Patient characteristics by persistent pain
| No persistent pain at 6 or 12 months (N=53) | Persistent pain at 6 or 12 months (N=71) | P value | |
| Patient variables | |||
| Age (years) | 59.13 (10.83) | 55.18 (11.56) | 0.06* |
| Height (cm) | 162.82 (6.60) | 163.26 (5.65) | 0.69* |
| Weight (kg) | 76.80 (67.00, 86.00) | 76.20 (67.13, 90.10) | 0.99† |
| BMI (kg/m2) | 28.30 (25.22, 33.54) | 29.06 (24.91, 32.05) | 0.73† |
| Race | 0.84‡ | ||
| African American | 16 (30.19) | 17 (23.94) | |
| Caucasian | 35 (66.04) | 51 (71.83) | |
| Other | 2 (3.77) | 3 (4.23) | |
| Education | 0.13‡ | ||
| Less than high school | 2 (4.55) | 6 (9.09) | |
| High school | 12 (27.27) | 9 (13.64) | |
| College | 25 (56.82) | 35 (53.03) | |
| Master’s degree/PhD | 5 (11.36) | 16 (24.24) | |
| Preoperative breast pain | 7 (13.21) | 15 (21.13) | 0.34‡ |
| Previous breast surgery | 8 (15.09) | 14 (19.72) | 0.50§ |
| Previous chemotherapy | 12 (22.64) | 23 (32.39) | 0.23§ |
| Previous radiotherapy | 4 (7.55) | 3 (4.23) | 0.46‡ |
| Baseline questionnaire scores | |||
| STAI score | 45.00 (42.00, 49.00) | 47.00 (42.00, 50.00) | 0.34 |
| Total MTS score (TS10–TS1) | 0.00 (0.00, 1.00) | 0.00 (0.00, 1.00) | 0.61 |
| MTS positive | 18 (33.96) | 27 (38.57) | 0.60 |
| DNIC | 0.00 (−0.80, 1.80) | 0.40 (−1.00, 2.00) | 0.66 |
| Total PCS | 4.00 (0.00, 12.00) | 6.00 (1.00, 14.00) | 0.28 |
| Total PCS category | 0.33 | ||
| <10 | 36 (67.92) | 44 (61.97) | |
| 10–19 | 10 (18.87) | 21 (29.58) | |
| ≥20 | 7 (13.21) | 6 (8.45) | |
| BDI score | 5.00 (2.00, 9.00) | 7.00 (3.00, 11.00) | 0.12 |
| Surgery-related variables | |||
| Laterality (bilateral) | 11 (20.75) | 14 (19.72) | 0.89§ |
| Axillary surgery type | 0.16§ | ||
| Axillary dissection | 5 (9.43) | 14 (19.72) | |
| Sentinel node biopsy | 28 (52.83) | 39 (54.93) | |
| None | 20 (37.74) | 18 (25.35) | |
| Type of surgery | 0.48‡ | ||
| Mastectomy with reconstruction | 3 (5.66) | 10 (14.08) | |
| Modified radical mastectomy | 6 (11.32) | 6 (8.45) | |
| Partial mastectomy | 31 (58.49) | 40 (56.34) | |
| Simple mastectomy | 13 (24.53) | 15 (21.13) | |
| Surgeon | 0.88§ | ||
| 1 | 18 (33.96) | 25 (35.21) | |
| 2 | 11 (20.75) | 16 (22.54) | |
| 3 | 20 (37.74) | 27 (38.03) | |
| 4¶ | 4 (7.55) | 3 (4.23) | |
| Duration of surgery (min) | 105.00 (71.00, 144.00) | 113.00 (73.00, 164.00) | 0.32† |
| Intraoperative opioids (mg morphine equivalents) | 2.70 (1.50, 3.75) | 2.50 (1.50, 3.75) | 0.82† |
| Regular analgesia | 6 (11.32) | 8 (11.27) | >0.99‡ |
| Paravertebral block | 30 (56.60) | 37 (52.11) | 0.62§ |
| General anesthesia | 24 (45.28) | 46 (64.79) | 0.03§ |
| Postoperative variables | |||
| Maximum acute pain score | 4.00 (2.00, 7.00) | 5.00 (4.00, 8.00) | 0.01† |
| Maximum acute pain category | <0.01§ | ||
| Mild (0–3) | 26 (49.06) | 14 (20.00) | |
| Moderate (4–6) | 13 (24.53) | 27 (38.57) | |
| Severe (7–10) | 14 (26.42) | 29 (41.43) | |
| Duration of PACU stay (min) | 89.00 (63.00, 124.00) | 83.00 (63.00, 115.00) | 0.55† |
| PACU opioids consumption (mg) | 0.00 (0.00, 5.00) | 1.67 (0.00, 5.00) | 0.60† |
| PACU acetaminophen consumption (mg) | 0.00 (0.00, 0.00) | 0.00 (0.00, 0.00) | 0.25† |
| Opioids 24 hours | 37 (69.81) | 54 (77.14) | 0.36§ |
| Acetaminophen 24 hours | 26 (49.06) | 45 (64.29) | 0.09§ |
| NSAIDs 24 hours | 2 (3.77) | 0 (0.00) | 0.18‡ |
| Opioids 72 hours | 24 (45.28) | 34 (50.00) | 0.61§ |
| Acetaminophen 72 hours | 21 (39.62) | 27 (39.71) | 0.99§ |
| NSAIDs 72 hours | 3 (5.66) | 4 (5.88) | >0.99‡ |
Data are median (Q1, Q3), mean (SD), or count (%).
*Equal variance t-test.
†Wilcoxon test.
‡Fisher exact test.
§Chi-square test.
¶Surgeon ID 4 is a combination of two surgeons who each treated five patients or less.
BDI, Beck depression inventory; BMI, body mass index; DNIC, diffuse noxious inhibitory control; MTS, mechanical temporal summation; NSAIDs, non-steroidal anti-inflammatory drugs; PACU, post-anesthesia care unit; PCS, pain catastrophizing scale; STAI, state trait anxiety inventory.