete 69% of the tasks compared to only 34% of those with MMSE scores of <24 (p = 0.04).[28] The automated medication dispenser used in this study was designed to deliver medications from single dose blister cards based on a schedule programmed by pharmacies. Up to 10 different blister cards could be loaded into this device and users interacted with the device through a touch screen interface. At the time of scheduled dose, the automated dispenser would beep and display a flashing message on the touch screen to alert the user to take their medication doses. Participants were then expected to confirm their readiness to take their medication as well as retrieve the blister card from the dispensing drawer, and extract the dose from the blister. The participants were tested on several usability tasks such as loading and unloading blister cards, removing pills from the blister cards, manual drop, and viewing inventory. Usability was measured with SUS and observed by researchers as they interacted with the dispenser. Only three of the 19 participants scored SUS at 80 or higher. Task success rates ranged from 10.5% for manual drop to 57.9% for viewing inventory.

In a more recent study, usability, usefulness, satisfaction and impact on caregiver burden of an automated medication dispenser was tested with 58 older adults and 11 caregivers.[28] Usability was measured with SUS and Usefulness, Satisfaction and Ease of Use questionnaire. In this study, the mean SUS scores was 85.74 (SD 12.7, range 47.5 – 100). More than 75% of participants agreed with the statement that the product was easy to use. The automated medication dispensing system, spencer, is a rectangular shaped device with a touch screen, a narrow opening in the front that allows the dispensation of single multidose medication pouch and opening at the top for loading of refill boxes. It dispenses multidose pouches of the participants’ medications at scheduled times. The multidose pouches are packaged in strips by pharmacies and supplied in boxes that are loaded into the dispenser. Pouches can be dispensed with the use of a touch screen interface. Although most participants found the automated dispenser easy to use, usability was only measured at the end of the 6 months intervention. Similar to the study conducted with the MD.2 automated dispenser, this study did not capture the usability of the device at the beginning of the intervention. Furthermore, the study did not observe the participants who successfully carried out the tasks and which required more assistance.

While all the automated medication dispensers appear to have a touch screen or LCD interface and all appear to dispence medications that are prepackaged into a multidose container, the usability of the different automated dispensers varies. Some digital interfaces may be challenging for some older adults, while others may not be able to complete the loading of refills. Therefore, it is necessary to observe how older adults interact with the automated dispenser at their initial interaction as well as after a period of time of regular use. Assessment of usability and task success at the initial interaction is necessary to identify whether the usability challenges encountered can be addressed before long-term use is implemented. Assessment of long-term usability is necessary to measure learnability of using the device appropriately to ensure safe medication dispensing.

Therefore, we aim to study the overall and task specific usability of a new automated medication dispenser with older adults at the start of the study intervention and after 6 weeks of use. We will also examine the usability of a connected real-time medication intake monitoring dashboard with the participants’ health care providers. The dashboard enables clinicians to view adherence metrics of medications their patients are prescribed while they use the automated medication dispenser. As with measuring the usability of automated dispensers, usability of accessing and viewing adherence data is also just as important to measure. If there are usability concerns with accessibility of the dashboard, or with interpretability of adherence metrics by clinicians, useful information may not be utilized in clinic to adherence medication non-adherence.