Degree Name

Doctor of Public Health


School of Health Sciences, Faculty of Health and Behavioural Sciences


Informed consent in human research involves a process of communicating information about a research study so as to promote informed decision-making. Current research suggests, however, that a high proportion of participants do not fully understand what it is they are consenting to when enrolling onto a research study. In other words, for many participants consent to participate in research is not truly informed. Evaluating informed consent information through the use of comprehension tests is one possible method for increasing the likelihood that consent to take part in research is truly informed. This thesis, therefore, comprises a series of both qualitative and quantitative studies that build upon one another culminating in the development comprehension of informed consent information. Assessments of readability provide a preliminary indication of document complexity in terms of writing style (word choice, sentence length). Therefore, a small-scale descriptive study, as described in Chapter 2, was conducted: i) to measure the readability of Australian-based clinical trial informed consent documents; and ii) to determine whether national or local ethics committees within Australia have formally established informed consent readability standards. The results of the study revealed that the majority of informed consent documents were written at a reading level appropriate for individuals with some university education thus beyond the reading ability of a majority of Australian adults. Official readability recommendations and/or standards could not be located at the national or local level. One method of gathering evidence of informed consent comprehension is through the use of comprehension tests. Chapter 3 consists of a systematic review, which identifies and critically evaluates instruments that have been developed to measure clinical trial informed consent comprehension in non-cognitively impaired adults. A total of three instruments were identified. Strengths and limitations of each instrument were evaluated against the following criteria: i) method of item generation; ii) type and format of test items; iii) administration and interpretation of test results; and iv) psychometric properties. None of the instruments identified in Chapter 3 were developed based on a construct definition. This may be due to the absence of an accepted construct definition of informed consent comprehension. A construct definition provides a framework for determining how an instrument should be constructed, implemented, interpreted and applied. Furthermore, the validity of what is being measured will rest largely on that definition. Chapter 4 describes and reports on the results of a qualitative study, involving an international expert panel, which was conducted to develop consensus for a construct definition of informed consent comprehension. The construct definition proposed in Chapter 4 was utilized as the conceptual framework for the development a new of informed consent comprehension instrument, called the Modular Informed Consent Comprehension Assessment (MICCA) instrument. Chapter 5 describes the methodologies used to develop the instrument and presents the results of preliminary readability and content validity testing. Chapter 6 is an extension of Chapter 5 in that it presents the results of a psychometric study conducted to assess the reliability, generalizability and validity of the MICCA. Results of the psychometric study provide preliminary evidence that the MICCA can be utilized in various clinical trial settings and can produce reliable and valid test scores. Evidence of comprehension through the use of comprehension instruments, such as the MICCA, can help ensure that consent to participate in a research study is truly informed.

02Whole.pdf (2295 kB)