A cross-lagged analysis of the relationship between quality of life and kidney function in CKD patients

Chronic kidney disease (CKD) significantly impacts patient well-being, with declining glomerular filtration rate (eGFR) often leading to worsening quality of life (QoL). However, the directionality of the eGFR-QoL relationship remains unclear due to limitations of prior cross-sectional and longitudinal studies.

This study applied cross-lagged analysis to investigate the reciprocal relationship between eGFR and QoL (measured using SF-36 Physical and Mental Component Scores [PCS and MCS]) over 36 months in 422 CKD patients recruited from nephrology units in Southern Italy. Generalized Method of Moments (GMM) models tested two hypotheses: (1) PCS as a determinant of MCS, or vice versa; and (2) eGFR as a determinant of MCS/PCS, or vice versa.

Cross-lagged analysis confirmed that lower eGFR significantly predicted declines in both PCS and MCS in subsequent visits (p < .05). At the same time, the reverse relationship (QoL affecting eGFR) was not statistically significant. Multivariable models, adjusting for potential confounders including demographic factors, comorbidities, and socioeconomic status, confirmed these findings.

Kidney function decline leads to worsening QoL, whereas deterioration in QoL does not impact eGFR decline. These findings support prioritising interventions that slow the progression of CKD as a means to preserve quality of life. This study highlights the utility of cross-lagged analysis in nephrology research and underscores the importance of early chronic kidney disease (CKD) management to maintain patient well-being.