Limits...
Validation of two prediction models of undiagnosed chronic kidney disease in mixed-ancestry South Africans.

Mogueo A, Echouffo-Tcheugui JB, Matsha TE, Erasmus RT, Kengne AP - BMC Nephrol (2015)

Bottom Line: Discrimination was better in men, older and normal weight individuals.Intercept adjustment significantly improved the calibration with an expected/observed risk of 'eGFR <60 ml/min/1.73 m(2)' and 'any nephropathy' respectively of 0.98 (0.87-1.10) and 0.97 (0.86-1.09) for the Thai model; but resulted in an underestimation by 24 % with the Korean model.This highlights the potential importance of using existing models for risk CKD screening in developing countries.

View Article: PubMed Central - PubMed

Affiliation: Non-Communicable Diseases Research Unit, South African Medical Research Council, Cape Town, South Africa. amely.mogueo@yahoo.fr.

ABSTRACT

Background: Chronic kidney disease (CKD) is a global challenge. Risk models to predict prevalent undiagnosed CKD have been published. However, none was developed or validated in an African population. We validated the Korean and Thai CKD prediction model in mixed-ancestry South Africans.

Methods: Discrimination and calibration were assessed overall and by major subgroups. CKD was defined as 'estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2)' or 'any nephropathy'. eGFR was based on the 4-variable Modification of Diet in Renal Disease (MDRD) formula.

Results: In all 902 participants (mean age 55 years) included, 259 (28.7 %) had prevalent undiagnosed CKD. C-statistics were 0.76 (95 % CI: 0.73-0.79) for 'eGFR <60 ml/min/1.73 m(2)' and 0.81 (0.78-0.84) for 'any nephropathy' for the Korean model; corresponding values for the Thai model were 0.80 (0.77-0.83) and 0.77 (0.74-0.81). Discrimination was better in men, older and normal weight individuals. The model underestimated CKD risk by 10 % to 13 % for the Thai and 9 % to 93 % for the Korean model. Intercept adjustment significantly improved the calibration with an expected/observed risk of 'eGFR <60 ml/min/1.73 m(2)' and 'any nephropathy' respectively of 0.98 (0.87-1.10) and 0.97 (0.86-1.09) for the Thai model; but resulted in an underestimation by 24 % with the Korean model. Results were broadly similar for CKD derived from the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula.

Conclusion: Asian prevalent CKD risk models had acceptable performances in mixed-ancestry South Africans. This highlights the potential importance of using existing models for risk CKD screening in developing countries.

No MeSH data available.


Related in: MedlinePlus

Calibration curves for the Thai model before (upper panels) and after intercept adjustment (lower panels), for the outcome of CKD (eGFR < 60 ml/min/1.73 m2) for the first and third column and ‘any nephropathy’ (eGFR < 60 ml/min/1.73 m2 or proteinuria) for the second and left columns. For each figure panel the broken diagonal line at 45° represents the ideal calibration. Participants are grouped into percentiles across increasing estimated probability. The vertical lines at the bottom of the graph depict the frequency distribution of the calibrated probabilities. eGFR is from MDRD equation (1st and 2nd columns) and CKD-EPI equation (3rd and 4th columns)
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4491228&req=5

Fig4: Calibration curves for the Thai model before (upper panels) and after intercept adjustment (lower panels), for the outcome of CKD (eGFR < 60 ml/min/1.73 m2) for the first and third column and ‘any nephropathy’ (eGFR < 60 ml/min/1.73 m2 or proteinuria) for the second and left columns. For each figure panel the broken diagonal line at 45° represents the ideal calibration. Participants are grouped into percentiles across increasing estimated probability. The vertical lines at the bottom of the graph depict the frequency distribution of the calibrated probabilities. eGFR is from MDRD equation (1st and 2nd columns) and CKD-EPI equation (3rd and 4th columns)

Mentions: CKD was slightly under estimated by the Thai model by 10 % (95 % CI: 1-21 %) and 13 % (2 %-23 %) for ‘eGFR < 60 ml/min/1.73 m2’ and ‘any nephropathy’ respectively. However, it was largely underestimated by the Korean model by 93 % (92-93 %) for ‘eGFR < 60 ml/min/1.73 m2’ and ‘any nephropathy’ (Table 2). The calibration curves are shown in Figs. 3 and 4. The curves were steeper for the Korean model and always above the diagonal line of perfect calibration, indicating a systematic risk underestimation. With the Thai model, the curve was parallel to and always above the diagonal line. It was mostly closer to this line in lower risk strata than in the upper ones, suggesting a selective risk underestimation among participants at high risk. The Yates slope and Brier score are also presented in Table 2.Fig. 3


Validation of two prediction models of undiagnosed chronic kidney disease in mixed-ancestry South Africans.

Mogueo A, Echouffo-Tcheugui JB, Matsha TE, Erasmus RT, Kengne AP - BMC Nephrol (2015)

Calibration curves for the Thai model before (upper panels) and after intercept adjustment (lower panels), for the outcome of CKD (eGFR < 60 ml/min/1.73 m2) for the first and third column and ‘any nephropathy’ (eGFR < 60 ml/min/1.73 m2 or proteinuria) for the second and left columns. For each figure panel the broken diagonal line at 45° represents the ideal calibration. Participants are grouped into percentiles across increasing estimated probability. The vertical lines at the bottom of the graph depict the frequency distribution of the calibrated probabilities. eGFR is from MDRD equation (1st and 2nd columns) and CKD-EPI equation (3rd and 4th columns)
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4491228&req=5

Fig4: Calibration curves for the Thai model before (upper panels) and after intercept adjustment (lower panels), for the outcome of CKD (eGFR < 60 ml/min/1.73 m2) for the first and third column and ‘any nephropathy’ (eGFR < 60 ml/min/1.73 m2 or proteinuria) for the second and left columns. For each figure panel the broken diagonal line at 45° represents the ideal calibration. Participants are grouped into percentiles across increasing estimated probability. The vertical lines at the bottom of the graph depict the frequency distribution of the calibrated probabilities. eGFR is from MDRD equation (1st and 2nd columns) and CKD-EPI equation (3rd and 4th columns)
Mentions: CKD was slightly under estimated by the Thai model by 10 % (95 % CI: 1-21 %) and 13 % (2 %-23 %) for ‘eGFR < 60 ml/min/1.73 m2’ and ‘any nephropathy’ respectively. However, it was largely underestimated by the Korean model by 93 % (92-93 %) for ‘eGFR < 60 ml/min/1.73 m2’ and ‘any nephropathy’ (Table 2). The calibration curves are shown in Figs. 3 and 4. The curves were steeper for the Korean model and always above the diagonal line of perfect calibration, indicating a systematic risk underestimation. With the Thai model, the curve was parallel to and always above the diagonal line. It was mostly closer to this line in lower risk strata than in the upper ones, suggesting a selective risk underestimation among participants at high risk. The Yates slope and Brier score are also presented in Table 2.Fig. 3

Bottom Line: Discrimination was better in men, older and normal weight individuals.Intercept adjustment significantly improved the calibration with an expected/observed risk of 'eGFR <60 ml/min/1.73 m(2)' and 'any nephropathy' respectively of 0.98 (0.87-1.10) and 0.97 (0.86-1.09) for the Thai model; but resulted in an underestimation by 24 % with the Korean model.This highlights the potential importance of using existing models for risk CKD screening in developing countries.

View Article: PubMed Central - PubMed

Affiliation: Non-Communicable Diseases Research Unit, South African Medical Research Council, Cape Town, South Africa. amely.mogueo@yahoo.fr.

ABSTRACT

Background: Chronic kidney disease (CKD) is a global challenge. Risk models to predict prevalent undiagnosed CKD have been published. However, none was developed or validated in an African population. We validated the Korean and Thai CKD prediction model in mixed-ancestry South Africans.

Methods: Discrimination and calibration were assessed overall and by major subgroups. CKD was defined as 'estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2)' or 'any nephropathy'. eGFR was based on the 4-variable Modification of Diet in Renal Disease (MDRD) formula.

Results: In all 902 participants (mean age 55 years) included, 259 (28.7 %) had prevalent undiagnosed CKD. C-statistics were 0.76 (95 % CI: 0.73-0.79) for 'eGFR <60 ml/min/1.73 m(2)' and 0.81 (0.78-0.84) for 'any nephropathy' for the Korean model; corresponding values for the Thai model were 0.80 (0.77-0.83) and 0.77 (0.74-0.81). Discrimination was better in men, older and normal weight individuals. The model underestimated CKD risk by 10 % to 13 % for the Thai and 9 % to 93 % for the Korean model. Intercept adjustment significantly improved the calibration with an expected/observed risk of 'eGFR <60 ml/min/1.73 m(2)' and 'any nephropathy' respectively of 0.98 (0.87-1.10) and 0.97 (0.86-1.09) for the Thai model; but resulted in an underestimation by 24 % with the Korean model. Results were broadly similar for CKD derived from the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula.

Conclusion: Asian prevalent CKD risk models had acceptable performances in mixed-ancestry South Africans. This highlights the potential importance of using existing models for risk CKD screening in developing countries.

No MeSH data available.


Related in: MedlinePlus