Table 2.

List and description of different methods of handling missing outcome data

Method of handling missing data	Handling participants with missing data in the numerator and denominator
	Intervention arm		Control arm
Complete case analysis	Numerator excluded	Denominator excluded	Numerator excluded	Denominator excluded
Implausible but commonly discussed assumptions:
Best case scenario*	Assumed that all had a favourable outcome	Denominator included	Assumed that all had an unfavourable outcome	Denominator included
None of the participants with missing data had the outcome	Assumed that none had the outcome	Denominator included	Assumed that none had the outcome	Denominator included
All participants with missing data had the outcome	Assumed that all had the outcome	Denominator included	Assumed that all had the outcome	Denominator included
Worst case scenario†	Assumed that all had an unfavourable outcome	Denominator included	Assumed that all had a favourable outcome	Denominator included
Plausible assumptions‡:
IMOR 1.5	IMOR 1.5§	Denominator included	IMOR 1	Denominator included
IMOR 2	IMOR 2§	Denominator included	IMOR 1	Denominator included
IMOR 3	IMOR 3§	Denominator included	IMOR 1	Denominator included
IMOR 5	IMOR 5§	Denominator included	IMOR 1	Denominator included

IMOR=informative missing odds ratio

^*When applying best case scenario, it was ensured it challenges the relative effect by shifting it away from the null value of no effect (see statistical notes in appendix section 3).

^†When applying worst case scenario, it was ensured it challenges the relative effect by shifting it closer to the null value of no effect (see statistical notes in appendix section 3).

^‡The “metamiss” command^{25 26} was used to implement the IMOR assumptions in Stata.

^§These calculations are applied when the relative effect is less than 1. When a relative effect is greater than 1, the values for the IMOR are flipped between the intervention and control arm whereby it is 1 for the intervention arm. For example, when an original relative effect is greater than 1, the IMOR value for the intervention arm would be 1 and that of the control arm would be 5.