Bioethical Inquiry (2021) 18:141–150

https://doi.org/10.1007/s11673-020-10085-w

ORIGINAL RESEARCH

Caregivers’ Understanding of Informed Consent

in a Randomized Control Trial
Dorothy Helen Boyd & Yinan Zhang & Lee Smith &
Lee Adam & L. Foster Page & W. M. Thomson

Received: 29 April 2019 / Accepted: 29 December 2020 / Published online: 15 January 2021
# Journal of Bioethical Inquiry Pty Ltd. 2021

Abstract There are differences in caregivers’ literacy Some caregivers enrolled their child in the RCT because
and health literacy levels that may affect their ability to they trusted the researchers, and the majority wanted to
consent to children participating in clinical research trials. improve dental care for children. The informed consent
This study aimed to explore the effectiveness, and care- process was not always effective despite high readability
givers’ understandings, of the process of informed con- of the informed consent documents. Researchers must
sent that accompanied their child’s participation in a consider the health literacy of the study group, and ac-
dental randomized control trial (RCT). Telephone inter- tively engaging with caregivers to achieve meaningful
views were conducted with a convenience sample of ten informed consent may be challenging. Future research
caregivers who each had a child participating in the RCT. could explore participants’ perspectives of informed con-
Pre-tested closed and open-ended questions were used, sent in populations with low health literacy and assess
and the findings were produced from an inductive anal- whether an underlying expectation not to comprehend
ysis of the latter and a descriptive analysis of the former. health-related information may be a barrier to informed
Participants had limited understanding of the purpose of consent.
the RCT and rated the readability of the consent form
more highly than they rated their understanding of the Keywords Informed consent . Clinical research . Health
research. All felt that informed consent was vital, but literacy . Children . Bioethics
some caregivers had not read the consent documents.

D. H. Boyd (*) Background

Faculty of Dentistry, University of Otago, 310 Great King Street,
Dunedin 9016, New Zealand
e-mail: dorothy.boyd@otago.ac.nz It is a legal and ethical requirement that researchers
obtain participants’ informed consent before including
Y. Zhang them in clinical studies. Thus, the process of informed
Stratford Dental, 82 Miranda Street, Taranaki, Stratford District consent must be taken seriously. Informed consent in-
4332, New Zealand
cludes making participants aware of the purpose of the
L. Smith study, what the research methods involve, the potential
Wellington Institute of Technology, Private Bag 39803, risks/benefits involved in participating, the extent to
Wellington Mail Centre, Lower Hutt 5045, New Zealand which their anonymity will be protected, and their abil-
L. Adam : L. Foster Page : W. M. Thomson ity to withdraw from the trial at any time without disad-
Faculty of Dentistry, University of Otago, 310 Great King Street, vantage (Kripalani et al. 2008; Nijhawan et al., 2013;
Dunedin 9016, New Zealand Smith-Tyler 2007). Informed consent centres on
142 Bioethical Inquiry (2021) 18:141–150

respecting participants’ rights, and their competence to 2013; Harth and Thong 1995; Tait et al. 2005). Factors
make informed decisions about participation without which have been identified as impacting on caregivers’
duress, coercion, or force (Erb et al. 2002; Nijhawan and/or participants’ ability to understand and recall clin-
et al., 2013). Children are minors and therefore are ical trial and informed consent information have includ-
considered to be a vulnerable population who may lack ed: limited knowledge of the pathophysiology of dis-
the cognitive capacity for informed decision-making ease; a desire for their child to receive treatment; stress
(Smith-Tyler 2007). Accordingly, researchers must en- and emotional decision-making; and the way in which
gage with the caregivers so that they understand the information about the trial has been presented (such as
study and can then give their proxy consent for their in lengthy text format that includes complex health
child to participate; the child’s assent must also be terminology) (Erb et al. 2002; Kadam 2017; Miller
obtained (Erb et al. 2002; Tait et al. 2003a). Caregivers et al. 2005; Tamariz et al. 2012). Poor literacy and health
make informed decisions on their child’s behalf and act literacy are further barriers to understanding (Meneguin
in their child’s best interest while, at the same time, and Ayers 2014; Ownby et al. 2015; Tait et al. 2003a;
children’s rights to self-determination are also respected Tamariz et al. 2012).
through seeking their assent (Erb et al. 2002; Grover There have been a number of suggestions for making
2003). informed consent documents and the process of gather-
Health literacy has been defined as “the ability to ing informed consent easier for those with low literacy.
make sound health decisions in the context of every day These strategies have included: using simple language,
life …” (Kickbusch et al. 2005, 8) and “the degree to tested with readability scores; presenting information
which individuals have the capacity to obtain, process verbally or visually (through DVDs or online); re-
and understand basic health information and services searchers asking participants to repeat information back
needed to make appropriate health decisions” (Seldon to them and spending one-on-one time with individual
et al. 2020, vi). It involves not just reading written participants (Kripalani et al. 2008; Tamariz et al. 2012);
information but also listening, understanding, and and using a separate generic booklet that covers partic-
questioning, in order to actively participate in health- ipants’ rights alongside short study-specific consent
related conversations and decisions. Findings from the forms (Benatar et al. 2012).
2006 Adult Literacy and Life Skills Survey in New One way of assessing the readability (the ease with
Zealand showed that, overall, New Zealanders had low which a person can read a document) of informed con-
health literacy and that it was poorer among Māori than sent texts is to use the Flesch-Kincaid readability index
non-Māori. Approximately four out of five Māori males (or Flesch-Kincaid Grade Level Score). Here, the read-
and three out of four Māori females had low health ability of materials is checked through computerized
literacy scores, while just over half of non-Māori males formulae to show the level of literacy needed to read
and females did so (Ministry of Health 2010). Low and comprehend documents (Mailloux et al., 1995).
health literacy presents a challenge to researchers in However, little evidence exists that indicates whether
obtaining informed consent because, in order for the those with poor literacy are able to read texts categorized
consent process to be effective, they must make health as “easy” or “standard” under the Flesch-Kincaid for-
information understandable. To date, there has been no mula (Paasche-Orlow et al., 2003).
research in New Zealand to (a) inform dental researchers In the New Zealand context, the National Ethics
about the informed consent process in trials involving Advisory Committee (NEAC) promulgates a set of
dental care for children or (b) explore the effects on guidelines for upholding participants’ rights in clinical
informed consent of low health literacy within a New trials (National Ethics Advisory Committee. 2019).
Zealand setting. These guidelines are underpinned by the Code of Health
Several studies have explored parent/caregivers’ un- and Disability Services Consumer Rights 1996 (Health
derstanding and recall of information when they have and Disability Commissioner 1996) and the Care of
consented to their child taking part in a study (Harth and Children Act 2004 (New Zealand Government 2004).
Thong 1995; Pletsch and Stevens 2001; Sanders et al. Under these guidelines, children have the right to be
2007). Findings show that many caregivers are unable to protected from exploitation in health research, the right
recall information that they were given about a study, to have their anonymity protected, and should not be
such as its purpose and procedures (Carvalho and Costa enticed to participate through financial rewards. The
Bioethical Inquiry (2021) 18:141–150 143

NEAC also requires all consent and information docu- drilling the tooth, usually under local anaesthetic, then
ments to be written with a Flesch-Kincaid processability cementing a SSC on a tooth). The Hall Technique has
score of 65, which is considered to be at a standard level been shown to be a successful treatment option in pri-
of reading difficulty (Kouame 2010). In the United mary care (Boyd et al. 2017; Boyd et al. 2018; Innes
States, this score is equivalent to an eighth-grade reading et al. 2007; Innes, Evans, and Stirrups 2011) and may be
age or lower (Tait et al. 2005), which equates to year easier for children to cope with than conventional treat-
nine (typically twelve to thirteen years of age) in the ment (Innes et al. 2007; Santamaria et al. 2015). The
New Zealand context. However, it is not known whether local NDHB dental therapists—who had been trained in
these NEAC requirements ensure a robust informed the study protocol, including the consent process—
consent process. undertook recruitment for the study and also carried
out the treatment. One hundred and nineteen children
and their parents consented to take part in the study,
Aims and Objectives while nine caregivers did not consent; the mean child
age was 72.8 months (range 48-109 months, SD 13.1),
The overall aim of this study was to assess the effec- with eighty-one (68 per cent) Māori, nine (8 per cent)
tiveness of the informed consent process undertaken for Pacific Island, twenty-eight (23 per cent) European, and
a RCT, the Northland Hall Technique Project (NHTP). one (1 per cent) Other. Some sixty-six (55.5 per cent) of
Northland children have some of the highest rates of the children were male.
dental decay in New Zealand (Gowda et al. 2009). The participant information sheets and consent forms
Northland is one of New Zealand’s most financially were designed to comply with the NEAC requirements
disadvantaged locations, with Māori comprising about and included a separate short version for children. Eth-
7.5 per cent of the population there (Statistics New ical approval for the study was obtained from the North-
Zealand 2017). The primary objective of the current ern Committee of the Health and Disability Ethics Com-
study was to explore whether a sample of caregivers mittee (14/NTA/141/AM01), and Māori consultation
who had enrolled their children in the NHTP showed was undertaken. Caregivers who had consented for their
understanding of the clinical trial’s purpose, as well as child to participate in the NHTP also gave their permis-
understanding the participant information sheets and sion to be approached by telephone for an interview
consent forms for both caregiver and child. A secondary focusing on the consent process. Caregivers who
objective was to investigate caregivers’ motivations for consented for their children to take part from the begin-
enrolling their child in the clinical trial and their under- ning of June 2015 were invited to take part in a tele-
standing of (and the importance they placed) on the phone interview. The first ten consecutive caregivers
process of informed consent. who agreed to be interviewed were then contacted to
arrange a time for the telephone interview. The tele-
phone interviews were conducted individually in the
Methods first week of July 2015. Interviews were audio-
recorded and later transcribed verbatim.
The NHTP commenced in February 2015. It was a split- An initial interview schedule including closed and
mouth randomized control trial (clinical trial registry open-ended questions was developed and piloted with
number ACTRN1261700123836) undertaken with three non-dental staff employed in the same institution
four- to eight-year-old children enrolled in the primary as the research team. The interview schedule contained
oral healthcare system (The Community Oral Health three initial closed questions that were adapted from the
Service [COHS]) within the Northland District Health Deaconess Informed Consent Comprehension Test
Board [NDHB]). The study investigated the outcomes (DICCT) (Miller et al. 1996) and required a Likert-
(clinical success and children’s self-reported pain and type scale response. These questions are included in
anxiety) of two different treatment techniques for Table 1, and data are presented using descriptive statis-
decayed primary molar teeth: the Hall Technique (which tics. The remaining six questions were open-ended ex-
involves no drilling or local anaesthesia and cementing a ploratory questions, designed to gather more detailed
preformed stainless steel crown [SSC] on a tooth) and responses regarding participants’ understanding of the
the conventional SSC technique (which involves purpose of the study, their comprehension of the consent
144 Bioethical Inquiry (2021) 18:141–150

forms, reasons for participation, and suggestions for Participants’ ratings of their understandings of the
how the consent process could be improved. clinical trial (Table 1) showed that four rated their
An inductive analysis of the open-ended questions understandings of the NHTP as 5 or below (where a
responses began when three members of the research team score of 1 indicated a poor understanding and 10 a
each undertook separate close readings of the raw data very good understanding), while the remaining six
(Thomas 2006). As they read, each researcher identified participants rated their understanding as between 6
themes that emerged in the participants’ responses. Ex- and 8 (ratings ranged from 3 to 8, mean 6.1). None
cerpts that evidenced these themes were subsequently rated their understanding of the NHTP as very good
coded and grouped under each theme. The researchers (scores of 9 or 10).
then compared their lists of themes, and they were found By contrast, most caregivers (seven) rated the ease of
to be consistent. The inductive thematic analysis and par- readability of the consent material highly; that is, at 8 or
allel coding process acted as a form of triangulation, which above. Of the remaining three participants, one said that
helped to ensure the trustworthiness of findings. A fourth s/he did not attempt to read it but flicked through it,
researcher was recruited and undertook a further inductive while the remaining two gave a score of 5 out of 10.
analysis of the data, which was largely consistent with the When asked about the readability of the children’s sec-
earlier analysis, with the additional identification of one tion, four participants stated that they could not remem-
new sub-theme. ber the form, while one other said that s/he did not read
it. Of the five participants who recalled reading the form,
three rated their comprehension of the section for chil-
dren on the consent form highly (10) and two mid-range
Results (5).
Analysis of the qualitative questions revealed the
The interview participants included seven mothers, two three broad themes, namely, (1) a lack of comprehen-
grandmothers, and one father who all resided in the sion and dental knowledge, (2) understanding the con-
Northland region. Participants (P) are identified in the sent process, and (3) trust and altruism. Each of these
text with the identifying number they were assigned in themes is explained in detail below.
the interviews (1-10).

Table 1 Caregivers’ rating of their understanding of the NHTP and readability of consent forms

Questions
On a scale of 1 to 10, with 1 being very poor and 10 being very good…

Participant number 1. How well do you rate 2. How easy was the 3. Did you read the section for children
your understanding of the study? consent form to read? (it had pictures to colour in)? If so, how
easy was the section for the children to read?

1 4 9 10
2 8 9 Can’t remember the form
3 3 I flicked through Can’t remember the form
4 7 9 Can’t remember the form
5 6 8 Can’t remember the form
6 8 8 Didn’t read
7 8 8 10
8 5 5 5
9 8 10 10
10 4 5 5
Average scores 6.1 7.1 8 (for those who answered)
Range 3 to 8 5 to 9 5 to 10
Bioethical Inquiry (2021) 18:141–150 145

Lack of Comprehension and Dental Knowledge description of the role of the dental therapist in
explaining the trial:
Five of the participants reported very limited under-
standing of the purpose of the NHTP and the dental It’s a new way of dealing with tooth decay. And,
procedures involved in the trial. In most instances, their um, I think the best explanation that the dental
understanding of the trial, as determined from the ex- technician gave us was, you know it’s a bit like a
planation they gave the researcher, was consistent with swimming cap, where you put over the tooth, it
the numerical rating they gave their understanding; doesn’t heal the decay but it prevents it from
these participants all rated their understanding between spreading. Um, yeah, yeah, so that’s my under-
3 and 6. However, one participant rated their under- standing. She did a pretty good job I think, the
standing at 8 but was unable to describe either the dentist or dental technician or whatever you call
purpose of the trial or the procedures involved. When them … She’d given heaps of explanation which I
asked to explain what the study was about, this partic- thought was better from her, we’ve talked about it
so it kind of made the form more understandable I
ipant responded, “can you give me a bit of background
guess.
about that?” (P10). The participant appeared to be ask-
ing the interviewer for clarification of the trial. Later in It was noteworthy that these two participants, along
the interview, this participant indicated limited under- with others in the study, seemed unaware that the oral
standing of the trial when they commented on seeing health professional treating their child was a dental
children involved in the trial: “I saw one of the little girls therapist; participants gave various titles to this profes-
here with the stuff … got a bit of the mould on her teeth, sional, including “dental lady” (P3), “dentist or dental
and how that will drop off or something.” The partici- technician” (P2), and “the ladies that was doing it” (P9).
pants who indicated in their rating that they had a poor
understanding of the trial confirmed this response in
their interview answers. For instance, when asked to Understanding the Consent Process
describe the trial, one participant said, “I’m not actually
sure to be quite honest” (P1), and another responded, All caregivers indicated that they understood the pur-
“Um it’s about her, um, her teeth getting, oh what’s the pose of the informed consent process and emphasized its
name called? … Yeah and um, the feelings for the kids importance; however, their responses revealed varying
and what they go through” (P7). levels of understanding. Participants’ comments often
By contrast, participant four gave a clear description featured two words, “okay” and/or “risks”. For instance,
of the trial, indicating a good understanding of the one participant commented that the purpose of a consent
purpose: “… trialling two different ways of using form was to gather “permission, to make sure it’s okay”
crowns on baby teeth … one method is to use a drill to (P1), and another explained it was to “make sure parents
remove the decay and one method you don’t, you just are okay with [the research]” (P5). These responses
lock it in there …” Interestingly, despite displaying a indicated a view of consent as simply giving permission
good understanding, participant four rated their under- for their child to be included in the trial. Other partici-
standing only as seven. Similarly, participant six was pants’ explanations indicated an understanding of con-
able to clearly articulate the purpose of the trial: sent as informed permission. For example, participant
“They’re trying two concepts. [The] old one, which nine explained that the purpose of the form was so that
was for the drilling, and one was to put the cap over “Mum[s] and dad[s] know the risks. [It’s a] safety
the decayed tooth.” This participant rated their under- thing.” Similarly, another participant explained: “[the
standing at “I’d say eight. Nine?” consent form] is to ensure caregivers understand the
Participants’ understandings of the trial and of the procedure that is about to take place, the risks …
consent forms were enhanced through the verbal expla- consenting that they fully understand … what could
nations that were provided by the “dental lady” (the happen” (P10). These two responses suggest a view of
dental therapist treating the children in the trial): “The consent forms as explaining the risks to—and safety
dental lady explained to me what was going on … I of—the children, as well as having a permission func-
mean she gave me the consent form, it was explained tion. Participant 10 also viewed the consent form as a
and I was quite happy” (P3). Participant two gave a clear liability waiver for the research team, stating that
146 Bioethical Inquiry (2021) 18:141–150

signing the consent form meant “we will probably be participant nine said, “I put my trust in them.” Similarly,
held accountable for whatever it is … yeah, so it is more participant two stated, “They obviously knew what
of a, yeah, from the dentist side of things more about they’re doing [and therefore I] didn’t even consult my
protecting themselves as well.” partner.” Participant three revealed an even more
Despite indications that half of the participants did trusting view when s/he explained that s/he volunteered
not have a good understanding of the clinical trial, most for the study because “They asked, it’s that simple …
indicated that they would not agree to participate in a and I agreed.”
research study without “being fully informed” (P2). The overwhelming majority of participants (eight)
However, this response was often contradicted by sub- explained that they consented for their child to partici-
sequent answers. For example, participant three said that pate in the trial because they wanted to improve dental
s/he agreed for her child to participate in the study visits and outcomes for children. Participant four stated,
without reading the consent form in detail: “I just agreed “If it means having an easier thing for the kids and not
really, I didn’t put that much effort into reading [the having all the drilling then that suits me.” Similarly,
consent form] actually. I’m a busy [parent].” participant two said, “I’m always keen to support trials
Some participants also reported that they were “not if it is going to be advantage[ous] for the kids later on.”
that clued up” (P6) or their family had low literacy Of note, both of these participants had rated and dem-
which made consent forms hard to read and compre- onstrated good understanding of the trial.
hend. For example, when participant ten was asked Participant ten elaborated more on the view that
whether the child section on the consent form was easy s/he wanted to improve children’s experiences of
to read, s/he replied: “For … people with … good … dental visits:
reading probably not too bad, but … most of our family
up this place … hardly can read … so … some of our It is to improve the access to the dentist … for our
kids come from the environment [where they are] not kids and make it fun way and not getting all crying
really educated properly so … somebody must … ex- and “I don’t wanna go,” so that’s what it is for me,
plain to them so they can understand.” Other partici- why [I volunteered] … [I] like the idea of non-
pants also indicated that, although they had found the painful and do the job … especially for our kids.
forms to be readable, they thought other members of the The two participants who did not indicate that they
community might struggle. At times it was not clear wanted to improve outcomes for children were not
whether the participant themselves had struggled to read explicitly asked why they decided to participate in the
it or if they thought others would. For example, “I know trial.
there were some parts of it, if you simplified it a lot
more, yeah, just some words so people can understand it
more” (P5). It is possible that pride prevented partici-
pants from disclosing difficulty in understanding the Discussion
forms. For example, when asked if s/he did not under-
stand any aspects of the consent form, participant eight This study set out to assess the effectiveness of the
responded, “No, they explained it to me, I couldn’t read consent process for the NHTP by exploring caregivers’
them very well, I didn’t, I don’t think I had my glasses understandings of the trial. Most participants had limited
that day.” This participant had rated her/his understand- understanding of the purpose of the NHTP and the
ing of the clinical trial as five. treatment procedures involved. Some participants’ com-
ments revealed low health literacy, including basic den-
Trust and Altruism tal terminology (e.g.“tooth mould” for the crown, or
“dental ladies” for dental therapists). One participant
Despite some reporting low understanding of the NHTP also stated that poor literacy levels in the Northland
(Table 1), one third of the participants said that they region would likely impact on caregivers’ abilities to
enrolled their child in the trial because they trusted the understand the consent forms. Accordingly, our findings
researchers. They consented for their child to participate support those of earlier studies, where poor literacy and
without feeling the need to question the researchers or, health literacy compromise the ability to make fully
alternatively, consult with their partner. For instance, informed choices about research participation
Bioethical Inquiry (2021) 18:141–150 147

(Meneguin and Ayers 2014; Ownby et al. 2015; Tait unwittingly been acting as a reader for participant eight
et al. 2003a, 2003b, 2004, 2005; Tamariz et al. 2012). who was attempting to “save face” by stating that s/he
The participants rated the readability of the consent was unable to read without her/his glasses (although we
form more highly than they rated their understanding of acknowledge that this is speculation).
the purpose of the research. Although the reason for All of the participants were aware of the purpose of
their self-reported differences in understanding cannot informed consent; that is, notifying caregivers of any poten-
be ascertained, it is possible that the standardized nature tial “risks” involved in the research and ensuring that parents
of consent forms meant that the participants had previ- were “okay” with their child’s participation. Most stressed
ous experience of these forms or alternatively, the re- its importance and asserted that they would not consent to
searchers were successful in matching the readability of their child participating in any study without being fully
written consent forms to the participants’ literacy level. informed. On the one hand, these comments highlight how
Furthermore, it may have been a lack of health the participants were upholding the principles of benefi-
literacy—as suggested by a lack of basic dental cence and non-maleficence that underpin the purpose of
terminology—and not poor literacy that impacted on the informed consent process (Berman et al. 2016); that is,
the participants’ low understanding of the clinical trial. as caregivers, they wanted to protect their child’s safety,
Thus, a basic health literacy assessment of the study well-being and rights. On the other hand, participant six said
population could be conducted prior to clinical trials, that s/he did not read this child’s consent form, which
in order to inform the design of consent forms (Brainard implies trust in the practitioners and also may indicate that
et al. 2016). This research highlights that good readabil- not understanding health-related information is the norm.
ity of participant information documents does not nec- The latter creates a complex environment for health-
essarily mean good understanding in health research, practitioners to engage in consent processes. When people
and having a signed standardized consent form does accept a position of non-understanding, it may be more
not necessarily mean that a participant’s informed con- challenging for practitioners and researchers to uphold the
sent has been obtained. principles of informed consent. This presents an ethical
Two participants said that verbal explanations pro- dilemma, as researchers and health practitioners are required
vided by dental therapists were a key to them under- to ensure that patients and research participants understand
standing the clinical trial and consent forms. This sup- treatment/research before they sign a consent form; howev-
ports the findings of previous research, where a re- er, if participants expect not to understand, this may be a
searcher (or in this instance, a local health professional) substantial barrier to engaging effectively.
talking with individual participants/caregivers enhanced A third of participants said that they enrolled their
their understanding of a clinical trial (Kripalani et al., child in the NHTP because they trusted the researchers.
2008; Tamariz et al., 2012). It also supports providing Although trust is desirable in a good practitioner/patient
adequate training in the consent process as part of the relationship (Armfield et al. 2016), patients may have
training of health professionals undertaking treatment in “blind trust” in health professionals as a result of their
a clinical study, so that they are thoroughly cognizant of professional status, authoritative position, or because
the research aims and objectives and the treatment they often treat patients when they are most vulnerable
methods involved and engage confidently in conversa- (Pearson and Raeke 2000; Rowe and Calnan 2006). In
tions about the study. In clinical trials, it is also essential this study local NDHB dental therapists carried out the
that someone familiar with health terminology (in this consent and treatment, and so they may have been
case, a dental therapist) can communicate information to familiar to the participants, which may have enhanced
participants with literacy challenges (Alaei et al. 2013). trust. Some parents have also stated that they feel
Participant eight said that the dental therapist read the obliged to participate in clinical research trials if partic-
consent form to her/him because s/he forgot her glasses. ipation has been suggested by a trusted health profes-
This may be the case; however, it is also possible that sional (van Stuijvenberg et al. 1998). Nevertheless,
the participant was trying to disguise poor literacy. It is “blind trust” in health researchers can be problematic,
well documented that people with limited literacy will as evidenced by instances of malpractice, research trials
attempt to disguise this because they feel shame (or “going wrong” and may be a disincentive for some
whakamā in a Māori cultural context) (Marcus 2006; health professionals to adapt to best evidence-
Sachdev 1990). The dental therapist may have based practice (Rowe and Calnan 2006). The
148 Bioethical Inquiry (2021) 18:141–150

responses highlight how important it is that re- educational backgrounds, literacy levels, ethnicity, and
searchers be mindful of the trust that some mem- socio-economic status. However, this may be seen as
bers of the public place in health professionals and invasive, threatening, or embarrassing for some caregivers
the ethical responsibilities implied by that trust. who may feel shame associated with low literacy levels
All but two participants said that they consented for and/or financial insecurity. A final consideration is the
their child to participate in the NHTP because research lapse in time between participants signing the consent form
findings may result in more child-friendly dental treat- and their interview. Participants were not interviewed on
ments that could ultimately benefit all children. At first the same day that they consented to their child participating
glance, it appears that the participants were acting altru- in the trial. They may have understood the research at the
istically by consenting for their child to participate in the time of signing but could have subsequently forgotten.
clinical trial, but there are other interpretations. If it was However, it could be argued that, as their child were to
verbally stated that the purpose of the clinical trial was receive a dental treatment that was intended to remain in
to test a more “child-friendly” method of treatment place for several years, caregivers’ basic understanding
(even though these words were not written in the con- should have persisted. Moreover, researchers need to en-
sent documents), then caregivers may have felt guilty if sure that caregivers’ informed consent is gathered through-
they declined to give their consent. Furthermore, Māori out the course of a study, because it is not a one-off process
culture is a collectivistic culture and thus, community that simply occurs prior to research participation (Gupta
well-being overshadows that of the individual (Cram 2013).
et al. 2003; Durie 1998). Consequently, some partici- There have been numerous studies focusing on chil-
pants may have felt it was imperative for their child to dren’s participation in RCTs, which have largely recom-
participate in a study that would ultimately result in mended strategies for fostering informed consent without
improved clinical procedures for their wider tamariki/ necessarily exploring caregivers’ understanding of re-
mokopuna (children/grandchildren) and whānau search documents and the importance they place on the
(family). consent process (Weintraub and Breland 2015). Conse-
Only ten caregivers participated in the study, which is a quently, this study adds a new dimension to research with
relatively small sample size. However, theoretical satura- children and caregivers. Further research could explore
tion (Saunders et al. 2018) occurred within these ten informed consent from the participants’ perspectives in
interviews, and, although not generalizable, they revealed populations with low health literacy. In particular, it would
valuable insights into the consent process. The perspec- be intriguing to explore in these groups whether there may
tives of the small number of caregivers who declined for be an underlying expectation not to comprehend health-
their child to participate in the NHTP, and those of the related information and whether this becomes a disincen-
children themselves, are not reported. Children’s perspec- tive for participants to engage with researchers.
tives are frequently missing in dental research and exam-
ining children’s understandings of the consent forms
would have benefitted the study (Marshman and Hall Conclusion
2008; Smith et al. 2018). The participants were gathered
from one relatively deprived region of New Zealand and The informed consent process was not always effective
from a population whose children had considerable dental despite the informed consent documents having high
caries experience. Dental caries disproportionately affects readability. Gathering caregivers’ informed consent for
disadvantaged groups, and this may mean that more im- their child to participate in a randomized control trial is a
portance must be attached to considering the health literacy complex undertaking. Caregivers differ in their literacy
of groups taking part in research on the condition. Al- and health literacy levels, socio-economic and cultural
though we did not gather socio-demographic details from backgrounds, and degrees of trust in health profes-
the ten participants, it is likely because of the setting, and sionals, and these all affect their ability to give their
the focus of the study, that this group had low health informed consent. Researchers must consider the health
literacy. Future studies focusing on caregivers’ understand- literacy of the study group, and actively engaging with
ings of informed consent in dental RCTs would benefit caregivers to achieve meaningful informed consent may
from recruiting participants from other locations and be challenging. Future research could explore in-
collecting more information about participants’ formed consent from the participants’ perspectives
Bioethical Inquiry (2021) 18:141–150 149

in populations with low health literacy and assess trials in health literacy. BMC Health Services Research
16(1): 246.
whether an underlying expectation not to compre-
Carvalho A.A. and L.R. Costa. 2013. Mothers’ perceptions of their
hend health-related information may be a barrier to child’s enrollment in a randomized clinical trial: Poor under-
informed consent. standing, vulnerability and contradictory feelings. BMC
Medical Ethics 14(1): 52.
Cram, F., L. Smith, and W. Johnston. 2003. Mapping the themes
Acknowledgments This study was funded by Lottery Health of Māori talk about health. The New Zealand Medical
and supported by 3M. We are grateful to the Northland District Journal 116: 1170-1177.
Health for supporting the study, to the research assistant Carleen Durie, M. 1998. Whaiora: Māori health development, 2nd ed.
Davis, and to the dental therapists, children, and their families who Auckland: Oxford University Press.
took part. Erb, T.O., S.R. Schulman, and J. Sugarman. 2002. Permission and
assent for clinical research in pediatric anesthesia. Anesthesia
and Analgesia 94(5): 1155-1160.
Authors’ Contributions DHB designed the study with guid-
Gowda, S., W.M. Thomson, L.A. Foster Page, and N.A. Croucher.
ance from WMT and LFP; YZ conducted and transcribed the
2009. Dental caries experience of children in Northland/Te
telephone interviews; DHB, YZ, LS, and LA analysed the tran-
Tai Tokerau. New Zealand Dental Journal 105(4): 116-120.
scripts; DHB drafted the manuscript, and all authors critically
appraised and revised the manuscript. All authors read and ap- Grover, S. 2003. On the limits of parental proxy consent:
proved the final manuscript. Children’s right to non-participation in non-therapeutic re-
search. Journal of Academic Ethics 1(4): 349-383.
Gupta, U.C. 2013. Informed consent in clinical research:
Revisiting few concepts and areas. Perspectives in Clinical
Compliance with ethical standards Research 4(1): 26-32.
Harth, S.C., and Y.H. Thong. 1995. Parental perceptions and
Competing interests This study was funded by a grant from the attitudes about informed consent in clinical research involv-
Lottery Health, New Zealand and supported by 3M. ing children. Social Science and Medicine 40(11): 1573-
1577.
Health and Disability Commissioner. 1996. Code of Health and
Disability Services Consumers’ Rights. https://www.hdc.org.
nz/your-rights/about-the-code/code-of-health-and-disability-
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