Table 4. Multivariable Models of Antibiotic Exposure by Age 48 Months With Body Mass at Age 48 to 68 Months.
| Measures of Antibiotic Exposure by Age ≤48 moa | Participants, No. | WHO Standard, BMI z Score (n = 4398) | IOTF Guidelines (n = 4398)b | ||||
|---|---|---|---|---|---|---|---|
| Overweight (n = 873) | Obese (n = 354) | ||||||
| Adjusted Mean (SE)a | P Value | Adjusted OR (95% CI)a | P Value | Adjusted OR (95% CI)a | P Value | ||
| Any Antibiotics | |||||||
| Any antibiotics by age ≤48 mo, No. of dispensings | |||||||
| None | 204 | 0.87 (0.09) | [Reference] | 1 [Reference] | [Reference] | 1 [Reference] | [Reference] |
| 1-3 | 1007 | 0.92 (0.06) | .57 | 0.95 (0.63-1.46) | .83 | 1.11 (0.48-2.57) | .81 |
| 4-6 | 997 | 1.06 (0.06) | .02 | 1.36 (0.90-2.07) | .15 | 1.85 (0.81-4.23) | .14 |
| 7-9 | 784 | 1.06 (0.06) | .02 | 1.38 (0.90-2.13) | .14 | 2.05 (0.90-4.70) | .09 |
| >9 | 1406 | 1.08 (0.05) | .01 | 1.23 (0.81-1.86) | .34 | 2.41 (1.07-5.41) | .03 |
| Timing of exposure to any antibiotics | |||||||
| Unexposed by age ≤48 mo | 204 | 0.89 (0.09) | [Reference] | 1 [Reference] | [Reference] | 1 [Reference] | [Reference] |
| Unexposed at ≤12 mo but exposed at >12 mo | 1522 | 1.02 (0.06) | .10 | 1.18 (0.79-1.78) | .42 | 1.69 (0.75-3.82) | .20 |
| Exposed at ≤12 mo with or without subsequent exposure | 2672 | 1.06 (0.05) | .03 | 1.21 (0.81-1.81) | .36 | 1.90 (0.86-4.23) | .11 |
| Type of Antibiotics | |||||||
| Penicillins, No. of dispensings | |||||||
| None by age ≤48 mo | 286 | 0.96 (0.08) | [Reference] | 1 [Reference] | [Reference] | 1 [Reference] | [Reference] |
| 1-3 | 1411 | 0.96 (0.06) | .96 | 0.95 (0.67-1.34) | .77 | 0.95 (0.51-1.78) | .87 |
| 4-6 | 1138 | 1.04 (0.06) | .22 | 1.10 (0.77-1.56) | .61 | 1.34 (0.71-2.50) | .37 |
| >6 | 1563 | 1.09 (0.05) | .04 | 1.11 (0.79-1.58) | .55 | 1.61 (0.87-2.98) | .13 |
| Macrolides, No. of dispensings | |||||||
| None by age ≤48 mo | 3072 | 1.02 (0.05) | [Reference] | 1 [Reference] | [Reference] | 1 [Reference] | [Reference] |
| 1 | 732 | 1.10 (0.06) | .08 | 1.16 (0.94-1.43) | .17 | 1.24 (0.90-1.70) | .19 |
| ≥2 | 594 | 1.09 (0.06) | .14 | 1.09 (0.86-1.37) | .49 | 1.61 (1.18-2.21) | .003 |
| Cephalosporins, No. of dispensings | |||||||
| None by age ≤48 mo | 2968 | 1.02 (0.05) | [Reference] | 1 [Reference] | [Reference] | 1 [Reference] | [Reference] |
| 1 | 758 | 1.07 (0.06) | .29 | 1.19 (0.97-1.47) | .10 | 1.11 (0.81-1.51) | .52 |
| ≥2 | 672 | 1.08 (0.06) | .22 | 1.10 (0.88-1.38) | .38 | 1.24 (0.90-1.70) | .19 |
| Co-trimoxazole, No. of dispensings | |||||||
| None by age ≤48 mo | 2793 | 1.00 (0.05) | [Reference] | 1 [Reference] | [Reference] | 1 [Reference] | [Reference] |
| 1 | 794 | 1.09 (0.06) | .05 | 1.05 (0.85-1.30) | .64 | 1.60 (1.18-2.17) | .002 |
| ≥2 | 811 | 1.11 (0.06) | .01 | 1.19 (0.97-1.45) | .10 | 1.52 (1.13-2.04) | .006 |
Abbreviations: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); IOTF, International Obesity Task Force; OR, odds ratio; WHO, World Health Organization.
Separate multivariable models were used for each measure. Each model adjusted for child’s sex; birth weight; delivery mode; birth season; birth order; antireflux medication dispensed by age 48 months; sleep duration at age 24 months; time spent (last weekday) watching television, DVDs, or videos at age 24 months; duration of exclusive breastfeeding; and dietary intake at age 24 months. Each model also adjusted for maternal age, ethnicity, education, socioeconomic deprivation, self-reported prepregnancy weight (log scale), and alcohol use and antibiotic exposure during pregnancy.
Multinomial logistic regression models with normal-weight or underweight children (n = 3171) as the reference group.