Table 1.

List of data extraction variables

Study characteristics
Intervention(s)	Type of HIV and/or syphilis testing activity or programme
Country	Location of study
Study population	Group targeted by intervention(s)
Setting	Service through which the intervention is delivered (e.g. health centre, hospital) and sector (e.g. public/private)
Time horizon	The duration over which costs and/or consequences are calculated
Study design	Randomized controlled trial, cross-sectional, cohort, case–control, modelling
Type of economic analysis (and ratio if applicable)	Cost analysis, cost‐effectiveness, cost‐utility or cost–benefit analysis. Includes ratio used (e.g. cost per DALY averted)
Data source(s)	Primary data collection, expert/stakeholder opinion, published data or literature or combination of those
Analytical approach to measure costs at scale	Econometric, empirical, modelling or a hybrid of these approaches (Kumaranayake, 2008)
Costs of scaling up
Definition of scaling up	As described by authors
Year (costs)	Year of currency values presented (e.g. 2018 dollars)
Unit(s) of output	Choice of output measure (e.g. number of clients tested, number of facilities with testing available)
Sample size	Total number of, e.g facilities, individuals, tests
Timeframe for decision	Short run (fixed inputs cannot be changed) and long run (all inputs can be changed) (Kumaranayake, 2008)
Cost categories	Categorization of costs as defined by author(s)
Economies/diseconomies of scale	How costs changed with scale of output and by how much.
Empirical results	Specific findings related to the costs of scaling up (e.g. coefficients of scale)
Key drivers of costs identified	Key drivers of the costs of scaling up (e.g. geography, population sub-group, type of providers)