Table 4.
Tests of convergent and discriminant validity of sarcopenia definitions using conceptually related physiologic and functional variables
| Convergent Validity | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Variable | Limited Definitions |
|||||||||
| EWGSOP2 |
FNIH |
Lowest Quartile |
||||||||
| Nonsarcopenic | Sarcopenic | P Value | Nonsarcopenic | Sarcopenic | P Value | Nonsarcopenic | Sarcopenic | P Value | ||
| 6MWD, m | 280 [175–366] | 203 [109–298] | <0.01* | 279 [175–366] | 200 [110–298] | <0.01* | 278 [179–366] | 246 [127–324] | 0.01* | |
| SPPB | 9.9 ± 2.7 | 8.3 ± 3.9 | <0.01* | 9.8 ± 2.9 | 9.3 ± 3.1 | 0.27 | 10.0 ± 2.6 | 8.9 ± 3.6 | <0.01* | |
| SF12-PCS | 27.2 ± 9.3 | 26.0 ± 9.3 | 0.40 | 27.1 ± 9.5 | 26.4 ± 8.4 | 0.66 | 27.1 ± 9.3 | 27.0 ± 9.4 | 0.94 | |
|
Expanded Definitions |
||||||||||
|
EWGSOP2 |
FNIH |
Lowest quartile |
||||||||
| Variable | Nonsarcopenic | Sarcopenic | P Value | Nonsarcopenic | Sarcopenic | P Value | Nonsarcopenic | Sarcopenic | P Value | |
| 6MWD, m | 283 [183–367] | 185 [100–276] | <0.01* | 282 [182–366] | 175 [93–226] | <0.01* | 282 [183–366] | 198 [119–312] | <0.01* | |
| SPPB | 10.0 ± 2.7 | 7.8 ± 3.8 | <0.01* | 9.9 ± 2.8 | 8.4 ± 3.4 | <0.01* | 10.1 ± 2.7 | 8.1 ± 3.6 | <0.01* | |
| SF12-PCS | 27.3 ± 9.4 | 25.8 ± 9.0 | 0.42 | 27.2 ± 9.5 | 26.8 ± 8.2 | 0.83 | 27.4 ± 9.5 | 26.0 ± 8.3 | 0.41 | |
|
Discriminant Validity |
||||||||||
|
Limited Definitions |
||||||||||
|
EWGSOP2 |
FNIH |
Lowest Quartile |
||||||||
| Variable | Nonsarcopenic | Sarcopenic | P Value | Nonsarcopenic | Sarcopenic | P Value | Nonsarcopenic | Sarcopenic | P Value | |
| Trails B Test, s | 92 [69–119] | 104 [76–139] | 0.07 | 92 [69–119] | 109 [76–141] | 0.053 | 88 [68–115] | 106 [77–142] | <0.01* | |
| SF12-MCS | 48.1 ± 10.7 | 48.8 ± 13.4 | 0.67 | 47.9 ± 11.0 | 50.2 ± 11.5 | 0.24 | 48.1 ± 10.7 | 48.2 ± 12.1 | 0.96 | |
|
Expanded Definitions |
||||||||||
|
EWGSOP2 |
FNIH |
Lowest Quartile |
||||||||
| Variable | Nonsarcopenic | Sarcopenic | P Value | Nonsarcopenic | Sarcopenic | P Value | Nonsarcopenic | Sarcopenic | P Value | |
| Trails B Test, s | 92 [69–119] | 105 [85–144] | 0.03* | 92 [69–118] | 117 [95–157] | 0.01* | 90 [69–117] | 110 [81–150] | 0.01* | |
| SF12-MCS | 48.2 ± 10.8 | 47.6 ± 12.7 | 0.75 | 48.2 ± 11.0 | 47.8 ± 11.8 | 0.89 | 48.2 ± 11.1 | 48.4 ± 10.7 | 0.89 | |
Definition of abbreviations: 6MWD = 6-minute walk distance; EWGSOP2 = European Working Group on Sarcopenia in Older People 2; FNIH = Foundation for the National Institutes of Health; Lowest Quartile = distribution-based lowest quartile of sarcopenic study participants; SF12-MCS = Short Form 12 Mental Health Composite Score; SF12-PCS = Short Form 12 Physical Health Composite Score; SPPB = Short Physical Performance Battery.
*
Statistically significant at P < 0.05. “Known-groups” validity testing by Student’s t and Hodge-Lehman tests.