Table 2.
Univariate analysis: select demographic and clinical characteristics and healthcare and medication exposures among study participants
| Variable | Cases No. (%) | Controls No. (%) | Unadjusted matched odds ratio (95% CI) | P-value |
|---|---|---|---|---|
| Demographic information | ||||
| White race | 54/68 (79.4) | 46/68 (67.6) | 1.73 (0.78–4.01) | 0.20 |
| Hispanic/Latino | 19/68 (27.9) | 18/68 (26.5) | 1.08 (0.46–2.59) | 1.00 |
| Have health insurance | 67/68 (98.5) | 67/67 (100.0) | 1.00 (0.00–19.00) | 1.00 |
| Household income >$50k | 37/62 (59.7) | 40/64 (62.5) | 1.17 (0.50–2.76) | 0.85 |
| Select medical conditions | ||||
| Any medical condition | 22/66 (33.3) | 8/66 (12.1) | 3.17 (1.22–9.69) | 0.01 |
| Congenital heart disease | 3/67 (4.5) | 1/67 (1.5) | 3.00 (0.24–157.49) | 0.63 |
| Cystic fibrosis | 1/67 (1.5) | 0/67 (0.0) | 1.00 (0.05–undef) | 1.00 |
| Gastrointestinal condition | 5/67 (7.5) | 1/67 (1.5) | 5.00 (0.56–236.49) | 0.22 |
| Short-gut disease | 3/67 (4.5) | 0/67 (0.0) | 3.85 (0.58–undef) | 0.25 |
| Asthma | 3/67 (4.5) | 1/66 (1.5) | 3.00 (0.24–157.49) | 0.63 |
| Bronchopulmonary dysplasia | 2/66 (3.0) | 0/67 (0.0) | 2.41 (0.29–undef) | 0.50 |
| Organ transplant | 1/67 (1.5) | 0/67 (0.0) | 1.00 (0.05–undef) | 1.00 |
| Neurologic illness | 7/67 (10.4) | 3/67 (4.5) | 2.33 (0.53–13.98) | 0.34 |
| Healthcare exposuresa | ||||
| Any higher-risk outpatient exposureb | 23/66 (34.9) | 12/68 (17.7) | 4.20 (1.09–19.36) | 0.03 |
| Any lower-risk outpatient exposureb | 31/66 (47.0) | 38/68 (55.9) | 1.34 (0.50–3.83) | 0.68 |
| Exposure to any outpatient setting | 54/66 (81.8) | 50/68 (73.5) | 1.63 (0.62–4.52) | 0.38 |
| Dentist's office | 8/65 (12.3) | 10/68 (14.7) | 0.75 (0.21–2.46) | 0.79 |
| Doctor's office | 47/62 (75.8) | 42/68 (61.8) | 1.90 (0.84–4.57) | 0.14 |
| Emergency department | 12/65 (18.5) | 5/68 (7.4) | 5.00 (1.07–46.93) | 0.04 |
| Haemodialysis | 0/66 (0.0) | 0/68 (0.0) | – | – |
| Hospital-based outpatient setting | 6/66 (9.1) | 1/68 (1.5) | 6.73 (1.22–undef) | 0.06 |
| Outpatient laboratory | 1/65 (1.5) | 5/68 (7.4) | 0.20 (0.004–1.79) | 0.22 |
| Outpatient procedure centre | 4/65 (6.2) | 4/68 (5.9) | 1.00 (0.13–7.47) | 1.00 |
| Outpatient surgery centre | 5/65 (7.7) | 0/68 (0.0) | 6.73 (1.22–undef) | 0.06 |
| Physical therapy centre | 4/65 (6.2) | 1/68 (1.5) | 4.00 (0.39–196.99) | 0.38 |
| Urgent care | 3/65 (4.6) | 3/68 (4.4) | 1.00 (0.13–7.47) | 1.00 |
| Received any outpatient procedure | 12/65 (18.5) | 13/68 (19.1) | 0.89 (0.29–2.59) | 1.00 |
| Dental cleaning | 6/65 (9.2) | 10/68 (14.7) | 0.50 (0.11–1.87) | 0.39 |
| Endoscopy | 1/65 (1.5) | 1/68 (1.5) | 1.00 (0.01–78.49) | 1.00 |
| X-ray that required bowel preparation | 0/65 (0.0) | 1/68 (1.5) | 1.00 (0.00–19.00) | 1.00 |
| Surgical procedure | 6/65 (9.2) | 3/68 (4.4) | 2.00 (0.43–12.36) | 0.51 |
| Visited or accompanied a person to a healthcare facility | 18/66 (27.3) | 12/67 (17.9) | 1.50 (0.63–3.73) | 0.42 |
| Had a feeding tube | 2/68 (2.9) | 0/68 (0.0) | 2.41 (0.29–undef) | 0.50 |
| Birth | ||||
| Delivered via C-section | 19/67 (28.4) | 22/67 (32.8) | 0.84 (0.41–1.73) | 0.74 |
| Stayed in NICU | 18/67 (26.9) | 8/67 (11.9) | 3.00 (1.04–10.55) | 0.04 |
| Medication exposuresa | ||||
| Any antibiotic use in prior 12 weeks | 37/68 (54.4) | 13/67 (19.4) | 5.80 (2.22–19.19) | <0.0001 |
| Any antibiotic use in prior 4 weeksc | 25/66 (37.9) | 6/66 (9.1) | 6.87 (2.20–29.21) | 0.0001 |
| Any antibiotic use in prior 4–12 weeksc | 10/66 (15.2) | 6/66 (9.1) | 3.32 (0.85–15.85) | 0.09 |
| Azithromycin | 2/68 (2.9) | 1/67 (1.5) | 2.00 (0.01–117.99) | 1.00 |
| β-lactam and/or β-lactamase inhibitor combination | 14/68 (20.6) | 9/67 (13.4) | 1.71 (0.62–5.14) | 0.36 |
| Cephalosporin | 14/68 (20.6) | 1/67 (1.5) | 14.00 (2.13–591.97) | 0.001 |
| Clindamycin | 1/68 (1.5) | 0/67 (0.0) | 1.00 (0.05–undef) | 1.00 |
| Erythromycin/sulfamethoxazole | 1/68 (1.5) | 0/67 (0.0) | 1.00 (0.05–undef) | 1.00 |
| Fluoroquinolone | 1/68 (1.5) | 2/67 (3.0) | 0.50 (0.01–9.60) | 1.00 |
| Metronidazole | 2/68 (2.9) | 0/67 (0.0) | 2.41 (0.29–undef) | 0.50 |
| Trimethoprim/sulfamethoxazole | 1/68 (1.5) | 0/67 (0.0) | 1.00 (0.05–undef) | 1.00 |
| Vancomycin (intravenous) | 1/68 (1.5) | 0/67 (0.0) | 1.00 (0.05–undef) | 1.00 |
| Any acid reducing medication | 4/66 (6.1) | 2/67 (3.0) | 3.00 (0.24–157.49) | 0.63 |
| Any antidepressant | 1/67 (1.5) | 0/66 (0.0) | 1.00 (0.05–undef) | 1.00 |
CI, confidence interval; NICU, neonatal intensive care unit.
Participants could have declined to answer a question; any missing response to a variable was excluded from the denominator.
Exposure period was during the 12 weeks preceding illness onset.
The reference group for the higher- and lower-risk exposure categories were participants with no outpatient exposure. A higher-risk outpatient exposure was defined as exposure to an emergency room, outpatient procedure centre, haemodialysis facility, hospital-based outpatient setting, urgent care or ambulatory surgical centre. A lower-risk outpatient exposure was defined as exposure to a dental office, doctor's office, outpatient laboratory or physical therapy centre.
Two case-patients and one control subject could not recall the exact time-frame of antibiotic exposure during the preceding 12 weeks.