Table 2

Clinical characteristics +/−24 hours from the index date according to LRTI manifestation group
Characteristics No infiltrate and no bacteraemia patients Infiltrate without bacteraemia patients Bacteraemia patients
n (%) a PR (95% CI) n (%) a PR (95% CI) n (%) a PR (95% CI)
Medical ward 188 (97) 1.0 (ref.) 229 (92) 0.9 (0.9-1.0) 249 (95) 1.0 (0.9-1.0)
Community acquired b 167 (87) 1.0 (ref.) 217 (87) 1.0 (0.9-1.1) 242 (92) 1.1 (1.0-1.1)
Antibiotics 155 (80) 1.0 (ref.) 235 (94) 1.2 (1.1-1.3) 260 (99) 1.2 (1.2-1.3)
Aetiology
Pneumococcal only 137 (71) 1.0 (ref.) 178 (71) 1.0 (0.9-1.1) 219 (84) 1.2 (1.1-1.3)
Pneumococcal mixed c 56 (29) 1.0 (ref.) 72 (29) 1.0 (0.7-1.3) 43 (16) 0.6 (0.4-0.8)
Respiratory symptoms d
0 0 (0) 1.0 (ref.) 20 (8) NA 35 (13) NA
1 33 (17) 1.0 (ref.) 25 (10) 0.6 (0.4-0.9) 56 (21) 1.3 (0.8-1.8)
2 44 (23) 1.0 (ref.) 59 (24) 1.0 (0.7-1.5) 79 (30) 1.3 (1.0-1.8)
≥3 116 (60) 1.0 (ref.) 146 (58) 1.0 (0.8-1.1) 92 (36) 0.6 (0.5-0.7)
Oxygen saturation (peripheral) 94 (91–96) 92 (88–95) 93 (89–95)
Temperature ≥38.5°C 35 (20) 1.0 (ref.) 86 (37) 1.8 (1.3-2.6) 126 (50) 2.5 (1.8-3.4)
MAP (mmHg) 91 (78–103) 88 (73–99) 80 (72–97)
CURB65 ≥2 68 (35) 1.0 (ref.) 121 (48) 1.4 (1.1-1.7) 160 (61) 1.7 (1.4-2.1)
PITT ≥4 12 (6) 1.0 (ref.) 28 (11) 1.8 (0.9-3.4) 41 (16) 2.5 (1.4-4.7)
CRP (mg/L)
Median 82 (36–140) 163 (70–246) 316 (219–404)
<50 54 (31) 1.0 (ref.) 41 (17) 0.6 (0.4-0.8) 8 (3) 0.1 (0.1-0.2)
50-99 46 (26) 1.0 (ref.) 36 (15) 0.6 (0.4-0.9) 14 (6) 0.2 (0.1-0.4)
100-199 52 (30) 1.0 (ref.) 68 (29) 1.0 (0.7-1.3) 32 (13) 0.4 (0.3-0.6)
≥200 24 (14) 1.0 (ref.) 91 (39) 2.8 (1.9-4.2) 196 (78) 5.7 (3.9-8.4)
Leukocyte count (109/L)
Median 14 (11–17) 14 (11–19) 17 (12–23)
<3,5 3 (1) 1.0 (ref.) 8 (3) 6.1 (0.8-48.0) 17 (7) 12.2 (1.6-90.5)
3.5-8.7 17 (10) 1.0 (ref.) 25 (11) 1.1 (0.6-2.0) 22 (9) 0.9 (0.5-1.7)
8.8-14.9 90 (51) 1.0 (ref.) 98 (42) 0.8 (0.7-1.0) 57 (23) 0.5 (0.3-0.6)
≥15.0 70 (40) 1.0 (ref.) 103 (44) 1.1 (0.9-1.4) 153 (61) 1.6 (1.3-1.9)

LRTI, lower respiratory tract infection; PR, prevalence ratio; CI, confidence interval; ref, reference; NA, not applicable; MAP, Mean Arterial Pressure; CURB65, Confusion Urea Respiration-frequency Blood-pressure 65years; PITT , Pitt’s bacteraemia severity score; CRP, C-reactive protein.

a In the n (%) columns data are either n (% of everyone we have data for) or median (interquartile range).

b Community acquired infections are defined as having the index date ≤ 2 days form admission.

c Mixed aetiology is defined as finding of other pathogenic bacteria than pneumococci in either blood or LRT specimen.

d Respiratory symptoms include dyspnoea, cough, sputum production and chest pain.

Results were available for >87% of the patients except the individual measures that constitute the CURB65 score (58-99% worst for respiratory frequency and carbamide). CURB65 and PITT were calculated out of everyone, though at least one measure pr. patient was missing in 60-62% of patients for the CURB65 score and 9-18% for the PITT score. Missing valuables were regarded as “no”. Sums were thus calculated as “minimums”.

Skovgaard et al.

Skovgaard et al. BMC Infectious Diseases 2013 13:197   doi:10.1186/1471-2334-13-197

Open Data