Table 3.
Tobit Models Predicting Upper-Body Disability: Adults Aged 45 and Older at Baseline, National Health and Nutrition Examination Survey, 1971 to 1992
| Upper-Body Disability, Wave 2 | Upper-Body Disability, Wave 4 | ||||||
|---|---|---|---|---|---|---|---|
| Independent Variables | Model 1 | Model 2 | Model 3 | Model 1 | Model 2 | Model 3 | Model 4 |
| Early Obesity | |||||||
| Obese at age 25 | .64 (1.23) | — | — | 1.44 (1.31) | — | — | — |
| Obese, Wave 1 | 1.44 (.74) | — | — | 2.92** (1.01) | — | — | — |
| Late Obesity | |||||||
| Obese, Wave 2 | — | .28 (.64) | — | — | 1.62 (1.33) | — | — |
| Obese, Wave 3 | — | — | — | — | 2.06 (1.66) | — | — |
| Obese, Wave 4 | — | — | — | — | .42 (1.16) | — | — |
| Lifetime Body Weight | |||||||
| Chronic obesity (times) a | — | — | .33 (.22) | — | — | .86*** (.22) | .72*** (.21) |
| Ever-underweight b | −.13 (.63) | −.39 (.64) | −.22 (.64) | 2.67** (.96) | 2.77** (.96) | 2.93** (.97) | 2.75** (.95) |
| Upper-body disability, Wave 2 | — | — | — | — | — | — | 1.38*** (.21) |
| Serious illness, Wave 1 | .69* (.33) | .79* (.32) | .72 (.33) | 1.40* (.61) | 1.42* (.60) | 1.30* (.60) | 1.39* (.57) |
| Chronic illness, Wave 1 | 2.68*** (.43) | 2.69*** (.43) | 2.69*** (.43) | 1.71** (.67) | 1.62* (.67) | 1.67* (.66) | 1.00 (.67) |
| Change in serious illness from Wave 1 to Wave 2 | — | — | — | .67 (.64) | .50 (.63) | .51 (.63) | .24 (.61) |
| Change in chronic illness from Wave 1 to Wave 2 | — | — | — | 2.79*** (.78) | 2.69*** (.79) | 2.76*** (.79) | 2.27** (.71) |
| Ceased regular exercise by Wave 2 | −.27 (1.21) | −.27 (1.23) | −.25 (1.23) | −3.28 (2.67) | −3.40 (2.68) | −3.39 (2.68) | .37 (2.89) |
| Began regular exercise by Wave 2 | −6.01*** (1.60) | −6.15*** (1.60) | −6.01*** (1.61) | −2.87 (3.06) | −3.21 (2.96) | −2.98 (3.04) | 2.05 (3.38) |
| Continued regular exercise, Wave 1 to Wave 2 | −9.31*** (1.33) | −9.44*** (1.33) | −9.35*** (1.34) | −6.54** (2.45) | −6.56** (2.47) | −6.52** (2.48) | −.32 (2.75) |
| Age | −.13 (.63) | −.15 (.10) | −.14 (.10) | −.09 (.19) | −.07 (.19) | −.07 (.20) | .07 (.19) |
| Female | 3.71*** (1.12) | 3.93*** (1.10) | 3.81*** (1.11) | 3.63** (1.24) | 3.42** (1.24) | 3.60** (1.24) | 2.96** (1.13) |
| Black | −4.43*** (1.18) | −4.47*** (1.20) | −4.44*** (1.19) | 1.14 (1.26) | 1.17 (1.27) | 1.06 (1.28) | 1.46 (1.31) |
| Lives alone | −.44 (.86) | −.44 (.85) | −.45 (.85) | −1.09 (1.17) | −1.16 (1.15) | −1.11 (1.16) | −.68 (1.06) |
| Education | −.17 (.21) | −.20 (.21) | −.19 (.21) | −.17 (.23) | −.18 (.24) | −.19 (.24) | −.17 (.22) |
| Income, previous wave c | .03 (.19) | .04 (.20) | .03 (.20) | .13 (.24) | .10 (.24) | .12 (.24) | .15 (.22) |
| Regular physician | −.07 (.83) | −.01 (.83) | −.05 (.83) | −.65 (1.38) | −.54 (1.37) | −.56 (1.38) | −.37 (1.39) |
| Medicaid | .60 (1.30) | .60 (1.30) | .62 (1.30) | −2.24 (1.57) | −1.83 (1.59) | −1.86 (1.53) | −1.98 (1.37) |
| Private insurance | .82 (.87) | .80 (.87) | .80 (.87) | −.24 (1.03) | −.45 (1.04) | −.26 (1.04) | −.28 (1.00) |
| Past smoker | .05 (.74) | .04 (.75) | .04 (.75) | 1.69 (.98) | 1.50 (.99) | 1.60 (.99) | 1.51 (.92) |
| Current smoker | .80 (.77) | .69 (.78) | .75 (.78) | .95 (.71) | .84 (.71) | .92 (.71) | 1.05 (.65) |
| Selection effect for mortality (λ) | 10.27** (3.87) | 10.39** (3.91) | 10.38** (3.91) | 10.79* (5.24) | 10.36* (5.22) | 10.75* (5.25) | 10.03* (4.67) |
| Selection effect for non-response attrition (λ) | 5.00 (7.65) | 5.92 (7.63) | 5.32 (7.70) | 5.00 (3.45) | 5.14 (3.42) | 4.82 (3.46) | 2.29 (3.59) |
| Intercept | 6.72 | 7.68 | 7.05 | −1.70 | −2.43 | −3.05 | −26.62 |
| Number of cases | 2,939 | 2,939 | 2,939 | 1,906 | 1,906 | 1,906 | 1,898 |
| F (Degrees of freedom) | 12.44 (21, 449) | 13.18 (20, 450) | 12.80 (20, 450) | 7.29 (23, 316) | 8.07 (24, 315) | 7.72 (22, 317) | 7.89 (23, 316) |
| Sigma | 8.00 | 8.02 | 8.02 | 9.63 | 9.60 | 9.60 | 9.09 |
Note: Model estimates are weighted to U.S. proportions and adjusted for clustering. Unstandardized slopes are presented; except where otherwise noted, numbers in parentheses are standard errors.
a
Variable range equals 0 to 5 for Wave 2 and equals 0 to 7 for Wave 4.
b
Five opportunities to be underweight by Wave 2; seven by Wave 4.
c
Income is lagged in each equation using the income value from the previous wave.
*
p < .05
**
p < .01
***
p < .001 (two-tailed tests)