Chapter 12 Biology

Biology identifier is [bi]

As biological features can be gather multiple times at each time point (i.e. several times during index hospitalization, or follow-up), they are gathered in a separate instrument. Naming process is standard, with

  • The second item referring to the biological parameter

  • The third item referring to the chronological position of the dosage.

E.g. bi_bnp_ini_value, refers to the BNP initial value

There are some biological features that do not pertain to a timing (e.g. normal value, or ever acquired status). Note that this is a bit twisted, since normal value may change if the patient gets his/her labs in a different place after being discharged.

12.1 Abbreviations

Abbreviation(s) Feature
uln Upper limit of normal
Biology timings
ini Initial value (can be slightly before or after the index cardiotoxicity date)
bimm Before first immunosuppressant was introduced during index hospitalization
pk Peak value of the parameter during index hospitalization
mr Most recent value (possibly after index hospitalization discharge)
Blood chemistry
bnp Brain Natriuretic Peptide
ntpbnp Nt-pro-BNP
crp C reactive protein
cre creatinin
cpk CK or CPK
ckmb CK-MB
trop Troponin (either I or T)
tropi

Troponin I

Be very careful that these parameters are used only if BOTH troponins were used.

When only one troponin is used, unit and uln are flagged with the trop abbreviation.

tropt

Troponin T

Same comment

Blood formula
cbc Complete blood count
neu Neutrophil count
lym Lymphocyte count
mon Monocyte count
eos Eosinophil count
bas Basophil count
igc Immature granulocyte count
pla Platelet count

12.2 Normal values and ratios

Most normal values of biological parameters are different from one lab to another. Also, users may report bio vars according to different scales.

Examples: troponin upper limit of normal may range from ~ 0.01 to ~ 50. Complete blood count can be reported in G/L or 10^-3/µL (even if the var field asked for reporting with one of them).

It is advised to express biological parameters according to their normal value upper or lower limits if known, or to contrast them into ratios that get rid of the unit (example: neutrophil to lymphocyte ratio)