Table 1. Population, concept and context framework.

	Inclusion criteria	Exclusion criteria
Population	Patients and staff involved in inter-hospital surgical referrals	Non-surgical referrals, intra-hospital referrals, community referrals and self-referrals
Concept	The functionality of referral networks, including referral patterns, pathways and obstacles	Papers where surgical referrals are mentioned but the main focus is not on the functionality of the referral system (e.g. papers depicting the range of surgical procedures performed or examining clinical and epidemiological aspects of referrals)
Context	District, secondary and tertiary hospitals LMICs	Primary care non-surgical facilities (e.g. health centres and dispensaries) Non-LMICs