Table 1.
Baseline Characteristics and Bivariate Associations Between Candidate Risk Factors and Long-Term Disability in Community Mobility
| First Analytic Sample Walking a Quarter Mile (n=568) |
Second Analytic Sample Driving a Car (n=507) |
||||
|---|---|---|---|---|---|
| Factor* | Measurement Details | Value† | Hazard Ratio (95% CI) | Value† | Hazard Ratio (95% CI) |
| Demographic | |||||
| Age, y | |||||
| Mean (SD) | 77.8 (5.0) | 77.4 (4.7) | |||
| 70–74 | 182 (32.0) | Reference | 169 (33.3) | Reference | |
| 75–79 | 181 (31.9) | 1.71 (1.27–2.31) | 167 (32.9) | 2.00 (1.44–2.78) | |
| 80–84 | 142 (25.0) | 2.72 (2.00–3.70) | 135 (26.6) | 3.55 (2.55–4.95) | |
| ≥ 85 | 63 (11.1) | 4.96 (3.41–7.21) | 36 (7.1) | 5.69 (3.56–9.08) | |
| Female | 343 (60.4) | 1.43 (1.14–1.81) | 277 (54.6) | 1.22 (0.96–1.56) | |
| Non-Hispanic white | 519 (91.4) | 1.28 (0.85–1.92) | 464 (91.5) | 0.89 (0.59–1.33) | |
| Living with others | 350 (61.6) | 0.65 (0.52–0.81) | 315 (62.1) | 0.73 (0.58–0.93) | |
| Did not complete high school | 171 (30.1) | 1.50 (1.19–1.88) | 124 (24.5) | 1.18 (0.90–1.54) | |
| Health related | |||||
| Chronic conditions, mean (SD) | 9 self-reported, physician diagnosed‡ | 1.6 (1.1) | 1.31 (1.19–1.45) | 1.6 (1.2) | 1.18 (1.07–1.31) |
| Visual impairment | %, assessed with a Jaeger card | ||||
| None or mild | < 6 | 416 (73.2) | Reference | 384 (75.7) | Reference |
| Moderate | 6–26 | 71 (12.5) | 1.28 (0.98–1.68) | 62 (12.3) | 1.74 (1.30–2.33) |
| Severe | > 26 | 81 (14.3) | 1.84 (1.40–2.40) | 61 (12.0) | 1.77 (1.29–2.42) |
| Hearing impairment | Tones missed out of 4§ | ||||
| None or mild | 0–1 | 249 (43.8) | Reference | 224 (44.2) | Reference |
| Moderate | 2–3 | 204 (35.9) | 1.51 (1.12–2.03) | 188 (37.1) | 1.64 (1.20–2.24) |
| Severe | 4 | 115 (20.3) | 2.14 (1.65–2.77) | 95 (18.7) | 2.39 (1.78–3.21) |
| Weight loss | ≥ 10 pounds in past year | 108 (19.0) | 2.00 (1.56–2.56) | 89 (17.6) | 1.96 (1.49–2.57) |
| Cognitive-psychosocial | |||||
| Cognitive impairment | Score on Folstein MMSE < 24 | 54 (9.5) | 2.73 (2.11–3.53) | 34 (6.7) | 2.46 (1.78–3.40) |
| Depressive symptoms | Score on CES-D ≥ 20 | 61 (10.7) | 2.02 (1.55–2.64) | 53 (10.5) | 1.68 (1.24–2.28) |
| Low functional self-efficacy∥ | Score ≤ 27 | 114 (20.1) | 4.43 (3.55–5.53) | 115 (22.7) | 2.79 (2.18–3.57) |
| Low social support∥ | Score on MOS ≤ 18 | 123 (21.7) | 1.27 (0.98–1.65) | 111 (21.9) | 1.33 (1.01–1.74) |
| Behavioral | |||||
| Current smoker | 50 (8.8) | 1.03 (0.66–1.60) | 40 (7.9) | 1.03 (0.62–1.71) | |
| Low physical activity | PASE score < 64 for men and < 52 for women¶ | 119 (21.0) | 3.09 (2.48–3.85) | 106 (20.9) | 3.49 (2.75–4.44) |
| Body mass index# | Self-reported height and weight, kg/m2 | ||||
| Normal or underweight | < 25 | 245 (43.1) | Reference | 191 (37.7) | Reference |
| Overweight | 25–29.9 | 224 (39.4) | 0.74 (0.58–0.94) | 206 (40.6) | 0.72 (0.55–0.94) |
| Obese | > 30 | 99 (17.4) | 0.95 (0.71–1.29) | 110 (21.7) | 0.85 (0.62–1.16) |
| Physical capacity | |||||
| SPPB score** | |||||
| High | 10–12 | 159 (28.0) | Reference | 152 (30.0) | Reference |
| Intermediate | 7–9 | 216 (38.0) | 3.40 (2.02–5.72) | 181 (35.7) | 2.30 (1.40–3.79) |
| Low | < 7 | 193 (34.0) | 11.4 (6.91–18.7) | 174 (34.3) | 6.93 (4.35–11.0) |
| Muscle weakness | |||||
| Hand grip†† | 276 (48.6) | 2.51 (1.96–3.22) | 236 (46.7) | 1.96 (1.51–2.52) | |
| Upper extremity‡‡ | Shoulder flexion < 11.5 (women), < 16.1 (men) | 137 (24.1) | 2.01 (1.58–2.55) | 123 (24.3) | 2.50 (1.91–3.28) |
| Lower extremity‡‡ | Hip abduction < 7.9 (women), < 12.6 (men) | 173 (30.5) | 1.94 (1.53–2.47) | 153 (30.2) | 2.38 (1.80–3.14) |
| Manual dexterity§§, s | 9-hole pegboard test | ||||
| < 21.8 | 115 (20.3) | Reference | 102 (20.1) | Reference | |
| 21.8–24.3 | 126 (22.2) | 1.19 (0.78–1.81) | 113 (22.3) | 2.01 (1.24–3.27) | |
| 24.4–27.5 | 155 (27.3) | 1.92 (1.31–2.80) | 136 (26.8) | 2.46 (1.54–3.93) | |
| ≥ 27.6 | 172 (30.3) | 3.45 (2.43–4.89) | 156 (30.8) | 4.45 (2.85–6.93) | |
| Gross motor coordination§§, s | 10 finger taps as described in the text | ||||
| < 8.8 | 104 (18.3) | Reference | 97 (19.1) | Reference | |
| 8.8–10.3 | 119 (21.0) | 1.49 (1.01–2.20) | 108 (21.3) | 2.09 (1.34–3.26) | |
| 10.4–12.4 | 161 (28.4) | 1.91 (1.32–2.77) | 147 (29.0) | 2.78 (1.82–4.25) | |
| ≥ 12.5 | 184 (32.4) | 3.40 (2.42–4.78) | 156 (30.6) | 4.65 (3.10–6.97) | |
| Low peak flow∥∥ | < 10% standardized residual percentile | 114 (20.1) | 1.96 (1.54–2.51) | 96 (18.9) | 2.07 (1.57–2.72) |
Abbreviations: CES-D, Center for Epidemiological Studies-Depression Scale; MMSE, Mini-Mental State Examination; MOS, Medical Outcomes Study Social Support Scale; SD, standard deviation; SPPB, Short Physical Performance Battery.
Values for candidate risk factors were updated, when applicable, using data from the subsequent comprehensive assessments.
Values are given as number (percentage) unless otherwise indicated. Percentages are based on totals for each factor and may not sum to 100 because of rounding.
Hazard ratios are per one unit increase in the number of chronic conditions, which included hypertension, myocardial infarction, heart failure, stroke, diabetes mellitus, arthritis, hip fracture, chronic lung disease, and cancer (other than minor skin cancers).
Based on 1000 and 2000 HZ measurements for the left and right ears.
Cutpoints demarcate the worst quartile, based on the first 356 enrolled participants who had been selected randomly from the source population.
These gender-specific cut-points denote the worse quintile of scores (34) among the first 356 enrolled participants who had been selected randomly from the source population (28).
Body-mass index was categorized into three groups based on published cut-points, as previously described (35).
Scores demarcated three groups based on previously defined cutpoints (36).
Value less than or equal to the gender- and body mass index-specific cut-points provided by Fried et al. (34).
Assessed with hand-held Chatillon MSE 100 dynamometer; cutpoints (kg) demarcate the worst sex-specific quartile for nondominant limb, based on the first 356 enrolled participants who had been selected randomly from the source population (37).
Because standard cutpoints have not been established, quartile scores were calculated based on the first 356 enrolled participants and subsequently applied to the entire cohort.
Based on previously validated cutpoint (37).