Characteristics of patients who filled prescriptions for either oxycodone or codeine within 7 days of discharge after delivery
| Characteristic | No. (%)* of patients receiving oxycodone n = 49 299 | No. (%)* of patients receiving codeine n = 21 308 | Unweighted SD | IPTW SD† |
|---|---|---|---|---|
| Maternal | ||||
| Median (IQR) age, yr | 32 (29–36) | 30 (27–34) | 0.399 | 0.018 |
| Age group, yr | ||||
| < 25 | 3672 (7.4) | 3423 (16.1) | 0.039 | – |
| 25–35 | 32 466 (65.9) | 14 428 (67.7) | 0.257 | – |
| > 35 | 13 161 (26.7) | 3457 (16.2) | 0.270 | – |
| Income quintile | ||||
| 1 (lowest) | 10 009 (20.3) | 4793 (22.5) | 0.053 | 0.010 |
| 2 | 9384 (19.0) | 4426 (20.8) | 0.044 | 0.008 |
| 3 | 9568 (19.4) | 4426 (20.8) | 0.034 | 0.001 |
| 4 | 10 122 (20.5) | 4370 (20.5) | 0.001 | 0.005 |
| 5 (highest) | 10 216 (20.7) | 3293 (15.5) | 0.137 | 0.013 |
| Rural residence | 4018 (8.2) | 2672 (12.5) | 0.145 | 0.004 |
| Year of delivery | ||||
| 2012 | 2264 (4.6) | 2106 (9.9) | 0.205 | 0.002 |
| 2013 | 7477 (15.2) | 5083 (23.9) | 0.221 | 0.006 |
| 2014 | 7481 (15.2) | 4050 (19.0) | 0.102 | 0.003 |
| 2015 | 7009 (14.2) | 3237 (15.2) | 0.028 | 0.002 |
| 2016 | 7152 (14.5) | 2673 (12.5) | 0.057 | 0.013 |
| 2017 | 6544 (13.3) | 1757 (8.2) | 0.163 | 0.011 |
| 2018 | 5255 (10.7) | 1262 (5.9) | 0.172 | 0.011 |
| 2019 | 4348 (8.8) | 804 (3.8) | 0.209 | 0.000 |
| 2020 | 1769 (3.6) | 336 (1.6) | 0.127 | 0.007 |
| Median (IQR) no. of previous live births | 0 (0–1) | 0 (0–1) | 0.144 | 0.005 |
| Primigravid | 27 625 (56.0) | 10 678 (50.1) | 0.119 | 0.014 |
| Mental health diagnosis | 5995 (12.2) | 2390 (11.2) | 0.029 | 0.004 |
| Substance abuse diagnosis | 636 (1.3) | 369 (1.7) | 0.036 | 0.002 |
| Median (IQR) ADG | 8 (5–10) | 7 (4–9) | 0.280 | 0.022 |
| ADG score | ||||
| 0–5 | 12 476 (25.3) | 7986 (37.5) | 0.265 | – |
| 6–10 | 27 020 (54.8) | 10 115 (47.5) | 0.147 | – |
| > 10 | 9803 (19.9) | 3207 (15.1) | 0.128 | – |
| Delivery | ||||
| Mode of delivery | ||||
| Vaginal | ||||
| Spontaneous | 3027 (6.1) | 7003 (32.9) | 0.716 | 0.006 |
| Operative | 2158 (4.4) | 1934 (9.1) | 0.188 | 0.002 |
| Cesarean | 44 114 (89.5) | 12 371 (58.1) | 0.765 | 0.005 |
| Median (IQR) gestational age, wk | 39 (38–40) | 39 (38–40) | 0.209 | 0.000 |
| ≥37 | 43 551 (88.3) | 19 892 (93.4) | 0.175 | – |
| 34 to 36 | 3626 (7.4) | 1052 (4.9) | 0.101 | – |
| < 34 | 2122 (4.3) | 364 (1.7) | 0.152 | – |
| Episiotomy | 2045 (4.1) | 2657 (12.5) | 0.305 | 0.003 |
| 1st- or 2nd-degree perineal tear | 2335 (4.7) | 4,654 (21.8) | 0.521 | 0.004 |
| 3rd- or 4th-degree perineal tear | 1204 (2.4) | 696 (3.3) | 0.050 | 0.006 |
| Median (IQR) hospital length of stay, d | 2 (2–3) | 2 (1–2) | 0.501 | 0.030 |
| Severe maternal morbidity | 1512 (3.1) | 352 (1.7) | 0.093 | 0.013 |
| Median (IQR) birthweight, g | 3360 (2975–3730) | 3404 (3078–3746) | 0.105 | 0.002 |
| Stillbirth | 69 (0.1) | 12 (0.1) | 0.027 | 0.005 |
Note: ADG = aggregated diagnosis groups defined using the Johns Hopkins ACG System version 10, IPTW = inverse probability of treatment weighting, IQR = interquartile range, SD = standardized difference.
↵* Unless otherwise specified.
↵† Weighted standardized differences are of the mean of continuous variables.