Table 1.
Demographic Characteristics of Participants in the Nested Case Control Cohort a
| Characteristic (Total No.)a | Missing, No. (%) | Serology Negative (n=562) | Serology Positive (n=281) | Matched Resultb OR (95% CI) (P Value) |
|---|---|---|---|---|
| Age at serum draw, y (n=843), | 0 (0) | 35.1 (9.5) | 35.1 (9.5) | NA |
| Female sex (n=843) | 0 (0) | 358 (64) | 179 (64) | NA |
| Race (n=755) | 88 (10) | Overall P=.02 | ||
| Caucasian | 453 (90%) | 243 (96%) | 1.0 (reference) | |
| African American | 20 (4%) | 2 (1%) | 0.13 (0.03–0.66) | |
| Asian | 24 (5%) | 3 (1%) | 0.23 (0.07–0.82) | |
| Other | 6 (1%) | 4 (2%) | 1.13 (0.29–4.36) | |
| Weight, kg (n=763) | 80 (9) | 81.1 (23.6) | 80.7 (19.6) | 0.99 (0.92–1.08) (.85)c |
| Height, cm (n=773) | 70 (8) | 169.5 (9.8) | 169.3 (9.6) | 0.98 (0.79–1.22) (.88)c |
| BMI, kg/m2 (n=737) | 106 (13) | 28.1 (7.3) | 28.1 (6.1) | 1.00 (0.79–1.27) (.99)c |
| BMI categories (n=737) a | 106 (13) | Overall P=.09 | ||
| <25 | 203 (42) | 90 (36) | 1.0 (reference) | |
| 25–30 | 127 (26) | 83 (33) | 1.66 (1.10–2.50) | |
| 30–35 | 76 (16) | 40 (16) | 1.34 (0.82–2.19) | |
| >35 | 81 (17) | 37 (15) | 1.10 (0.66–1.82) |
Abbreviations: BMI, body mass index; NA, not applicable; OR, odds ratio; CI, confidence interval.
a
Categorical variables are presented as number (percentage) of available responses and continuous data as mean (±SD).
b
Each variable was assessed for an association with positive serology using matched analysis (conditional logistic regression analyzed on matched sets, with matching variables included as adjusting covariates in each model).
c
Data were rescaled in regression model to express the OR per 10-unit increase (ie, a 10-kg increase in weight).