Table 3.
Results of cognitive testing stratified by depression status.
| Function Tested/Cognitive Test |
Test Scores | Univariate | Parsimonious* | Multivariable | ||||
|---|---|---|---|---|---|---|---|---|
| CES-D <16 | CES-D ≥16 | β coefficient | p-value | β coefficient | p-value | β coefficient | p-value | |
| Screen | ||||||||
| MMSE | 26.7 ± 2.8 | 26.4 ± 2.8 | −0.2 | 0.6 | −0.2 | 0.7 | −0.3 | 0.4 |
| Intelligence | ||||||||
| NAART** | 101.7 ± 12.0 | 101.9 ± 12.0 | 0.2 | 0.9 | 1.0 | 0.6 | 2.0 | 0.2 |
| Primarily Cortical (memory) |
||||||||
| Percent Retention | 54.5 ± 28.4 | 47.6 ± 28.0 | −6.8 | 0.1 | −6.7 | 0.1 | −7.7 | 0.07 |
| Recognition | 20.8 ± 3.2 | 20.5 ± 2.7 | −0.3 | 0.6 | −0.3 | 0.5 | −0.4 | 0.3 |
| Primarily Subcortical (executive function & processing speed) |
||||||||
| Block Design | 26.8 ± 10.5 | 23.7 ± 10.5 | −3.0 | 0.06 | −2.7 | 0.06 | −2.9 | 0.03 |
| Digit Symbol Coding | 41.4 ± 17.2 | 34.2 ± 14.7 | −7.2 | 0.008 | −6.8 | 0.002 | −5.5 | 0.01 |
| Trails A | 58.8 ± 33.4 | 67.9 ± 47.2 | 8.5 | 0.1 | 7.5 | 0.2 | 9.2 | 0.09 |
| Trails B | 135.9 ± 65.8a | 157.9 ± 62.0b | 40.3 | 0.02 | 37.3 | 0.01 | 34.6 | 0.02 |
Scores are provided as mean ± standard deviation. All tests represent number or percent correct except Trails A and B, which are reported in seconds required to complete the task. Trails B analyses were performed using Tobit regression to account for failure to complete the task within 5 minutes. A negative B coefficient is consistent with poorer performance on all tests except the Trails A and B, where a positive coefficient identifies worse performance.
Abbreviations: BMI, body mass index; CAD, coronary artery disease ; CES-D, Center for Epidemiological Studies Depression Scale ; CHF, congestive heart failure ; ESRD, end-stage renal disease; MMSE, Mini-Mental State Exam ; NAART, North American Adult Reading Test; PTH, parathyroid hormone; PVD, peripheral vascular disease; SBP, systolic blood pressure
Parsimonious models adjust for age, education, and sex.
full multivariable models adjust for age, education, and sex as well as additional variables that vary by cognitive test: MMSE (cause of ESRD, smoking status, race, BMI, PTH, Kt/V, and phosphate); NAART (cause of ESRD, race, PTH, hematocrit, and PVD); Percent Retention (CAD, CHF, race, and BMI); Recognition (smoking status, race, BMI, SBP, and Kt/V); Block Design (CAD, vintage, race, BMI, Kt/V, and PVD); Digit Symbol Coding (CAD, CHF, cause of ESRD, race, SBP, weight change, stroke, and PVD); Trails A (smoking status and vintage); and Trails B (CAD, cause of ESRD, race, BMI, Kt/V, and PVD).
For those who completed; 19.9% did not complete.
For those who completed; 29.6% did not complete.