A comparison of the quality of informed consent for phase I oncology trials over a 30-year period

Efforts are underway in improving the informed consent process. The success of these efforts to improve quality of informed consent forms (ICFs) for phase I oncology trials has not been previously measured.

We reviewed and compared ICFs of all phase I trials for metastatic cancer conducted between 1986 and 1999 and 2000–2015 periods at our institution. Information pertaining to ICF length, study purpose description, research regimen/methods, potential risks and benefits was extracted. The reading level was assessed by Flesch–Kincaid readability tests.

Of 364 ICFs screened, 310 ICFs were included in this analysis. The median length of ICFs from 1986 to 1999 and 2000–2015 was 12 and 23 pages, respectively. Only 42% (1986–1999) and 57% (2000–2015) of ICFs stated that individual participants might not benefit from treatment. Only 21% (1986–1999) and 12% (2000–2015) of all ICFs were written at ≤ 8th grade reading level. The median FRE, FKGL and GFI readability scores of ICFs from 1986 to 1999 were 53.6, 8.8, and 9.5, respectively. The median FRE, FKGL, and GFI scores of studies from 2000 to 2015 were 48.5, 10.7, and 12.4, respectively. These scores indicate that the ICF text was too hard for most people to read. The mechanism of action of the treatment, study schema/calendar, possibility of experiencing unexpected risks or death, and risks to pregnant/lactating women were not reported in a substantial number of forms.

Our results show that ICFs for phase I oncology trials over last 30 years have become longer, more difficult to read but are still lacking some important information.