Table 2 Sample size calculations
Outcome | Estimated rate for standard of carea | Improvement to be tested/expected | Power |
|---|---|---|---|
Patient-reported outcomes | |||
Satisfaction with care | 108.4 (SD 14.4) | 115.6 | 98 % |
Perceptions of quality of care | 83.9 (SD 22.8) | 91.9 | 86 % |
Prenatal stress | 12.9 (SD 7.1) | 16.5 | 98 % |
Maternal/fetal outcomes and standards of care | |||
Low birth weight | 11 % | 6 % | 24 % |
Gestational age at delivery | 38.9 (SD 2.5) | 40.2 | 99 % |
Standard of prenatal care (measured as receiving at least 20 out of 24 items from the ACOG standards of prenatal care list) | 90 % | 95 % | 30 % |
Health care utilization | |||
Number of antenatal visits | 14.7 (SD 4.2) | 12 | 99 % |