Table 2. Odds Ratios and Relative Risks for Very Preterm Birth at Less Than .
| Phase | Births, No. | OR (95% CI) | RR | P valuea | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2020 | 2017-2019 | ||||||||
| <32 wk | ≥37 wk | <32 wk | ≥37 wk | ||||||
| All | 572 | 40 943 | 2064 | 128 262 | 0.87 (0.79-0.95) | 0.87 (0.79-0.95) | .003 | ||
| March 14 to May 15 | 144 | 8472 | 445 | 26 457 | 1.01 (0.83-1.22) | 1.01 (0.84-1.21) | .92 | ||
| May 16 to October 18 | 316 | 23 049 | 1097 | 71 721 | 0.90 (0.79-1.02) | 0.90 (0.79-1.02) | .09 | ||
| October 19 to December 31 | 112 | 9422 | 522 | 30 084 | 0.69 (0.55-0.84) | 0.06 (0.56-0.84) | <.001 | ||
Abbreviations: OR, odds ratio; RR, relative risk.
a
Calculated with Fisher exact test.