Skip to main content
. Author manuscript; available in PMC: 2010 Jun 27.
Published in final edited form as: J Am Geriatr Soc. 2010 Feb 11;58(3):527–532. doi: 10.1111/j.1532-5415.2010.02719.x

Table 1.

Comparison of Characteristics of Methicillin-Resistant Staphylococcus aureus (MRSA) Cases with Uninfected Controls and Methicillin-Susceptible S. aureus (MSSA) Controls

Variable MRSA (N = 86) No Infection (N = 167) OR (95% CI) P-Value MSSA (N = 64) OR (95% CI) P-Value
Demographic
 Age, mean ± SD (range) 73.4 ± 5.7 (65–94) 73.7 ± 6.0 (65–94) – .85 73.0 ± 5.3 (65–87) – .67
 Aged ≥75, n (%) 25 (29.1) 63 (37.7) 0.59 (0.33–1.07) .17 20 (31.2) 0.90 (0.45–1.82) .08
 Male, n (%) 32 (37.2) 78 (46.7) 0.72(0.41–1.25) .15 33 (51.6) 0.56 (0.29–1.07) .08
 White, n (%) 63 (73.2) 139 (84.2) 0.55 (0.28–1.08) .06 53 (82.8) 0.57 (0.25–1.27) .17
 Private insurance, n (%) 3 (3.6) 10 (6.0) 1.27 (0.33–4.88) .55 0 – –
 Admission not from home, n (%) 25 (32.9) 50 (30.9) 0.92 (0.49–1.73) .75 10 (17.0) 2.40 (1.05–5.52) .04
Comorbidities, n (%)
 Obesity (body mass index, kg/m2, >30.0) 26 (32.9) 36 (22.2) 1.58 (0.85–2.92) .07 24(10.0) 0.72 (0.36–1.43) .38
 Diabetes mellitus 28 (32.6) 47 (28.1) 1.20 (0.67–2.16) .47 13 (20.3) 1.89(0.88–4.04) .09
 Diabetes mellitus with end organ damage 4 (4.7) 6 (6.6) 1.09 (0.49–2.45) .68 3 (4.7) 0.99 (0.46–2.14) .99
 Myocardial infarction 19 (22.1) 51 (30.5) 0.60 (0.31–1.73) .15 15 (23.4) 0.93 (0.43–2.00) .85
 Congestive heart failure 33 (38.4) 34 (20.4) 3.21 (1.61–6.40) .002 12 (18.8) 2.70 (1.26–5.79) .01
 Perivascular disease 16 (18.1) 30 (18.0) 0.86 (0.41–1.84) .90 9 (14.1) 1.40 (0.57–3.40) .46
 Cerebrovascular accident 12 (13.9) 16 (9.6) 1.26 (0.55–2.87) .29 5 (7.8) 1.91 (0.64–5.74) .24
 Chronic obstructive pulmonary disease 18 (20.9) 15 (9.0) 2.77 (2.30–5.90) .009 15 (23.4) 0.87 (0.40–1.88) .71
 Renal disease 11 (12.8) 8 (4.8) 2.92 (1.02–8.36) .02 4 (6.3) 2.20 (0.67–7.26) .18
 Charlson score
  0 8 (9.3) 42 (25.1) 1 — 18 (28.1) 1 —
  1 or 2 40 (46.5) 59 (35.3) 3.22 (1.30–7.98) .01 30 (46.9) 3.00 (1.15–7.82) .02
  ≥3 38 (44.2) 29 (17.4) 4.71 (1.77–12.56) .002 16 (25.0) 5.34 (1.93–14.77) .002
 Taking immunosuppressants 11 (13.4) 12 (7.4) 1.73 (0.72–4.13) .13 4 (6.5) 2.04 (0.75–5.60) .18
Preoperative functional status, n (%)
 Need assistance in
  Ambulation 37 (45.1) 46 (28.4) 2.08 (1.06–4.09) .009 14 (23.3) 2.70 (1.29–5.66) .009
  Bathing 30 (36.6) 25 (15.4) 3.78 (1.72–8.34) .001 8(13.3) 3.75 (1.57–8.95) .003
  Dressing 30 (36.6) 25 (15.4) 3.78 (1.72–8.34) .001 8 (13.3) 3.75 (1.57–8.95) .003
  Feeding 12 (14.6) 9 (5.6) 2.71 (1.03–7.17) .02 1 (1.7) 9.94 (1.26–78.74) .03
 Bowel incontinence 2 (2.4) 4 (2.5) 0.87 (0.14–5.32) >.99 0 (0) — —
 Urine incontinence 3 (3.7) 6 (3.7) 0.83 (0.18–3.79) >.99 2 (3.4) 1.08 (0.18–6.69) >.99
 Lack of independence in >3 activities of daily living 30 (34.9) 25 (15.0) 3.26 (1.52–7.03) .029 7 (10.9) 4.36 (1.77–10.75) .01
Hospital and surgical variables
 Postoperative glucose > 200 mg/dL, n (%) 32 (39.5) 59 (37.6) 1.14 (0.52–2.07) .77 17 (29.3) 1.58 (0.77–3.24) .21
 Preoperative length of stay, mean ± SD 2.4 ± 3.6 1.6 ± 2.6 1.10 (1.00–1.21) .08 1.2 ± 2.4 1.15 (1.01–1.31) .02
 Orthopedic surgery, n (%) 34 (39.5) 61 (36.5) — * .64 28 (43.8) 0.84 (0.44–1.62) .60
 Cardiothoracic surgery, n (%) 34 (39.5) 75 (44.9) — * .41 19 (29.7) 1.55 (0.78–3.08) .21
 American Society of Anesthesiologists physical classification score >4, n (%) 33 (38.8) 67 (40.4) 1.12 (0.48–2.60) .81 21 (33.3) 1.27 (0.64–2.51) .49
 Appropriate perioperative antibiotics, n (%) 59 (72.0) 122 (75.3) 1.02 (0.52–2.02) .57 45 (76.3) 0.80 (0.37–1.72) .57
 Wound class >1 (not clean), n (%) 19 (22.1) 16 (19.7 7.58 (1.61–35.67) .007 7 (10.9) 2.31 (0.91–5.89) .07
 Repeat surgery, n (%) 9 (10.5) 16 (9.6) 0.99 (0.42–2.38) .82 8 (12.5) 0.81 (0.30–2.24) .69
 Surgical time >75% of cut point, n (%) 36 (41.9) 49 (29.3) 1.94 (1.04–3.61) .05 16 (25.0) 2.20 (1.08–4.49) .03
*

Matched criteria, including procedure type, year, and hospital.

SD = standard deviation; OR = order ratio.