Assessment of Attrition Bias: Completing Practices and All Practices With Imputation
| Measure | Usual Care | CRP Training | Communication Training | Combination |
|---|---|---|---|---|
| Practices completing 12 months of follow-up | ||||
| Patients prescribed antibiotics, % | 51.0 | 42.9 | 39.8 | 47.1 |
| Difference, % (95% CI) [P value]a | ref | −7 (−15 to 2) [.11] | −7 (−15 to 1) [.09] | −4 (−12 to 4) [.30] |
| All practices, with imputation for missing data | ||||
| Patients prescribed antibiotics, % | 49.7 | 42.9 | 41.9 | 47.0 |
| Difference, % (95% CI) [P value]a | ref | −6 (−14 to 3) [.22] | −7 (−15 to 1) [.10] | −4 (−12 to 4) [.34] |
CRP = C–reactive protein; ref = reference group.
Note: A practice-level analysis.
↵a Reduction in proportion compared with usual care controlling for baseline prescribing and practice-level averages of patient characteristics: age, type of infection (lower respiratory tract infection vs upper respiratory tract infection), presence of symptoms (crackles, wheeze, pulse higher than 100 beats per minute, temperature higher than 37.8°C), respiratory rate, physician’s rating of severity, and duration of cough.