Table 1.
Selected respondent and Medicare-data linkage characteristics stratified by middle age LTPA status
| Middle age leisure time physical activity | Overall | <1 hour/week |
1–3 hours/week |
4–7 hours/week |
>7 hours/week |
| N (%) | 21 750 (100.0) | 4916 (22.6) | 5635 (25.9) | 5774 (26.5) | 5425 (24.9) |
| Sociodemographic characteristics | |||||
| Mean age, years (SD) | 59.9 (3.2) | 59.7 (3.2) | 59.7 (3.2) | 59.9 (3.2) | 60.1 (3.1) |
| White, non-Hispanic (%) | 94.8 | 93.3 | 94.5 | 95.6 | 95.6 |
| Male (%) | 54.2 | 55.2 | 54.5 | 53.7 | 53.7 |
| Married (%) | 72.3 | 69.4 | 72.1 | 72.9 | 74.3 |
| Education level (%) | |||||
| <11 years schooling | 21.8 | 23.7 | 20.6 | 20.7 | 23.4 |
| High school | 34.4 | 35.6 | 33.9 | 33.9 | 34.4 |
| College degree | 41.9 | 39.1 | 43.9 | 44.2 | 39.9 |
| Health behavior characteristics | |||||
| Smoking history (%) | |||||
| Never smoker | 38.0 | 36.6 | 38.4 | 38.6 | 38.1 |
| Former smoker | 47.2 | 45.2 | 46.6 | 48.2 | 48.5 |
| Current smoker | 11.9 | 14.9 | 12.2 | 10.5 | 10.4 |
| BMI category at age 18 (%) | |||||
| BMI <25.0 kg/m2 | 83.0 | 81.2 | 83.0 | 83.4 | 84.2 |
| 25.0 ≤BMI < 30.0 kg/m2 | 9.1 | 10.1 | 8.9 | 9.1 | 8.6 |
| BMI ≥30.0 kg/m2 | 1.4 | 2.2 | 1.4 | 1.1 | 1.0 |
| BMI category at age ~60 (%) | |||||
| BMI <25.0 kg/m2 | 37.3 | 28.7 | 34.2 | 40.6 | 44.8 |
| 25.0 ≤BMI < 30.0 kg/m2 | 41.0 | 39.5 | 42.1 | 42.3 | 39.9 |
| BMI ≥30.0 kg/m2 | 20.2 | 30.1 | 22.0 | 15.9 | 14.0 |
| Television viewing (%) | |||||
| 0–2 hours/day | 36.1 | 32.6 | 35.4 | 37.7 | 38.5 |
| 3–4 hours/day | 45.4 | 45.1 | 46.9 | 45.3 | 44.2 |
| 5+ hours/day | 18.2 | 22.1 | 17.5 | 16.8 | 17.0 |
| Clinical characteristics | |||||
| Self-reported health status (%) | |||||
| Excellent/very good | 58.5 | 45.6 | 55.3 | 62.2 | 69.7 |
| Good | 33.4 | 41.5 | 36.3 | 31.6 | 25.2 |
| Fair | 7.0 | 11.9 | 7.1 | 5.3 | 4.3 |
| Self-reported clinical history (%) | |||||
| Any health problem | 34.2 | 39.7 | 34.1 | 32.3 | 31.6 |
| Heart disease | 9.9 | 10.7 | 10.0 | 9.7 | 9.2 |
| Diabetes | 6.6 | 9.7 | 6.6 | 5.5 | 4.8 |
| Osteoporosis | 2.7 | 2.8 | 2.9 | 2.8 | 2.6 |
| Stroke | 1.0 | 1.5 | 0.8 | 1.0 | 0.9 |
| Medicare data characteristics | |||||
| Reason for linkage (%) | |||||
| Consented alive | 87.5 | 84.1 | 88.4 | 88.3 | 89.0 |
| Dead | 12.5 | 15.9 | 11.6 | 11.7 | 11.0 |
| Mean age at Medicare entry, years (SD) | 65.0 (0.1) | 65.0 (0.1) | 65.0 (0.1) | 65.0 (0.1) | 65.0 (0.1) |
| Years of Medicare data (SD) | 6.2 (2.9) | 5.8 (2.8) | 6.2 (3.1) | 6.4 (3.1) | 6.7 (3.1) |
Column percentage may not total 100% because of ‘unknown’ category response. See online supplemental appendix table S1 for full distributions. χ2 statistics (χ) for table 1 with p<0.001 when stratifying by middle age LTPA except for sex (p=0.203) heart disease (p=0.047); osteoporosis (p=0.790) stroke (p=0.004). The analytical sample had a mean of 6.2 years of Medicare coverage (range 1–10 years) with an unadjusted average annual healthcare cost of US$7813 during this time period. The <1 hour/week is based on respondents that responded never, rarely, or <1 hour/week when asked how often they participated in moderate and vigorous activities in middle age.
BMI, body mass index; LTPA, long-term leisure time physical activity.