NEWS

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pmsampsize 2023-12-05

• added options to specify the cox-snell or nagelkerke's r-squared directly for binary outcome models
• simplified continuous outcome models criteria 3 calculation fixing MMOE=10% so that N=234+p

pmsampsize 2022-02-12

• fixes issue for continuous outcome models in criteria 4 in calculating the CI for the intercept based on final SS
• edit to criteria 2 for continuous outcomes to round up N

pmsampsize 2021-11-21

• fixes issues with rounding leading to small differences in Max_Rsq and subsequently sample size calculations
• additional output including Nagelkerke's R-sq (binary & survival outcomes)

pmsampsize 2021-06-24

• update allowing user to input C-statistic from existing model to approximate Cox-Snell R-squared (for binary outcome model sample size calculations)
• additional parameter checks

pmsampsize 2020-07-24

• version issues fixes

pmsampsize 2020-07-23

Continuous outcomes:

• calculation of shrinkage for each criteria based on N needed in specific criteria

• also allowance for the unique scenario when starting N already meets shrinkage requirement set by user (this is more for academic exercise, as in practice a high shrinkage will be desired and so it is very rare that the base N (set to p+2) will provide good shrinkage)

Binary and TTE outcomes:

• more informative error message added for rare scenario where shrinkage is specified lower than r-squared which results in NaNs from shrinkage formula

pmsampsize 2019-11-15

• update forces the time-unit to be the mean follow-up time, as described in forthcoming BMJ paper which extends the original Statistics in Medicine paper (see reference in help file)

• updated in calculation of max R-sq for survival option, to prevent manipulation based on time units used

pmsampsize 2019-08-02

• updated in line with correction to original article in eq. 13

pmsampsize 2019-01-02

• this is a new release