Effect of motivational interviewing on treatment adherence and self- efficacy of adolescents with asthma: A randomized controlled trial

Aims: This study examined the short- term effect of motivational interviewing on treatment adherence and self- efficacy of adolescents with asthma. Design: The randomized controlled trial. Method: In

parents have primary control over disease regulation and they remain an important source of social support, as a child with asthma ages, management responsibilities are often shifted from the parents to the adolescent (Ayala et al., 2009). Many adolescents with asthma have suboptimal disease control despite the availability of effective therapies. For some, poor asthma control will be a consequence of suboptimal self-management, particularly adherence to treatment (Holley et al., 2019). On the other hand, in relation to asthma, low adherence is one of the most common causes of lack of clinical and functional disease control. In the case of children, when parents have a negative perception of asthma, they may be hesitant in terms of the need for inhaled drugs considering the side effects of drugs. In addition, when they do not have the necessary information about the disease, thus their adherence levels will be even lower (Jentzsch et al., 2017).
In asthma control, psychological, therapeutic and environmental factors are effective including behaviours focusing on the self-efficacy (Gomes et al., 2017). Self-efficacy is referred to the individual's self-confidence in his/her ability to perform a specific behaviour in a specific situation and is one of the important requirements for changing the health behaviours in patients with asthma (Martin et al., 2009). Among adolescents, higher levels of self-efficacy are associated with using more asthma management strategies and being more adherent makes it an important target for behavioural interventions (Ayala et al., 2009). So, interventions are needed for adolescents with asthma to control the disease with the aim of improving their self-efficacy and treatment adherence.

| BACKG ROU N D
The key principle of asthma control is higher self-efficacy and stronger treatment adherence in patients (Bektas et al., 2021;Jentzsch et al., 2017). According to previous studies, low levels of self-efficacy in patients with asthma are probably related to the emotional stress, which in turn has direct physiological effects (Martin et al., 2009). Adolescents with high levels of self-efficacy are more aware of their health status and health problems compared to those with low and moderate levels of self-efficacy (Bektas et al., 2021).
In addition to self-efficacy, adherence to treatment is the other factor related to control of the disease. Patients' understanding from illness and treatment plays an important role in adherence, which is often overlooked. The patient's decisions for follow-up are heavily influenced by his beliefs and attitudes towards illness and treatment (Chiu et al., 2014). A study (Kaplan & Price, 2020) showed that nonadherence is particularly concerning in adolescents, who have specific age-related barriers to taking their medication, which can have a disastrous impact on asthma control and subsequent outcomes.
Some previous studies reported that adolescents with asthma suffer from a number of problems, including a recent study (Al Kindi et al., 2021) which reported that Children with asthma have more susceptibility for physical and emotional disabilities, and that their academic achievement is more likely to decline. Almost including 36,000 children estimated who miss school every day due to the disease symptoms, putting them at greater risk for poor academic performance and poor intellectual development. Another study (Myers et al., 2018) reported that global pharmaceutical cost of the disease is also more than $ 5 billion a year.
Motivational interviewing is an advisory and patient-based approach that can be focused on the patients' challenges briefly; it was specially designed to provide incentives for change among the patients who are not ready for change (Borrelli et al., 2007;Fortune et al., 2019). The process involves detection, identification; and solving the doubt (Mirkarimi et al., 2017). The motivational interviewing helps patients to resolve their persistency in behaviour change, and provides an inherent motivation before offering the education. The motivational interviewing consists of some underlying motivational strategies that can be implemented concisely and easily in medical environments (including planning, assessing the motivation and confidence for change and providing medical consultation and health feedback). Reflexive listening is used to help the patients to recognize the duality and increase the resistance (Borrelli et al., 2007). Motivational interviewing can be more appropriate for adolescents because of the promotion of personal control and autonomy in decision making for change, focusing on individual goals and values, and their relationship with the target's behaviour, and willingness to change (Morton et al., 2015).
Despite the recent use of this method in the health systems, for health promotion, especially in the field of education and rehabilitation of mental disorders (Mirkarimi et al., 2017), few studies have been done on patients with asthma, especially adolescents in this field.
The purpose of this study was to examine the short-term effects of motivational interviewing on adherence and self-efficacy in adolescents with asthma.

| Study design
A randomized clinical controlled trial design was used in this study.

| Participants
Participants included the adolescents with uncontrolled asthma who were referred to paediatric clinics. The inclusion criteria were adolescents aged 10-15; all of them had a history of asthma clinically diagnosed at least 1 year ago as well as using the inhaled corticosteroids under the supervision of the paediatrician. The exclusion criteria were those who were receiving medical treatment for physical and/or mental illnesses and who were absent for more than one session. After preparing the list of adolescents, those who were willing to participate in the study were selected. The sample size was calculated based on the results of a Zarei et al study , and with a standard deviation in intervention group of 3.55, and 6.82 in control group and absolute error 4.5, power of 0.90 and confidence level of 95%. The sample size calculation equation ( Figure 1) showed that 31 participants were needed for each group.
The sample size was increased to 36 considering of 20% attrition rate (72 adolescents with asthma).
After attending the appointment and obtaining the written informed consent from the parents, adolescents were randomly assigned in experimental and control groups. Figure 2 shows how the study participants were recruited.

| Data collection procedures
Demographic information, the asthma self-efficacy questionnaire (ASQ), adherence self-report and asthma control questionnaire (Kercsmar et al.) were measured before the intervention for two groups. The intervention group received the motivational interviewing for 5 weeks, and the control group received no treatment, then F I G U R E 1 Sample size calculation equation. all the mentioned variables were measured 2 weeks and 3 months after the intervention in both groups.

| Ethical considerations
The study was approved by the university research ethics committee (code: IR.BUMS.REC.1395.179). Before the intervention, the adolescents and their parents were given information about the aim of the study and intervention. They also were informed about their rights as participants. Then a written informed consent form was filled out by the parents. In order to privacy protection the data collected from adolescents were coded anonymously.

| Control group
The adolescents in the control group just receive regular nursing care. They did not receive psychological or motivational interventions except in special cases.

| Intervention group: Motivational interviewing
The experimental group was randomly divided into three subgroups of 12 persons, and motivational interviewing was per- Then, adolescents were encouraged to verbalize potential benefits of following physician's recommendations and taking their medication (and the potential disadvantages of not following physician's recommendations and not taking their medication). Finally, when the adolescents declared their interest in change, they discussed about the change and the pattern of its creation (Table 1).

| General characteristics
To obtain the demographic information, a questionnaire was used including the questions about age, sex, education level, mother's occupation, father's occupation and family income.
TA B L E 1 Conceptual framework of motivational interviewing sessions.

First session Orientation
The first meeting included the familiarity and initial assessment of the participants, and introduction of the rules and regulations of the group. Then, the assessments were done to determine the level of freedom and independence of individuals in decisionmaking, the dimensions of the effect of behaviour, as well as the assessment of commitment, confidence and assurance

Second Session
Emotional Exercise Adolescents became aware of their feelings about the different dimensions of life influenced by the behaviours related to asthma. Each person identified his/her feelings and shared them in the group.

Third Session
Practicing the benefits and harms With the help of subjective pretensions, short and long-term profits and losses of behaviour were identified, and the suggestions were made on how to change the behaviour by describing the alternative exercises. The researcher helped the adolescents in this regard. In addition, the level of adolescent self-efficacy was discussed through validation and reflection, or more options. Finally, the purpose of the fifth session was identifying the temptation as well as final assessment, which led to the readiness and beginning of the change in the approach of the participants 3.7.2 | Asthma self-efficacy To assess the adolescents' self-efficacy, an ASQ was used that included five aspects of asthma control (five items), dealing with acute asthma attack (six items), regular use of medication (one item), stimuli and environment (four items), and relationship with the physician (four items), and the responses were scored in five scales: at all (score 1), low (score 2), relatively (score 3), high (score 4) and perfectly (score 5) respectively. Its reliability coefficient has been reported in the study by Martin et al. 0.82 (Martin et al., 2009). In Iran, the content validity of the instrument was confirmed by Valizadeh et al and its reliability was calculated by them. Cronbach's alpha for the scale was 0.85 (Valizadeh et al., 2014).

| Treatment adherence
To assess treatment adherence, an adherence self-report form was administered (Celano et al., 1998) According to this form, the adolescents were asked to take notes from the daily dose of medication It was equal to 0.89, which indicated the good reliability of this questionnaire (Dashti et al., 2016).

| Characteristics of the participants
Seventy-two participants were included in the study. The sample was comprised of 46 males. The demographic characteristics of the participants were not statistically different in terms of age, sex, level of education, father's occupation, mother's occupation and family income between the two groups (p > 0.05). Table 2 shows the demographic characteristics of the participants.

| Self-efficacy
The mean score of self-efficacy in all five areas was significantly higher in the experimental group than the control group 2 weeks after the intervention (p < 0.001). It is mentioned that asthma selfefficacy increased in the experimental group compared to the control group. In addition, a 3-month follow-up for the study showed that self-efficacy was significantly better in the experimental group than the control group (p < 0.001). This indicates that the motivational interviewing did not lose its effect even 3 months after the intervention. (Table 3).

| Treatment adherence
Treatment adherence was measured by the self-report adherence form. Before the intervention, the mean of adherence scores did not differ significantly (p = 0.39) between the two groups. In other words, the experimental group had a better adherence compared to the control group. The adherence self-report score also showed a better adherence of the adolescents in the experimental group than the control group 2 weeks (p = 0.006) and 3 months after the intervention (p = 0.04). (Table 4).

| Asthma control
Before the intervention, the mean of treatment adherence scores did not differ significantly in asthma control questionnaire (p = 0.62).
The asthma control score was significantly lower in the experimental group than the control group 2 weeks (p = 0.03) and 3 months (p < 0.001) after the intervention. (Table 5).

| Marginal model with generalized estimating equation (GEE) approach
After adjusting demographic characteristic effect, there is a significant relationship between the group variable and self-efficacy, so that the intervention group had an average of 14.44 more selfefficacy points than the control group (p < 0.001). Also, treatment adherence in the intervention group was significantly higher than the control group (β = 6.14, p = 0.05). But asthma control was not significant (β = −2.29, p = 0.064). It should be noted that adjusting the effects of demographic variables has reduced the significance of this variable (Table 6).

| DISCUSS ION
In this study, we investigated the effect of motivational interviewing on adherence and self-efficacy in adolescents with uncontrolled asthma. The findings showed that there were statistically significant differences between the experimental and control group in the mean of adherence and self-efficacy scores at 2 weeks and 3 months after the intervention. In motivational interviewing, health information is shared in a manner that increases the chance that a patient hears, understands and finally accepts the information. This can be done using clear and understandable language and reflections empathizing with and reducing the patient's concerns. The motivational interviewing uses the 'encouragement and threat process' to provide patients' feedback about their own health (Borrelli et al., 2007).
Reviewing the literatures, we found that although several studies have been done about the effect of motivational interviewing on the adherence and behavioural changes of patients with disorders including psychiatric, blood pressure and diabetes (Ellingson et al., 2019;Fortune et al., 2018;Freira et al., 2017;Ma et al., 2014;Navidian et al., 2017), but few studies have been conducted on the effect of motivational interviewing on adherence and self-efficacy of patients with asthma.
Miller & Rose mentioned that the theory of motivational interviewing emphasizes two active components underlying the change process in motivational interviewing which can lead to strengthen self-efficacy. A relational component related to empathy and interpersonal morale and a technical component that involves motivating and empowering the clients, discussion changes (expressions of their desire, ability, reasons and need for change). In addition to therapist attitudes considered for motivational interviewing style and consistency (unconditional positive attention, acceptance, empathy, genuine interest and intimacy, avoidance of coercion), some specific techniques such as strategies to elicit and enhance self-efficacy have also been considered (Miller & Rose, 2009.
The result of a recent study by Barikani et al. to investigate the effect of motivational interviewing on self-efficacy, beliefs about medicines and medication adherence among adolescents with asthma, that was conducted on 52 adolescents with asthma in 2021 showed that the difference between the mean scores in medication adherence,

TA B L E 3
Between-and within-group comparisons concerning self-efficacy.  beliefs about medicines and self-efficacy in the post-test between the two groups were significant, which is consistent with the results of our study (Barikani et al., 2021). Schmelling et al. conducted another study aimed at changing the attitudes towards medication adherence to asthma on 25 adults with asthma, the results showed a significant difference in the attitudes towards drugs after the intervention. In their study, changes in the attitude of patients towards the drug have been measured, but whether this change in attitude has improved the adherence of individuals has not been studied; however, it shows the positive effect of motivational interviewing, so their findings were consistent with the results of our study (Schmaling et al., 2001). Also, Lavoie et al. performed a study on 54 patients with asthma, which their results were similar to those of the present study achieved within a 3-month follow-up in both adherence and self-efficacy dimensions even within 1 year after the intervention (Lavoie et al., 2014).

Riekert et al. in 2011 investigated the effect of motivational in-
terviewing on adherence of 37 adolescents with asthma (aged 10-15 years old) and their caregivers, and showed that the motivational interviewing increased the motivation of adolescents for treatment, but no significant difference was found in the drug adherence score of the adolescents which is not consistent with the present study.
However, in our study, therapeutic adherence was examined and not drug adherence (Riekert et al., 2011). The purpose of the intervention and the target group in the study of Riekert is similar to that of the present study, but their results are not consistent with our study in terms of adherence. It may be because our focus was on adolescents rather than caregivers.

| CON CLUS ION
The results presented in this study showed that motivational interviewing is beneficial for adolescents with asthma, and the effects were sustained for 3 months following the intervention. In general, the analysis in this study showed a significant effect of motivational interviewing on adolescents' treatment adherence and self-efficacy in asthma management and treatment. Therefore, based on the results, some recommendations such as holding short courses of motivational interviewing at appropriate intervals for adolescents can be made for the future.

AUTH O R S' CO NTR I B UTI O N S
FT and AN were involved in forming the idea and designing the study, article preparation. AN was responsible for critical revision and final approval of the manuscript. SN was responsible for educational sessions design and data collection. FS conducted and performed data analysis and provided final results.

ACK N O WLE D G E M ENTS
We are grateful to the university for supporting this project, and acknowledge all the patients who participated in this study.

CO N FLI C T O F I NTE R E S T S TATE M E NT
None declared.

FU N D I N G I N FO R M ATI O N
This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.

DATA AVA I L A B I L I T Y S TAT E M E N T
Data available on request from the authors

PATI E NT CO N S E NT
Participants and their parents were informed about the study, and then they signed the consent form.