Association of HLA-B*5801 allele and allopurinol-induced stevens johnson syndrome and toxic epidermal necrolysis: a systematic review and meta-analysis

Table 1 Characteristics of studies included in the meta-analysis

Author	Year	Study Design	SJS/TEN Cases^a (n)	Controls		Data Collection		Specific Requirement for Case Allopurinol-Exposure^b	Matching Criteria	NOS
				Matched (n)	Population (n)	SJS/TEN Cases	Controls
Hung SI [10]	2005	Case-control	21	135	93^c	R	R	Yes	Drug, hospital	7
Kaniwa N [11]	2008	Case-population control^d	10	-	493^e	R	-	NR	-	3
Lonjou C [12]	2008	Case-population control^d	31	-	1822^f	R (N = 70), P (N = 80)	-	Yes	-	3
Tassaneeyakul W [13]	2009	Case-control^g	27	54	-	R	R	Yes	Drug, hospital	7
Kang HR [14]	2011	Case-control	5	57	485^h	R	R	Yes	Drug, hospital	4
Jung JW [15]	2011	Retrospective cohort	2	432	485^h	R	R	Yes	Drug, hospital	6

Abbreviation: R = retrospective, P = prospective, NOS = Newcastle-Ottawa Scale, NR = not report
^a Only patients that received drugs of interest (Allopurinol) were included.
^b Including: maximum time to develop adverse drug reaction (ADR) from drug initiation [10, 12, 13], improvement of symptom upon drug discontinuation [10, 13], and exclusion of patients without symptoms upon re-exposure [10].
^c Healthy subjects randomly selected from a biobank under nationwide population study, in which 3312 Han Chinese descendants were recruited based on the geographic distribution across Taiwan. There was no self-report of adverse drug events by any of the population control.
^d Using population based as control group.
^e Data of healthy Japanese reported by Tanaka H, et al. [20].
^f Using allele frequencies from European populations available on dbMHC: http://0-www-ncbi-nlm-nih-gov.brum.beds.ac.uk/projects/mhc/ihwg.cgi
^g Author described the study as cross-sectional case-control study.
^h Using allele frequency from the general population of Korea.

ISSN: 1471-2350