Table 1. PICOS Criteria for the (a) Epidemiology SLR and (b) BOI SLR.

a. Epidemiology SLR
Category	Inclusion Criteria	Exclusion Criteria
Patient Population	Adult patients (age ≥18) with IgAN regardless of comorbidities*	Non-human Pediatric patients (age <18) only Patients with other diseases
Intervention	Any treatment or management No treatment or management	Any non-IgAN treatment or management
Outcomes Measures	Incidence, prevalence, rate of IgAN Progression rate of IgAN through CKD stage and to ESRD Patient distribution across CKD stage Treatment rate Mortality	Studies that did not have ≥1 outcome in the inclusion criteria
Study Design	RWE studies including: Prospective observational studies Retrospective studies Registry analyses Database analyses Natural history studies and non-interventional studies SLRs and meta-analyses (for cross-checking only)	Reviews Editorials Notes/comments/letters Interventional studies Studies with <20 patients in the whole population Case reports/case series
Restrictions	English language Studies in the United States, Western Europe, or Australia Year limitation: 2010 to June 2020	Non-English language studies Studies outside of United States, Western Europe, or Australia
* Studies with mixed populations of adults and children were included Abbreviations: BOI, burden of illness; CKD, chronic kidney disease; ESRD, end-stage renal disease; IgAN, immunoglobulin A nephropathy; PICOS, Population, Intervention, Comparators, Outcomes, and Study Design; RWE, real-world evidence; SLR, systematic literature review.
b. BOI SLR
Category	Inclusion Criteria	Exclusion Criteria
Patient Population	Patients with IgAN regardless of comorbidities	Non-human Patients with other diseases
Intervention	Any treatment or management No treatment or management	Any non-IgAN treatment or management
Outcomes Measures	HRQoL outcomes PROs Utilities Symptom burden Costs (direct and indirect)/HCRU BOI Other QoL or economic burden	Studies that did not have ≥1 outcome in the inclusion criteria
Study Design	RWE studies including: Prospective observational studies Retrospective studies Registry analyses Database analyses Natural history studies and non-interventional studies SLRs and meta-analyses (for cross-checking only)	Reviews Editorials Notes/comments/letters Interventional studies Case reports/case series
Restrictions	English language Year limitation: 2010 to June 2020	Non-English language studies
Abbreviations: BOI, burden of illness; HCRU, health-care resource utilization; HRQoL, health-related quality of life; IgAN, immunoglobulin A nephropathy; PRO, patient-reported outcome; QoL, quality of life; RWE, real-world evidence; SLR, systematic literature review.