Ing. Helmut Schütz
Articles
This series of articles was inspired by recurrent discussions at the Bioequivalence and Bioavailability Forum and questions I received from my clients or regulatory assessors.
The content expressed in the articles presents my sole personal opinion. Although regulatory requirements are incorporated to a high degree, some strong views are strictly scientifically based on my 40+ years of experience in the field and do not represent any type of »cookbook approach« which should be followed unreflecting.
I do not make any representations or warranties regarding the accuracy of such content.
never wants to talk anyone into anything.
No, he does not even want to convince;
all the time he is aware that he may be wrong.
– Karl R. Popper
To the right articles are listed in chronological order. Below are articles arranged by topic.
- 🃏 Related to questions commonly asked by regulatory assessors.
- 🆕 Published within the last two weeks.
- 🚧 Article under construction.
To reproduce the articles’ examples is required.
since formulas in the articles will not be rendered. Furthermore, the TOC in the left column for navigation will not be available and code-folding not supported. Sorry for the inconvenience.A Short History of Bioequivalence 418 KB (2024-04-09, update 2024-08-26)
Power Calculation and Sample Size Estimation
Equivalence
- Hypotheses. Not only in Equivalence 74 KB (2022-03-29, update 2024-08-02)
- Parallel Design 317 KB (2021-02-26, update 2024-07-07)
- 2×2×2 Design 423 KB (2021-03-11, update 2024-08-01)
- Higher-Order Crossover Designs 355 KB (2021-03-17, update 2023-10-01)
- Replicate Designs
- Average Bioequivalence 171 KB (2021-03-12, update 2024-07-24)
- Scaled Average Bioequivalence
- ABE, RSABE, ABEL. A Comparison 297 KB (2021-04-22, update 2024-07-29)
- Inflation of the Type I Error in SABE 318 KB (2021-05-04, update 2024-07-06)
- Two-Stage Designs
- Group sequential (fixed sample design) 🚧
- Adaptive (sample size re-estimation) 🃏 🚧
Non-Inferiority/Superiority, Non-Superiority 121 KB (2022-07-24, update 2024-04-08)
Dose Proportionality 🚧
Prospective Power
- Power Analysis 55 KB (2021-04-18, update 2022-10-19)
- Power Table 190 KB (2022-10-24, update 2022-10-28)
- Sensitivity Analysis 240 KB (2021-11-27, update 2022-10-19)
Noncompartmental Analysis
- Trapezoidal Rules 259 KB (2021-04-03, update 2023-12-12)
- Estimation of λz 🚧
- Extrapolation to Infinity. Observed or Predicted Clast? 109 KB (2022-03-06, update 2024-05-12)
- Demonstration of Steady State Achievement? 169 KB (2022-01-16, update 2024-07-05)
- Partial AUC 🚧
- Cut-off Times for Biphasic Release Products 🚧
- Cmin and Cτ 🚧
Miscellaneous
Statistics
- Carryover. A Never Ending Story 275 KB (2021-03-19, update 2024-09-07) 🃏
- Significant Treatment Effect 134 KB (2021-03-18, update 2022-10-19) 🃏
- Fixed or mixed effects? 🚧
- Group ‘Effect’. To Pool or Not to Pool? 🃏 382 KB (2022-07-29, update 2024-09-05)
- Post hoc Power 204 KB (2021-04-28, update 2024-08-12) 🃏
- ‘Apparent’ Difference in tmax? 372 KB (2021-04-19, update 2023-06-13)
- Simulations 101 235 KB (2021-03-13, update 2024-08-28)
- ‘Nice Numbers’. A Rant 154 KB (2021-03-30, update 2024-08-04)
- Subgroup Analyses 🚧
- Adjusted Indirect Comparisons 🚧
- Detecting Data Manipulation / Fraud 🚧
Design Issues
- Washout Phase – Tricks and Traps 🃏 🚧
- Pilot → Pivotal Studies 🚧
- SABE planned based on the CVw of a Crossover Design 51 KB (2022-06-19, update 2022-10-19)
- Limited Capacity of a Clinical Site. Groups or Replicates? 150 KB (2022-06-28, update 2024-07-02)
- Stratified Randomization – Why? 🚧
Software
- Representing Numbers in Computers. A Wonderland 111 KB (2021-03-14, update 2022-10-19)
- 🇷 on Windows 101 65 KB (2021-04-13, update 2024-10-04)
- Software Validation 🚧
are a great annoyance to those of us who do.
– Isaac Asimov
All articles are licensed under 
Creative Commons Attribution 4.0 Helmut Schütz 2024.
document date 2021-03-12 | last update 2024-07-07