Category	Details of previous reviews/meta‐analyses
Number of reviews and meta‐analyses	5 systematic reviews: Gilmartin 2017; McGowan 2016; Pezaro 2017a; Rogers 2016; Sanderson 2017 Of these, Sanderson 2017, did not merely aim to identify resilience interventions but had other review questions also (e.g. concerning concepts or measures of resilience); thus, the number of resilience intervention studies was limited in this publication (no RCTs) 1 meta‐analysis: Lo 2018a, which largely included studies without an explicit focus on resilience (e.g. resilience was not mentioned in the publication)
Methodological characteristics	Eligibility criteria: The 6 publications either investigated healthcare students such as medical students (Lo 2018; McGowan 2016; Sanderson 2017) or combinations of healthcare students and healthcare professionals, i.e. with completed training (Gilmartin 2017: nurses, physicians, student nurses, and medical trainees; Pezaro 2017: midwives and student midwives; Rogers 2016: healthcare professionals and students) Each publication used different inclusion and exclusion criteria for studies with respect to interventions and study design (e.g. only RCTs in Lo 2018 versus various study designs in McGowan 2016) While some reviews included training programmes with the stated intention to enhance resilience (McGowan 2016: interventions defined "as those relating to the experience and development of resilience", p 2274), the eligibility criteria for the types of intervention have not been described in detail in other publications (e.g. reviews not focusing solely on interventions, Sanderson 2017)
	Search strategy: Each review varied in the breadth of the search strategy, as well as the extent of reporting the strategy used. For example, while some reviews searched for resilience and associated terms (e.g. coping behaviour; Pezaro 2017) or used specific intervention terms (e.g. stress management, mindfulness; Gilmartin 2017), others have used a narrow search (e.g. resilience combined with one term for healthcare students; McGowan 2016) Most previous reviews were restricted to English‐language publications, and grey literature was not always considered
	Review protocol/registration: Aside from Gilmartin 2017 and Pezaro 2017, most of these reviews did not have a published protocol or protocol registration, which reduces transparency and comparability in the reviews' procedures and potentially restricts the evidence found
	Review according to guidelines: 1 review did not specify whether it had been conducted according to guidelines, such as PRISMA or Cochrane guidelines, or other validated frameworks (Rogers 2016)
	Quality assessment of included studies: The assessment and reporting of risk of bias and quality of the included studies differed between reviews, as they often relied on different guidelines depending on the study design considered (e.g. Downs and Black Checklist; Downs 1998) Sanderson 2017 performed no formal 'Risk of bias' assessment
RCT: Randomised controlled trial