Table 1.
Demographic and Clinical Characteristics by Group [Mean (SD) / % (n)]
| Demographic and Clinical Variables |
Controls: No Pain Disorder | Knee Osteoarthritis (ACR) | Total Sample | ||
|---|---|---|---|---|---|
| RDC Good sleeper |
RDC Primary Insomnia |
RDC Good Sleeper |
RDC Insomnia | ||
| Age (mean ± SD) | 57.6 (7.3) | 58.9 (8.6) | 66.55 (10.6)*** | 59.2 (9.1) | 60.0 (9.4) |
| Female | 62.1 (18) | 80.0 (24) | 51.6 (16) | 78.0 (92) | 72.1 (150) |
| Race/Ethnicity | N = 29 | N = 30 | N = 31 | N = 118 | N = 208 |
| Non-Hispanic White American | 69.0 (20) | 50.0 (15) | 74.2 (23) | 55.1 (65) | 59.1 (123) |
| African American | 24.1 (7) | 46.7 (14) | 22.6 (7) | 41.5 (49) | 37.0 (77) |
| Asian American | 3.4 (1) | 3.3 (1) | 3.2 (1) | 2.5 (3) | 2.9 (6) |
| Multiracial | 3.4 (1) | 0 | 0 | .8 (1) | 1.0 (2) |
| Education Level | N = 29 | N = 30 | N = 31 | N = 117 | N = 207 |
| High School/Some College | 31.0 (9) | 43.2 (13) | 32.3 (10) | 51.4 (60) | 44.4 (92) |
| College Graduate | 44.8 (13) | 30.0 (9) | 22.6 (7) | 21.4 (25) | 26.1 (54) |
| Graduate Studies | 24.1 (7) | 26.7(8) | 45.1 (14) | 27.4 (32) | 29.5 (61) |
| Occupational Status | N = 29 | N = 30 | N = 31 | N = 117 | N = 207 |
| Full-Time Employment | 34.5 (10) | 30 (9) | 25.8 (8) | 29.1 (34) | 29.5 (61) |
| Part-Time Employment | 20.7 (6) | 23.3 (7) | 16.1 (5) | 13.7 (16) | 16.4 (34) |
| Student | 3.4 (1) | 0 | 0 | 0 | 0.5 (1) |
| Homemaker | 3.4 (1) | 10.0 (3) | 3.2 (1) | 5.1 (6) | 5.3 (11) |
| Unemployed | 17.2 (5) | 13.3 (4) | 0 | 20.5 (24) | 15.9 (33) |
| Retired | 20.7 (6) | 23.3 (7) | 54.8 (17) | 31.6 (37) | 32.4 (67) |
| Marital Status | N = 29 | N = 30 | N = 31 | N = 117 | N = 207 |
| Single/Divorced/Separated/Widowed | 58.6 (17) | 53.4 (12) | 38.8 (12) | 53.8 (63) | 52.2 (108) |
| Living with partner | 3.4 (1) | 0 | 3.2 (1) | 2.6 (3) | 2.4 (5) |
| Married | 34.5 (10) | 46.7 (14) | 48.4 (15) | 41.9 (49) | 42.5 (88) |
| Yearly Household Income | N = 28 | N = 27 | N = 30 | N = 101 | N = 186 |
| $25,000 or less | 21.4 (6) | 18.5 (5) | 3.3 (1) | 28.7 (29) | 22.0 (41) |
| $25,001–$50,000 | 39.3 (11) | 18.5 (5) | 36.7 (11) | 31.7 (32) | 31.7 (59) |
| $50,001–$75,000 | 17.9 (5) | 25.9 (7) | 33.3 (10) | 13.9 (14) | 19.4 (36) |
| >$75,000 | 21.4 (6) | 37.0 (10) | 26.7 (8) | 25.7 (26) | 26.9 (50) |
| Clinical Variables | N = 28–29 | N = 26–31 | N = 29–30 | N = 114–118 | N = 198–208 |
| BMI | 26.0 (4.8) | 26.8 (5.1) | 29.1 (4.7)* | 31.2 (6.5)*** | 29.5 (6.2)*** |
| SBP | 124.8 (17.0) | 122.6 (17.5) | 132.4 (22.2) | 129.7 (19.3) | 128.3 (19.3) |
| DBP | 77.9 (12.4) | 77.9 (12.1) | 79.0 (12.4) | 81.3 (11.0) | 80.0 (11.6) |
| WOMAC (total score) | .11 (.1) | .22 (.2) | 3.0 (2.2)*** | 4.9 (2.2)*** | 3.3 (2.8)*** |
| Diary Pain (0–100) | 12.9 (9.2) | 18.1 (12.5) | 31.2 (18.8)*** | 46.0 (18.5)*** | 36.4 (21.3)*** |
| PSQI | 2.6 (1.8) | 12.5 (3.3)*** | 3.4 (2.2) | 11.9 (3.2)*** | 9.4 (5.1)*** |
| ISI | 1.3 (1.7) | 17.6 (5.1)*** | 2.2 (2.5) | 17.2 (4.9)*** | 12.8 (8.3)*** |
| ESS | 4.3 (3.0) | 7.1 (6.0)* | 5.6 (3.9) | 9.5 (5.1)*** | 7.8 (5.2)*** |
| PCS | 6.1 (8.4) | 6.9 (9.4) | 4.4 (4.4) | 15.2 (10.3)*** | 11.1 (10.4*** |
| CES-D | 3.1 (3.3) | 13.9 (8.2)*** | 3.5 (4.1) | 14.1 (8.5)*** | 10.9 (8.8)*** |
Differ from Non Pain Control Good Sleeper Reference group, two-tailed t-test
*
(p<.05),
**
(p<.01),
***
(p<.001).
Omnibus significance level is noted in the Total Sample column
Abbreviations: BMI: Body Mass Index; SBP: Systolic Blood Pressure; DBP: Diastolic Blood Pressure; WOMAC: Western Ontario McMaster Universities Osteoarthritis Scale; PSQI: Pittsburgh Sleep Quality Index; ISI: Insomnia Severity Index; ESS: Epworth Sleepiness Scale; PCS: Pain Catastrophizing Scale; CES-D: Center for Epidemiologic Studies Depression Scale