Several frameworks were reviewed to find the theoretical framework that is most likely to capture the determinants of medication adherence. They are presented below.
2.5.1 Behavioural Perspective
The behavioural perspective integrates the behavioural learning theory which focuses on the environment and the teaching of skills to patients to manage
adherence (Dick et al., 2003). It is characterised by the use of the principles of antecedents (which are either internal thoughts or external environmental cues) and consequents, and patients’ influence on behaviour (Munro, Lewin, Swart, et al., 2007). The consequents are rewarded if they are a positive behaviour or a punished if they are a negative behaviour. Despite studies indicate the importance to compliance of patients’ organization and comprehension, there is a little chance in the attitude that leads to compliance with the treatment instructions (Leventhal & Cameron, 1987)
2.5.2 Self-Regulation Perspective
Self-regulatory theory is the most popular theory in the field of medication adherence. The theory is developed to conceptualize the adherence process in a way that focuses on the patient (Leventhal & Cameron, 1987). The theory assumes that people are motivated to avoid or treat illness and are active, self- regulating problem solvers. The patients need to be interested in improving his/her health for treatment to be effective (Nouwen, Urquhart Law, Hussain, McGovern, & Napier, 2009).
The behavioural perspective focuses on the environment and patients’ skill development to cope with treatment and self-regulation theory assumes patients are active, motivated and problem solvers for their own health. Therefore, both models focus on inviduals’ behaviours towards their health. However, the current study investigates 3 main aspects, namely health service delivery, social and demographic and individual factors. These two models were used as a guide for the individual disease related factors. However, the conceptual framework for the study was derived from the literature.
2.5.3 Conceptual Framework
The literature review revealed many factors associated with adherence to tuberculosis treatment. Figure 1 presents the mapping of literature related to health service delivery, social and economic and disease related factors. Arrows in Figure 1 explains the links and relationships among all variables in the literature. For example lack of health service accessibility would force individual
patients to travel to and from an available health service. As a consequence, patients would require financial support to meet such need.
In comparison to Figure 2, the arrows of health service, social and eocnomnic and personal and disease related factors directly linked with adherence. This explains by the fact that the current study investigated the relationship of each aspect with treatment adherence rather than the interaction of each of the three main domains.The structure of the literature mapping in Figure 1 is retained in
Figure 2 to ensure consistency of variables in the categories. However, only variables that were relevant to be investigated in the current study were included in the conseptual framework in Figure 1.
Those factors are divided into three main categories, as follows: a. Health service and delivery factors
There are numerous aspects identified in the literature which are related to health service delivery. However, this study will mainly focus on investigating the aspects of accessibility and availability factors due to limited time and resources. Accessibility aspects include cost, time and distance, and availability includes information, presence of health care workers and quality of services i.e. counseling.
b. Social and economic factors
Social and economic factors are two broad areas which also cover a lot of factors. This includes demographic characteristics, including socio- economic status, gender, age, education, occupation and marital status. Social motivation, such as family support, financial support and other social support i.e. support from friends and relatives, will also be examined.
c. Individual and disease-related factors including:
treatment: illness characteristics and severity, treatment duration, treatment progress over time. Regimen: Complexity of treatment, dosage level and side- effects, knowledge, beliefs and attitudes towards treatment and mental health problems such as depression, helplessness, stress and isolation (refer to Figure
Figure 2 Survey Conceptual Framework Accessibility
Cost, time and distance
Availability
Information, presence of health carer & quality of service
Health Service Delivery Factors Social & Economic Factors
Socio-demographic characteristics
SES, gender, age, education, occupation & marital status
Social motivation
Family support, financial support & health professional support Other supports: friends, relatives &
other social supports
Personal & Disease Related Factors
Treatment
Illness characteristics and severity, treatment duration, and treatment
progress over time
Regimens
Complexity, dosage level & side effect
Knowledge, belief & attitude towards treatment
Mental health problems (depression, anxiety, stress & isolation) Locus of control (internal, chance and
other power)
Risk behaviour
Alcohol, drug use & smoking
Level of dose
ADHERENCE
SUMMARY
Treatment adherence has been recognised as a pivotal aspect of the fight against TB, as poor adherence has a negative influence at both individual and population levels. A major public health problem that threatens the progress made in TB care and control worldwide is the development of multi-drug resistance TB (MDR-TB). It has been documented in many different settings around the world that drug resistance arises as a result of improper treatment and failure to ensure that the patients complete the whole course of their treatment regimen successfully. Research continues to show thresholds that vary between 75% and 100% as optimal adherence, while the recommended threshold for TB adherence is at 80%. There are a number of ways in which adherence to TB treatment can be measured. A common measure is the self- report of the estimated percentage of prescribed doses taken over a given period of time. Yet, the self-report method sometimes leads to social desirability bias, which may influence the overestimation of medication adherence. Understanding the barriers and enabling factors to TB medication adherence is of paramount importance, especially in designing effective strategies to optimize adherence.TB is a key public health issue in Timor-Leste, and key stakeholders for TB programs have limited data available on the level of treatment adherence.Therefore, this research is designed to develop a better understanding of the situation for TB treatment adherence among patients in Timor Leste.