Results of the study
The Pulse Oximetry Trial was completed and published in the New England Journal of Medicine in 2010. The main findings of the study were:
- Babies in the low target oxygen saturation group were less likely to have severe retinopathy (P < 0.001).
- However, they were also more likely to die than those maintained at the high saturation range (P = 0.04).
- Hence, the researchers cautioned physicians against lowering target oxygen saturation levels to reduce retinopathy in extremely preterm babies.
You may read the full paper ‘Target Ranges of Oxygen Saturation in Extremely Preterm Infants’ (SUPPORT Study Group, 2010).
Debates around informed consent
The parents of three babies (two developed neurological impairment and one retinopathy) filed lawsuits in 2013. They claimed that their babies’ impairments were caused by the trial and that they were not forewarned about such risks during the consent process.
The judge dismissed the claim, stating that the babies were themselves extremely vulnerable in the first place and could still have suffered from the same impairments had they not participated in the trial. (9,11)
Yet, dismissal of the lawsuit did not cease the ethical debates over how the researchers had conveyed the risks of this trial to parents: (10)
(Click on each tab for further elaboration)
The ‘Possible risks’ section of the PIS stated that ‘There is no known risk to your baby from monitoring with the pulse oximeters used for this study’.
Critics disagreed about the risk level of this trial. Although the two ranges of target oxygen saturation levels used in the study were within the range used in standard practice, they were narrower and thus more restrictive than the standard range.
Besides, there was no mention about the use of blinding and modified pulse oximeters.
The researchers could have explained the differences between research and standard clinical practice more clearly. They should also have considered the risks imposed by the experimental methods and conveyed these to parents.
The ‘Possible benefits’ section of the PIS stated that ‘It is possible that using lower pulse oximeter ranges will result in fewer babies with severe Retinopathy of Prematurity (ROP)’.
The researchers were criticised for mentioning the reduced risk of retinopathy as a potential benefit of using lower oxygen saturation targets, yet did not mention the possible increase in risk of brain injury / death with lower targets, nor the risk of blindness with higher targets.
The researchers and their supporters argued that these risks were not mentioned because they were hypothetical. The trial was in fact conducted to test these hypotheses.
Nevertheless, there appeared to be an imbalance in how the risks and benefits of the trial were presented in the PIS.
Lantos JD. Vindication for SUPPORT. New England Journal of Medicine. 2015 Oct 8;373(15):1393–5. Available from: https://doi.org/10.1056/NEJMp1510876
United States District Court for Northern District of Alabama. Looney v. Moore, Case No.: 2:13-cv -00733-KOB [Internet]. 2014. Available from: https://www.govinfo.gov/content/pkg/USCOURTS-alnd-2_13-cv-00733/pdf/USCOURTS-alnd-2_13-cv-00733-0.pdf
Furlow B. SUPPORT controversy’s lessons for informed consent. The Lancet Respiratory Medicine. 2015 Dec 1;3(12):928–9. Available from: https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(15)00417-8/abstract