Inverse Association between Prediagnostic IgE Levels and the Risk of Brain Tumors: A Systematic Review and Meta-Analysis

Table 1

Characteristics of all studies.

Study	Year	Brain tumors	Origins	Number of cases	Number of controls	Baseline time	Matching factors
Amirian et al. [17]	2013	Glioma	USA	362	462	2001–2006	Age, sex, and frequency
Schwartzbaum et al. [20]	2012	Glioma	Norway	594	1177	1974–2007	Date of blood collection, 2-year age interval at blood collection, and sex
Schlehofer et al. [19]	2011	Glioma	Europe	275	528	2002–2005	Study centre, gender, data of birth, age, date of blood collection, time of blood collection, and length of followup
Schlehofer et al. [19]	2011	Meningioma	Europe	175	343	2002–2005	Study centre, gender, data of birth, age, date of blood collection, time of blood collection, and length of followup
Calboli et al. [18]	2011	Glioma	USA	169	520	1976–2009	Age, age at blood draw, age at diagnosis, and ethnicity
Wiemels et al. [23]	2011	Meningioma	USA	265	145	2006–2009	Age, frequency, and state of residence
Wiemels et al. [22]	2009	Glioma	USA	393	470	2001–2004	Age, sex, ethnicity, and frequency
Wiemels et al. [21]	2004	Glioma	USA	228	289	1997–2000	Age, sex, ethnicity, and frequency