Table 1

Summary of studies that have examined the impact of age on mortality in cases of Staphylococcus aureus bacteremiaa

Study (outcome of interest)No. of MSSA and MRSA bacteremic episodesOverall mortality rate (%)Age variable; OR (95% CI; P)Reference
Studies that found age to be an independent predictor of mortality (multivariate analysis)
    Single-center retrospective Taiwan study (1990–2004); 30-day all-cause mortality297 MSSA, 851 MRSA44.1Age >65 yr; 1.85 (1.37–2.50; <0.01) 308
    Single-center retrospective Spanish study (1991–1998); in-hospital infection-related mortality683 MSSA, 225 MRSA12.1Age per 10 yr; 1.17 (1.05–1.31; ND) 275
    Single-center retrospective Canadian study (1991–2005); 30-day mortality746 MSSA, 96 MRSA24.0Age >65 yr; 2.31 (1.43–3.73; <0.01) 5
    Single-center prospective Spanish study (1991–2005); 30-day all-cause mortality0 MSSA, 414 MRSA28.0Age per yr; 1.02 (1.00–1.04; 0.013) 273
    Single-center retrospective Belgian study (1992–1998); 30-day in-hospital mortality38 MSSA, 47 MRSA37.6Age per yr; 1.02 (1.00–1.02; 0.01) 18
    Single-center prospective Danish study (1994–1996); 150-day mortality275 MSSA, 3 MRSA34Age ≥60 yr; 2.4 (1.1–5.3; 0.03) 127
    Single-center prospective U.S. study (1994-1998); 90-day all-cause mortality385 SAB20.5Age >65 yr; 2.39 (1.45–3.95; ND) 192
    Single-center retrospective U.S. study (1995–1999); 30-day all-cause mortality204 MSSA, 89 MRSA23.2Age >65 yr; 2.0 (1.0–3.8; 0.048) 206
    Single-center retrospective Chinese study (2001–2007); 90-day all-cause mortality0 MSSA, 115 MRSA21.7Age per yr; 1.03 (1.01–1.05; 0.019) 32
    Multicenter retrospective U.S. study (1995–2003); 90-day infection-related mortality245 MSSA, 193 MRSA26.0Age >65 yr; 2.3 (1.38–3.8; <0.01) 266
    Single-center retrospective U.S. study (1996–2006); all-cause mortality0 MSSA, 489 MRSA25.0Age per yr; 1.05 (1.03–1.07; <0.001) 202
    Single-center retrospective Taiwan study (1997–2001); 30-day infection-related mortality0 MSSA, 162 MRSA47.5Age ≥60 yr; 2.90 (1.25–6.75; 0.01) 59
    Multicenter retrospective United Kingdom study (1997–2004); 30-day mortality229 MSSA, 232 MRSA29.0Age per decade; 1.79 (1.75–1.82; ND) 322
    Single-center retrospective Australian study (1997–2008); 30-day all-cause mortality0 MSSA, 401 MRSA28.7Age per yr; 1.03 (1.01–1.05; 0.005) 301
    Single-center retrospective Swiss study (1998–2002); in-hospital all-cause mortality302 MSSA, 6 MRSA19.5Age per 10 yr; 1.3 (1.2–1.6; <0.01) 131
    Single-center retrospective Taiwan study (2001–2006); in-hospital infection-related mortality0 MSSA, 177 MRSA33.3Age per yr; 1.04 (1.01–1.08; 0.01) 167
    Single-center retrospective Taiwan study (2001–2007); 90-day all-cause mortality0 MSSA, 115 MRSA21.7Age per yr; 1.01 (1.0–1.02; <0.05) 33
    Single-center retrospective Germany study (2002–2004); in-hospital all-cause mortality454 MSSA, 67 MRSA21.7Age ≥60 yr; 2.4 (1.4–4.2, <0.01) 237
    Single-center retrospective Israeli study (2003–2006); in-hospital infection related-mortality0 MSSA, 250 MRSA37.2Age per yr; 1.02 (1.004–1.04; 0.013) 185
    Single-center retrospective U.S. study (2003–2008); in-hospital mortality326 MSSA, 488 MRSA13.3Age per yr; 1.04 (1.03–1.05; ND) 257
    Single-center prospective U.S. study (2004); in-hospital mortality0 MSSA, 132 MRSA22.0Age >55 yr; 8.09 (2.02-32.5; 0.03) 261
    Multicenter prospective post hoc analysis Asian study (2004–2006); 30-day all-cause mortality380 MSSA, 329 MRSA24.5Age ≥65 yr; 1.69 (1.15–2.48; 0.008) 133
    Multicenter prospective post hoc analysis Asian study (2004–2006); 30-day all-cause mortality1,701 MSSA, 2,007 MRSA13.4Age per 10 yr; 1.19 (1.12–1.27; <0.01) 134
    Single-center retrospective Taiwanese study (2004–2006); 30-day all-cause mortality186 MSSA, 30 MRSA12.6Age per yr; 1.03 (1.01–1.06; <0.01) 310
    Single-center retrospective Singaporean study (2005–2006); in-hospital infection-related mortality100 MSSA, 0 MRSA23.9Age >65 yr; 13.7 (2.75–68.3; <0.01) 35
    Single-center, prospective U.S. study (2005–2006), 30-day all-cause mortality90 MSSA, 163 MRSANot statedAge per yr; 1.04 (1.01-1.07) 77
    Multicenter retrospective European study (2007); 30-day all-cause mortality257 MSSA, 77 MRSA24.0Age per yr; 1.06 (1.03–1.10; <0.01) 6
    Multicenter prospective Australian study (2007–2008); 30-day all-cause mortality1,415 MSSA, 450 MRSA20.6Age >70 yr; ND (ND; <0.001) 296
    Multicenter prospective Australian study (2007–2008); 30-day all-cause mortality324 MSSA, 199 MRSA17.2Age per yr; 1.06 (1.04–1.08; <0.01) 101
Studies where age was not an independent predictor of mortality
    Single-center prospective Spanish study (1990–1993); infection-related mortality100 MSSA, 84 MRSA44.0Age >65 yr; ND 244
    Single-center retrospective Turkish study (1990–1994); infection-related mortality55 MSSA, 46 MRSA21.8ND 291
    Single-center retrospective Brazilian study (1991–1992); 14-day all-cause mortality46 MSSA, 90 MRSA39.0Age >60 yr; ND 39
    Single-center retrospective French study (1997–1998); infection-related mortality69 MSSA, 30 MRSA27.3Age ≥60 yr; ND 286
    Single-center retrospective U.S. study (1997–2000); in-hospital mortality250 MSSA, 96 MRSA20.7Age >65 yr; ND 41
    Single-center retrospective Korean study (1998–2001); 60-day infection-related mortality111 MSSA, 127 MRSA37.0Age ≥65 yr; 1.88 (0.97–3.62; ND) 142
    Single-center retrospective Korean study (1998–2006); infection-related mortality294 MSSA, 0 MRSA19.4Age ≥65 yr; 1.4 (0.8–2.5; 0.29) 140
    Single-center retrospective Brazilian study (2000–2001); infection-related mortality50 MSSA, 61 MRSA39.0Age per yr; 0.98 (0.96–1.00; 0.07) 89
    Single-center retrospective Taiwanese study (2000–2008); 30-day all-cause mortality0 MSSA, 227 MRSA44.9Age ≥65 yr; 1.93 (0.98–3.78; ND) 171
    Single-center retrospective Belgian study (2002–2004); infection-related in-hospital mortality88 MSSA, 66 MRSA40.0ND 168
Multicenter retrospective U.S. study (2004–2005); in-hospital mortality32 MSSA, 36 MRSA19.1Age per yr; 1.05 (1.0–1.1; 0.08) 184
Single-center retrospective Taiwanese study (2006–2008); 30-day all-cause mortality0 MSSA, 253 MRSA30.5ND 309
  • a Studies employed a multivariate logistic regression model.

  • OR, odds ratio; CI, confidence interval; P, probability; ND, not described.