Baseline characteristics of patients with relatively high estimated glomerular filtration rate
| Characteristic | Drug; no. (%) of patients* | Standardized difference relative to nitrofurantoin, %† | |||||
|---|---|---|---|---|---|---|---|
| Nitrofurantoin n = 70 758 | Ciprofloxacin n = 29 095 | Norfloxacin n = 45 116 | TMP–SMX n = 37 665 | Ciprofloxacin | Norfloxacin | TMP– SMX | |
| Age, yr, mean ± SD | 75 ± 7 | 75 ± 7 | 76 ± 7 | 75 ± 7 | 3 | 8 | 1 |
| Year of cohort entry | |||||||
| 2002–2005 | 18 091 (25.6) | 7 037 (24.2) | 20 452 (45.3) | 15 383 (40.8) | 3 | 42 | 33 |
| 2006–2009 | 25 745 (36.4) | 11 588 (39.8) | 16 078 (35.6) | 12 958 (34.4) | 7 | 2 | 4 |
| 2010–2013 | 26 922 (38.0) | 10 470 (36.0) | 8 586 (19.0) | 9 324 (24.8) | 4 | 43 | 29 |
| Rural residence‡ | 7 522 (10.6) | 3 171 (10.9) | 5 025 (11.1) | 6 589 (17.5) | 1 | 2 | 20 |
| Prescription supply of 3–7 d | 57 679 (81.5) | 21 331 (73.3) | 35 385 (78.4) | 29 476 (78.2) | 20 | 8 | 8 |
| Health care use, mean ± SD§ | |||||||
| Primary care visits¶ | 8.99 ± 7.9 | 9.37 ± 8.1 | 9.26 ± 8.0 | 8.50 ± 7.4 | 5 | 4 | 7 |
| Emergency department visits | 3.19 ± 3.7 | 3.25 ± 3.5 | 3.04 ± 3.2 | 3.12 ± 3.4 | 3 | 8 | 3 |
| Hospital discharges | 1.77 ± 1.3 | 1.85 ± 1.5 | 1.81 ± 1.4 | 1.81 ± 1.4 | 8 | 4 | 4 |
| Urine cultures | 5.08 ± 6.3 | 5.72 ± 7.1 | 5.55 ± 6.6 | 4.41 ± 5.6 | 16 | 12 | 19 |
| Prior antibiotic prescriptions | |||||||
| 0 | 12 159 (17.2) | 4 208 (14.5) | 6 639 (14.7) | 7 034 (18.7) | 7 | 7 | 4 |
| 1 or 2 | 20 718 (29.3) | 7 818 (26.9) | 12 634 (28.0) | 11 716 (31.1) | 5 | 3 | 4 |
| 3 or 4 | 14 083 (19.9) | 5 696 (19.6) | 8 943 (19.8) | 7 488 (19.9) | 1 | 0 | 0 |
| ≥ 5 | 23 798 (33.6) | 11 373 (39.1) | 16 900 (37.4) | 11 427 (30.3) | 11 | 8 | 7 |
| Comorbidities** | |||||||
| Coronary artery disease†† | 19 573 (27.7) | 9 053 (31.1) | 13 941 (30.9) | 10 328 (27.4) | 8 | 7 | 1 |
| Dementia | 5 421 (7.7) | 2 290 (7.9) | 3 325 (7.4) | 2 618 (7.0) | 1 | 1 | 3 |
| Diabetes mellitus‡‡ | 9 413 (13.3) | 4 171 (14.3) | 5 429 (12.0) | 4 603 (12.2) | 3 | 4 | 3 |
| Heart failure | 5 695 (8.0) | 2 654 (9.1) | 4 009 (8.9) | 2 998 (8.0) | 4 | 3 | 0 |
| Peripheral vascular disease | 495 (0.7) | 220 (0.8) | 360 (0.8) | 276 (0.7) | 1 | 1 | 0 |
| Stroke | 1 337 (1.9) | 588 (2.0) | 918 (2.0) | 672 (1.8) | 1 | 1 | 1 |
| Urinary incontinence§§ | 2 205 (3.1) | 892 (3.1) | 1 381 (3.1) | 1091 (2.9) | 0 | 0 | 1 |
| Baseline medications ¶¶ | |||||||
| No. of unique medications, mean ± SD | 5.02 ± 3.60 | 5.36 ± 3.75 | 4.97 ± 3.53 | 4.69 ± 3.44 | 9 | 1 | 9 |
| ACE inhibitor | 19 334 (27.3) | 7 926 (27.2) | 12 606 (27.9) | 10 429 (27.7) | 0 | 1 | 1 |
| ARB | 10 638 (15.0) | 4 899 (16.8) | 6 192 (13.7) | 4 715 (12.5) | 5 | 4 | 7 |
| β-Blocker | 16 878 (23.8) | 7 258 (24.9) | 11 170 (24.8) | 8 778 (23.3) | 3 | 2 | 1 |
| Calcium-channel blocker | 17 724 (25.0) | 7 600 (26.1) | 11 242 (24.9) | 8 764 (23.3) | 2 | 0 | 4 |
| Loop diuretic | 4 392 (6.2) | 2 210 (7.6) | 3 105 (6.9) | 2 264 (6.0) | 5 | 3 | 1 |
| Potassium-sparing diuretic | 3 619 (5.1) | 1 625 (5.6) | 2 860 (6.3) | 2 241 (6.0) | 2 | 5 | 4 |
| Thiazide diuretic | 13 726 (19.4) | 5 256 (18.1) | 8 855 (19.6) | 7 871 (20.9) | 3 | 1 | 4 |
| Prescriber characteristics | |||||||
| Sex, female | 26 409 (37.3) | 8 036 (27.6) | 12 297 (27.3) | 10 813 (28.7) | 21 | 12 | 18 |
| Time since graduation, yr, mean ± SD | 23.69 ± 10.8 | 26.60 ± 10.8 | 27.54 ± 10.1 | 23.90 ± 11.1 | 12 | 15 | 1 |
Note: ACE = angiotensin-converting enzyme, ARB = angiotensin II receptor blocker, SD = standard deviation, TMP–SMX = trimethoprim–sulfamethoxazole.
↵* Unless otherwise indicated.
↵† Standardized differences are less sensitive to sample size than traditional measures for testing hypotheses. They provide a measure of the difference between groups divided by the pooled SD, where a value greater than 10% is considered to represent a meaningful difference.25
↵‡ Municipalities with population < 10 000 were considered to be rural.
↵§ Health care use (except for primary care visits) was assessed as the mean number of visits by a patient in the preceding 5 years.
↵¶ Primary care visits were assessed as the mean number of visits by a patient in the preceding year.
↵** Comorbidities were assessed for the preceding 5 years.
↵†† Coronary artery disease includes undergoing coronary artery bypass graft surgery or percutaneous coronary intervention and diagnosis of angina.
↵‡‡ Diabetes mellitus was assessed through use of oral hypoglycemic medications and insulin prescriptions in the preceding 120 days.
↵§§ Urinary incontinence was assessed through prescriptions for overactive bladder medication in the preceding 120 days.
↵¶¶ Baseline medications were assessed for the preceding 120 days.