test/testing notes 2021-02-08.md

In UCL/mimix: Reference-Based Imputation for Longitudinal Clinical Trials with Protocol Deviation

Ian's mimix testing notes, 8feb2021

version tested

Runmimix.R committed to github 8feb2021

Help file

• Description is weak: prefer "Multiply impute missing data using reference-based imputation".
• Details needs some clarification too
• Value, what does "impdatset" mean? sholdn't this say "an object of type xxx containing yyy"?
• Examples: why "Not run"?
• need to say "mle" option is not encouraged: "this option produces data that are NOT suitable for combination using Rubin's rules"
• dlag are "delta lags" not "delta values"; typo "Roger's", doc not paper, and give location
• harmonise capitalisation
• is there a vignette?

Output

• typo "begining"
• suppress "interim at id=#" (except as debugging option)
• is "test pass2 in runmimx" correct?

Main methods - J2R, CIR, CR, MAR - after discontinuation

• show all methods give exactly the same imputed values in reference arm YES

• show similar results (imputed values and treatment effect) when used with a different seed YES VERY SIMILAR, AND ABOUT THE RIGHT DEGREE OF SIMILARITY

• show similar results (imputed values and treatment effect) to Stata YES SIMILAR WITHIN MC ERROR

Causal model

I suggest looking at just one case e.g. K0=1, K1=0.9

• show K0=0 corresponds to J2R

• show K0=K1=1 corresponds to CIR

• increment all observed outcomes at a particular time t in the non-reference arm, and show this causes all later imputed values in individuals who discontinue at t to increase by K0*K1^time, and does not affect other imputed values.

-- done by Ian (Ian_test_causal.r)

• show similar results (imputed values and treatment effect) to SAS

??

Interim missing, imputed as MAR

• show interim imputed values are exactly the same for all methods (J2R, CIR, CR, MAR, LMCF, causal) and all reference arms (active, placebo)

CHECKED FOR J2R/ref 1 = CIR/ref 2

• show changing the interim method changes only the interim imputed values

NOT NOW AVAILABLE - ONLY DOING MAR

Delta method

• show that a simple specification of delta increases all post-discontinuation imputed values correctly and does not affect interim imputed values

CHECKED - CORRECT!

UCL/mimix documentation built on Sept. 7, 2024, 5:26 p.m.