Ranasinghe, A. V., Kumara, G. W. G. P., Karunarathna, R. H., De Silva, A. P., Sachintani, K. G. D., Gunawardena, J. M. C. N., Kumari, S. K. C. R., Sarjana, M. S. F., Chandraguptha, J. S., & De Silva, M. V. C. BMC Nephrology, 2019
Introduction
This study by Ranasinghe et al. examines the incidence, prevalence, and trends of Chronic Kidney Disease (CKD) and CKD of uncertain etiology (CKDu) in Sri Lanka’s North Central Province. Given the high burden of CKDu in this region, understanding its epidemiology is crucial for public health interventions. The study presents data from 30,566 patients diagnosed between 2003 and 2017, focusing on demographic characteristics, survival rates, and spatial clustering of cases. The research highlights the importance of mapping disease prevalence and identifying vulnerable populations, particularly farmers, males, and older adults.
Critique
A significant strength of this study is its extensive dataset, which includes both retrospective and prospective data collection from multiple hospitals. The large sample size enhances the reliability of the findings, and the study’s use of GPS mapping provides valuable insights into geographic clustering. Additionally, the stratification of data into different time periods allows for an analysis of trends over time, which is useful for policy and intervention planning. The inclusion of survival rates further strengthens the study by offering a perspective on disease prognosis.
The use of appropriate statistical methods, including chi-square tests, log-rank tests, and survival analysis, adds rigor to the findings. The differentiation of CKD and CKDu based on existing diagnostic criteria is also a noteworthy aspect, although the lack of distinction in earlier years limits interpretation. The study’s emphasis on potential risk factors, such as occupational exposure and drinking water sources, aligns with previous research on CKDu.
However, several limitations must be considered. The study does not account for all potential confounders, such as genetic predisposition, dietary habits, or other environmental exposures that could influence CKDu risk. The reliance on hospital-based data may introduce selection bias, as individuals with milder disease or those who did not seek medical care may be underrepresented. Additionally, the inability to determine exact causes of death among CKDu patients is a limitation that could have been mitigated by accessing more comprehensive mortality data. The declining incidence in 2017 is attributed to increased access to safe drinking water, but this conclusion is speculative without direct evidence linking intervention efforts to reduced case numbers.
Another concern is the potential underestimation of CKD stage distribution, as staging data was available only for a subset of patients. The definition of CKDu has evolved over time, and the study does not differentiate CKD from CKDu in earlier cases, which could affect trend analysis. Finally, the study’s focus on North Central Province limits generalizability to other regions of Sri Lanka or countries experiencing similar epidemics of CKDu.
Conclusion
Ranasinghe et al.’s study provides an important epidemiological overview of CKD and CKDu in Sri Lanka, demonstrating an increasing incidence until 2016 followed by a slight decline. The findings confirm previous reports that males, older adults, and farmers are at higher risk, and that CKDu exhibits geographic clustering. While the study contributes significantly to the understanding of CKDu trends, further research is needed to identify specific causal factors and evaluate the effectiveness of interventions. Future studies should incorporate longitudinal cohort data, environmental exposure assessments, and genetic analyses to provide a more comprehensive understanding of CKDu etiology and progression.
Overall, this research challenges the assumption that CKDu follows a uniform progression and underscores the need for targeted preventive measures to reduce disease burden in affected communities.
