Table 3.
Study Design Characteristics of Articles Included in an Analysis of Race and Ethnicity in Epidemiologic Research (n = 414), 1995–2018
| Time Period | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
1995–1999
(n = 92) |
2000–2004
(n = 95) |
2005–2009
(n = 87) |
2010–2014
(n = 67) |
2015–2018
(n = 73) |
||||||
|
Study
Characteristic |
No. of
Studies |
% |
No. of
Studies |
% |
No. of
Studies |
% |
No. of
Studies |
% |
No. of
Studies |
% |
| Study design | ||||||||||
| RCT | 3 | 3 | 1 | 1 | 1 | 1 | 3 | 4 | 0 | 0 |
| Cohort study | 66 | 72 | 73 | 77 | 68 | 78 | 56 | 84 | 68 | 93 |
| Case-control study | 22 | 24 | 20 | 21 | 18 | 21 | 8 | 12 | 5 | 7 |
| Ecological study | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
| Study outcomea | ||||||||||
| Health behavior | 4 | 4 | 11 | 12 | 8 | 9 | 4 | 6 | 7 | 10 |
| Physical or mental | 71 | 77 | 74 | 78 | 69 | 79 | 53 | 79 | 47 | 64 |
| Health-care access | 4 | 4 | 2 | 2 | 5 | 6 | 3 | 4 | 4 | 5 |
| Other | 14 | 15 | 13 | 14 | 8 | 9 | 10 | 15 | 19 | 26 |
| Sample size, no. of personsb | ||||||||||
| <1,000 | 38 | 41 | 38 | 40 | 17 | 20 | 17 | 25 | 19 | 26 |
| 1,000–5,000 | 33 | 36 | 32 | 34 | 31 | 36 | 16 | 24 | 20 | 27 |
| 5,001–10,000 | 8 | 9 | 11 | 12 | 7 | 8 | 9 | 13 | 8 | 11 |
| 10,001–100,000 | 18 | 20 | 20 | 21 | 23 | 26 | 24 | 36 | 20 | 27 |
| >100,000 | 4 | 4 | 5 | 5 | 10 | 11 | 10 | 15 | 13 | 18 |
| Missing data | 2 | 2 | 1 | 1 | 1 | 1 | 2 | 3 | 2 | 3 |
Abbreviation: RCT, randomized controlled trial.
a Study outcomes were classified as health behaviors (e.g., smoking, dietary intake, physical activity, sexual behaviors), mental or physical health (e.g., obesity, high blood pressure, cancer, depression), health-care access or utilization (e.g., health insurance status, number of primary care visits, quality of care), or other. Study outcomes are not mutually exclusive, and percentages may sum to more than 100.
b Some studies listed more than 1 analytical sample size; percentages may sum to more than 100.