Table 2. Study characteristics.

No	Included studies	Group, region (N. centers)	Treatment period in years	N. analyzed patients; subgroups indicated HSCT vs. IST	N. patients other* than SAA (%); HSCT vs. IST	N. patients other† than first-line treatment (%); HSCT (MRD) vs. IST	Median follow-up in years
1	Ahn 2003 [31]	Seoul, Korea (10)	1990–2001	64 vs. 156	0 vs. 0	0 vs. 0
2	Arranz 1994 [32]	Madrid, Spain (1)	1983–1991	21 vs. 29. Subgroup age 20–40 ys: 11 vs. 13	0 vs. 2 (7)	5 (24) vs. 1 (3)	–
3	Bacigalupo 1988 [33]	EBMT, Europe (57)	1981–1986	218 vs. 291. Subgroup age + PMN: <20 ys + <0.2 G/L: 55 vs. 46; <20 ys + ≥0.2 G/L: 63 vs. 57; ≥20 ys + <0.2 G/L: 32 vs. 89; ≥20 ys + ≥0.2 G/L: 44 vs. 36	45 (21) vs. 92 (32)	47 (22) vs. 0	2.6 vs. 2.7
4	Bacigalupo 2000 [34]	EBMT, Europe (?)	1976–1998	Subgroup year (IST = ALG) 1976–1989: 915 vs. 523; 1990–1998: 844 vs. 116. Subgroup year (IST = ALG+CSA) 1976–1989: 915 vs. 56; 1990–1998: 844 vs. 53	0 vs. 0	0 vs. 0	–
5	Bayever 1984 [35]	Los Angeles, USA (1)	1977–1982	35 vs. 22	0 vs. 0	0 vs. 0	–
6	Champlin 1984 [36]	Los Angeles, USA (1)	unclear	61 vs. 69. Subgroup age <20: 35 vs. 21; 20–<35: 21 vs. 21; ≥35: 5 vs. 27	0 vs. 0	0 vs. 5 (7)	–
7	De Planque 1990 [37]	Leiden, Netherlands (1)	1974–1987	19 vs. 63	0 vs. 0	8 (42) vs. 19 (30)	2.8 vs. 1.8
8	Doney 1997 [38]	Seattle, USA (1)	1978–1991	168 vs. 227. Subgroup age (<6 ys: 12 vs. 25); 6–<20 ys: 63 vs. 62; 20–<40 ys: 82 vs. 73; ≥40 ys: 11 vs. 67. Subgroup PMN <0.2 G/L: 70 vs. 94; ≥0.2 G/L: 98 vs. 133	0 vs. 34 (15)	0 vs. 0
9	Fouladi 2000 [39] ‡	Toronto, Canada (1)	1987–1997	21 vs. 20	0 vs. 0	0 vs. 0	–
10	Führer 1998 [40]	SAA 94, Germany (37)	1993–1997	28 vs. 86	2 (7) vs. 7 (8)	0 vs. 0	4.3 vs. 3.0
11	Führer 2005 [41]	Germany (53)	1993–2001	Subgroup PMN <0.2 G/L: 40 vs. 97; <0.2–<0.5 G/L: 27 vs. 49	0 vs. 0	0 vs. 0	–
12	Ghavamzadeh 2004 [42]	Tehran, Iran (1)	1990–2001	29 vs. 24	0 vs. 0	0 vs. 0	–
13	Gillio 1997 [43]	New York, USA (1)	1983–1992	25 vs. 23. Subgroup year 1983–1987: not extractable; 1988–1992: not extractable	0 vs. 0	0 vs. 0	–
14	Gluckman 1979 [44] §	Paris, France (1)	unclear	37 vs. 28	0 vs. 0	0 vs. 0	6.8 vs. 7.2
15	Halperin 1989 [45]	Toronto, Canada (1)	1977–1987	14 vs. 12	0 vs. 0	0 vs. 0	–
16	Kahn 2002 [46]	Kansas City, USA (1)	1977–1999	15 vs. 16	0 vs. 0	0 vs. 0	6.0 vs. 2.0
17	Kim 2003 [47]	Seoul, Korea (1)	1990–1999	22 vs. 74	0 vs. 0	0 vs. 0	0.4 vs. 4.4
18	Kojima 2000 [48] ∥	Nagoya, Japan (2)	1984–1998	37 vs. 63	7 (19) vs. 14 (22)	0 vs. 0	–
19	Lawlor 1997 [49]	Vancouver, Canada (1)	1982–1994	9 vs. 18	0 vs. 0	0 vs. 0	3.0 vs. 2.7
20	Locasciulli 1990 [50]	EBMT, Europe (29)	1970–1988	171 vs. 133	0 vs. 0	23 (13) vs. 0	–
21	Locasciulli 2007 [51]	EBMT, Europe (257)	1991–2002	1567 vs. 912. Subgroup year (HSCT among patients with MSD) 1991–1996: 614 vs. 608; 1997–2002: 550 vs. 304. Subgroup age (IST among patients with PMN ≥0.2 G/L (vs. PMN <0.2 G/L)); <16 ys: 607 vs. 129 (vs. 175); ≥16 ys: 960 vs. 442 (vs. 141)	1183 (75) vs. 368 (40)	197 (13) vs. 0	4.6 vs. 4.7
22	Paquette 1995 [52]	Los Angeles, USA (1)	1977–1989	Subgroup year 1977–1983: 37 vs. 40; 1984–1989: 18 vs. 16	0 vs. 0	0 vs. 3 (5)	2.4 vs. 4.5
23	Pitcher 1999 [53] ¶	London, UK (1)	1973–1996	Subgroup year 1973–1988: unclear; 1989–1996: unclear	unclear	unclear	–
24	Tzeng 1989 [54]	Taipei, ROC (1)	1985–1988	9 vs. 7	0 vs. 0	0 vs. 0	–
25	Viollier 2005 [55] **	Basel, Switzerland (1)	1976–1999	52 vs. 155	14 (27) vs. 50 (32)	0 vs. 0	2.0 vs. 0.5
26	Werner 1989 [56] ††	Cincinnati, USA (2)	1981–1986	6 vs. 9	0 vs. 2 (22)	0 vs. 0	11.5 vs. 11.3

*other than SAA: MAA or not reported degree of severity.

^†other than first-line MRD: second-line HSCT, first-line mismatched related HSCT, first-line- unrelated HSCT.

^‡Fouladi 2000: 5 patients in the IST group received second-line HLA-matched unrelated donor transplantation after failed IST.

^§Gluckman 1979: 5 patients of the IST group received second-line HLA-identical sibling donor transplantation after failed IST; 2 patients with Fanconi anemia and 2 patients with paroxysmal nocturnal hemoglobinemia were included.

^∥Kojima 2000: 11 patients in the IST group received second-line unrelated donor transplantation after failed IST.

^¶Pitcher 1999: outcome from 1973–1988 has been reported by Webb 1991 [69]; number of patients other than SAA estimated.

**Viollier 2005: Follow-up of Nissen 1999 [70], Speck 1994 [71], Tichelli 1988 [72], Speck 1986 [73], Speck 1984 [74], Speck 1983 [75], Speck 1981 [76], Speck 1980 [77], Speck 1977 [78]; 8 patients of the IST group received HSCT.

^††Werner 1989: 1 patient in the IST group received second-line haploidentical transplantation after failed IST.

Abbreviations: HLA: human leukocyte antigen; IST immunosuppressive therapy; PMN: polymorphonuclear neutrophil granulocytes; ROC: Republic of China; UK: United Kingdom of Great Britain and Nothern Ireland; USA: United States of America.