Study Design and Reference	Study period	N	Diagnosis Rate of IgAN
Retrospective database (Kaiser Permanente, Northern California)[@82814]	2018	673	14.3%
Retrospective single-center (University of North Carolina Chapel Hill Division of Nephropathology)[@82825]	1986 to 2015		6.6%
Retrospective database (Kaiser Permanente Southern California Health System)[@82812]	2000 to 2011	4071	6.3%
Retrospective, single-center (Saint Louis University Hospital)[@82821]	1999 to 2006	634	7.7%
Retrospective, single-center (Rural center, Missouri)[@82822]	2013 to May 2019	118	8.4%
Meta-analysis of IgAN rates among patients with biopsy		38 887	8.17%
Abbreviations: IgAN, immunoglobulin A nephropathy; US, United States.