Bioequivalence and Bioavailability Forum • zero (0), missing (NA), or BLLOQ (0 or NA) in bear

zero (0), missing (NA), or BLLOQ (0 or NA) in bear [🇷 for BE/BA]

posted by yjlee168 – Kaohsiung, Taiwan, 2016-02-03 10:04 (2999 d 01:19 ago) – Posting: # 15922
Views: 24,216

Dear mittyri and others,

I guess the issue (zero, BLLOQ or missing) may not be solved quickly. Thus I leave the decision to users if it is a real zero conc. (0) or a missing (NA), or a BLLOQ (0 or NA). Basically, the drug plasma conc. should be input as either a zero or a NA in bear. If it is a NA, it will be ignored (or deleted). If it is a zero conc., it will be treated as a number in AUC/AUMC calculation. However, since a zero conc. cannot be used to estimate λz, any zero conc. will not be counted as a valid data point. Like the following example:

-> the subj# 1 (Ref.) in sequence# 2, period# 2,

    λz (kel) cannot be calculated with ARS or AIC.

 subj seq prd drug  time conc

    1   2   2    1  0.00    0

    1   2   2    1  0.25    0

    1   2   2    1  0.50  125

    1   2   2    1  0.75    0

    1   2   2    1  1.00  932

    1   2   2    1  1.50 1343

    1   2   2    1  2.00 1739

    1   2   2    1  3.00 1604

    1   2   2    1  4.00    0

    1   2   2    1  8.00  797

    1   2   2    1 12.00    0

    1   2   2    1 24.00    0

❝ I think you are close enough to pre-processing of datasets (as in PHX - BQL rules, I can send you PDF guide if needed, there are some examples of rules), so the users can define their own rules of data handling (missing, BLOQ depending on position of data).

—
All the best,
-- Yung-jin Lee
bear v2.9.1:- created by Hsin-ya Lee & Yung-jin Lee
Kaohsiung, Taiwan https://www.pkpd168.com/bear
Download link (updated) -> here

Complete thread:

bear v2.7.0 released yjlee168 2015-12-07 09:18
- Suggestion ElMaestro 2015-12-07 10:12
  - Suggestion yjlee168 2015-12-07 10:55
    - Suggestion Helmut 2015-12-07 14:01
      - Suggestion yjlee168 2015-12-07 18:51
- bear v2.7.0 released Astea 2015-12-10 16:36
  - if Clast is zero in bear yjlee168 2015-12-10 17:23
    - if Clast is zero in bear Astea 2015-12-10 20:50
      - if Clast is zero in bear yjlee168 2015-12-11 03:28
        
        if Clast is zero in bear Astea 2015-12-11 09:39
        
        if Clast is zero in bear yjlee168 2015-12-11 17:16
    - bear v2.7.1 yjlee168 2015-12-15 10:21
      - bear v2.7.1 Astea 2015-12-15 19:32
        
        BLLOQ ≠ 0 with measured drug plasma conc. yjlee168 2015-12-15 20:17
        
        BLLOQ ≠ 0 with measured drug plasma conc. Helmut 2015-12-16 01:45
        
        BLLOQ ≠ 0 with measured drug plasma conc. yjlee168 2015-12-16 11:38
        
        BLLOQ ≠ 0 ∀ t > 0 Helmut 2015-12-16 12:40
        
        BLLOQ ∋ { 0, ≈0, BLLOQ{...} ∀ t > 0} yjlee168 2015-12-16 18:22
        
        BLLOQ at first two time ponts, AUC calculation Astea 2016-01-30 17:11
        
        zero-zero with AUC calculation in bear yjlee168 2016-01-30 19:00
        
        BQL rules in bear mittyri 2016-02-01 22:16
        
        BQL rules in bear yjlee168 2016-02-02 10:59
        possible solutions? yjlee168 2016-02-02 21:30
        zero (0), missing (NA), or BLLOQ (0 or NA) in bearyjlee168 2016-02-03 09:04
        
        zero (0), missing (NA), or BLLOQ (0 or NA) in bear mahmoud-teaima 2016-02-08 21:28
        
        Please avoid Full Quotes (“TOFU”)! Ohlbe 2016-02-09 00:51
        
        error message in bear mahmoud-teaima 2016-02-09 04:55
        
        please check your dataset file yjlee168 2016-02-09 06:40
        
        please check your dataset file mahmoud-teaima 2016-02-09 15:00
        
        please check your dataset file yjlee168 2016-02-09 15:38
        
        A possible R bug? yjlee168 2016-02-09 19:14