Table 5.

Pooled odds ratio for mortality in patients with AKI relative to patients without AKI in studies that adopted a KDIGO-equivalent AKI definition

Subgroup	Studies (n)	Patients with AKI (n)	Deaths (n)	Patients without AKI (n)	Deaths (n)	Pooled Odds Ratio	95% Confidence Interval	P Value	Test for Heterogeneity
									I2 Index	Q Test P Value
Age category
Adults	81	403,880	98,348	1,760,311	91,915	4.92	4.07 to 5.93	<0.001	99.6	<0.001
Children	11	1736	260	5263	158	5.57	3.49 to 8.89	<0.001	54.7	<0.001
Clinical setting
Community acquired	4	3875	1,724	17,202	6978	2.56	1.31 to 5.01	0.01	95.9	<0.001
Critical care	24	182,393	46,880	269,613	28,923	3.93	3.12 to 4.96	<0.001	99.28	<0.001
Cardiac surgery	22	21,402	1852	64,776	1118	6.31	4.81 to 8.28	<0.001	87.3	<0.001
Trauma	3	2387	593	11,989	894	6.62	1.75 to 24.99	0.01	98.9	<0.001
Heart failure	1	221	47	461	52	2.13	1.38 to 3.27	0.001	—	—
Hematology/oncology	2	278	76	1604	27	15.50	8.40 to 28.60	<0.001	37.5	0.21
Nephrotoxins	1	81	12	2112	140	2.45	1.30 to 4.63	0.01	—	—
Hospital acquired, unspecified	35	194,979	47,424	1,397,817	53,941	5.15	3.86 to 6.87	<0.001	99.4	<0.001
Continent
Australia and New Zealand	6	136,888	33,190	210,289	21,413	3.34	2.14 to 5.22	< 0.001	99.8	<0.001
Asia	10	13,702	3424	208,457	5374	8.10	4.78 to 13.71	<0.001	98.3	<0.001
Europe	33	44,525	13,743	150,667	10,776	5.21	4.39 to 6.18	<0.001	95.0	<0.001
America	41	207,120	46,337	1,194,232	53,832	4.57	3.30 to 6.33	<0.001	99.5	<0.001
Multiple continents	2	3381	1914	1929	678	2.12	1.42 to 3.16	<0.001	82.8	0.02
World zonea
Australia and New Zealand	6	136,888	33,190	210,289	21,413	3.34	2.14 to 5.22	<0.001	99.8	<0.001
Eastern Asia	6	11,133	3023	182,810	5062	6.73	3.41 to 13.29	<0.001	98.9	<0.001
Western Asia	2	2011	333	23,978	303	9.18	2.95 to 28.62	<0.001	87.2	0.01
South Asia	2	558	68	1669	9	49.45	0.57 to 4275.16	0.09	89.5	0.002
Eastern Europe	2	639	111	1961	131	6.06	3.896 to 9.43	<0.001	36.2	0.21
Western Europe	9	4473	1114	16,732	955	6.25	3.93 to 9.94	<0.001	90.9	<0.001
Northern Europe	8	7764	1005	68,554	2008	5.70	3.95 to 8.24	<0.001	85.6	<0.001
Southern Europe	11	4639	1410	9371	1410	4.73	3.23 to 6.92	<0.001	90.2	<0.001
Multi-zone Europe	3	27,010	10,103	54,049	6272	4.34	2.84 to 6.64	<0.001	99.2	<0.001
North America	38	206,460	46,204	1,193,397	53,769	4.49	3.21 to 6.29	<0.001	99.5	<0.001
South America	3	660	133	835	63	5.64	2.18 to 14.62	<0.001	65.6	0.06
Multiple zones	2	3381	1914	1929	678	2.12	1.42 to 3.16	<0.001	82.8	0.02
Latitude
North	82	267,604	65,107	1,554,136	70,512	5.15	4.29 to 6.19	<0.001	99.2	<0.001
South	9	137,548	33,323	211,124	21,476	3.71	2.50 to 5.51	<0.001	99.7	<0.001
North and South	1	464	178	314	85	1.68	1.23 to 2.29	0.001	—	—
Country income classificationb
Low income	1	399	32	648	9	6.19	2.92 to 13.11	<0.001	—	—
Lower middle income	1	159	36	1021	0	597.37	36.43 to 9796.52	<0.001	—	—
Upper middle income	9	11,336	3064	181,135	5051	6.57	3.68 to 11.74	<0.001	98.2	<0.001
High income	80	389,629	93,987	1,570,079	85,383	4.73	3.89 to 5.75	<0.001	99.6	<0.001
Not available	1	4093	1489	12,691	1630	3.88	3.57 to 4.21	<0.001	—	—
Country total health expenditure (% of GDP)c
<5	3	6201	1379	175,079	4133	13.85	8.76 to 21.89	<0.001	87.4	<0.001
5–10	42	191,213	49,672	401,894	32,656	4.69	3.83 to 5.74	<0.001	99.1	<0.001
>10	46	204,109	46,068	1,175,910	53,654	4.83	3.54 to 6.59	<0.001	99.4	<0.001
Not available	1	4093	1489	12,691	1630	3.88	3.57 to 4.21	<0.001	—	—
Duration of follow-up (mo)
<3	79	390,221	93,750	1,725,376	82,092	5.58	4.60 to 6.76	<0.001	99.5	<0.001
3–6	3	4178	1695	16,947	6913	2.25	1.09 to 4.68	0.03	94.8	<0.001
>6	10	11,217	3163	23,251	3068	2.74	2.09 to 3.58	<0.001	93.9	<0.001

KDIGO, Kidney Disease Improving Global Outcomes; GDP, gross domestic product.

^aAccording to the United Nations geo-scheme classification (11).

^bAccording to the World Bank's classification of income of countries (12).

^cAccording to the World Health Organization (14).