TABLE 1.
Characteristics of study sample at baseline (Year 0, 1985-86) and end of follow-up (Year 25, 2010-11) a
| Characteristic | Year 0 (1985- 86) |
Year 25 (2010- 11) |
|---|---|---|
| Individual-level factors | ||
| White (%) | 49.7 | 53.1* |
| Age, years | 25.0 | 50.0 |
| Male (%) | 45.2 | 43.4* |
| Income b (%) | ||
| ≤$34,999/y | 52.1 | 19.2* |
| $35,000-74,999/y | 31.2 | 22.8 |
| ≥$75,000/y | 16.8 | 57.8 |
| Individual-level diet behaviors and cardiometabolic outcomes | ||
| Weekly visits to fast food restaurants (median (IQR)) | 1.0 (0.5, 3.0) | 0.5 (0.0, 1.4)* |
| BMI, kg/m2 (median (IQR)) | 23.5 (21.1, 26.4) |
28.7 (24.9, 33.7)* |
| HOMA-IR (median (IQR)) | 1.43 (1.13, 1.88) |
2.06 (1.19, 3.55)* |
| Community-level factors | ||
| Neighborhood fast food price c (median (IQR)) | 1.52 (1.48, 1.55) |
1.48 (1.36, 1.52)* |
| Population density d (median (IQR)) | 3,133 (1,666, 4,138) |
1,312 (636, 2,628)* |
| Cost-of-living e (median (IQR)) | 1.03 (1.00, 1.11) |
1.12 (0.94, 1.31)* |
| Socioeconomic status | ||
| Education at age 25: <HS (%) | 29.9 | 12.5* |
| Education at age 25: ≥college (%) | 22.2 | 64.7* |
| Median household income (median (IQR)) | 14,288 (10,701, 18,705) |
58,068 (41,224, 81,250)* |
| % population <150% FPL | 28.9 | 23.2* |
| Total number of food stores and restaurants (median (IQR)) | 103 (49, 204) | 93 (39, 213)* |
| Count of fast food restaurants (median (IQR)) | 14 (5, 27) | 21 (9, 40)* |
| Percentage of fast food restaurants relative to total food stores and restaurants (median (IQR)) |
12.5 (9.1, 15.6) | 20.5 (15.6, 25.3)* |
| Count of fast food restaurants (chain only) (median (IQR)) | 3 (2, 6) | 7 (3, 11)* |
| Percentage of fast food restaurants (chain only) relative to total food stores and restaurants (median (IQR)) |
2.4 (1.6, 7.7) | 5.0 (3.0, 8.6)* |
BMI, body mass index; HOMA-IR, HOMA-insulin resistance; FPL, federal poverty line; SD=standard deviation; IQR=interquartile range
Statistically significant difference from baseline values at the p<0.05 level, using one-way analysis of variance for categorical variables; paired t-test for normally distributed continuous variables; and Wilcoxon signed rank sum test for non-normally distributed continuous variables
n=4,741 participants with income, education, and food price data across CARDIA Exam Years 0-25
Values for Year 0 correspond to Year 5, as income was collected from CARDIA years 5-25 only; one-way analysis of variance (exam year 0 versus 25 values) was used for all 3 categories simultaneously (p<0.05)
Neighborhood fast food price index based on simple average of hamburger (1/4 pound (lb) burger, purchased away-from-home), pizza (¼ of 12-13 inch cheese, thin crust purchased away-from-home), and fried chicken (pieces, thigh and drumstick, purchased away-from-home) in respondents’ corresponding metropolitan statistical area (MSA); prices derived from the Council for Community and Economic Research (C2ER) and inflated to corresponding quarterly exam year dollars using the consumer price index (CPI), with a 1982-84 reference base.
Population per square kilometer
Relative to a standard of 1 from years 1982-84