Table 3.
Hepatitis C virus antibody screening at 12 months
| Substudy | Completed antibody screening, n (%; 95% CI)* | Difference, % (95% CI) | P value† |
|---|---|---|---|
| Substudy A: opt in or opt out | |||
| Letter only (n=813) | 279 (34.3; 31.1 to 37.6) | 21.9 (17.2 to 26.6) | <0.001 |
| Letter+laboratory order (n=829) | 466 (56.2; 52.8 to 59.6) | ||
| Substudy B: content | |||
| Usual care messaging (n=9828) | 2855 (29.0; 28.2 to 29.9) | −0.9 (−2.2 to 0.3) | 0.15 |
| Behavioral messaging (n=9833) | 2765 (28.1; 27.2 to 29.0) | ||
| Substudy B: communication mode | |||
| Mailed letter (n=1897) | 638 (33.6; 31.5 to 35.8) | −4.4 (−6.7 to −2.1) | <0.001 |
| Patient portal message (n=9498) | 2778 (29.3; 28.3 to 30.2) | ||
*
Includes only patients screened using antibody testing.
†
P value less than 0.05 was threshold for statistical significance using χ2 test of proportions.