Experience of a chronic kidney disease during childhood or young adulthood has been shown to have a negative impact on quality of life1 and is related to higher psychological morbidity.2 Young adults with end-stage renal disease achieve fewer developmental milestones or achieve them later than their healthy peers3 and have lower mental quality of life.4 Adherence to immunosuppressive medication is also typically lower among adolescents and young adults than among children or older adult transplant recipients.5,6 Adherence to immunosuppressive medication is essential for graft survival.7 Graft survival has been shown to be lower among patients aged 18 to 25 years compared to those over 25 years.8 As many studies focus on adolescents, in the current study, we aimed to explore factors associated with adherence and well-being among young adult kidney transplant recipients in the next decade of the lifespan (20‐30 years). Specifically, we investigated (1) the extent to which psychological factors were associated with subjective well-being and nonadherence to immunosuppressive medication, and (2) the relationship between these two outcomes.
Despite striving to achieve the same life goals as healthy peers,9 young adults who grew up with chronic kidney disease lag behind in autonomy, psychosexual, and social development,4,5 which has been related to lowered mental quality of life, vitality, and greater emotional problems.4 According to the Self-Determination Theory10, emotional well-being is dependent on satisfaction of the basic psychological needs of autonomy, competence, and relatedness.10 Autonomy refers to the need to determine one’s own behavior. Competence refers to the need to feel effective in one’s actions and interactions. Relatedness refers to the need to feel connected to, and accepted by, one’s social network. There is little research on satisfaction of psychological needs among transplant recipients; however, greater perceived competence among diabetes patients has been shown to be related to higher quality of life.11 In addition to psychological needs, psychological theories emphasize the role of coping in emotional well-being.12 Coping can be defined as efforts to manage demands that are deemed to exceed the person’s resources.13 Greater use of passive or avoidance strategies have been related to lower health-related quality of life14,15 and greater psychological symptoms.16 Cognitive restructuring has been related to greater life satisfaction.16
Despite the clinical importance of adherence after transplantation and the elevated nonadherence among young adult patients, there has been relatively little research conducted on the relationship with psychological factors. Evidence is mixed for a relationship between indicators of well-being (such as depression) and nonadherence.17-22 One study suggested that youths who focus on the influence of medication on appearance may be at higher risk of nonadherence.8 Little research has explored the importance of needs satisfaction, coping, and achievement of developmental milestones for adherence among kidney transplant recipients. Among other patient groups, greater perceived competence and autonomy have been shown to be related to higher medication adherence.11,23 Transition from pediatric to adult nephrology services (around age 18 years) may be a particular period of risk for graft rejection and nonadherence21,24 although evidence for this is again mixed.25 The age at which renal insufficiency is diagnosed or when renal replacement therapy (RRT) is required may influence subsequent psychological and behavioral outcomes.
To summarize, we formulated the following research questions:
- (1) To what extent are age at first RRT, satisfaction of psychological needs, coping, and achievement of developmental milestones related to subjective well-being and medication adherence?
- (2) To what extent is there an association between subjective well-being and immunosuppressive medication adherence?
Patients were recruited from the transplant clinic at the Department of Internal Medicine, Section Nephrology & Transplantation at the Erasmus Medical Centre. Inclusion criteria were: recipients of a kidney transplant, current age (20-30 years) and sufficient mastery of the Dutch language. To rule out the influence of medical status on outcomes, exclusion criteria were transplantation within the previous year, current dialysis, and cognitive limitations that could influence the validity of the interview.
This was a single-center, cross-sectional interview study. Patients were invited to participate by letter. Those who returned the informed consent form were subsequently contacted to arrange the face-to-face interview. If possible, the interview was combined with a check-up at the outpatient clinic or conducted at their home for maximum convenience. The study was approved by the Medical Ethics Committee (MEC-2011-275).
Socio-demographic characteristics: age, sex, ethnicity, marital status, living situation, employment, children (see Table 1).
Medical characteristics: primary diagnosis, duration of illness, age at primary kidney transplant (KT) number of KT, preemptive primary KT, ever received a living donor KT (see Table 1). Participants were divided into 2 groups according to age at first RRT as an indication of when the kidney disease had reached a severity level that would have significant impact on the patients’ lives: group 1 (RRT < 17 years; group 2 ≥17 years). Participants who started RRT at 17 years were treated within adult services.
Satisfaction of psychological needs: was measured using the Basic Psychological Needs Scale, a 20-item questionnaire consisting of 3 subscales: autonomy (7-items), relatedness (8-items), and competence (5-items). Respondents indicated to what extent the statement applied to their lives on a scale from 1 (not at all true) to 7 (very true). Higher scores indicate higher needs satisfaction.
Dispositional coping: was measured using the Dutch version of the brief COPE, the COPE-Easy questionnaire,26,27 a 32-item questionnaire which can be grouped into 3 main theoretical dimensions: active problem-focussed coping, support-seeking coping, and avoidant coping.26 Respondents indicated to what extent they use each coping strategy in response to stressful events or problems on a scale from 1 (not at all) to 4 (a lot). Higher scores indicate greater use of the strategy.
Achievement of developmental milestones: was measured using the Dutch version of the Course of Life Questionnaire.28,29 This instrument consists of 5 subscales: autonomy development (6 items; range, 6‐12); psychosexual development (4 items; range, 4‐8); social development (12 items, range, 12‐24); anti–social behavior (4 items; range, 4‐8); and substance use and gambling (12 items; range, 12‐24). Higher scores on autonomy, psychosexual, and social development indicate greater achievement of developmental milestones. Higher scores on antisocial behavior and drug use and gambling indicate higher deviant behavior.
Subjective well-being was measured using the Positive And Negative Affect Schedule and Satisfaction With Life Scale. The Positive And Negative Affect Schedule30 is a list of 10 positive affective (PA) and 10 negative affective (NA) states which form 2 separate subscales. Participants rate the extent to which they generally experience that mood on a scale from 1 (very little or not at all) to 5 (very much). A higher score indicates greater positive or negative affect. The Satisfaction With Life Scale31 is a 5-item questionnaire rated on a scale from 1 (totally disagree) to 7 (totally agree). High scores indicate high satisfaction with life.
Adherence was measured using the Basel Assessment of Adherence to Immunosuppressive Medication Scale (BAASIS; see Table 2).32 Patients are classified as nonadherent if they give an affirmative answer on question 1a, 1b, 2, or 3. In addition, overall adherence is rated on a Visual Analogue Scale (VAS) from 0 (never take medication as prescribed) to 100 (always take medication as prescribed) in the past 4 weeks. A score of 95% or above was categorized as adherent (7). For this study, we added an identical VAS to explore overall adherence rating since transplantation.
Independent t tests, χ2 and one-way analysis of variance tests were used to test group differences on continuous, dichotomous, and categorical variables respectively. Pearson correlations were used to test associations between continuous variables. One-sample t tests were conducted to compare mean scores to norm data. Linear and logistical regression was conducted, respectively, to assess the association between independent variables and subjective well-being and adherence classification. Using a forward stepwise procedure (pairwise), only significant independent variables were entered to obtain the most parsimonious model.
At the moment of recruitment, there were 101 potential participants who satisfied the inclusion criteria. Seventeen patients were excluded, 9 due to cognitive limitations, 4 due to transplantation in the previous year, and 4 due to (re)initiation of dialysis after transplant failure. Of the 84 patients who satisfied the inclusion criteria and were invited to participate, 21 declined to participate and 1 was unreachable, leaving a total sample size of 62 (response rate, 74%). There were 31 participants who started RRT before the age of 17 years (group 1) and 31 after the age of 17 years (group 2). Eighteen patients in group 2 had received the diagnosis of kidney disease before the age of 17 years and had therefore experienced transition from pediatric to adult services.
Sociodemographic and Medical Characteristics
Table 1 shows that there were no significant differences between groups 1 and 2 on sociodemographic characteristics. Groups 1 and 2 significantly differed on all medical characteristics except diagnosis and preemptive primary transplantation.
Table 2 shows that 35.5% (n = 22) patients were classified as adherent according to the BAASIS in the past 4 weeks. In contrast, the median self-reported overall adherence rating was 99.5% in the past 4 weeks and 95% since transplantation. Figure 1 illustrates this contrast. Nonadherence was greatest on the taking (31%) and timing dimensions (53%; see Table 2). Drug holidays, dose reduction, and (lack of) persistence were not common issues.
Table 3 shows that PA and satisfaction with life (SWL) in the whole group, and NA among the men was significantly higher than healthy comparison groups.
Research Question 1: Influence of Age at First RRT, Satisfaction of Psychological Needs, Coping and Developmental Milestones on Subjective Well-being and Medication Adherence
Age at first RRT
Table 3 shows the mean values of all variables for the total group and group 1 versus group 2. There were no significant differences between the 2 groups on medication adherence, subjective well-being, satisfaction of psychological needs, use of coping strategies, or achievement of developmental milestones. There was a trend for lower autonomy among those who commenced RRT before the age of 17 years. As 18 patients in group 2 had experienced transition, we conducted an additional exploratory analysis to compare patients who had received the diagnosis of kidney disease before (n = 49) or after the age of 17 years (n = 13). There were no significant differences between these groups on subjective well-being and adherence with 1 exception: those who received a diagnosis before 17 years were significantly more satisfied with life (P < 0.05).
None of the sociodemographic or medical characteristics were significantly related to PA and were therefore not included in the model. Linear regression demonstrated that PA was positively related to satisfaction of competence needs (Std β = 0.41, P < 0.001), relatedness (Std β = 0.25, P < 0.05), psychosexual development (Std β = 0.28, P < 0.01), and active coping style (Std β = .27, P < .01). This model explained 48% of the variance in PA (F = 11.79, P < 0.001).
In the univariable analyses, men scored significantly higher than women on NA, (20.5 ± 5.6; 17.4 ± 5.5, respectively; P < 0.05). None of the medical characteristics were significantly related to NA. When controlling for sex (Std β = −0.22, P < 0.05), NA was negatively related to satisfaction of competence needs (Std β = −0.55, P < 0.001), psychosexual development (Std β = −0.22, P < 0.05), and social development (Std β = −0.31, P < 0.01), and positively related to active coping (Std β = 0.28, P < 0.01). This model explained 56% of the variance in NA (F = 12.54, P < 0.001).
In univariable analyses, being married/living with a partner was associated with higher SWL (α = 0.80) compared to being unmarried (28.7 ± 5.6; 24.6 ± 6.3, respectively), t(59) = −2.34, P < 0.01. There was a trend for higher SWL among participants with 1 or more children compared to those without (29.4 ± 4.7; 25.2 ± 6.4, respectively; t = −1.76, P = 0.08). Duration of illness was also positively related to SWL (r = 0.27, P < 0.05). When controlling for marital status (Std β = 0.29, P < 0.05), children (Std β = 0.12, P = 0.32) and duration of illness (Std β = 0.25, P < 0.05), greater SWL was found to be related to greater satisfaction of autonomy needs (Std β = 0.47, P < 0.001). This model explained 38% of the variance in SWL (F = 7.92, P < 0.001).
None of the sociodemographic or medical characteristics were significantly related to medication adherence classification. Similarly, none of the independent psychological variables were found to be significantly related to adherence classification. As with the adherence classification, none of the sociodemographic and medical characteristics or psychological variables were significantly related to overall adherence rating in the past 4 weeks or since transplantation.
Research Question 2: Association Between Subjective Well-Being and Adherence
Independent samples t tests demonstrated that there was no significant difference between adherent and nonadherent patients on PA or SWL. There was a trend for patients classified as adherent to score higher on NA than those classified nonadherent (t) = 2.12, P = 0.06). Overall adherence ratings for the past 4 weeks and since transplantation were unrelated to PA (r = 0.24, P = 0.06; r = 0.15, P = 0.24), NA (r = −0.13, P = 0.32; r = −0.16, P = 0.20), and SWL (r = 0.13, P = 0.34; r = 0.10, P = 0.46).
In summary, two thirds of the young adult transplant recipients were classified as nonadherent in contrast to high self-ratings of adherence; outcomes did not differ according to age of diagnosis or commencement of RRT; positive affect and life satisfaction were higher than healthy comparisons; and delay in developmental milestones and lack of satisfaction of psychological needs were related to reduced well-being.
In this study, we found that satisfaction of psychological needs and achievement of developmental milestones was related to greater subjective well-being among young adult transplant recipients.10 Specifically, greater feelings of competence, relatedness, and autonomy and achievement of social and psychosexual developmental milestones were related to either higher positive affect, lower negative affect, or greater satisfaction with life. Age at diagnosis and first treatment were unrelated to psychological well-being outcomes. This finding may indicate that successful completion of developmental tasks regardless of the challenges of concurrent illness or treatment is more important for psychological well-being than the experience of the illness itself. These findings are in line with earlier studies that have demonstrated that youths with a chronic illness strive to achieve the same developmental goals as their healthy peers, however that these goals can be disrupted by the illness.9 This study adds that among young transplant recipients, achievement of these age-appropriate goals is imperative for optimal well-being.
In general, well-being among this sample of young adult transplant recipients was satisfactory. Positive affect and life satisfaction were high among participants compared to the general population.31,33 Negative affect was comparable to the general population for female participants but was higher among male participants. Young male recipients may therefore be at greater risk of poorer psychological outcomes however this requires more research. Similar to survivors of childhood cancer, these young adults with kidney disease lagged behind in autonomy development and display greater antisocial behavior compared to health peers.3 As demonstrated above, these developmental delays are associated with reduced well-being.
Substantial immunosuppressive medication nonadherence (64%) was found in this sample of young adult transplant recipients. This is higher than previous levels reported (17%–54%) using the same instrument at varying times since kidney transplant.34-36 Previous studies have demonstrated a relationship between nonadherence and poorer clinical outcomes.36-38 The greatest issue was observed with the timing of medication. Nonadherence was high in proportion rather than severity as the majority who missed a dose did this only once, and there were few drug holidays or discontinuations. Although under-reporting is often an issue when assessing adherence with self-report.39 In line with this thesis, our data demonstrated incongruence in adherence findings depending on the type of questions asked. The classification based on taking and timing questions suggest low adherence however the self-reported overall adherence rating was universally high. This may be an artefact of the type of question used,39 but may also be an indication of differences in perception regarding adherence. The BAASIS classification is a researcher-defined definition of adherence based on relatively objective questions that a professional may pose, whereas the overall rating (using a VAS) represents a subjective estimation by the patient. A study among Swedish transplant recipients also found similarly high subjective ratings of adherence using this VAS.34
Of all the psychological concepts measured, only negative affect was found to be related at trend level to nonadherence. Specifically, there was a tendency for adherent patients to report higher negative affect. This is in contrast to findings that depression is related to greater nonadherence40-42 or that there is no relationship.43 One previous study demonstrated similar findings of a tendency toward more depressive symptoms in adherent patients.17 We speculate that those who adhere to the strict regime may experience greater negative mood due to the restrictions they feel this imposes on their lives.
The findings presented need to be interpreted in light of some limitations of the study. Given the cross-sectional, retrospective nature of the study, it is also not possible to make conclusions regarding the causality of relationships reported. Selection bias may influence the results due to both the self-selected nature of the participants and exclusion criteria. Seventeen percent of potential participants were excluded due to cognitive limitations, recent transplantation, or dialysis. The factors that contribute to well-being and adherence among young adults on dialysis is an interesting topic for future studies. We also note the difficulty in capturing the age at which the illness had the greatest impact. We therefore explored age at first diagnosis as well as first RRT. Finally, we note that the sample size in this study is limited for statistical analyses.
The high nonadherence level found in this study highlights the importance of continued support and guidance for optimal medication taking among young adult recipients up to the age of 30 years. Ongoing support for adherence should be offered to all young recipients regardless of age at which the patient was diagnosed or started treatment because these factors did not influence adherence level. During clinical consultations, attention should be paid not only to taking but also timing of medication because this was the area in which highest nonadherence was observed.7 Physicians should be aware that the type of questions (objective vs subjective) asked may influence the type of response they elicit and consequently the estimation of adherence. Additionally, exploration of how a patient defines “good medication taking” (adherence) may reveal discrepancies in definitions between the health care professional and patient which can then be discussed so both parties can come to an agreement about satisfactory medication management. Young patients may not be aware of the degree of accuracy required to prevent rejection episodes and this must therefore be emphasized. This recommendation is in line with findings demonstrating the effectiveness of shared decision-making interventions in improving clinical outcomes.44 The findings also offer potential targets for interventions aimed at improving the well-being among young adult renal transplant patients. Support in achieving age appropriate developmental tasks and development of autonomy and competence may promote well-being among young transplant recipients. Interventions that promote integration and acceptance of self-management tasks into daily life alongside achievement of age appropriate tasks to prevent reduced well-being may be useful in this age group.
In the current study, we limited the focus to young adults and were not able to make a comparison between these patients and those who were diagnosed as children and are now older (> 30 years). This is an area of interest for future research to gain greater insights into the long-term impact of kidney disease and transplantation during childhood and adolescence. Moreover, a prospective research design would enable long-term follow-up of children transplanted using immunosuppressive medication currently available. Given the high level of nonadherence, further research is needed into factors that may influence adherence after kidney transplantation particularly among young adult recipients. This study focussed on personal attributes; however, other factors, such as social context, health care provider, and system-related factors, also impact adherence to medication.6,20
The authors thank Judith Kal-van Gestel for providing data management support.
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