Table 2.

Study information and co-morbidity status of included participants.

Authors	Excluded Comorbidity to Define CKDu	Comorbidity Status
ChannaJayasumana et al. [20]	DM or chronic and/or severe HTN, history of snakebite, urological disease of known etiology, glomerulonephritis	Not mentioned
VanDervort DR. [21]	Not mentioned	Not mentioned
SA. Hamilton et al. [22]	DM, HTN, and Heavy Proteinuria	Obese = 54, HIV positive = 3, Overweight = 177
M Gonzalez et al. [23]	Self-reported CKD, DM, or HTN	Not mentioned
E Siriwardhana et al. [24]	DM, long-standing HTN, glomerular nephritis, urolithiasis, congenital kidney diseases, history of snake bite and leptospirosis	Not mentioned
N Jayatilake et al. [16]	Glomerulonephritis, pyelonephritis, renal calculi or snake bite, hypertension	Not mentioned
S Nanayakkara [25]	History of DM and HbA1c >6.5% or HTNor other known renal diseases such as autoimmune diseases, glomerular nephritis, Fanconi syndrome or IgA nephropathy	NCDs = 43%
L Lopez et al. [26]	HTN, DM, glomerulopathies, polycystic kidney disease and obstructive kidney disease, HIV positivity	Glomerulomegally(73.3%), Tubular atrophy(89.1%), Mono nuclear inflammatory infiltration, Intimal proliferation, thickening of the tunica media in blood vessels
T Rango et al. [27]	Not mentioned	Normal weight =72 , Underweight = 34). Overweight = 27, and Obese= 1.
K Gobalarajah et al. [28]	The patients’ disease history revealed that they were secondarily diagnosed with DM & HTN only after they developed CKDu.	DM & HTN, but these are secondarily developed.
S Mascarenhas et al. [29]	DM & HTN
JM jayaseka ra et al. [30]	DM, HTN, UTI or other renal diseases in the history	Not mentioned
E Siriwardhana et al. [31]	DM, long-standing HTN, glomerular nephritis, urolithiasis, and congenital kidney diseases and having a history of snake bite and leptospirosis	Not mentioned
MA Jayasumana [32]	Not mentioned	Not mentioned
R Osorio et al. [33]	Antecedents of renal disease, DM, HTN, UTI	Not mentioned
X Xing et al. [34]	Secondary renal damage, chronic glomerulonephritis, nephritic syndrome, polycystic kidney disease	Hepatitis, tuberculosis, acute and chronic glomerulonephritis, respiratory infections, Urinary calculus and urinary tract infection (UTI), hydronephrosis(50 individuals)
R Chandrajith et al. [35]	Not mentioned	Anaemia is mild in the early stage of CKD, HTN in the late stage, edema is a late feature.Tubular atrophy and glomerular sclerosis
M Selvarajah et al. [36]	DM, chronic or severe HTN, snake bite, glomerulonephritis or urological diseases, active renal or peri-renal infection, structural and anatomical renal abnormalities of the kidney, cysts and renal masses and those with a solitary kidney, coagulopathy, and uncontrolled HTN.	Not mentioned
Nanayakkara et al. [37]	Not clearly stated	Not mentioned
N Athuraliya et al. [38]	HTN, DM	Co-morbidity status among CKDu: Not Mentioned
de Silva MW et al. [39]	DM, HTN, UTI or other diseases likely toaffect renal function	Interstitial nephritis in all CKDu cases
S Wijetunge et al. [40]	DM and long-standingessential HTN	Glomerular sclerosis (GS), Interstitial fibrosis (IF), Interstitial inflammation (II), Tubular atrophy (TA) and Hypertension associated changes in blood vessels
Siddarth et al. [41]	DM and any other known causes of CKD such as chronic glomerulonephritis, hypertensive nephrosclerosis, autosomal dominant polycystic kidney disease, chronic tubulointerstitial nephropathy or evidence of systemic/local (UTI) infection	Not mentioned
B Guttierrez et al. [42]	T2DM, essential HTN, glomerulonephritis, infections, drugs	Not mentioned
S Sayanthooran et al. [43]	DM, chronic or severe HTN snake bite, glomerulonephritis or urological diseases	Asthma = 3

T2DM: type 2 diabetes mellitus, CKD: chronic kidney disease, HTN: hypertension, DM: diabetes mellitus, NCDs non-communicable diseases, UTI: urinary tract infection.