The impact of influences in a medical screening programme invitation: a randomized controlled trial
May 7, 2023, BY CANCER ROSE
Christian Patrick Jauernik 1,2, Or Joseph Rahbek 1,2, Thomas Ploug 3, Volkert Siersma 1, John Brandt Brodersen 1,2
1 Department of Public Health, The Research Unit for General Practice and Section of General Practice, University of Copenhagen, Copenhagen, Denmark
2 The Primary Health Care Research Unit, Zealand Region, Sorø, Denmark
3 Centre for Applied Ethics and Philosophy of Science, Department of Communication and Psychology, Aalborg University Copenhagen, Copenhagen, Denmark
European Journal of Public Health, ckad067, https://doi.org/10.1093/eurpub/ckad067
The authors of this publication had the idea of screening for a fictitious disease, "cytoliosis," non-transmissible and potentially fatal, and sent out invitations for screening using pamphlets, which were also fictional.
This trial is randomized with seven arms, i.e., seven groups of people in a total of 600 people studied. Each group received a pamphlet with messages that differed to a greater or lesser extent in their incentive to participate in screening.
The objectives of the study were:
1) to assess whether the different methods of influence had a significant effect on the intention to participate in a screening program, and
2) to assess whether participants were aware of these influences and whether there was a relationship between intention to participate and awareness.
Introduction and background
According to the authors:
"Screening programs for different cancers are implemented in many developed countries. They have intended benefits, including a reduction in mortality and morbidity plus less radical treatments.1"
However, cancer screening programmes come with many unintended harms such as false-positive results, overdiagnosis and overtreatment, possibly leading to physical, psychological or social harms.2 The quality of screening programmes is sometimes evaluated by a considerable participation rate.3–5"
From the perspective of health authorities, it is assumed that a cancer screening program is more beneficial than harmful, and that a high participation rate would maximize the expected benefits of the screening program. In addition, citizens with lower socioeconomic status are found to have a higher incidence of cancer diseases (except breast cancer) but are less likely to participate in screening programs.
“This creates another incentive for health authorities to make screening participation barrier-free and simple to promote equality in health. The healthcare authorities can systematically influence citizens in subtle ways that may increase participation rates without making the choice to participate adequately informed.”
« Not all citizens will share the same assessment of the benefits/harms as the health authorities. And even if they agree with the health authorities that the benefits outweigh the harms on a population level, they may still not wish to participate because they on an individual level might receive more harm than benefit—current evidence suggests that the more informed citizens are less likely to participate in cancer screening.10,11 »
The authors refer to a study published in 2019 on the methods of influence health authorities use to push populations to participate in various screening programs. These methods range from anxiety-provoking messages to minimizing the risks and harms of screening.
Our French National Cancer Institute (INCa) was cited in this study in the categories of 1) Misrepresentation of statistics and 2) Unbalanced representation of harm versus benefit.
It is amusing, by the way, that said INCa is very keen to classify the screening controversy as fake news on a page titled "enlightenment" while itself being caught at fault for manipulating the public with its biased and misleading documentation. The author of this 2019 study on public manipulation is a co-author of this current study; in 2019, he distinguished in his publication 5 categories of people's influences:
1. Tendentious presentation of statistics Biased presentation of statistics,
2. Omission of harmful effects and emphasis on benefits,
3. Recommendations of participation,
4. Opt-out systems -This consists of assigning citizens a pre-determined appointment at the time of the invitation. If the person does not wish to participate, the person must actively opt-out. The patient's non-refusal is considered de facto acceptance to participate.
5. Fear appeals.
These types of influences significantly affect individual participation by circumventing or thwarting reflection and may be incompatible with informed decision-making.
This disease created for the study, supposedly deadly, was invented to avoid a bias due to preconceived ideas and fears related to cancer.
“The pamphlet for screening for cytoliosis (i.e. 'the neutral') was partially based on the Danish colorectal cancer (CRC) screening pamphlet, and cytoliosis shared the same incidence and mortality as CRC.17 The screening programme for cytoliosis shared the same benefits (e.g., mortality reduction) and harms (e.g., false positives, physical harm, and overtreatment) as CRC screening for a 50–60-year-old male. The harms of the fictitious screening programme were increased compared with CRC screening to better balance the benefits and harms of participation.”
Seven different brochures were distributed, one for each of the seven groups in this randomized study:
A- The "neutral" pamphlet
B- A pamphlet with relative risk reductions to accentuate the reduction in mortality.
( Similar to the INCa process for breast cancer, giving percentages of mortality reduction that correspond to comparison rates between populations, but not at all to the real, absolute data.
This technique of misleading in the presentation of mortality reduction is constantly used by INCa, even though the citizens criticized it during the citizens consultation on breast cancer screening in 2016; nothing has changed in the communication of INCa, and we can still read in the documents a "20% mortality reduction", which corresponds in real life to a single woman whose life is prolonged by screening on women 2000 screened and on 10 years of screening, which is no longer the same thing ....)
C- The third pamphlet misrepresented the harms versus the benefits, omitting the harmful effects and emphasizing the benefits, again very similar to INCa's methods with deliberate omission of the most important risks,(read https://cancer-rose.fr/en/2021/10/23/inca-still-outrageously-dishonest-and-unethical-2/)
D- The fourth pamphlet was based on pre-booked appointments (opt-out system, see above)
E- The fifth pamphlet contained an explicit recommendation to participate
F- The sixth pamphlet appealed to fear
G- And finally, a last pamphlet contained all the influence systems at the same time.
All the types of influence studied were inspired by real examples of cancer screening programs (pamphlets 2 and 4 for our French institute)
All the pamphlets can be found in the PDF appendix
A- Main result: a measure of intention to participate
"The lowest proportion of people intending to participate (31.8%) was observed in the group that received the neutral pamphlet (A), while the proportion of people with the intention to participate ranged from 39.2% to 80.0% when the other, non-neutral pamphlets were distributed.."
See Table 2
Intention to participate (without adjustment for socio-demographic status) increased statistically significantly in groups that received brochures containing relative risk reductions (B), misrepresentation of harms versus benefits (C), an explicit recommendation to participate (E), fear appeals (F), and all influences combined(G)
B- Secondary outcome: awareness of influences and effect of awareness of influences on intention to participate
Were participants aware of the influences they were subject to participate more, and was there a relationship between intention to participate and this awareness of the influences experienced?
"A majority ranging from 60.0% to 78.3% of participants," the authors say, "reported no awareness that their choice was attempting to be influenced (pamphlets B through G).
There was no clear difference between responses to the neutral brochure (A) and the pamphlets containing a deliberate attempt to influence participants' choice."
"Participants who received a pamphlet with influence (B-G) and did not indicate awareness that their choice was influenced had a higher intention to participate than those who felt the pamphlet was trying to influence their choice and then correctly located an influence."
The authors also say that participants with an influential pamphlet who were unaware of this had more intention to participate than those who felt the pamphlet was trying to direct their choice but failed to locate the influence correctly.
Nevertheless, the authors warn that "Secondary outcomes should be interpreted cautiously. Because secondary outcomes are measured after participants have indicated their intention to participate, this may affect their response about whether the pamphlet was trying to guide their choice. We hypothesize that participants who intended to participate may be more reluctant to admit they were potentially influenced."
In any case, it is certain and demonstrated that the five categories of influence increase intention to participate when used in materials sent to screening targets.
Less than half of the participants recognized these influences, and not knowing about them was de facto associated with an increase in intention to participate.
"These results call for reflection and discussion on using different types of influence to increase participation rates in cancer screening programs. The potential risks of participation in cancer screening programs can be serious and substantial, and the intended effect of increasing participation rates through the use of influences must be carefully weighed against the unintended effect of potentially circumventing participants' informed choice.
Thus, there is a need to find alternative ways to evaluate cancer screening programs besides participation rates.
One such alternative could be the rate of informed decisions made by potential screening participants."
This is even though, as the authors speculate, citizens might feel helpless upon learning about the multiple risks of screenings.
Other aspects in a person's decision-making to participate or not are also to be considered:
"Information material is not the only aspect of decision making, and this study does not examine external reasons for participants' choices, e.g., society's (health) culture, society's own and general attitudes toward health interventions, sense of duty, behavior, and opinions of significant others, barriers to intention and actual behavior, financial incentives of health professionals to increase screening uptake, etc. ...Research on external reasons can quantify the importance of decision making on information materials."
"The considerable effect of influences that are further reinforced by unawareness (of these influences) suggests that the application of these influences should be carefully considered for interventions where informed participation is intended."
The editors of this publication suggest that further research into the potential negative effects of these influences be considered, as the negative effects of these influence techniques on the population result in a weakening of trust in health authorities.
Cancer Rose Commentary
This publication, along with Rahbek's from 2019, is another reminder of the disastrous effects on people's health of the harmful influences that misleading and unbalanced information materials can cause.
It should always be kept in mind that materials for screenings are sent to populations that are doing well and have, a priori, no clinical complaints. The influence used to get them into potentially harmful screening processes is akin to imposing a potentially harmful health device without informing and deceiving people. This is ethically indefensible, yet done by health authorities.
The French INCa is cited in this 2019 study, as can be seen in a summary table of the study (https://cancer-rose.fr/wp-content/uploads/2021/04/nouveau-tableau.pdf; see highlighted parts); rather than devoting resources to pointing the finger at a growing controversy about the relevance of breast cancer screening, the institute would do well to devote time and resources to correcting its serious communication flaws that mislead French citizens on breast cancer screening.
Concerning breast cancer screening, we can put this study in relation to another one, a French one, published in 2016, showing that when women are given a little more objective information about breast cancer screening by mammography, they participate less.(https://cancer-rose.fr/en/2021/01/24/objective-information-and-less-acceptance-of-screening-by-women/ )
This study went relatively unnoticed, and for a good reason, since for the health authorities, only one criterion counts, that is the uptake, the misleading of women is a fully assumed scientific theme. (https://cancer-rose.fr/en/2020/12/17/manipulation-of-information/)
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