Usual care and informed consent in clinical trials of oxygen management in extremely premature infants

Abstract

Objective: The adequacy of informed consent in the Surfactant, Positive Pressure, and Pulse Oximetry Randomized Trial (SUPPORT) has been questioned. SUPPORT investigators and publishing editors, heads of government study funding agencies, and many ethicists have argued that informed consent was adequate because the two oxygen saturation target ranges studied fell within a range commonly recommended in guidelines. We sought to determine whether each oxygen target as studied in SUPPORT and four similar randomized controlled trials (RCTs) was consistent with usual care. Design/Participants/Setting: PubMed, EMBASE, Web of Science, and Scopus were searched for English articles back to 1990 providing information on usual care oxygen management in extremely premature infants. Data were extracted on intended and achieved oxygen saturation levels as determined by pulse oximetry. Twenty-two SUPPORT consent forms were examined for statements about oxygen interventions. Results: While the high oxygen saturation target range (91 to 95%) was consistent with usual care, the low range (85 to 89%) was not used outside of the SUPPORT trial according to surveys and clinical studies of usual care. During usual care, similar lower limits (< 88%) were universally paired with higher upper limits (≥ 92%) and providers skewed achieved oxygen saturations toward the upper-end of these intended ranges. Blinded targeting of a low narrow range resulted in significantly lower achieved oxygen saturations and a doubling of time spent below the lower limit of the intended range compared to usual care practices. The SUPPORT consent forms suggested that the low oxygen saturation arm was a widely practiced subset of usual care. Conclusions: SUPPORT does not exemplify comparative effectiveness research studying practices or therapies in common use. Descriptions of major differences between the interventions studied and commonly practiced usual care, as well as potential risks associated with these differences, are essential elements of adequate informed consent.