Antibiotic use, medication use and imaging use among subgroups of patients with community-acquired pneumonia admitted to general internal medicine (Apr. 1, 2010, to Oct. 31, 2017), identified by cluster analysis according to coexisting conditions*
| Variable | No. (%) of patients | p value† | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Overall n = 11 085 | Low comorbidity n = 3052 | DM-HF-Pulm n = 1710 | Pulmonary n = 1621 | Diabetes n = 1281 | Heart failure n = 1370 | Dementia n = 1038 | Cancer n = 1013 | ||
| Third-generation cephalosporin‡ | 6696 (60.4) | 1921 (62.9) | 1021 (59.7) | 885 (54.6) | 767 (59.9) | 840 (61.3) | 658 (63.4) | 604 (59.6) | < 0.001 |
| Macrolide§ | 6305 (56.9) | 1803 (59.1) | 950 (55.6) | 892 (55.0) | 700 (54.6) | 768 (56.1) | 562 (54.1) | 630 (62.2) | < 0.001 |
| Fluoroquinolone¶ | 4592 (41.4) | 1136 (37.2) | 784 (45.8) | 781 (48.2) | 523 (40.8) | 566 (41.3) | 434 (41.8) | 368 (36.3) | < 0.001 |
| Penicillin-derived β-lactamases** | 2131 (19.2) | 614 (20.1) | 310 (18.1) | 357 (22.0) | 240 (18.7) | 247 (18.0) | 170 (16.4) | 193 (19.1) | 0.006 |
| Piperacillin–tazobactam | 1472 (13.3) | 334 (10.9) | 232 (13.6) | 148 (9.1) | 169 (13.2) | 173 (12.6) | 132 (12.7) | 284 (28.0) | < 0.001 |
| Other†† | 862 (7.8) | 253 (8.3) | 110 (6.4) | 104 (6.4) | 88 (6.9) | 124 (9.1) | 70 (6.7) | 113 (11.2) | < 0.001 |
| MRSA coverage‡‡ | 592 (5.3) | 164 (5.4) | 82 (4.8) | 58 (3.6) | 75 (5.9) | 78 (5.7) | 60 (5.8) | 75 (7.4) | 0.002 |
| Simple penicillins§§ | 296 (2.7) | 96 (3.1) | 43 (2.5) | 43 (2.7) | 34 (2.7) | 39 (2.8) | 24 (2.3) | 17 (1.7) | 0.292 |
| Ceftazidime | 159 (1.4) | 24 (0.8) | 35 (2.0) | 46 (2.8) | 12 (0.9) | 19 (1.4) | 8 (0.8) | 15 (1.5) | < 0.001 |
| Tetracyclines (doxycycline) | 115 (1.0) | 19 (0.6) | 19 (1.1) | 23 (1.4) | 15 (1.2) | 20 (1.5) | 7 (0.7) | 12 (1.2) | 0.07 |
| Carbapenems (pseudomonas coverage)¶¶ | 106 (1.0) | 16 (0.5) | 15 (0.9) | 11 (0.7) | 17 (1.3) | 12 (0.9) | 10 (1.0) | 25 (2.5) | < 0.001 |
| Clindamycin | 59 (0.5) | 11 (0.4) | 11 (0.6) | 6 (0.4) | 10 (0.8) | 8 (0.6) | 8 (0.8) | 5 (0.5) | 0.468 |
| Carbapenems (no pseudomonas coverage) | 38 (0.3) | 7 (0.2) | 5 (0.3) | 7 (0.4) | 7 (0.5) | 5 (0.4) | 6 (0.6) | 1 (0.1) | 0.352 |
| CT thorax*** | 2032 (18.3) | 609 (20.0) | 241 (14.1) | 341 (21.0) | 180 (14.1) | 234 (17.1) | 59 (5.7) | 368 (36.3) | < 0.001 |
| Furosemide | 3217 (29.0) | 441 (14.4) | 1054 (61.6) | 314 (19.4) | 342 (26.7) | 694 (50.7) | 205 (19.7) | 167 (16.5) | < 0.001 |
| Glucocorticoid | 3119 (28.1) | 351 (11.5) | 874 (51.1) | 1052 (64.9) | 176 (13.7) | 232 (16.9) | 119 (11.5) | 315 (31.1) | < 0.001 |
| Short-acting β agonist | 5179 (46.7) | 976 (32.0) | 1245 (72.8) | 1355 (83.6) | 451 (35.2) | 466 (34.0) | 345 (33.2) | 341 (33.7) | < 0.001 |
| Short-acting muscarinic antagonist | 3611 (32.6) | 530 (17.4) | 1021 (59.7) | 1093 (67.4) | 251 (19.6) | 280 (20.4) | 233 (22.4) | 203 (20.0) | < 0.001 |
| Long-acting β agonist | 100 (0.9) | 8 (0.3) | 24 (1.4) | 48 (3.0) | 3 (0.2) | 7 (0.5) | 2 (0.2) | 8 (0.8) | < 0.001 |
| Long-acting muscarinic antagonist | 1770 (16.0) | 126 (4.1) | 595 (34.8) | 733 (45.2) | 57 (4.4) | 52 (3.8) | 101 (9.7) | 106 (10.5) | < 0.001 |
Note: CT = computed tomography, DM-HF-Pulm = patients with diabetes, congestive heart failure and chronic lung disease; MRSA = methicillin-resistant Staphylococcus aureus.
↵* Antibiotics included only those specifically mentioned in the Infectious Diseases Society of America guidelines (13), (23) or Dragen and colleagues. (22) Cephalexin was also included since it has the same spectrum of activity to cefazolin.
↵† 2-tailed p value for differences between subgroups overall, determined by χ2 test.
↵‡ Ceftriaxone, cefotaxime, cefepime, cefdinir, cefditoren, cefpoxidime and ceftaroline.
↵§ Azithromycin, clarithromycin, erythromycin.
↵¶ Levofloxacin, moxifloxacin, ciprofloxacin, gemifloxicin.
↵** Amoxicillin–clavulinic acid, ampicillin–sulbactam, ticarcillin–clavulanate.
↵†† Aztreonam, streptomycin, colistin, gentamicin, trimethoprim–sulfamethoxazole), first-and second-generation cephalosporins (cefazolin, cefprozil, cefuroxime, cephalexin).
↵‡‡ Vancomycin, linezolid.
↵§§ Penicillin G, amoxicillin, ticarcillin, flucloxacillin, ampicillin, pipracillin.
↵¶¶ Carbapenems with pseudomonas coverage include meropenem, imipenem, impenem–cilastatin. Carbapenoms without pseudomonas coverage include ertapenem.
↵*** CT thorax performed in the first 4 days of admission.