Table 2.
Descriptive Baseline Characteristics of Study Participants With and Those Without Persistent Musculoskeletal Pain at 12 Monthsa.
| Variable | Total Sample (n = 279) | Participants With Persistent Pain (n = 101) | Participants Without Persistent Pain (n = 178) | P |
|---|---|---|---|---|
| Demographic | ||||
| Age, y, mean (SD) | 46.5 (S) | 48.3 (15.1) | 45.4 (16.5) | .152 |
| Sex, women | 183 (65.6) | 73 (72.3) | 110 (61.8) | .173 |
| Race | .276 | |||
| American Indian/Alaska native | 2 (0.7) | 1 (1.0) | 1 (0.6) | |
| Asian | 17 (6.1) | 2 (2.0) | 15 (8.4) | |
| Black or African American | 30 (10.8) | 11 (10.9) | 19 (10.7) | |
| White | 226 (81.0) | 86 (85.1) | 140 (78.7) | |
| Prefer not to answer | 4 (1.4) | 1 (1.0) | 3 (1.7) | |
| Household income | .004 | |||
< 20,000 |
30 (10.8) | 20 (19.8) | 10 (5.6) | |
 20,000– 35,000 |
39 (14.0) | 16 (15.8) | 23 (12.9) | |
 35,001– 50,000 |
33 (11.8) | 8 (7.9) | 25 (14.0) | |
 50,001– 70,000 |
32 (11.5) | 12 (11.9) | 20 (11.2) | |
> 70,000 |
112 (40.1) | 32 (31.7) | 80 (44.9) | |
| Prefer not to answer | 33 (11.8) | 13 (12.9) | 20 (11.2) | |
| Employment | .055 | |||
| Employed full-time | 149 (53.4) | 48 (47.5) | 101 (56.7) | |
| Employed part-time | 41 (14.7) | 10 (9.9) | 31 (17.4) | |
| Unemployed | 30 (10.8) | 15 (14.9) | 15 (8.4) | |
| Retired | 47 (16.8) | 22 (21.8) | 25 (14.0) | |
| Prefer not to answer | 12 (4.3) | 6 (5.9) | 6 (3.4) | |
| Education | .208 | |||
| High school or lower | 18 (6.5) | 6 (5.9) | 12 (6.7) | |
| Some college | 63 (22.6) | 29 (28.7) | 34 (19.1) | |
| Graduated from college | 79 (28.3) | 32 (31.7) | 47 (26.4) | |
| Some postgraduate course work | 41 (14.7) | 14 (13.9) | 27 (15.2) | |
| Completed postgraduate degree | 74 (26.5) | 19 (18.8) | 55 (30.9) | |
| Prefer not to answer | 4 (1.4) | 1 (1.0) | 3 (1.7) | |
| Geographical region | .095 | |||
| Portland, OR | 16 (5.7) | 4 (4.0) | 12 (6.7) | |
| Los Angeles, CA | 43 (15.4) | 10 (9.9) | 33 (18.5) | |
| Greenville, SC | 58 (20.8) | 24 (23.8) | 34 (19.1) | |
| Boulder, CO | 16 (5.7) | 6 (5.9) | 10 (5.6) | |
| Jacksonville, FL | 29 (10.4) | 9 (8.9) | 20 (11.2) | |
| Gainesville, FL | 80 (28.7) | 37 (36.6) | 43 (24.2) | |
| Philadelphia, PA | 13 (4.7) | 1 (1.0) | 12 (6.7) | |
| Chicago, IL | 11 (3.9) | 5 (5.0) | 6 (3.4) | |
| Terra Haute, IN | 13 (4.7) | 5 (5.0) | 8 (4.5) | |
| Clinical | ||||
| Body region | .403 | |||
| Neck | 59 (21.1) | 23 (22.8) | 36 (20.2) | |
| Low back | 72 (25.8) | 31 (30.7) | 41 (23.0) | |
| Shoulder | 66 (23.7) | 21 (20.8) | 45 (25.3) | |
| Knee | 82 (29.4) | 26 (25.7) | 56 (31.5) | |
| Surgery, yes | 46 (16.5) | 16 (15.8) | 30 (16.9) | .827 |
| Persistent pain at baseline, yes | 222 (79.6) | 84 (83.2) | 138 (77.5) | .261 |
| Episodes over past year, yes | 143 (51.3) | 62 (61.4) | 81 (45.5) | .036 |
| Pain intensity, NPRS, mean (SD) | 3.9 (1.7) | 4.7 (1.5) | 3.4 (1.6) | <.0001 |
| Comorbidityb | <.0001 | |||
| 0 | 79 (28.3) | 17 (16.8) | 62 (34.8) | |
| 1 | 54 (19.4) | 14 (13.9) | 40 (22.5) | |
| ≥2 | 144 (51.6) | 70 (69.3) | 74 (41.6) | |
| OSPRO-ROS, 10 items, mean (SD) | 2.6 (2.3) | 3.4 (2.7) | 2.1 (1.9) | <.0001 |
| OSPRO-ROS + additional 13 items,c mean (SD) | 1.2 (1.6) | 1.8 (1.9) | 0.8 (1.2) | <.0001 |
| OSPRO-YF, 10 items, mean (SD) | 16.9 (6.3) | 19.4 (7.1) | 15.5 (5.3) | <.0001 |
| OSPRO-YF + additional 7 items,c mean (SD) | 14.3 (4.9) | 16.0 (5.3) | 13.4 (4.4) | <.0001 |
aData are reported as number (percentage) of participants unless otherwise indicated. NPRS = numerical pain rating scale (potential range = 0–10, with higher scores indicating higher pain intensity), OSPRO-ROS = Optimal Screening for Prediction of Referral and Outcome Review of Systems; OSPRO-YF = Optimal Screening for Prediction of Referral and Outcome Yellow Flag.
bComorbidity data included composite counts (0, 1, or ≥2) from the Charlson Comorbidity Index and the Functional Comorbidity Index.
cAdditional items were from longer versions of the corresponding tool.