Constructs the cost-saving (downward) portion of the cost-effectiveness frontier
by iteratively selecting solutions with the best ICERs among cost-saving options.
Prioritizes solutions that improve impact when available, but considers all
cost-saving options if no impact-improving solutions exist.
Usage
build_frontier_down(x, start_pos, threshold, down_filter)
Arguments
- x
A data.frame containing ordered cost and impact data
- start_pos
Integer. Position of the starting solution in the ordered data
- threshold
Numeric. Willingness-to-pay threshold for ICER acceptability
- down_filter
Function. Optional user-defined filter for cost-saving candidates
Value
A data.frame containing cost-saving frontier solutions with step numbers
(negative values indicating cost-saving steps)