Table 2. Main steps of the cascade approach applied to the European Society of Gastrointestinal Endoscopy guidelines.

Cascade steps
1. Selection of suitable ESGE guidelines	Factors to be considered:
	Epidemiology
	Dependence of the recommended interventions on the level of available resources
	Availability of local expert to substantiate the proposal of alternative strategies
2. Selection of the working group	Members of the IAWG
	Author(s) representative of the original ESGE guideline
	Local experts
	Others
3. Definition of the level of resources required for each intervention	Basic level  Core resources or fundamental services absolutely necessary for an endoscopy care system to function. By definition, a healthcare system lacking any basic-level resource would be unable to provide endoscopic services to its patient population. It includes diagnostic procedures (gastroscopy and colonoscopy), as well as fundamental monitoring abilities (blood pressure, basic blood biochemistry).
	Limited level  Second-tier resources or services that produce major improvements in outcome, such as increased survival, but that are attainable with limited financial means and modest infrastructure. It includes minor endoscopic procedures to improve major clinical outcomes (i. e. sclerotherapy/adrenaline injection, band ligation, plasma expanders, basic surgical interventions).
	Enhanced level  Third-tier resources or services that are optional but important. Enhanced-level resources may produce minor improvements in outcome but increase the number and quality of therapeutic options. Most procedures that improve clinical outcome are available (i. e. biliopancreatic endoscopy, electrosurgical unit, polypectomy/mucosectomy, anesthesia back-up).
	Maximal level  High-level resources or services that may be used in some high-resource countries or be recommended in guidelines that assume unlimited resources. To be useful, maximal-level resources typically depend on the existence and functionality of all lower-level resources.
4. Adaptation of intervention according to the level of resources	Factors to be considered:
	Cost
	Endoscopy
	Other technology
	Economic
	Infrastructure
	Organizational
	Professional
	Training
5. Modified Delphi process	Local experts who are representative of different African areas (economic, geographical, level of resources, etc.)

ESGE, European Society of Gastrointestinal Endoscopy; IAWG, International Affairs Working Group.