Evaluative criteria for least-cost economic analysis of citywide inclusive sanitation: a scoping review

Abstract

ABSTRACT Compared to health interventions, where evaluative criteria have been established, uncertainty about how comparative economic analysis methodologies should be applied to heterogeneous urban sanitation interventions in cities of low- and middle-income countries persists. Gaps between least-cost principles and current approaches constrain emerging citywide inclusive sanitation (CWIS) planning frameworks. Furthermore, a lack of comparable evidence about the economic efficiency of service provision interventions impacts the delivery of urban sanitation as an inclusive public service. This review scopes how least-cost principles may be applied to methodologies for urban sanitation interventions in two iterations. We devise and discuss evaluative criteria, embodying CWIS principles, that will improve the quality of these methodologies. They include how (i) the inclusion of diverse cost perspectives, particularly populations with marginal access to sanitation, are accommodated within an analysis; (ii) a context-specific without-project case may be used as an appropriate basis for comparison; (iii) tangible and intangible costs and outcomes may influence decisions; and (iv) diverse mixtures of interventions at different scales may be compared with integrity. The resulting evaluative criteria define principles that may inform future systematic reviews on practices that enhance CWIS planning frameworks.