Abstract
Joseph Mathew, Belmont Private Hospital, Carina Queensland and John McGrath, Queensland Centre for Schizophrenia Research, Wolston Park Hospital, Wacol, Queensland, Australia:
Informed consent in schizophrenia research has been the focus of considerable public and scientific interest in recent years [1]. Commentators have been concerned that the neurocognitive deficits associated with schizophrenia may impair the capacity to understand a study and thus provide ‘true’ informed consent. This issue has been compounded in recent years as consent forms have become more detailed.
The aim of this study was to assess the readability of consent forms used in schizophrenia research. As part of a quality assurance project, the local Health District Ethics Committee reviewed all consent forms related to schizophrenia research for a five-year period ending August 2000. The consent forms were scanned into digital form and then converted into text using an optical character recognition program. The text was checked against the original to ensure accuracy. For each consent form, we calculated the Flesch score of readability [2]. This widely used formula is derived from the average sentence length and the average number of syllables per word. It provides a readability score ranging from 0 (extremely difficult) to 100 (extremely easy), which can then be used to predict readability based on years of schooling. Word count and Flesch scores were obtained by a computer program (Microsoft Word).
Of the 23 consent forms, the mean (standard deviation, range) number of words was 583 (SD = 327, r = 207–1557). The mean Flesch score was 52.7 (SD = 8.5, r = 41–66.7). Based on recent Australian research [3], only six of the 23 forms would be judged as ‘standard’ readability (Flesch scores between 60 and 70), requiring eight to nine years of education. Nine of the 23 forms had Flesch scores less than 50. These forms would be judged as ‘Difficult’ and would require a university level of education.
The recent survey of psychotic disorders in Australia found that 58.1% of patients with psychosis had left school at age 16 or earlier, and that 47.8% has neither completed secondary school nor attained any subsequent qualifications [4]. Our study suggests that many consent forms are written in a style that will not facilitate comprehension by people with schizophrenia. Researchers should be encouraged to write important documents such as consent forms in a style that reflects the educational achievements of the target group. The Flesch score can be calculated quickly by employing the readability programs available in word processors (i.e. Microsoft Word). Ethics committees may wish to encourage researchers to provide a readability grade with important documents such as consent forms.