Skip to main content
NCBI home page
NIHPA Author Manuscripts logoLink to NIHPA Author Manuscripts
. Author manuscript; available in PMC: 2024 Mar 1.
Published in final edited form as: J Ren Care. 2022 May 31;49(1):24–34. doi: 10.1111/jorc.12435

A novel health behaviour intervention to promote adherence in kidney failure

Christopher M Celano 1,2, Juliana Zambrano 1,2, Lauren Harnedy 2, Daniel Arroyo-Ariza 1,2, Alba Carrillo 1,2,3, Wei-Jean Chung 1,2, Christina N Massey 1,2, Abraham Cohen-Bucay 4,5, Jeff C Huffman 1,2
PMCID: PMC9708944  NIHMSID: NIHMS1808965  PMID: 35638610

Abstract

Background:

Health behaviour adherence is associated with improved survival in kidney failure (KF); however, most patients with KF do not adhere to one or more health behaviours. Existing health behaviour interventions have significant limitations and do not focus on psychological factors that are associated with adherence and health.

Objectives:

To examine the feasibility, acceptability, and preliminary efficacy of a 12-week, phone-delivered, positive psychology-motivational interviewing (MI) intervention to promote psychological well-being and adherence in KF.

Design:

Single-arm, proof-of-concept trial (N = 10).

Participants:

Participants were adults with KF undergoing haemodialysis and reporting suboptimal adherence to physical activity, diet, and/or medications. Participants attended weekly phone sessions with a study trainer, completed weekly positive psychology exercises (focused on gratitude, strengths, and meaning), and worked towards physical activity, diet, and/or medication goals.

Measurements:

Feasibility was measured by the percentage of sessions completed, while acceptability was assessed through participant ratings of positive psychology and MI session ease and utility (0–10 Likert scales). We explored the intervention’s impact on psychological outcomes and health behaviour adherence using validated scales and accelerometers.

Results:

Participants completed 78% of sessions and rated the program’s components as easy to complete (positive psychology: 8.7 ± 1.5; MI: 8.3 ± 2.0) and subjectively helpful (positive psychology: 8.8 ± 1.2; MI: 8.8 ± 1.6). The intervention led to promising but nonsignificant improvements in psychological and adherence measures.

Conclusions:

This 12-week, phone-delivered program was feasible, well-accepted, and associated with nonsignificant improvements health behaviour adherence, highlighting the need for a larger efficacy trial.

Keywords: adherence, health behaviours, kidney failure, physical activity, positive psychology

INTRODUCTION

Among individuals with chronic kidney disease, including those with kidney failure (KF) receiving haemodialysis, adherence to medications, dialysis treatments, fluid restriction, and a healthy diet is associated with improved physical health, including a reduced risk of hospitalisations and mortality (Fotheringham et al., 2020; Kelly et al., 2017; Lee et al., 2011; Leggat et al., 1998; Saran et al., 2003; Umeukeje et al., 2018). Additionally, physical activity, which has been linked to a reduced risk of cardiovascular disease and improved survival (Kodama et al., 2013), is routinely recommended for patients with KF receiving haemodialysis (K/DOQI, 2005). However, individuals with KF are frequently nonadherent to these behaviours. In observational studies, 20%–30% of patients either skip or shorten dialysis sessions, 20% are nonadherent to medications, and up to 39% are nonadherent to diet or fluid restriction (Clark et al., 2014; Leggat et al., 1998; Ozen et al., 2019). Similarly, levels of physical activity are quite low in this population (Delgado & Johansen, 2012; Kopple et al., 2015). This nonadherence places patients with KF at higher risk for poor health outcomes.

LITERATURE REVIEW

Interventions have been developed to both promote adherence to dialysis self-care activities and to increase physical activity. Those that focus on adherence to medications, dietary change, and dialysis sessions have been somewhat helpful. In a recent systematic review and meta-analysis of 36 randomised, controlled trials (N = 3510), 28 of 36 led to improvements in one or more study outcomes, and meta-analyses showed that the interventions led to small- to medium-sized reductions in phosphate levels (standardised mean difference [SMD] = −0.45) and small-sized reductions in interdialytic weight gain (SMD = −0.20) (Murali et al., 2019). Similarly, exercise training interventions have led to substantial improvements in aerobic capacity (SMD = 0.73) and walking capacity (d = 1.01), and to smaller improvements in health-related quality of life (HRQoL; physical HRQoL: SMD = 0.34; mental HRQoL: SMD = 0.27) (Huang et al., 2019).

However existing interventions have several limitations. First, most interventions focus on only one or two health behaviours, and no interventions combine a focus on dialysis self-care and physical activity, despite the potential benefits of both (Clarkson et al., 2019; Huang et al., 2019; Murali et al., 2019). Second, many interventions are intensive, require multiple staff members to deliver, and may be difficult to implement in clinical practice (Clarkson et al., 2019; Huang et al., 2019; Murali et al., 2019; Wilund et al., 2019). Third, most exercise training programs (76% in a recent review) have occurred during dialysis sessions, rather than at home (Clarkson et al., 2019); this may limit the development of long-term physical activity habits that may be required to have cardiovascular benefits (Moholdt et al., 2018). Finally, few interventions have focused on psychological constructs (e.g., depression, optimism) that have been linked to adherence and health (Cukor et al., 2014; Pasyar et al., 2015; Tsay, 2003).

Psychological factors may play a role in adherence to these healthy behaviours. Negative psychological constructs, such as depressive symptoms, are associated with physical inactivity (Kopple et al., 2015; Mendes et al., 2019), nonadherence to a healthy diet (Khalil & Frazier, 2010; Riera-Sampol et al., 2021), and nonadherence to medications (Kauric-Klein, 2017; Mendes et al., 2019; Ossareh et al., 2014). In contrast, positive psychological constructs, such as positive affect, self-efficacy, and optimism, are associated with improved adherence to these behaviours in individuals with chronic medical illnesses (Celano et al., 2013; Dubois et al., 2012; Nafradi et al., 2017). Positive psychology (PP) interventions, which involve the performance of systematic exercises to cultivate well-being (Seligman et al., 2005), consistently promote well-being and reduce depression (Bolier et al., 2013; Sin & Lyubomirsky, 2009) and have been linked to greater adherence (Ogedegbe et al., 2012; Peterson et al., 2012), particularly when combined with motivational interviewing (MI) (Celano et al., 2020; Huffman et al., 2019; Huffman et al., 2020), a therapeutic approach to enhance motivation and resolve ambivalence (Miller & Rollnick, 2002), and other behaviour change techniques. Interventions to promote well-being are particularly promising, as most patients with KF could benefit from the cultivation of well-being constructs, while only a fraction (i.e., those with a mental health condition) might benefit from interventions focused solely on reductions of depression or anxiety symptoms. However, to date only one study has evaluated a PP-based program in patients with KF (N = 14), finding that an internet-based PP-alone program delivered during dialysis session was easy to complete and subjectively useful (Hernandez et al., 2018).

Accordingly, we developed INSPIRED (Improving Nutrition, Spirit, and Physical Activity in Renal Disease), a 12-week, phone-delivered, PP-MI intervention to promote adherence to physical activity, diet, and medications in KF. In this single-arm, proof-of-concept trial, we aimed to assess its feasibility, acceptability, and preliminary efficacy in 10 individuals with KF and suboptimal adherence to health behaviours.

MATERIALS AND METHODS

In this single-arm, quasi-experimental, proof-of-concept trial, we assessed the feasibility, acceptability, and preliminary efficacy of INSPIRED. All participants provided full, verbal informed consent, and all study procedures were approved by the Mass General Brigham Institutional Review Board (IRB) before the initiation of recruitment.

Participants

Participants were adults who were followed in an outpatient clinic or undergoing kidney transplant evaluation at an urban academic medical centre. Study staff approached participants through an IRB-approved process involving introductory letters from the study team and clinicians, followed by phone calls to describe the study and assess for eligibility. Interested and eligible participants were mailed a study information sheet, then provided informed consent, completed baseline outcome assessments, and received the intervention.

Inclusion criteria included a diagnosis of KF, current receipt of haemodialysis, and suboptimal adherence to health behaviours, as measured by a score of ≤15 on the diet, medication, and physical activity items of the Medical Outcomes Study Specific Adherence Scale (MOS-SAS) (DiMatteo et al., 1992). Participants were excluded due to cognitive deficits (measured using a six-item tool) (Callahan et al., 2002), poor prognosis (<6-month projected survival), impaired ability to engage in physical activity, lack of a telephone, inability to speak English, and current participation in a similar program.

Sample size determination

Consistent with other single-arm studies of behavioural interventions in individuals with chronic medical conditions (Hernandez et al., 2018; Millstein et al., 2020), a sample size of 10 was chosen for this project, as it allowed for the obtainment of sufficient feasibility/acceptability data and participant feedback to further refine the intervention before a more costly randomised pilot trial.

Procedures

After confirmation of eligibility, participants were mailed a study information fact sheet and were scheduled for an initial phone session. During this initial session, a study team member reviewed the details of the study, obtained informed consent, administered all self-report outcome measures, and mailed each participant an Actigraph GT3X-BT accelerometer (Actigraph LLC) to measure baseline physical activity. Participants wore the accelerometer for 1 week and returned it by mail. Once adequate wear time was confirmed (at least 4 days with ≥10 h of wear), participants were mailed a treatment manual and a step counter to monitor physical activity, then attended a second phone session with a study interventionist to initiate the INSPIRED program. Over the next 12 weeks, participants engaged in weekly phone sessions with a study interventionist, then completed PP activities and worked towards health behaviour goals between sessions. At the end of the program, participants completed a final phone session, during which they completed all self-assessment measures and a qualitative exit interview, and they wore an accelerometer for 1 week to measure post-intervention physical activity.

Study intervention

This 12-week, PP-MI intervention was based upon existing interventions in individuals with other chronic medical conditions (e.g., heart failure, type 2 diabetes, coronary artery disease) (Celano et al., 2020; Huffman et al., 2019; Huffman et al., 2020) and adapted to individuals with KF. PP exercises focused on constructs associated with improved kidney health, and the MI content was developed in concert with our team’s nephrologist (A.C.) and a nutritionist experienced with patients receiving haemodialysis.

The PP component of the program contained PP exercises from the literature (Langston, 1994; Moskowitz et al., 2012; Seligman et al., 2005). PP activities were grouped into modules based on their targeted psychological construct (gratitude, using personal strengths, and meaning/purpose in life; see Table 1). Each week participants completed a PP activity independently. During the weekly phone sessions, they reviewed the activity, discussed the positive thoughts and emotions that occurred in response to the activity, and learned about a new PP activity. To promote the continued use of PP skills, the final session of each module was devoted to reviewing the PP skills used in the module and identifying ways to integrate them into daily life.

TABLE 1.

Positive psychology intervention component

Session Module Activity Description
1 Gratitude Gratitude for positive events Participants recall three positive events and write about associated feelings.
2 Expressing gratitude Participants write a letter of gratitude about something for which they are thankful.
3 Capitalising on positive events Participants identify positive events, then capitalise on them by sharing or celebrating them.
4 Integrating gratitude into daily life Participants use gratitude-based skills in daily life.
5 Strengths Recalling a past success Participants recall a past success and the qualities that helped them to be successful.
6 Using strengths part 1 Participants use one of their signature strengths in a new way.
7 Using strengths part 2 Participants use a second signature strength in a new way over the course of the week.
8 Integrating strengths into daily life Participants use strength-based skills in daily life.
9 Meaning Enjoyable and meaningful activities Participants perform enjoyable activities alone and with others, and a meaningful activity over the week.
10 Performing acts of kindness Participants perform three acts of kindness for others.
11 The “good life” Participants write about their ideal life in 1 year.
12 Integrating meaning into daily life Participants use meaning-based skills in daily life.
13 Planning for the future Participants review all activities and make plans for continued use.
Open in a new tab

The MI component of the intervention focused on physical activity, a low-phosphorous diet, and adherence to dialysis-specific treatments, including medication adherence (see Table 2). We chose these three health behaviours as all three are linked to improved health outcomes in KF (Clark et al., 2014; Qiu et al., 2017). For each health behaviour, participants learned to track the health behaviour in a structured way, set SMART (specific, measurable, attainable, relevant, and time-based) goals, identify resources to reach goals, and problem-solve barriers to adherence. Participants continued to set goals related to these behaviours for the remainder of the program, allowing 12 weeks of physical activity goals, 8 weeks of diet goals, and 4 weeks of haemodialysis-related self-care goals. Physical activity was addressed first and for the longest period of time to allow participants to gradually increase their activity over time, while self-care was addressed last given that common self-care goals (e.g., using a pill box for medications) could be implemented more quickly. In the final session, study interventionists reviewed the progress participants made towards their health behaviour goals, helped participants to identify ways to continue to use their PP skills, and set new long-term goals for health behaviours.

TABLE 2.

Motivational interviewing-based goal-setting component of the intervention

Session Behaviour Topic Description
1 Physical Activity Monitoring activity Participants monitor their activity using a step counter.
2 Setting a SMART goal Participants set a SMART (specific, measurable, attainable, relevant, and time-based) activity goal.
3 Problem-solving barriers and using resources Participants identify barriers to physical activity and problem-solve them. They also identify resources to help them achieve their activity goals.
4 Review and Reflect Participants review their progress and adjust their overall activity goal.
5 Diet Monitoring phosphorous and fluid intake Participants review the benefits of a low phosphorous and fluid-restricted diet and monitor phosphorous and fluid intake.
6 Setting a SMART goal Participants set a SMART dietary goal.
7 Diet-related barriers and resources Participants problem-solve barriers and identify resources for achieving their diet goals.
8 Review and Reflect Participants review their progress and adjust their overall physical activity and diet goals.
9 Dialysis-specific treatments Monitoring medications Participants develop a system to monitor medication adherence and set a medication adherence goal.
10 Dialysis self-care Participants learn about dialysis self-care and set goals related to dialysis-specific treatments/medications.
11 Barriers to and resources for treatment adherence Participants problem-solve barriers and identify resources related to dialysis-specific treatments.
12 Managing slips Participants learn how to manage slips in health behaviour adherence.
13 Planning for the future/Relapse prevention Participants develop plans for continued activity, diet, and dialysis-specific treatment adherence.
Open in a new tab

Interventionists were trained psychologists with experience delivering psychological interventions in study settings. Weekly supervisory meetings were held to monitor participant progress through the intervention, discuss issues that developed related to the intervention, and ensure consistent intervention delivery.

Outcomes

Feasibility (primary study outcome) and acceptability

Intervention feasibility was measured by the number of phone sessions completed. For acceptability, participants rated the ease and utility of the PP and MI components of the weekly phone sessions on 0–10 Likert scales (0 = very difficult/not at all helpful, 10 = very easy/very helpful). A priori, we set 70% of sessions completed and ease and utility scores of ≥7.0/10 as thresholds for feasibility and acceptability, respectively.

Additionally, at 12 weeks we performed structured qualitative exit interviews to obtain feedback from participants. Specifically, we inquired about the burden and utility of the intervention components, the impact of the intervention on health behaviour adherence, and participants’ preferences related to the frequency, duration, and content covered in the intervention. These were audio-recorded and professionally transcribed.

Immediate impact

To ensure that the PP exercises were effectively targeting positive psychological constructs, participants were asked to rate their happiness and optimism on a 0–10 Likert scale (0 = not at all happy/optimistic, 10 = very happy/optimistic) immediately before and after completing each PP exercise.

Exploratory analyses: Psychological and health behaviour outcomes

Finally, we explored the impact of the intervention on health behaviour adherence, psychological, and functional outcomes. Self-reported overall adherence was assessed with the MOS-SAS items related to diet, medications, and physical activity (DiMatteo et al., 1992). The MOS-SAS has been used in multiple prior studies assessing adherence in patients with chronic medical illness (Celano et al., 2020; Lee et al., 2011; Ziegelstein et al., 2000). Diet and fluid restriction adherence were measured using the Dialysis Diet and Fluid Nonadherence Questionnaire (DDFNQ) (Vlaminck et al., 2001), which has been validated and used in studies of patients with KF (Kugler et al., 2011; Vlaminck et al., 2001). Medication adherence was assessed using a scale from the Heart and Soul study (Gehi et al., 2005). Finally, we measured overall physical activity (steps per day), moderate to vigorous physical activity (MVPA; minutes per day), and sedentary time (minutes per day) using Actigraph GT3X-BT accelerometers.

Additionally, we assessed the intervention’s impact on psychological outcomes. Psychological measures included positive affect (Positive And Negative Affect Schedule; internal consistency in this sample: Cronbach’s α = 0.56) (Watson et al., 1988), optimism (Life Orientation Test-Revised [LOT-R]; α = 0.48) (Scheier et al., 1994), depression and anxiety (depression and anxiety subscales of the Hospital Anxiety and Depression Scale [HADS-D and HADS-A]; α = 0.52 and 0.85, respectively) (Bjelland et al., 2002), and self-efficacy (General Self-Efficacy Scale; α = 0.85) (Schwarzer & Jerusalem, 1995). These validated outcome measures have been used in studies with chronic medical illnesses, including cardiovascular disease (Celano et al., 2020; Huffman et al., 2019), type 2 diabetes (Huffman et al., 2020), and KF (Cwiek et al., 2017; Gerogianni et al., 2019).

Data analysis

We used descriptive statistics for feasibility and acceptability outcomes and performed paired t tests to examine the immediate impact of the PP exercises. Mixed effects regression analyses were used to assess change from baseline to follow-up on the preliminary efficacy measures. We used these analyses, rather than paired t tests, as they allow for the inclusion of individuals with some missing data. Because of the small sample size of this initial trial, we did not focus on statistical significance of findings for this exploratory aim. To estimate the size of the pre-post changes for future studies, we calculated effect sizes (modified Cohen’s d) by dividing the time coefficient by the square root of twice the variance of the residual in the regression model.

To analyse the exit interviews, transcriptions were reviewed by two study team members independently. For each question, response themes were identified, and similar responses were grouped into general categories, similar to prior work (Celano et al., 2021; Huffman et al., 2016). We assessed whether participants found the PP and MI components of the program to be useful, whether the intervention led to changes in health behaviour adherence (and if so, which ones), which portions of the program were most helpful or difficult, and preferences related to the frequency of the phone calls and the duration of the program. Discrepancies in categories were resolved through discussion between the two study team members and the senior author.

RESULTS

Of 50 participants contacted by phone, 11 ultimately enroled in the trial, 10 began the treatment program and were included in our analyses, and 9 provided follow-up data at 12 weeks (see Figure 1). The most common reasons for ineligibility were lack of nonadherence or inability to participate in physical activity. On average, participants were 60.9 (SD 15.1) years of age and had KF for 2.4 (1.3) years. All participants had been undergoing haemodialysis for at least 6 months. Forty percent were women, and 40% were from racial/ethnic minority backgrounds (see Table 3).

FIGURE 1.

FIGURE 1

Open in a new tab

Recruitment and study flow

TABLE 3.

Baseline characteristics of participants (N = 10)

Characteristic Value
Sociodemographic characteristics; N (%), unless otherwise noted
 Age; mean (SD) 60.9 (15.1)
 Female gender 4 (40)
 Caucasian race 6 (60)
 Lives alone 2 (20)
 Married 5 (50)
Highest education
 High school graduate 3 (30)
 Some college 3 (30)
 College graduate 2 (20)
 Advanced degree 2 (20)
Medical characteristics; N (%), unless otherwise noted
 KF duration (years); mean (SD) 2.4 (1.3)
 Type 2 diabetes 5 (50)
 Hyperlipidaemia 8 (80)
 Hypertension 10 (100)
 Coronary artery disease 3 (30)
 Heart failure 4 (40)
 Age-adjusted Charlson Comorbidity Index; mean (SD) 6.0 (2.8)
 Current smoking 0 (0)
Psychological outcomes; all mean (SD)
 Positive affect (PANAS; range 10–50) 35.4 (4.2)
 Optimism (LOT-R; range 0–24) 16.5 (4.5)
 Anxiety (HADS-A; range 0–21) 6.1 (4.8)
 Depression (HADS-D; range 0–21) 5.6 (3.2)
 Self-efficacy (GSES; range 0–30) 24.3 (4.8)
Health behaviour outcomes; mean (SD), unless otherwise noted
 Self-reported adherence (MOS-SAS; range 3–18) 13.8 (0.8)
 Frequency of nonadherence to kidney-healthy diet (DDFNQ; range 0–14)a 2.8 (4.8)
 Degree of nonadherence to kidney-healthy diet (DDFNQ; range 0–4)a 0.5 (0.7)
 Frequency of nonadherence to fluid restriction (DDFNQ; range 0–14)a 0.9 (1.5)
 Degree of nonadherence to fluid restriction (DDFNQ; range 0–4)a 0.7 (1.2)
 Medication adherence; N (%) 10 (100)
 MVPA (min/day) 11.3 (10.8)
 Overall activity (steps/day) 2963 (1634)
 Sedentary time (min/day) 651 (73)
Open in a new tab

Abbreviations: DDFNQ, Dialysis Diet and Food Nonadherence Questionnaire; GSES, General Self-Efficacy Scale; HADS-A, Hospital Anxiety and Depression Scale; Anxiety subscale; HADS-D, Hospital Anxiety and Depression Scale; Depression subscale; KF, Kidney Failure; LOT-R, Life Orientation Test-Revised; MOS-SAS, Medical Outcomes Study Specific Adherence Scale; MVPA, moderate to vigorous physical activity; PANAS, Positive And Negative Affect Schedule; SD, standard deviation.

a

Higher numbers indicate greater nonadherence.

Feasibility, acceptability and immediate impact

Participants completed 9.4 out of 12 sessions (78%), and 80% completed more than half the sessions, above our a priori threshold for feasibility. Similarly, participants rated both the PP and MI components of the program as easy to complete (PP: 8.7 ± 1.5; MI: 8.3 ± 2.0) and subjectively helpful (PP: 8.8 ± 1.2; MI: 8.8 ± 1.6). Individual PP exercises led to significant pre-post improvements in happiness (7.3 ± 1.4 [pre] vs. 8.8 ± 0.9 [post], t = 9.5, p < 0.001) and optimism (7.5 ± 1.7 [pre] vs. 8.8 ± 1.1 [post], t = 8.3, p < 0.001).

Exploratory outcomes: Overall impact on psychological and health behaviour outcomes

In exploratory analyses, the intervention was associated with nonsignificant improvements in some, but not all, psychological outcomes (see Table 4). The intervention was linked to small- to medium-sized pre-post improvements in positive affect (d = 0.29) and optimism (d = 0.51), medium- to large-sized reductions in anxiety (d = −0.57) and depression (d = −0.62), and very small improvements in self-efficacy (d = 0.11).

TABLE 4.

Intervention impact on psychological outcomes, health behaviours and physical outcomes

B 95% Confidence interval p value Effect size
Psychological outcomes
 Positive affect (PANAS) 2.03 −2.46, 6.52 0.38 0.29
 Optimism (LOT-R) 2.82 −0.70, 6.35 0.12 0.51
 Anxiety (HADS-A) −2.13 −4.56, 0.29 0.085 −0.57
 Depression (HADS-D) −1.84 −3.77, 0.09 0.062 −0.62
 Self-efficacy (GSES) 0.70 −3.22, 4.62 0.73 0.11
Health behaviour outcomes
 Self-reported adherence (MOS) 1.06 0.28, 1.86 0.008 0.95
 MVPA (min/day) 4.37 −1.31, 10.06 0.13 0.56
 Overall activity (steps/day) 763 −24, 1549 0.057 0.71
 Sedentary time (min/day) −4.35 −57.00, 48.30 0.87 −0.06
Frequency of nonadherence to kidney-healthy diet (DDFNQ)a −1.47 −4.75, 1.81 0.38 −0.28
Degree of nonadherence to kidney-healthy diet (DDFNQ)b 0.48 −0.23, 1.20 0.18 0.44
Frequency of nonadherence to fluid restriction (DDFNQ)a −0.15 −1.28, 0.98 0.80 −0.08
Degree of nonadherence to fluid restriction (DDFNQ)b −0.26 −1.10, 0.57 0.54 −0.20
Open in a new tab

Abbreviations: DDFNQ, Dialysis Diet and Food Nonadherence Questionnaire; GSES, General Self-Efficacy Scale; HADS-A, Hospital Anxiety and Depression Scale; Anxiety subscale; HADS-D, Hospital Anxiety and Depression Scale; Depression subscale; LOT-R, Life Orientation Test-Revised; MOS-SAS, Medical Outcomes Study Specific Adherence Scale; MVPA, moderate to vigorous physical activity; PANAS, Positive And Negative Affect Schedule.

a

Positive numbers reflect increases in the frequency of nonadherence, while negative numbers indicate reductions in the frequency of nonadherence.

b

Positive numbers reflect increases in the degree/severity of nonadherence, while negative numbers indicate reductions in the degree/severity of nonadherence.

The intervention also was associated with pre-post improvements in overall adherence and physical activity (see Table 4). The intervention led to large-sized improvements in overall adherence (d = 0.95). Additionally, both MVPA and overall physical activity, as measured via accelerometer, increased over the course of the intervention (change in MVPA: d = 0.56, 4.4 min/day; change in overall activity: d = 0.71; 763 steps/day), and a very small reduction in sedentary time (d = −0.06) was noted. Results related to dietary and medication adherence were more mixed. Over the course of the program, participants reported more frequent adherence to diet and fluid restriction guidelines (diet: d = −0.28; fluid restriction: d = −0.08), as well as less severe nonadherence to fluid restriction recommendations (d = −0.20). However, participants reported more severe nonadherence to kidney diet guidelines (d = 0.44). Finally, the program led to no change in medication adherence (all participants were categorised as adherent at both time points).

Exit interviews

Seven participants completed exit interviews. All seven found the PP content to be helpful, with one noting that the exercises “reaffirmed my happiness and my emotional health” (ID 1). Similarly, the MI portion was well-accepted, with participants identifying different types of content (e.g., diet content, using a pillbox for medications, engaging in physical activity) as particularly helpful for them. The intervention frequently led to changes in behaviour, with participants most commonly noting that they had increased their physical activity (N = 4) and performed acts of kindness (N = 3) in response to phone sessions. Three participants identified challenges meeting their physical activity goals (“…I found [it] very difficult [to do more than just walking]—I just get winded way too fast” [ID 7]), and one felt that tracking phosphorous and fluid intake was difficult (“I don’t like keeping track of food…I’m having a hard time with that…I felt like I know what I’m supposed to be doing. It just isn’t going well, so it didn’t help to talk about it” [ID 5]). Six of seven participants felt the frequency of phone sessions was optimal (one thought they should be spread out in the second half of the program), and six of seven felt the intervention’s 12-week duration was appropriate (one felt that it could be longer).

DISCUSSION

In this trial, a 12-week, phone-delivered, PP-MI intervention tailored to individuals receiving haemodialysis was feasible and well-accepted, with participants completing 78% of intervention sessions and rating both intervention components as easy to complete (8.3–8.7/10) and subjectively helpful (8.8/10). Additionally, exploratory efficacy analyses suggested that the intervention was associated with promising but nonsignificant improvements in positive affect, optimism, anxiety, and depression, as well as substantial but nonsignificant improvements in most adherence outcomes, though these results should be treated cautiously, due to given the study’s small sample size. Finally, exit interviews supported our quantitative results and suggested that the intervention was well-accepted by participants.

Our feasibility and acceptability findings are consistent with the literature, which increasingly has found PP-MI interventions to be feasible and subjectively useful in individuals with chronic medical conditions, such as coronary artery disease (84% of sessions completed; ease of PP/MI components = 8.1–8.3/10; utility of PP/MI components = 8.0–8.2/10) (Huffman et al., 2019), type 2 diabetes (92% of sessions completed; ease of PP/MI components = 8.5–8.6/10; utility of PP/MI components = 8.6–8.8/10) (Huffman et al., 2020), and heart failure (73% of sessions completed; ease of PP exercises = 7.5/10; utility of PP exercises = 7.5/10) (Celano et al., 2020). Though there has been limited study of PP-based programs in KF, our feasibility and acceptability findings mirror those of a single-arm trial of an internet-delivered PP intervention for patients with KF receiving haemodialysis, which found the intervention modules to be easy to complete (range 6.8–8.4 out of 10) and helpful (range 6.6–7.6 out of 10) (Hernandez et al., 2018). The current study confirms the acceptability of PP-based programs in this population and suggests that PP-based content can be successfully delivered via telephone and combined with MI-based health behaviour content.

Though the efficacy analyses in this small, single-arm trial were exploratory, the PP-MI program’s impact on psychological outcomes and health behaviour adherence is consistent with PP-MI and PP-alone interventions in other populations. In randomised pilot trials of phone-based PP-MI interventions in patients with heart disease or diabetes, PP-MI has been linked to medium- to large-sized improvements in positive affect (weighted mean effect size = 0.48) and health behaviour adherence (e.g., MVPA [weighted mean effect size = 0.78]) (Celano et al., 2020; Huffman et al., 2019, 2020) compared to active control conditions (typically MI alone). Similarly, PP-alone interventions are associated with small but significant increases in well-being (effect sizes = 0.20–0.34) and reductions in depression (effect sizes = 0.23–0.31) (Bolier et al., 2013; Sin & Lyubomirsky, 2009), and among medical populations, PP-based programs have been linked to significant, small- to medium-sized reductions in anxiety (effect size = −0.34) (Brown et al., 2019). The current trial demonstrates that a phone-delivered PP-MI program tailored to individuals with KF has the potential to enhance well-being, reduce depression and anxiety, and improve adherence in this population as well, though larger, randomised trials are needed to examine its impact more formally.

The preliminary efficacy findings also are consistent with other adherence-related interventions in patients with KF. In general, existing behavioural interventions focus on either dietary/fluid/dialysis adherence or physical activity promotion (Huang et al., 2019; Murali et al., 2019). The former types of programs typically include educational sessions, with or without additional psychological/behavioural interventions (e.g., cognitive behavioural therapy, MI alone) (Murali et al., 2019), while the latter programs focus on exercise training, usually during dialysis sessions (Huang et al., 2019). Both intervention types appear to be effective at improving adherence, with those focusing on diet/fluid/dialysis adherence associated with reductions in phosphate (SMD = −0.45) and inter-dialytic weight gain (SMD = −0.20) (Murali et al., 2019), and those focusing on physical activity associated with increases in aerobic capacity (SMD = 0.73) and physical HRQoL (SMD = 0.34) (Huang et al., 2019). The current study demonstrates thatKF-focused health behaviour and physical activity interventions have the potential to be combined and delivered to participants remotely, which may increase the likelihood of developing sustainable habits of adherence that may be needed to impact health outcomes (Moholdt et al., 2018).

The current PP-MI program has several features that may enhance its efficacy in patients with KF. In contrast to some existing in-person adherence programs (Clarkson et al., 2019; Huang et al., 2019; Murali et al., 2019; Wilund et al., 2019), the current PP-MI program was delivered remotely, which may increase accessibility for patients who often must attend appointments several times per week for dialysis and other medical problems. Additionally, the inclusion of content related to physical activity, diet, and dialysis self-care allowed for the intervention to be adapted to address those health behaviours that are most relevant to individual patients. This has the potential to promote engagement and increase the reach of the program to individuals who struggle with adherence to different health behaviours. Finally, the current intervention’s added focus on psychological health is novel and has the potential to enhance its efficacy, as increases in positive constructs and reductions in negative ones are associated with both health behaviour adherence and health outcomes in individuals with chronic illnesses (Celano et al., 2013; Kubzansky et al., 2018).

This study has several limitations. The small sample size limited the statistical power of our analyses, while the lack of a control group made it difficult to assess the impact of the intervention independent of potential confounding factors (e.g., changes in clinical status over time). Furthermore, our study sample was self-selected, with a substantial portion of eligible participants not interested in participating, and included only individuals receiving haemodialysis, which limits the generalisability of the findings. Though physical activity was objectively measured, many of our outcome measures were self-reported, which may be prone to reporting bias. Finally, though participant feedback was obtained in the exit interviews, individuals with KF were not involved in the development of the intervention or design of the study.

These limitations can be addressed in several ways in future trials. Including a larger sample would increase statistical power to detect between-group differences on outcome measures, while the inclusion of objective markers of adherence (e.g., weight gain, electrolyte changes) and clinical outcomes (e.g., hospitalisations, mortality) would reduce the risk of reporting bias. Incorporation of participant feedback into intervention development and study design may lead to a more effective intervention and may increase recruitment and retention rates, which would increase generalisability. Finally, tailoring of the intervention to individuals receiving peritoneal dialysis, those who do not yet require kidney replacement therapy, and those who have undergone kidney transplantation may increase the reach of the intervention and thus broaden its impact overall.

IMPLICATIONS FOR CLINICAL PRACTICE

Despite these limitations, this proof-of-concept trial confirms the feasibility and acceptability of a phone-delivered behavioural intervention for individuals with KF receiving haemodialysis. Furthermore, the intervention’s medium-sized effects on depressive symptoms, anxiety, optimism, physical activity, and self-reported adherence provide preliminary evidence of the potential of the program to improve these symptoms and behaviours. Though larger, controlled trials are needed, the established relationships between psychological health, health behaviour adherence, and health outcomes suggest that interventions aimed at improving psychological health and adherence have the potential to improve kidney-related health outcomes.

CONCLUSION

In this trial, a 12-week, phone-delivered PP-MI intervention was feasible, well-accepted, and associated with nonsignificant improvements in psychological outcomes, KF-related adherence, and physical activity. Larger, randomised, controlled trials in diverse populations are needed to confirm the results of this trial on psychological and health behaviour outcomes and to explore the potential impact of PP-MI on kidney-related outcomes in this high-risk patient group.

ACKNOWLEDGEMENTS

Funding: Time for analysis and article preparation was also funded by the National Heart, Lung, and Blood Institute through grants R01HL155301 (to Dr. Celano) and R01HL113272 (to Dr. Huffman). The content is solely the responsibility of the authors and does not represent the official views of the National Institutes of Health. The sponsor had no role in the design, analysis, interpretation, or publication of the study.

Funding information

National Heart, Lung, and Blood Institute, Grant/Award Numbers: R01HL113272, R01HL155301

AUTHOR BIOGRAPHY

graphic file with name nihms-1808965-b0001.gif

Dr. Christopher M. Celano is a Psychiatrist and Clinical Investigator at the Massachusetts General Hospital (MGH). After completing his undergraduate training at the Johns Hopkins University, Dr. Celano received his M.D. degree from the Mount Sinai School of Medicine in New York, NY (USA). He attended the MGH/McLean Adult Psychiatry Residency Program and then completed a clinical fellowship in Psychosomatic Medicine at MGH. He now serves as the Associate Director for MGH’s Cardiac Psychiatry Research Program (CPRP). Dr. Celano’s research focuses on the development and implementation of interventions to promote well-being and health behaviour adherence. He has served as the Principal Investigator of NIH- and foundation-funded studies to develop and implement health behaviour interventions, including an ongoing R01-funded project to evaluate the efficacy of a psychological intervention to promote adherence in heart failure. He also has served as the Principal or Co-Investigator of multiple other projects related to health behaviour promotion or the use of collaborative care to better identify and treat depression and anxiety disorders in individuals with heart disease. He has published over 80 articles and has presented the results of his work at both national and international conferences.

Footnotes

CONFLICTS OF INTEREST

Dr. Celano has received salary support for research from BioXcel Pharmaceuticals and honoraria for talks to Sunovion Pharmaceuticals on topics unrelated to this research. The authors declare no conflicts of interest.

DATA AVAILABILITY STATEMENT

The dataset supporting the conclusions of this article are available by contacting the corresponding author.

REFERENCES

  1. Bjelland I, Dahl AA, Haug TT & Neckelmann D (2002) The validity of the hospital anxiety and depression scale: an updated literature review. Journal of Psychosomatic Research, 52, 69–77. [DOI] [PubMed] [Google Scholar]
  2. Bolier L, Haverman M, Westerhof GJ, Riper H, Smit F & Bohlmeijer E (2013) Positive psychology interventions: a meta-analysis of randomized controlled studies. BMC Public Health, 13, 119. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Brown L, Ospina JP, Celano CM & Huffman JC (2019) The effects of positive psychological interventions on medical patients’ anxiety: a meta-analysis. Psychosomatic Medicine, 81, 595–602. [DOI] [PubMed] [Google Scholar]
  4. Callahan CM, Unverzagt FW, Hui SL, Perkins AJ & Hendrie HC (2002) Six-item screener to identify cognitive impairment among potential subjects for clinical research. Medical Care, 40, 771–81. [DOI] [PubMed] [Google Scholar]
  5. Celano CM, Beale EE, Moore SV, Wexler DJ & Huffman JC (2013) Positive psychological characteristics in diabetes: a review. Current Diabetes Reports, 13, 917–29. [DOI] [PubMed] [Google Scholar]
  6. Celano CM, Freedman ME, Harnedy LE, Park ER, Januzzi JL, Healy BC et al. (2020) Feasibility and preliminary efficacy of a positive psychology-based intervention to promote health behaviors in heart failure: The REACH for Health study. Journal of Psychosomatic Research, 139, 110285. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Celano CM, Massey C, Long J, Kim S, Velasquez O & Healy BC et al. (2021) An adaptive, algorithm-based text message intervention to promote health behavior adherence in type 2 diabetes: treatment development and proof-of-concept trial. Journal of Diabetes Science and Technology (Online) 19322968211065067. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Clark S, Farrington K & Chilcot J (2014) Nonadherence in dialysis patients: prevalence, measurement, outcome, and psychological determinants. Seminars in Dialysis, 27, 42–9. [DOI] [PubMed] [Google Scholar]
  9. Clarkson MJ, Bennett PN, Fraser SF & Warmington SA (2019) Exercise interventions for improving objective physical function in patients with end-stage kidney disease on dialysis: a systematic review and meta-analysis. American Journal of Physiology. Renal Physiology, 316, F856–F872. [DOI] [PubMed] [Google Scholar]
  10. Cukor D, Ver Halen N, Asher DR, Coplan JD, Weedon J, Wyka KE et al. (2014) Psychosocial intervention improves depression, quality of life, and fluid adherence in hemodialysis. Journal of the American Society of Nephrology, 25, 196–206. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Cwiek A, Czok M, Kurczab B, Kramarczyk K, Drzyzga K & Kucia K (2017) Association between depression and hemodialysis in patients with chronic kidney disease. Psychiatria Danubina, 29, 499–503. [PubMed] [Google Scholar]
  12. Delgado C & Johansen KL (2012) Barriers to exercise participation among dialysis patients. Nephrology, Dialysis, Transplantation, 27, 1152–7. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Dimatteo MR, Hays RD & Sherbourne CD (1992) Adherence to cancer regimens: implications for treating the older patient. Oncology (Williston Park), 6, 50–7. [PubMed] [Google Scholar]
  14. Dubois CM, Beach SR, Kashdan TB, Nyer MB, Park ER, Celano CM et al. (2012) Positive psychological attributes and cardiac outcomes: associations, mechanisms, and interventions. Psychosomatics, 53, 303–18. [DOI] [PubMed] [Google Scholar]
  15. Fotheringham J, Smith MT, Froissart M, Kronenberg F, Stenvinkel P, Floege J et al. (2020) Hospitalization and mortality following nonattendance for hemodialysis according to dialysis day of the week: a European cohort study. BMC Nephrology, 21, 218. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Gehi A, Haas D, Pipkin S & Whooley MA (2005) Depression and medication adherence in outpatients with coronary heart disease: findings from the Heart and Soul Study. Archives of Internal Medicine, 165, 2508–13. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Gerogianni G, Polikandrioti M, Babatsikou F, Zyga S, Alikari V & Vasilopoulos G et al. (2019) Anxiety-depression of dialysis patients and their caregivers. Medicina (Kaunas), 55(5), 168. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Hernandez R, Burrows B, Wilund K, Cohn M, Xu S & Moskowitz JT (2018) Feasibility of an internet-based positive psychological intervention for hemodialysis patients with symptoms of depression. Social Work in Health Care, 57, 864–879. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Huang M, Lv A, Wang J, Xu N, Ma G, Zhai Z et al. (2019) Exercise training and outcomes in hemodialysis patients: systematic review and meta-analysis. American Journal of Nephrology, 50, 240–254. [DOI] [PubMed] [Google Scholar]
  20. Huffman JC, Feig EH, Millstein RA, Freedman M, Healy BC, Chung WJ et al. (2019) Usefulness of a positive psychology-motivational interviewing intervention to promote positive affect and physical activity after an acute coronary syndrome. American Journal of Cardiology, 123, 1906–1914. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Huffman JC, Golden J, Massey CN, Feig EH, Chung WJ, Millstein RA et al. (2020) A positive psychology-motivational interviewing intervention to promote positive affect and physical activity in type 2 diabetes: the BEHOLD-8 controlled clinical trial. Psychosomatic Medicine, 82, 641–649. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Huffman JC, Millstein RA, Mastromauro CA, Moore SV, Celano CM, Bedoya CA et al. (2016) A positive psychology intervention for patients with an acute coronary syndrome: treatment development and proof-of-concept trial. Journal of Happiness Studies, 17, 1985–2006. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. K/Doqi. (2005) Clinical practice guidelines for cardiovascular disease in dialysis patients. American Journal of Kidney Diseases, 45, 16–153. [PubMed] [Google Scholar]
  24. Kauric-Klein Z (2017) Depression and medication adherence in patients on hemodialysis. Current Hypertension Reviews, 13, 138–143. [DOI] [PubMed] [Google Scholar]
  25. Kelly JT, Palmer SC, Wai SN, Ruospo M, Carrero JJ, Campbell KL et al. (2017) Healthy dietary patterns and risk of mortality and ESRD in CKD: a meta-analysis of cohort studies. Clinical Journal of the American Society of Nephrology, 12, 272–279. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Khalil AA & Frazier SK (2010) Depressive symptoms and dietary nonadherence in patients with end-stage renal disease receiving hemodialysis: a review of quantitative evidence. Issues in Mental Health Nursing, 31, 324–30. [DOI] [PubMed] [Google Scholar]
  27. Kodama S, Tanaka S, Heianza Y, Fujihara K, Horikawa C, Shimano H et al. (2013) Association between physical activity and risk of all-cause mortality and cardiovascular disease in patients with diabetes: a meta-analysis. Diabetes Care, 36, 471–9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Kopple JD, Kim JC, Shapiro BB, Zhang M, Li Y, Porszasz J et al. (2015) Factors affecting daily physical activity and physical performance in maintenance dialysis patients. Journal of Renal Nutrition, 25, 217–22. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Kubzansky LD, Huffman JC, Boehm JK, Hernandez R, Kim ES, Koga HK et al. (2018) Reprint of: positive psychological well-being and cardiovascular disease: JACC Health Promotion Series. Journal of the American College of Cardiology, 72, 3012–3026. [DOI] [PubMed] [Google Scholar]
  30. Kugler C, Maeding I & Russell CL (2011) Non-adherence in patients on chronic hemodialysis: an international comparison study. Journal of Nephrology, 24, 366–75. [DOI] [PubMed] [Google Scholar]
  31. Langston CA (1994) Capitalizing on and coping with daily-life events: expressive responses to positive events. Journal of Personality and Social Psychology, 67, 1112–1125. [Google Scholar]
  32. Lee CS, Moser DK, Lennie TA & Riegel B (2011) Event-free survival in adults with heart failure who engage in self-care management. Heart and Lung, 40, 12–20. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Leggat J Jr., Orzol S, Hulbert-Shearon T, Golper TA, Jones CA, Held PJ & Port FK (1998) Noncompliance in hemodialysis: predictors and survival analysis. American Journal of Kidney Diseases, 32, 139–45. [DOI] [PubMed] [Google Scholar]
  34. Mendes R, Martins S & Fernandes L (2019) Adherence to medication, physical activity and diet in older adults with diabetes: its association with cognition, anxiety and depression. Journal of Clinical Medicine and Research, 11, 583–592. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Miller WR & Rollnick S (2002) Motivational interviewing: preparing people for change. New York: Guilford Press. [Google Scholar]
  36. Millstein RA, Thorndike AN, Kim S, Park ER & Huffman JC (2020) A community-based positive psychology group intervention to promote physical activity among people with metabolic syndrome: proof of concept results to inform a pilot randomized controlled trial protocol. Contemp Clin Trials Commun, 19, 100626. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Moholdt T, Lavie CJ & Nauman J (2018) Sustained physical activity, not weight loss, associated with improved survival in coronary heart disease. Journal of the American College of Cardiology, 71, 1094–1101. [DOI] [PubMed] [Google Scholar]
  38. Moskowitz JT, Hult JR, Duncan LG, Cohn MA, Maurer S, Bussolari C et al. (2012) A positive affect intervention for people experiencing health-related stress: development and non-randomized pilot test. Journal of health psychology, 17, 676–92. [DOI] [PMC free article] [PubMed] [Google Scholar]
  39. Murali KM, Mullan J, Roodenrys S, Hassan HC, Lambert K & Lonergan M (2019) Strategies to improve dietary, fluid, dialysis or medication adherence in patients with end stage kidney disease on dialysis: a systematic review and meta-analysis of randomized intervention trials. PLoS One, 14, e0211479. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Nafradi L, Nakamoto K & Schulz PJ (2017) Is patient empowerment the key to promote adherence? A systematic review of the relationship between self-efficacy, health locus of control and medication adherence. PLoS One, 12, e0186458. [DOI] [PMC free article] [PubMed] [Google Scholar]
  41. Ogedegbe GO, Boutin-Foster C, Wells MT, Allegrante JP, Isen AM, Jobe JB et al. (2012) A randomized controlled trial of positive-affect intervention and medication adherence in hypertensive African Americans. Archives of Internal Medicine, 172, 322–6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Ossareh S, Tabrizian S, Zebarjadi M & Joodat RS (2014) Prevalence of depression in maintenance hemodialysis patients and its correlation with adherence to medications. Iranian Journal of Kidney Diseases, 8, 467–74. [PubMed] [Google Scholar]
  43. Ozen N, Cinar FI, Askin D, Mut D & Turker T (2019) Nonadherence in hemodialysis patients and related factors: a multicenter study. The Journal of Nursing Research, 27, e36. [DOI] [PMC free article] [PubMed] [Google Scholar]
  44. Pasyar N, Rambod M, Sharif F, Rafii F & Pourali-Mohammadi N (2015) Improving adherence and biomedical markers in hemodialysis patients: the effects of relaxation therapy. Complementary Therapies in Medicine, 23, 38–45. [DOI] [PubMed] [Google Scholar]
  45. Peterson JC, Charlson ME, Hoffman Z, Wells MT, Wong SC, Hollenberg JP et al. (2012) A randomized controlled trial of positive-affect induction to promote physical activity after percutaneous coronary intervention. Archives of Internal Medicine, 172, 329–36. [DOI] [PMC free article] [PubMed] [Google Scholar]
  46. Qiu Z, Zheng K, Zhang H, Feng J, Wang L & Zhou H (2017) Physical exercise and patients with chronic renal failure: a meta-analysis. BioMed Research International, 2017, 7191826. [DOI] [PMC free article] [PubMed] [Google Scholar] [Retracted]
  47. Riera-Sampol A, Bennasar-Veny M, Tauler P, Nafría M, Colom M & Aguilo A (2021) Association between depression, lifestyles, sleep quality and sense of coherence in a population with cardiovascular risk. Nutrients, 13(2), 585. [DOI] [PMC free article] [PubMed] [Google Scholar]
  48. Saran R, Bragg-Gresham JL, Rayner HC, Goodkin DA, Keen ML, Van Dijk PC et al. (2003) Nonadherence in hemodialysis: associations with mortality, hospitalization, and practice patterns in the DOPPS. Kidney International, 64, 254–62. [DOI] [PubMed] [Google Scholar]
  49. Scheier MF, Carver CS & Bridges MW (1994) Distinguishing optimism from neuroticism (and trait anxiety, self-mastery, and self-esteem): a reevaluation of the Life Orientation Test. Journal of Personality and Social Psychology, 67, 1063–78. [DOI] [PubMed] [Google Scholar]
  50. Schwarzer R & Jerusalem M (1995) Generalized Self-Efficacy Scale. In Measures in Health Psychology: A User’s Portfolio. In: Weinman J, Wright S & Johnston M (Eds.) Causal and Control Beliefs. Windsor, UK: NFER-NELSON. pp. 35–37 [Google Scholar]
  51. Seligman ME, Steen TA, Park N & Peterson C (2005) Positive psychology progress: empirical validation of interventions. American Psychologist, 60, 410–21. [DOI] [PubMed] [Google Scholar]
  52. Sin NL & Lyubomirsky S (2009) Enhancing well-being and alleviating depressive symptoms with positive psychology interventions: a practice-friendly meta-analysis. Journal of Clinical Psychology, 65, 467–487. [DOI] [PubMed] [Google Scholar]
  53. Tsay SL (2003) Self-efficacy training for patients with end-stage renal disease. Journal of Advanced Nursing, 43, 370–5. [DOI] [PubMed] [Google Scholar]
  54. Umeukeje EM, Mixon AS & Cavanaugh KL (2018) Phosphate-control adherence in hemodialysis patients: current perspectives. Patient Preference and Adherence, 12, 1175–1191. [DOI] [PMC free article] [PubMed] [Google Scholar]
  55. Vlaminck H, Maes B, Jacobs A, Reyntjens S & Evers G (2001) The dialysis diet and fluid non-adherence questionnaire: validity testing of a self-report instrument for clinical practice. Journal of Clinical Nursing, 10, 707–15. [DOI] [PubMed] [Google Scholar]
  56. Watson D, Clark LA & Tellegen A (1988) Development and validation of brief measures of positive and negative affect: the PANAS scales. Journal of Personality and Social Psychology, 54, 1063–70. [DOI] [PubMed] [Google Scholar]
  57. Wilund KR, Jeong JH & Greenwood SA (2019) Addressing myths about exercise in hemodialysis patients. Seminars in Dialysis, 32, 297–302. [DOI] [PubMed] [Google Scholar]
  58. Ziegelstein RC, Fauerbach JA, Stevens SS, Romanelli J, Richter DP & Bush DE (2000) Patients with depression are less likely to follow recommendations to reduce cardiac risk during recovery from a myocardial infarction. Archives of Internal Medicine, 160, 1818–23. [DOI] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Data Availability Statement

The dataset supporting the conclusions of this article are available by contacting the corresponding author.

RESOURCES