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A. OUTCOME DEFINITIONS AND EVENT COUNTS

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                          population    n  events  prevalence_pct  subjects  epv_parsimonious  epv_expanded

         incident AKI, full risk set 1895     207           10.92      1849              34.5          23.0

incident AKI, complete ascertainment 1109     161           14.52      1084              26.8          17.9

            incident AKI within 48 h 1777     168            9.45      1735              28.0          18.7



The 48-hour population drops patients censored before 48 hours: they could not have had the event observed, so keeping them would dilute the denominator with people who were never eligible to contribute one.



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B. INCREMENTAL DISCRIMINATION (500 subject-level replicates)

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                          population        model    n  events  auc_full_apparent  auc_full_corrected  auc_null_apparent  auc_null_corrected  delta_auc_apparent  delta_auc_corrected  calibration_slope_apparent  calibration_slope_corrected

         incident AKI, full risk set parsimonious 1895     207             0.6378              0.6254             0.6122              0.6078              0.0255               0.0176                      1.0097                       0.9288

         incident AKI, full risk set     expanded 1895     207             0.7012              0.6880             0.6955              0.6875              0.0057               0.0005                      1.0090                       0.9274

incident AKI, complete ascertainment parsimonious 1109     161             0.5932              0.5696             0.5660              0.5545              0.0272               0.0151                      1.0201                       0.8126

incident AKI, complete ascertainment     expanded 1109     161             0.6707              0.6489             0.6685              0.6543              0.0021              -0.0054                      1.0145                       0.8811

            incident AKI within 48 h parsimonious 1777     168             0.6445              0.6303             0.6105              0.6037              0.0339               0.0266                      1.0125                       0.9267

            incident AKI within 48 h     expanded 1777     168             0.7010              0.6860             0.6900              0.6796              0.0110               0.0064                      1.0117                       0.9267



Out-of-bag incremental C-index from adding lactate:

                          population        model  delta_auc_oob  ci_low  ci_high  auc_full_oob  replicates

         incident AKI, full risk set parsimonious         0.0129 -0.0280   0.0431        0.6193         500

         incident AKI, full risk set     expanded        -0.0018 -0.0325   0.0162        0.6793         500

incident AKI, complete ascertainment parsimonious         0.0129 -0.0388   0.0558        0.5594         500

incident AKI, complete ascertainment     expanded        -0.0082 -0.0443   0.0132        0.6364         500

            incident AKI within 48 h parsimonious         0.0223 -0.0247   0.0601        0.6223         500

            incident AKI within 48 h     expanded         0.0037 -0.0279   0.0266        0.6751         500



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C. CENSORING-AWARE CONCORDANCE (time to incident AKI)

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                         metric  c_with_lactate_apparent  c_without_lactate_apparent  delta_apparent  delta_oob  ci_low  ci_high  replicates

Harrell C, time to incident AKI                   0.6913                      0.6851          0.0062    -0.0008 -0.0263   0.0149         300



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D. DECISION CURVES

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--- incident AKI, full risk set ---

 threshold  nb_with_lactate  nb_without_lactate  nb_treat_all  delta_nb  delta_ci_low  delta_ci_high  net_true_positives_per_1000

     0.050          0.06199             0.06530       0.06235  -0.00331      -0.00640        0.00279                        -3.31

     0.075          0.04845             0.04513       0.03701   0.00332      -0.00600        0.00530                         3.32

     0.100          0.03706             0.03882       0.01026  -0.00176      -0.01022        0.00585                        -1.76

     0.150          0.02024             0.01583      -0.04796   0.00441      -0.00730        0.01214                         4.41

     0.200          0.01187             0.00554      -0.11346   0.00633      -0.00437        0.01104                         6.33

     0.250          0.00018             0.00106      -0.18769  -0.00088      -0.00698        0.00576                        -0.88

     0.300          0.00113            -0.00188      -0.27252   0.00302      -0.00476        0.00512                         3.02



--- incident AKI, complete ascertainment ---

 threshold  nb_with_lactate  nb_without_lactate  nb_treat_all  delta_nb  delta_ci_low  delta_ci_high  net_true_positives_per_1000

     0.050          0.10156             0.10023       0.10019   0.00133      -0.00702        0.00285                         1.33

     0.075          0.07280             0.07604       0.07587  -0.00324      -0.00849        0.00596                        -3.24

     0.100          0.05921             0.05781       0.05020   0.00140      -0.01257        0.00742                         1.40

     0.150          0.03400             0.03803      -0.00568  -0.00403      -0.01875        0.01168                        -4.03

     0.200          0.02367             0.01443      -0.06853   0.00924      -0.01125        0.01546                         9.24

     0.250          0.00451             0.00571      -0.13977  -0.00120      -0.01363        0.01350                        -1.20

     0.300          0.00193            -0.00000      -0.22118   0.00193      -0.01246        0.01022                         1.93



--- incident AKI within 48 h ---

 threshold  nb_with_lactate  nb_without_lactate  nb_treat_all  delta_nb  delta_ci_low  delta_ci_high  net_true_positives_per_1000

     0.050          0.04908             0.04928       0.04689  -0.00021      -0.00524        0.00389                        -0.21

     0.075          0.03732             0.03637       0.02113   0.00096      -0.00715        0.00678                         0.96

     0.100          0.02614             0.02657      -0.00607  -0.00044      -0.01020        0.00961                        -0.44

     0.150          0.01450             0.01016      -0.06525   0.00434      -0.00666        0.01361                         4.34

     0.200          0.00535             0.00169      -0.13182   0.00366      -0.00705        0.01090                         3.66

     0.250         -0.00056            -0.00225      -0.20728   0.00169      -0.00592        0.00492                         1.69

     0.300          0.00000             0.00056      -0.29351  -0.00056      -0.00659        0.00482                        -0.56



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E. SUMMARY: DOES LACTATE ADD ANYTHING, FOR EITHER ENDPOINT?

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                          population        model  delta_auc_oob  ci_low  ci_high  interval_excludes_zero

         incident AKI, full risk set parsimonious         0.0129 -0.0280   0.0431                   False

         incident AKI, full risk set     expanded        -0.0018 -0.0325   0.0162                   False

incident AKI, complete ascertainment parsimonious         0.0129 -0.0388   0.0558                   False

incident AKI, complete ascertainment     expanded        -0.0082 -0.0443   0.0132                   False

            incident AKI within 48 h parsimonious         0.0223 -0.0247   0.0601                   False

            incident AKI within 48 h     expanded         0.0037 -0.0279   0.0266                   False



Outputs: <local path>\analysis\results\gate4

