MIMIC-IV KDIGO AKI Stage 3 is wrongly defined

[starmpcc]

Hello.

mimic-code/mimic-iv/concepts/organfailure/kdigo_stages.sql

Line 22 in 14b9f5f

and (cr.creat_low_past_48hr <= 3.7 OR cr.creat >= (1.5*cr.creat_low_past_7day))

In KDIGO AKI criteria(link, page 21), AKI Stage 3 is defined by satisfying both of

1. sCR >=4.0
2. sCR increment >=0.3 within 48h or sCR baseline * 1.5

However, the logic of above code was defined by fixed number 3.7.
I think this it was defined wrongly, so should be changed onto

and (cr.creat >= (cr.creat_low_past_48hr+0.3) OR cr.creat >= (1.5*cr.creat_low_past_7day))

Thanks you

[alistairewj]

A bit more context gives a broader view of the approach:

mimic-code/mimic-iv/concepts/organfailure/kdigo_stages.sql

Lines 14 to 23 in 14b9f5f

	, case
	-- 3x baseline
	when cr.creat >= (cr.creat_low_past_7day*3.0) then 3
	-- *OR* cr >= 4.0 with associated increase
	when cr.creat >= 4
	-- For patients reaching Stage 3 by SCr >4.0 mg/dl
	-- require that the patient first achieve ... acute increase >= 0.3 within 48 hr
	-- *or* an increase of >= 1.5 times baseline
	and (cr.creat_low_past_48hr <= 3.7 OR cr.creat >= (1.5*cr.creat_low_past_7day))
	then 3

With that I can see what you mean and that makes sense, this would not catch AKI for folks with an initial creatinine of 4.0 or higher. I'll look to fix it soon, probably worth doing a before/after comparison.

[starmpcc]

@alistairewj Thank you for your response!
Note that there is also a same issue on MIMIC-III.

mimic-code/mimic-iii/concepts/organfailure/kdigo_stages.sql

Lines 14 to 22 in 2068cca

	when cr.creat >= (cr.creat_low_past_7day*3.0) then 3
	-- *OR* cr >= 4.0 with associated increase
	when cr.creat >= 4
	-- For patients reaching Stage 3 by SCr >4.0 mg/dl
	-- require that the patient first achieve ... acute increase >= 0.3 within 48 hr
	-- *or* an increase of >= 1.5 times baseline
	and (cr.creat_low_past_48hr <= 3.7 OR cr.creat >= (1.5*cr.creat_low_past_7day))
	then 3
	-- TODO: initiation of RRT

[arielhasidim]

I have corrected the stage 3 serum creatinine definition in this fork. Moreover, I have added staging logic for RRT initiation and also preferred the use of baseline creatinine over the last creatinine in 7 days if applicable.

I can PR this if you would like @alistairewj. If the added changes are not wanted I can also remove them and PR it afterward.