Table 1 Framework for assessment of economic studies

Study perspective

What is the study perspective? The study perspective (s) is the viewpoint from which the intervention’s costs and consequences are evaluated [42].

Patient perspective

Example: out-of-pocket costs or patient preference, costs that the patient pays for that are not covered by their health insurance

Healthcare payer perspective

Example: attributable costs to the payers of healthcare including insurers or national payers

Healthcare system perspective

Example: cost effectiveness analysis of stewardship programs, additional length of hospital stay, impact of resistant infections on structuring of cares such as infection control, increased use of isolation rooms

Societal perspective

Example: broader costs to society such as productivity loss due to morbidity or premature death, can include cost to other sectors such as impact on trade and economy

Methodology

Did the study match the resistant cases and susceptible control groups based on LOS prior to infection? or

Did the study adjust statistically for prior LOS? or

Did the study conduct sensitivity analysis that considered hospital LOS prior to infection? or

Was multistate modelling used to take into account the time-varying nature of infections?

 If yes, low to moderate risk of time dependent bias

 If no, high risk

 If unsure, check:

Did the study estimate excess LOS, mortality or costs without matching by LOS prior to infection

Did the study express only post-infection LOS or costs?

 If yes to any of the above then high risk of time-dependent bias

Did the study adjust for underlying co-morbidities or severity of illness on clinical outcomes

 If yes, did they adjust for time-dependent bias (above)?

 If no, high-risk of bias

Did the study adjust for inappropriate antibiotic therapy

 If yes, did they adjust for time-dependent bias (above)?

 If no, high-risk of bias

Minimum study characteristics to be reported

Country

Year of data used for analysis

Organism, susceptibility, and site of infection

Comparator

Study design and analysis methods

Cost driver/ costs explored (e.g., excess LOS, mortality)

Type of costs (including year of cost data and currency)

Statistical significance