How do clinical and psychological variables relate to quality of life in end-stage renal disease? Validating a proximal-distal model.

PURPOSE: The aims of this study were to: (1) validate the proximal-distal (PD) model in predialysis and early dialysis and (2) examine the role of hemoglobin on quality of life (QoL) in these patient groups. METHODS: Cross-sectional observational studies of 475 participants recruited from four major university teaching hospitals were conducted. The multi-sample structural equation modeling with latent composite techniques was employed to test the PD model. Seven factors were measured, including QoL, positive affect, depression, physical functioning, kidney disease symptoms, comorbidity and hemoglobin. RESULTS: The results showed that both the equality-constrained and equality-unconstrained PD models were supported by fit statistics. The chi square difference test of the two models was non-significant, indicating that the PD model was consistent across groups. The alternative models were rejected by fit statistics, suggesting that hemoglobin does not impact on psychological states but QoL. CONCLUSIONS: This study validates the PD model across the end-stage renal disease (ESRD) patient groups and shows a hierarchical causal relationship between clinical factors, physical functioning, psychological states and QoL, with hemoglobin as an exception. This model provides an empirical framework for integrating and studying a range of clinical factors and health outcomes in ESRD.

The effect of acceptance on health outcomes in patients with chronic kidney disease.

The concept of acceptance has both research and clinical significance. There may be two types of acceptance leading to different health outcomes. By assessing their level and type of acceptance, clinicians could provide patients with appropriate treatments to encourage 'active' acceptance, thereby leading to positive health outcomes.

The psychosocial correlates of quality of life in the dialysis population: a systematic review and meta-regression analysis.

PURPOSE: The psychosocial correlates of quality-of-life (QoL) research in end-stage renal disease (ESRD) are important in identifying risk and protective factors that may account for the QoL variability. Thus, the present study provides a meta-analysis of these research results. METHODS: Published studies reporting associations between any psychosocial factors and QoL were retrieved from Medline, Embase, and PsycINFO. Mean effect sizes were calculated for the associations across psychosocial constructs (affect, stress, cognitive appraisal, social support, personality attributes, and coping process). Multiple hierarchical meta-regressions were applied to moderator analyses. RESULTS: Eighty-one studies covering a combined sample of 13,240 participants were identified resulting in 377 effect sizes of the association between psychosocial factors and QoL. The overall effect size of the association was medium (0.38). Stress, affect, and cognitive appraisal had the largest effect sizes. Location of study, dialysis type, gender, age and QoL domains measured (general well-being, subjective QoL, and health-related QoL) were significant substantive moderators for the associations. CONCLUSIONS: The present study shows that there is a moderate association between psychosocial variables and QoL in patients with ESRD, consistent across different QoL domains. The psychosocial constructs that have the strongest association with QoL are stress, affect, and cognitive appraisal.

Examining internet-delivered cognitive behaviour therapy for patients with chronic kidney disease on haemodialysis: A feasibility open trial.

OBJECTIVE: Treating depression among patients with chronic kidney disease (CKD) is imperative because of its high prevalence and health-related costs. However, many patients with CKD experience significant barriers to effective face-to-face psychological treatments. Internet-delivered cognitive behaviour therapy (iCBT) may help overcome the treatment barriers. The aim of the present study was to explore the acceptability and preliminary efficacy of iCBT for depression and anxiety among patients with CKD on haemodialysis. METHODS: A single-group open trial design involving 22 patients on dialysis and an established iCBT treatment for anxiety and depression was employed. The primary outcomes were symptoms of depression, anxiety and general psychological distress. The secondary and tertiary outcomes were disability, quality of life, kidney disease-related loss and kidney disease burden. A generalised estimation equation modelling technique was employed. RESULTS: Clinically significant improvements (avg. % of improvement) were observed in the primary outcomes of depression (34%), anxiety (31%) and general distress (26%), which were maintained or further improved to 3-month follow-up. Improvements were also observed for quality of life (12%) and kidney disease-related loss (30%). However, no improvements in disability and kidney disease burden were found. High levels of acceptability were reported and relatively little clinician time (99.45min; SD=14.61) was needed to provide the treatment. CONCLUSION: The present results provide encouraging support for the potential of iCBT as an innovative way of increasing access to effective psychological treatment for CKD patients. These results provide much needed support for further research in this area. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry: ACTRN12613000103763.

Studying psychosocial adaptation to end-stage renal disease: the proximal-distal model of health-related outcomes as a base model.

OBJECTIVE: Studying psychosocial adaptation in end-stage renal disease (ESRD) is increasingly important, as it may explain the variability in health outcomes unaccounted for by clinical factors. The Brenner et al. proximal-distal model of health-related outcomes provides a theoretical foundation for understanding psychosocial adaptation and integrating health outcomes, clinical, and psychosocial factors (Brenner MH, Curbow B, Legro MW. The proximal-distal continuum of multiple health outcome measures: the case of cataract surgery. Med Care. 1995;33(4 Suppl):AS236-44). This study aims to empirically validate the proximal-distal model in the dialysis population and examine the impact of psychosocial factors on the model. METHODS: A cross-sectional observational study was conducted with a sample of long-term dialysis patients (n=201). Eleven factors: quality of life (QoL), depression, positive affect, comorbidity, symptoms, physical functioning, disease accommodation, loss, self-efficacy, illness acceptance, and social support were measured by standardized psychometric scales. A three-month average of hemoglobin was used. Latent composite structural equation modeling was used to examine the models. RESULTS: The proximal-distal model with slight modification was supported by fit statistics [χ(2)=16.04, df=13, P=.25, root mean square error of approximation (RMSEA)=0.024], indicating that the impact of clinical factors on QoL is mediated through a range of functional and psychological factors, except for hemoglobin which impacts directly on QoL. The model with additional psychosocial factors was also supported by fit statistics (χ(2)=43.59, df=41, P=.36, RMSEA=0.018). These additional factors mainly impact on symptom status, psychological states, and QoL components of the model. CONCLUSION: The present study supported the proximal-distal model in the dialysis population and demonstrated the considerable impact of psychosocial factors on the model. The proximal-distal model plus psychosocial factors as a biopsychosocial model can be applied to studying psychosocial adaptation in ESRD.

Psychosocial risk and protective factors for depression in the dialysis population: a systematic review and meta-regression analysis.

OBJECTIVE: Research into the association between psychosocial factors and depression in End-Stage Renal Disease (ESRD) has expanded considerably in recent years identifying a range of factors that may act as important risk and protective factors of depression for this population. The present study provides the first systematic review and meta-analysis of this body of research. METHODS: Published studies reporting associations between any psychosocial factor and depression were identified and retrieved from Medline, Embase, and PsycINFO, by applying optimised search strategies. Mean effect sizes were calculated for the associations across five psychosocial constructs (social support, personality attributes, cognitive appraisal, coping process, stress/stressor). Multiple hierarchical meta-regression analysis was applied to examine the moderating effects of methodological and substantive factors on the strength of the observed associations. RESULTS: 57 studies covering 58 independent samples with 5956 participants were identified, resulting in 246 effect sizes of the association between a range of psychosocial factors and depression. The overall mean effect size (Pearsons correlation coefficient) of the association between psychosocial factor and depression was 0.36. The effect sizes between the five psychosocial constructs and depression ranged from medium (0.27) to large levels (0.46) with personality attributes (0.46) and cognitive appraisal (0.46) having the largest effect sizes. In the meta-regression analyses, identified demographic (gender, age, location of study) and treatment (type of dialysis) characteristics moderated the strength of the associations with depression. CONCLUSION: The current analysis documents a moderate to large association between the presence of psychosocial risk factors and depression in ESRD.

Measuring kidney disease-related loss in samples of predialysis and dialysis patients: validating the kidney disease loss scale.

BACKGROUND AND OBJECTIVES: Kidney disease-related loss is clinically significant in patients with ESRD and is related to depression and quality of life. The Kidney Disease Loss Scale (KDLS) was recently developed for long-term dialysis patients as a means of studying loss and applying it to clinical practice; however, its validity and usability in the other developmental stages of ESRD-predialysis and early dialysis-remain unknown. This study examined the validity and reliability of the KDLS in the long-term dialysis, early dialysis, and predialysis populations. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Four groups of participants were recruited from four large university teaching hospitals in the Sydney metropolitan area. Participants were long-term dialysis (n=151), early dialysis (n=163), and predialysis (n=111) patients. An additional independent group of dialysis (n=50) patients were recruited to measure the test-retest reliability. Multisample confirmatory factor analysis and correlational analysis were used. RESULTS: Results demonstrated good internal consistency and test-retest reliability for KDLS. Multisample confirmatory factor analysis indicated that the factor structure of KDLS was invariant across samples and thus supported its construct validity. The convergent and discriminant validities of KDLS were supported by its correlations with scales that measure health-related quality of life, depression, and positive affect in the expected directions and magnitudes. The KDLS was sensitive to the developmental stages of ESRD. CONCLUSIONS: These findings demonstrated that the concept of loss exists in dialysis patients. The KDLS is a reliable measure of loss in ESRD and valid in the developmental stages of ESRD.

The effects of kidney-disease-related loss on long-term dialysis patients' depression and quality of life: positive affect as a mediator.

BACKGROUND AND OBJECTIVES: In kidney disease, the concept of loss is widely discussed but minimally researched. It appears that dialysis patients who grieve a range of losses suffer increased depression and reduced quality of life (QoL). Limited research is partly due to the lack of a relevant loss measure. The study presented here developed a measure and tested the criterion validity of loss in relation to depression and QoL. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In a cross-sectional observational study, 151 long-term dialysis patients were interviewed using standardized psychometric measures and the Kidney Disease Loss Scale (KDLS), developed for the study. Factor, path and multigroup analyses were conducted. RESULTS: The factor structure and reliability of KDLS were supported. The path analyses supported the criterion validity of loss. It was a stronger contributor to depression than other clinical variables. Its effect on QoL was fully mediated by depression and positive affect (coping). The magnitude of the paths from loss to QoL through depression and positive affect was larger in home-based dialysis patients than in hospital-based patients. CONCLUSIONS: KDLS is a promising measure of loss. Patient-defined losses may contribute to the high level of depression and in turn a reduction in patients' coping and QoL. These findings suggest several points of intervention to improve long-term dialysis patients' QoL.