- The researchers improperly calculated statistical significance. "Significance" means that the difference between outcomes is unlikely to be due to chance. When there is a laundry list of outcomes, the odds go up for finding what look like real differences that are actually due to chance. For this reason, the significance threshold must be set higher. The authors don't indicate that they did this. A stricter standard could drop some or all of their results below the significance threshold. In particular, the key finding, increased newborn deaths, just barely exceeds this threshold.
Next Page: Learn if the study contained exaggerated claims
"Two times the risk of newborn death" sounds alarming, but the absolute difference is 1 per 1,000. Absolute differences for very low five-minute Apgar score and the need for breathing assistance for more than 30 minutes amount to 2 per 1,000. And this assumes that the numbers are sound, which, based on the above criticisms, is highly doubtful. It also assumes that these differences don't simply represent the effects of a higher incidence of congenital problems in the homebirth population.
In contrast to the Pang study, the Washington State government study concluded (3):
[T]he results of this study are consistent with a large body of literature which has documented the safety of planned homebirth for low-risk women when attended by a trained provider.
Next Page: Did the study authors have a bias?