OptionalweightKey holding the study's weight in the pooled estimate, as a fraction of one. A forest plot encodes this as marker area, which no reader is otherwise told: two studies whose intervals look alike can contribute wholly differently to the result.
OptionalpooledKey whose truthy value marks a row as the pooled summary rather than a study.
OptionalpooledIndex of the pooled summary row, for data that carries no flag column.
A meta-analysis draws the pooled row last, so this is usually
data.length - 1.
OptionalnullThe value that means "no effect" — 1 for a ratio measure, 0 for a
difference. It is the <ReferenceLine> the chart draws, and whether a
study's interval crosses it is that study's result.
There is deliberately no default: guessing 0 for a ratio chart reports every study as not crossing, since odds ratios are all positive.
Configuration for forest plots. Optional when
chartTypeis'forest', but a forest plot that declares nonullValuegets no claim about significance — see nullValue.