**12. Different dispensing models used to measure adherence**

Dispensing models include interviewing patients, questionnaires, pill count, prescription refills data, electronic monitoring system, measurement of drug levels, digital medicine, and directly observed technique [73].

Patient's interview is when a physician questions the patient about adherence to medicines. The physician asks the patient questions related to medicine-taking behavior thus, communication skills of the physician and the ability to conduct nonjudgmental discussion is important [73]. The health care professional asks the patient to estimate their own medication-taking behavior, such as which percentage of dose that they may miss within a designated period or the frequency that they are unable to follow the medication regime [83]. On the other hand, questions asked to the patient by the health care professional can be based on the patient's knowledge on the prescribed regime, including drugs' name, schedule, and indications [83]. Health care professionals then evaluate their response to determine the level of adherence [83].

Questionnaires are forms which can be completed by patients, trained nurses or healthcare professionals as a tool to monitor adherence [73]. Types of questionnaires used to measure adherence are the Brief Medication Questionnaire, Hill-Bone Compliance Scale (Hill-Bone), Eight-Item Morisky Medication Adherence Scale (MMAS-8), Medication Adherence Questionnaire (MAQ ), Self-Efficacy for Appropriate Medication Use Scale (SEAMS), and the Medication Adherence Report Scale (MARS) [85, 86]. A well-known and mainly used questionnaire to measure adherence is the Morisky questionnaire [69, 83].

Pill count is a frequently used dispensing model to monitor adherence where counting returned pills by a patient gives an overview of what has been taken by the patient [73]. The health care provider counts the number of dosage units that have been taken by the patient between two scheduled appointments or clinic visits [83]. This number would then be compared with the total number of units received by the patient to calculate the adherence ratio [83]. The equation for calculating pill count is as follows: (Number of dosage units dispensed − Number of dosage units remained) / (prescribed number of dosage unit per day × number of days between 2 visits) [83].

Prescription refill data requires availability of electronic monitoring of drug prescriptions in pharmacies [73]. Prescription refill data assists with obtaining a rough estimate of medicines adherence and persistence by calculating the percentage of days covered by the prescriptions [73]. When measuring adherence using prescription refills, it is assumed that prescription-refilling patterns correspond to the patient medication-taking behavior and that the medication is taken exactly as prescribed [83].

Electronic monitoring system consists of a device in which a microcircuit is incorporated into medication packages and any removal of a dose of the medicine is detected in real time, time stamped, analyzed, stored, and communicated [73, 83]. Commonalities of different electronic monitoring devices include (i) recorded dosing events and stored records of adherence, (ii) audiovisual reminders to signal time for the next dose, (iii) digital displays, (iv) real-time monitoring, and (v) feed-back on adherence performance [83]. The commonly used electronic monitoring device is the Medication Event Monitoring System (MEMS) [73, 83].

Measurement of drug levels involves the measurement of the medicine or its metabolite concentration in body fluids, such as blood or urine, and evaluation of the presence of a biological marker given with the medicine and direct observation of patient's medication-taking behavior [73, 83]. Complete absence of medicine in a sample indicates that the medicine has not been taken by the patient for a duration equivalent to half-lives of the medicine [73].

Directly observed technique is an approach when medicine is given and taken by the patient under supervision of a member of the clinical staff every day for a certain period of time [73].

Digital medicine consists of ingestible sensors incorporates in the pill during manufacturing process, which will be ingested by the patient [73]. After ingestion, an electrochemical reaction is triggered in the stomach leading to an activation of the sensor and generating a unique message coded for the medication name and dose to a wearable patch worn by the patient on the torso and recorded the date and time of the sensor ingestion [73]. The information collected by the patch is encrypted and transmitted wireless to a designated device using Bluetooth. The sensors are then eliminated as solid waste within 72 hours [73].

There are other dispensing models used to monitor patient medication adherence thus, treatment outcome. Modern technology can be used to monitor adherence and includes the use of internet, real time medication monitoring (such as electronic pill boxes), and mobile phones [69]. The use of electronic pill boxes combined with Short Message Service (SMS) reminders are specifically designed to improve unintentional adherence [69]. These interventions have resulted in an increase in refill adherence in diabetic patients with suboptimal adherence [68]. Mobile phones can be used to send alerts to take medication to patients, track doses, and provide appropriate medication instructions [86]. Automatic home medication dispenser (AHMD) integrated with a smartphone application can be used to address adherence issues especially for elderly patients [86]. The AHMD holds up to 90 day's supply of several medications, and addresses cognitive impairment and age-related changes using components such as counter, clock dispensing mechanism, power source, input/output interface, locking system, transceiver and antenna, and physical indicators for alarms [86]. The AHMD also notifies the patient of due dosage per set dosage time or due refills through audio/visual reminders, and notifies the caregiver of missing dosages through calls or text messages [86–88].

In conclusion, it is important to monitor adherence of patients with chronic diseases to their medicines using appropriate dispensing models (either alone or in combination) as uninterrupted life-long consumption of medicines will prove patients' health outcome. In instances where non-adherence has been identified, it is essential to note factors affecting adherence of patients to their medicines and address those factors.

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**Author details**

mvramathebane@gmail.com

Masebata Ramathebane\*, Lineo Maja and Molungoa Sello

\*Address all correspondence to: mv.ramathebane@nul.ls;

© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

National University of Lesotho, Maseru, Lesotho

provided the original work is properly cited.

*Exploring Cardiovascular Diseases Treatment in Africa DOI: http://dx.doi.org/10.5772/intechopen.95871*

*Exploring Cardiovascular Diseases Treatment in Africa DOI: http://dx.doi.org/10.5772/intechopen.95871*

*Lifestyle and Epidemiology - The Double Burden of Poverty and Cardiovascular Diseases...*

equivalent to half-lives of the medicine [73].

certain period of time [73].

Measurement of drug levels involves the measurement of the medicine or its metabolite concentration in body fluids, such as blood or urine, and evaluation of the presence of a biological marker given with the medicine and direct observation of patient's medication-taking behavior [73, 83]. Complete absence of medicine in a sample indicates that the medicine has not been taken by the patient for a duration

Directly observed technique is an approach when medicine is given and taken by the patient under supervision of a member of the clinical staff every day for a

Digital medicine consists of ingestible sensors incorporates in the pill during manufacturing process, which will be ingested by the patient [73]. After ingestion, an electrochemical reaction is triggered in the stomach leading to an activation of the sensor and generating a unique message coded for the medication name and dose to a wearable patch worn by the patient on the torso and recorded the date and time of the sensor ingestion [73]. The information collected by the patch is encrypted and transmitted wireless to a designated device using Bluetooth. The

There are other dispensing models used to monitor patient medication adherence thus, treatment outcome. Modern technology can be used to monitor adherence and includes the use of internet, real time medication monitoring (such as electronic pill boxes), and mobile phones [69]. The use of electronic pill boxes combined with Short Message Service (SMS) reminders are specifically designed to improve unintentional adherence [69]. These interventions have resulted in an increase in refill adherence in diabetic patients with suboptimal adherence [68]. Mobile phones can be used to send alerts to take medication to patients, track doses, and provide appropriate medication instructions [86]. Automatic home medication dispenser (AHMD) integrated with a smartphone application can be used to address adherence issues especially for elderly patients [86]. The AHMD holds up to 90 day's supply of several medications, and addresses cognitive impairment and age-related changes using components such as counter, clock dispensing mechanism, power source, input/output interface, locking system, transceiver and antenna, and physical indicators for alarms [86]. The AHMD also notifies the patient of due dosage per set dosage time or due refills through audio/visual reminders, and notifies the

sensors are then eliminated as solid waste within 72 hours [73].

caregiver of missing dosages through calls or text messages [86–88].

In conclusion, it is important to monitor adherence of patients with chronic diseases to their medicines using appropriate dispensing models (either alone or in combination) as uninterrupted life-long consumption of medicines will prove patients' health outcome. In instances where non-adherence has been identified, it is essential to note factors affecting adherence of patients to their medicines and

**312**

address those factors.
