ICCs (and 95% Empirical Bootstrap Cls), Adjusted Cluster Sizes (m), and VIFs Calculated for Patient-Level Variables (N = 5,042 Patients)
| Within 61 Practices | Within 8 PBRNs | ||||||
|---|---|---|---|---|---|---|---|
| Variable | n | ICC (95% CI) | m | VIF | ICC (95% CI) | m | VIF |
| Age | 4,984 | 0.151 (0.144–0.191) | 80.08 | 12.94 | 0.054 (0.043–0.071) | 554.35 | 30.63 |
| Sex | 5,004 | 0.050 (0.050–0.089) | 80.38 | 4.99 | 0.010 (0.006–0.019) | 555.93 | 6.68 |
| Race | 5,042 | 0.265 (0.246–0.296) | 81.01 | 22.23 | 0.152 (0.133–0.175) | 560.20 | 86.19 |
| Smoking status | 4,893 | 0.118 (0.117–0.187) | 78.60 | 10.19 | 0.072 (0.059–0.099) | 543.43 | 40.15 |
| Unhealthy diet | 4,922 | 0.206 (0.178–0.252) | 79.04 | 17.11 | 0.239 (0.197–0.284) | 545.48 | 131.26 |
| Inactivity | 4,787 | 0.064 (0.062–0.095) | 70.23 | 5.43 | 0.062 (0.054–0.092) | 484.4 | 30.87 |
| Minutes of physical activity per day | 4,639 | 0.053 (0.051–0.094) | 74.54 | 23.49 | 0.057 (0.046–0.082) | 519.25 | 30.75 |
| Average drinks per day | 3,312 | 0.076 (0.067–0.142) | 53.25 | 4.98 | 0.076 (0.054–0.111) | 360.80 | 28.23 |
| Average drinks per month | 433 | 0.001 (0.000–0.103) | 46.86 | 1.06 | Data from 9 clinics within a single PBRN | ||
| Intent to reduce drinking | 193 | 0.207 (0.002–0.600) | 18.18 | 4.56 | Data from 9 clinics within a single PBRN | ||
| Intent to quit smoking | 378 | 0.000 (0.000–0.075) | 40.74 | 1.00 | Data from 9 clinics within a single PBRN | ||
| Intent to improve diet | 1,355 | 0.012 (0.003–0.037) | 148.26 | 2.76 | Data from 9 clinics within a single PBRN | ||
| Intent to increase exercise | 917 | 0.007 (0.000–0.042) | 100.27 | 1.65 | Data from 9 clinics within a single PBRN | ||
ICC= Intraclass correlation coefficient; PBRN = practice-based research network; VIF = variance inflation factor.