CODEBOOK
Chronic Kidney Disease in Children (CKID) Study: GFRCALIBRATEDSUMMARY Summary File                              7-30-2020
UPDATED: 28JUL2020

Start  ____Field____                      Section/
Column Len  Format       Variable         Question          Description		     Code
------ --- --------- ---------------- ------------ ------------------------------ ------------------------------
    1    6 6.0       CASEID                        Participant ID                 100000= 100000
                                                                                  .
                                                                                  .
                                                                                  699999= 699999

    7    4 4.0       VISIT                         Visit #                        0= enrollment
                                                                                  10= v1a
                                                                                  15= v1b
                                                                                  20= v2
                                                                                  30= v3
                                                                                  .
                                                                                  .
                                                                                  90= v9
                                                                                  x1 or x6= Transitional
                                                                                  (visstatus=2)

   11    3 3.0       VISSTATUS                     Visit Status                   0= Regular
                                                                                  1= Irregular
                                                                                  2= Transitional
                                                                                  3= Dialysis
                                                                                  4= Transplant
                                                                                  5= Phone/In-Person (PIP)
                                                                                     Follow-up
                                                                                  9= Disenrollment

   14    7 7.3       GFRVDATE                      Visit Date in duration of      0.000= 0.000 years
                                                   year from the baseline visit   .
                                                                                  .
                                                                                  50.000= 50.000 years

   21    3 3.0       MALE1FE0                      Participant's gender           1= Male
                                                                                  0= Female
                                                                                  -9= missing

   24    7 7.2       AVWEIGHT                      Average Weight (kg),           3.0= 3.0
                                                   collected from PE              .
                                                                                  .
                                                                                  175.0= 175.0
                                                                                  -9= missing

   31    6 6.1       AVHEIGHT                      Average Height (cm),           60.0= 60.0
                                                   collected from PE              .
                                                                                  .
                                                                                  230.0= 230.0
                                                                                  -9= missing

   37    7 7.3       BSA                           Body Surface Area (m^2),       1.00= 1.00
                                                   Haycock formula                .
                                                                                  .
                                                                                  10.00= 10.00
                                                                                  -9= missing

   44    6 6.2       SCr                           Serum Creatinine (mg/dL),      1.00= 1.00
                                                   from L05 (CBL) or L03 (Local)  .
                                                                                  .
                                                                                  10.00= 10.00
                                                                                  -9= missing

   50    7 7.2       bedGFR                        bedside estimated GFR ( ml/    1.0= 1.0
                                                   min|1.73m^2) defined as        .
                                                   41.3*(ht/scr)                  .
                                                                                  999.9= 999.9
                                                                                  -9= missing

   57    4 4.0       BUN                           BUN (mg/dL), from L05 (CBL)    7= 7
                                                   or L03 (Local)                 .
                                                                                  .
                                                                                  120= 120
                                                                                  -9= missing

   61    6 6.2       CYC_IFCC                      Cystatin-C (mg/L), IFCC assay  1.0= 1.0
                                                   (assayed at CBL)               .
                                                                                  .
                                                                                  9.99= 9.99
                                                                                  -1= NA
                                                                                  -9= missing

   67    7 7.2       e2012GFR                      eGFR ( ml/min|1.73m^2) based   1.0= 1.0
                                                   on estimating equations (see   .
                                                   Schwartz et al., Kidney Int,   .
                                                   2012) using Scr, BUN &         999.9= 999.9
                                                   Cystatin (CYC_DB, Siemens)     -9= missing

   74    3 3.0       e2012GFRmeth                  Indicator for which e2012GFR   1= BUN
                                                   equation was used              2= Cystatin
                                                                                  3= SCr
                                                                                  4= Cystatin & BUN
                                                                                  5= SCr & BUN
                                                                                  6= SCr & Cystatin
                                                                                  7= SCr, Cystatin & BUN
                                                                                  8= SCr, Cystatin, BUN, Sex &
                                                                                     Height
                                                                                  0= SCR(updated Schwartz)
                                                                                  -9= missing

   77    7 7.2       iGFRc                         Calibrated iohexol-based GFR   1.0= 1.0
                                                   (ml/min|1.73m^2).              .
                                                                                  .
                                                                                  999.9= 999.9
                                                                                  -1= NA
                                                                                  -9= missing
                                                                                  GFRs were calculated without
                                                                                  applying additional
                                                                                  imputations to correct for
                                                                                  measurement errors and
                                                                                  procedural deviations.

   84    3 3.0       calibrated                    Have the reported L07 iohexol  0= No
                                                   concentrations been            1= Yes
                                                   calibrated by the              -1= NA (no iohexol study
                                                   GFRcalibratedsummary.sas          performed)
                                                   program (i.e., divide
                                                   concentration by 0.89)?

   87    6 $         VERSION                       Version number of data         P01= Version 01
                                                                                  .
                                                                                  .
                                                                                  P99= Version 99