Table 1. Preoperative Baseline Characteristics of Patients According to Immediate Postoperative Pain Cluster of Average Pain Trajectories.
| Preoperative Baseline Characteristic | No. (%)a | |
|---|---|---|
| Low Pain Cluster | High Pain Cluster | |
| Patients, No. | 193 | 178 |
| Age, mean (SD), y | 55.8 (12.5) | 57.6 (10.7) |
| Men | 82 (42.7) | 64 (36.2) |
| Marital status | ||
| Never married | 11 (6.0) | 18 (10.5) |
| Married | 136 (73.5) | 122 (71.4) |
| Living with someone | 8 (4.3) | 6 (3.5) |
| Divorced or separated | 24 (13.0) | 18 (10.5) |
| Widowed | 6 (3.2) | 7 (4.1) |
| Race | ||
| American Indian/Alaska Native | 10 (5.5) | 4 (2.5) |
| Asian/Pacific Islander | 17 (9.4) | 7 (4.3) |
| White | 138 (76.2) | 137 (84.6) |
| African American | 8 (4.4) | 8 (4.9) |
| Other | 8 (4.4) | 6 (3.7) |
| Ethnicity | ||
| Hispanic or Latino | 14 (7.8) | 13 (8.0) |
| Disability claimb | ||
| Filed | 63 (33.3) | 78 (44.8) |
| Pending | 16 (8.8) | 29 (17.6) |
| Employment status | ||
| Full-time | 85 (45.7) | 64 (37.9) |
| Part-time | 17 (9.1) | 18 (10.7) |
| Unemployed | 35 (18.8) | 38 (22.5) |
| Retired | 49 (26.3) | 49 (29.0) |
| Treatment group | ||
| Active placebo | 86 (44.6) | 90 (50.6) |
| Gabapentin | 107 (55.4) | 88 (49.4) |
| Surgery typec | ||
| Thoracotomy | 7 (3.6) | 7 (3.9) |
| Total knee replacement | 43 (22.3) | 97 (54.5) |
| Total hip replacement | 48 (24.9) | 41 (23.0) |
| Mastectomy | 25 (13.0) | 16 (9.0) |
| Lumpectomy | 27 (14.0) | 2 (1.1) |
| VATS | 17 (8.8) | 12 (6.7) |
| Hand surgery | 15 (7.8) | 2 (1.1) |
| Carpal tunnel surgery | 2 (1.0) | 1 (0.6) |
| Knee arthroscopy | 2 (1.0) | 0 |
| Shoulder arthroplasty | 3 (1.6) | 0 |
| Shoulder arthroscopy | 4 (2.1) | 0 |
| Baseline pain, mean (SD)c,d | ||
| At surgical site | 4.3 (3.0) | 6.2 (3.0) |
| Other than surgical site | 1.9 (2.2) | 2.9 (2.5) |
| Self-perceived likelihood of developing chronic pain after surgery | ||
| Not at all | 49 (26.5) | 34 (19.8) |
| Unlikely | 106 (57.3) | 108 (62.8) |
| Somewhat likely | 27 (14.6) | 24 (14.0) |
| Very likely | 3 (1.62) | 6 (3.5) |
| Self-perceived likelihood of developing chronic pain after injury | ||
| More likely | 29 (15.7) | 29 (17.1) |
| Less likely | 156 (84.3) | 141 (82.9) |
| Self-perceived sensitivity to painb | ||
| More than average | 10 (5.4) | 22 (13.0) |
| Average | 106 (56.7) | 94 (55.6) |
| Less than average | 71 (38.0) | 53 (31.4) |
| History of unexpectedly long recovery times from injuries in the pastb | 22 (11.8) | 35 (20.7) |
| Past 30-d prescription opioid use | 13 (6.7) | 21 (11.9) |
| Self-perceived likelihood of addiction to pain medication after surgeryb | ||
| Not at all | 99 (53.5) | 88 (51.2) |
| Unlikely | 82 (44.3) | 65 (38.4) |
| Somewhat likely | 3 (1.6) | 16 (9.3) |
| Very likely | 1 (0.5) | 2 (1.2) |
| Opioid Risk Tool scoree,f | 1.9 (2.8) | 2.8 (3.5) |
| History of alcohol or drug abuse treatmentb | 4 (2.2) | 13 (7.7) |
| Marlow-Crowne Social Desirability Scale score, mean (SD)g | 20.3 (5.8) | 20.6 (6.0) |
| Barratt Impulsivity Scale score, mean (SD)h | 68.7 (5.8) | 68.5 (7.7) |
| PTSD Checklist-Civilian Version score, mean (SD)i | 24.0 (8.1) | 25.7 (9.6) |
| State Anxiety Inventory score, mean (SD)b,j | 33.3 (10.5) | 36.4 (11.3) |
| Trait Anxiety Inventory score, mean (SD)b,k | 31.5 (9.9) | 34.2 (10.8) |
| Beck Depression Inventory-ll score, mean (SD)e,l | 8.6 (6.2) | 10.9 (7.3) |
| Euroqol VAS, mean (SD)b,m | 74.2 (18.8) | 68.8 (18.8) |
| Postoperative, median (IQR), d | ||
| Pain duration | 40.0 (16.0-82.0) | 92.0 (50.0-234.0) |
| Opioid use duration | 12.0 (5.0-32.0) | 39.0 (21.0-72.0) |
| Time to full recovery | 49.0 (24.0-130.0) | 89.0 (41.0-162.0) |
Abbreviations: IQR, interquartile range; PTSD, posttraumatic stress disorder; VAS, visual analog scale; VATS, video-assisted thoracoscopic surgery.
Percentages do not include patients with missing data.
Significant difference between clusters, P < .05.
Significant difference between clusters, P < .001.
Scale range, 1 to 10 (1, no pain; 10, pain as bad as you can imagine).
Significant difference between clusters, P < .005.
Scale range, 0 to 26 (0-3, low risk; 4-7, moderate risk; ≥8, high risk).
Scale range, 0 to 33 (0-8, low concern for social approval; 20-33, high concern for social approval).
Scale range, 30 to 120 (higher scores represent greater impulsiveness).
Scale range, 17 to 85 (higher scores represent more self-reported PTSD symptoms).
Scale range, 20 to 80 (higher scores represent increasing state of anxiety-anxiety in response to a specific situation).
Scale range, 20 to 80 (higher scores represent increasing trait anxiety-propensity to experience anxiety).
Scale range, 0 to 63 (higher scores represent higher depressive symptoms: 0-13, minimal; 14-19, mild; 20-28 moderate; 29-63, severe).
Scale range, 0 to 100 for self-assessment of health (0, worst imaginable health state; 100, best imaginable health state).