Abstract
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.
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Abbreviations
- ESRD:
-
End-stage renal disease
- QoL:
-
Quality of life
- PD:
-
Proximal–distal
- eGFR:
-
Estimated glomerular filtration rate
- IQoL:
-
Individual quality of life
- PA:
-
Positive affect
- SEIQoL-DW:
-
The schedule for evaluation of individual quality-of-life direct weighting
- DASS21:
-
Depression anxiety stress scale 21
- PAS:
-
Positive affect scale
- CMI:
-
Comorbidity index
- KDSS:
-
Kidney disease symptom status
- SLS:
-
Symptoms list scale
- KDQoL-SF™:
-
Kidney disease quality of life short form
- PCS:
-
Physical component scale
- SEM:
-
Structural equation modeling
- MSEM:
-
Multi-sample structural equation modeling
- LC:
-
Latent composite
- GFI:
-
Goodness-of-fit index
- AGFI:
-
Adjusted goodness-of-fit index
- SRMR:
-
Standardized root mean square residual
- RMSEA:
-
Root mean square error of approximation
- NNFI:
-
Non-normed fit index
- CFI:
-
Comparative fit index
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Acknowledgments
The results of this paper were presented at the 46th Annual Scientific Meeting of the Australian and New Zealand Society of Nephrology, Perth, Australia, 2010. The abstract of this paper has been published in Nephrology (Chan, R., Brooks, R., Erlich, J., Gallagher, M., Snelling, P., Chow, J., and Suranyi, M.: Integrating clinical variables, health outcomes, and quality of life in ESRD: The PD model of health-related outcomes, [Abstract], Nephrology 15 (S4), 75, 2010). We wish to thank all staff and patients in participating hospitals for their support and assistance.
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Chan, R., Brooks, R., Erlich, J. et al. How do clinical and psychological variables relate to quality of life in end-stage renal disease? Validating a proximal–distal model. Qual Life Res 23, 677–686 (2014). https://doi.org/10.1007/s11136-013-0499-1
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DOI: https://doi.org/10.1007/s11136-013-0499-1