Table 1.
Baseline characteristics of individuals in included studies (N = 25,390)
| Study | Description of study sample | No | Age, median (range), years | Women, no (%) | Subclinical hypothyroidism, no (%) | Subclinical hyperthyroidism, no (%)* | Thyroid medication users, no (%)† | Follow-up‡ | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| ||||||||||||
| At baseline | During follow-up | At anytime | Start | Duration, median (Q1–Q3) | Person-years | |||||||
| United States | ||||||||||||
| Cardiovascular Health Study | Community-dwelling adults with Medicare eligibility in 4 US communities | 3064 | 71 (64–100) | 1840 (60.1%) | 495 (16.2%) | 43 (1.4%) | 0 (0.0%) | 158 (5.2%) | 158 (5.2%) | 1989–1990 | 12.3 (7.0–16.3) | 34′531 |
| Health, Aging and Body Composition Study | Community-dwelling adults with Medicare eligibility in 2 US communities | 2762 | 74 (69–81) | 1407 (50.9%) | 335 (12.1%) | 82 (3.0%) | 267 (9.7%) | 383 (13.9%) | 392 (14.2%) | 1997 | 7.1 (6.1–8.2) | 17′869 |
| Europe | ||||||||||||
| EPIC-Norfolk Study | Adults living in Norfolk, England | 13,066 | 58 (40–78) | 7104 (54.4%) | 720 (5.5%) | 360 (2.8%) | 0 (0.0%) | NA | 0 (0.0%) | 1995–1998 | 11.4 (10.7–12.3) | 143′694 |
| Leiden 85-plus Study | All adults aged 85 years living in Leiden, the Netherlands | 514 | 85 | 336 (65.4%) | 35 (6.8%) | 23 (4.5%) | 17 (3.3%) | 20 (3.9%) | 26 (5.1%) | 1997–1999 | 4.8 (2.0–5.0) | 1′861 |
| Bari cohort | Outpatients with HF followed by Cardiology Department in Bari, Italy | 335 | 66 (21–92) | 77 (23.0%) | 39 (11.6%) | 7 (2.1%) | 22 (6.6%) | 61 (18.2%) | 61 (18.2%) | 2006–2008 | 1.1 (0.5–1.7) | 370 |
| Prospective Study of Pravastatin in the Elderly at Risk | Older community-dwelling adults at high-cardiovascular risk in the Netherlands, Ireland and Scotland | 5649 | 75 (69–83) | 2884 (51.0%) | 444 (7.9%) | 133 (2.3%) | 207 (3.7%) | NA | 207 (3.7%) | 1997–1999 | 3.3 (3.0–3.5) | 17′923 |
| Overall | 6 studies | 25,390 | 70 (21–100) | 13,648 (53.8%) | 2068 (8.1%) | 648 (2.6%) | 513 (2.0%) | 622 (2.4%) | 844 (3.3%) | 1989–2008 | 10.4 (3.7–12.0) | 216′248 |
Abbreviations: HF, Heart failure; NA, data not available; Q1, first quartile; Q3, third quartile.
*
We used a common definition of subclinical hypothyroidism and hyperthyroidism, whereas TSH cutoff values varied among the previous reports from each cohort, resulting in different numbers of subclinical hypothyroidism and hyperthyroidism from previous reports.
†
Data on thyroid medication use were not available for 1 participant in CHS and 8 participants in the Health ABC Study at baseline, and for all participants during follow-up in EPIC-Norfolk.
‡
For all cohorts, we used the maximal follow-up data that were available, which might differ from previous reports for some cohorts.