Reporting Down syndrome screening results: women's understanding of risk

Taxonomies for synthesizing the evidence on communicating numbers in health: Goals, format, and structure

Many people, especially those with low numeracy, are known to have difficulty interpreting and applying quantitative information to health decisions. These difficulties have resulted in a rich body of research about better ways to communicate numbers. Synthesizing this body of research into evidence-based guidance, however, is complicated by inconsistencies in research terminology and researcher goals. In this article, we introduce three taxonomies intended to systematize terminology in the literature, derived from an ongoing systematic literature review. The first taxonomy provides a systematic nomenclature for the outcome measures assessed in the studies, including perceptions, decisions, and actions. The second taxonomy is a nomenclature for the data formats assessed, including numbers (and different formats for numbers) and graphics. The third taxonomy describes the quantitative concepts being conveyed, from the simplest (a single value at a single point in time) to more complex ones (including a risk-benefit trade-off and a trend over time). Finally, we demonstrate how these three taxonomies can be used to resolve ambiguities and apparent contradictions in the literature.

Imprecision and Preferences in Interpretation of Verbal Probabilities in Health: a Systematic Review

INTRODUCTION

Many health providers and communicators who are concerned that patients will not understand numbers instead use verbal probabilities (e.g., terms such as "rare" or "common") to convey the gist of a health message.

OBJECTIVE

To assess patient interpretation of and preferences for verbal probability information in health contexts.

METHODS

We conducted a systematic review of literature published through September 2020. Original studies conducted in English with samples representative of lay populations were included if they assessed health-related information and elicited either (a) numerical estimates of verbal probability terms or (b) preferences for verbal vs. quantitative risk information.

RESULTS

We identified 33 original studies that referenced 145 verbal probability terms, 45 of which were included in at least two studies and 19 in three or more. Numerical interpretations of each verbal term were extremely variable. For example, average interpretations of the term "rare" ranged from 7 to 21%, and for "common," the range was 34 to 71%. In a subset of 9 studies, lay estimates of verbal probability terms were far higher than the standard interpretations established by the European Commission for drug labels. In 10 of 12 samples where preferences were elicited, most participants preferred numerical information, alone or in combination with verbal labels.

CONCLUSION

Numerical interpretation of verbal probabilities is extremely variable and does not correspond well to the numerical probabilities established by expert panels. Most patients appear to prefer quantitative risk information, alone or in combination with verbal labels. Health professionals should be aware that avoiding numeric information to describe risks may not match patient preferences, and that patients interpret verbal risk terms in a highly variable way.

Does women's place of birth affect their opportunity for an informed choice about Down syndrome screening? A population-based study in France

Background

To examine disparities by maternal place of birth in the opportunity to make an informed choice about Down syndrome screening, in France, where the national guidelines recommend that physicians offer it to all pregnant women.

Methods

We used population-based data from the nationally representative French Perinatal Surveys in 2010 and 2016 (N=24,644 women) to analyze the opportunity for an informed choice for prenatal screening, measured by a composite indicator.

Results

Among the 24 644 women in the study, 20 612 (83.6%) were born in France, 861 (3.5%) elsewhere in Europe, 1550 (6.3%) in North Africa, and 960 (3.9%) in sub-Saharan Africa. The probability of screening was lower for women born outside France. After adjustment for survey year, maternal age, parity, education level, and the maternity unit’s level of perinatal care, women born outside France had the opportunity to make an informed choice less often than women born in France. This association remained essentially the same even after excluding women without adequate prenatal care.

Conclusions

Women born outside France, including those with adequate prenatal care, had less opportunity than women born in France to make an informed choice about prenatal screening for Down syndrome.

Impact of delivery models on understanding genomic risk for type 2 diabetes

BACKGROUND

Genetic information, typically communicated in-person by genetic counselors, can be challenging to comprehend; delivery of this information online--as is becoming more common--has the potential of increasing these challenges.

METHODS

To address the impact of the mode of delivery of genomic risk information, 300 individuals were recruited from the general public and randomized to receive genomic risk information for type 2 diabetes mellitus in-person from a board-certified genetic counselor or online through the testing company's website.

RESULTS

Participants were asked to indicate their genomic risk and overall lifetime risk as reported on their test report as well as to interpret their genomic risk (increased, decreased, or same as population). For each question, 59% of participants correctly indicated their risk. Participants who received their results in-person were more likely than those who reviewed their results on-line to correctly interpret their genomic risk (72 vs. 47%, p = 0.0002) and report their actual genomic risk (69 vs. 49%, p = 0.002).

CONCLUSIONS

The delivery of personal genomic risk through a trained health professional resulted in significantly higher comprehension. Therefore, if the online delivery of genomic test results is to become more widespread, further evaluation of this method of communication may be needed to ensure the effective presentation of results to promote comprehension.

Continuity of midwifery care and gestational weight gain in obese women: a randomised controlled trial

Background

The increased prevalence of obesity in pregnant women in Australia and other developed countries is a significant public health concern. Obese women are at increased risk of serious perinatal complications and guidelines recommend weight gain restriction and additional care. There is limited evidence to support the effectiveness of dietary and physical activity lifestyle interventions in preventing adverse perinatal outcomes and new strategies need to be evaluated. The primary aim of this project is to evaluate the effect of continuity of midwifery care on restricting gestational weight gain in obese women to the recommended range. The secondary aims of the study are to assess the impact of continuity of midwifery care on: women's experience of pregnancy care; women's satisfaction with care and a range of psychological factors.

Methods/Design

A two arm randomised controlled trial (RCT) will be conducted with primigravid women recruited from maternity services in Victoria, Australia. Participants will be primigravid women, with a BMI≥30 who are less than 17 weeks gestation. Women allocated to the intervention arm will be cared for in a midwifery continuity of care model and receive an informational leaflet on managing weight gain in pregnancy. Women allocated to the control group will receive routine care in addition to the same informational leaflet. Weight gain during pregnancy, standards of care, medical and obstetric information will be extracted from medical records. Data collected at recruitment (self administered survey) and at 36 weeks by postal survey will include socio-demographic information and the use of validated scales to measure secondary outcomes.

Discussion

Continuity of midwifery care models are well aligned with current Victorian, Australian and many international government policies on maternity care. Increasingly, midwifery continuity models of care are being introduced in low risk maternity care, and information on their application in high risk populations is required. There is an identified need to trial alternative antenatal interventions to reduce perinatal risk factors for women who are obese and the findings from this project may have application in other maternity services. In addition this study will inform a larger trial that will focus on birth and postnatal outcomes.

Trial Registration

Australian New Zealand Clinical Trials Registry ACTRN12610001078044.

Are adolescents' decisions about prenatal screening for Down syndrome informed? A controlled, prospective study

STUDY OBJECTIVE

Maternal serum screening is routinely offered to pregnant women in public hospitals in Victoria, Australia, regardless of their age. The aim of this study was to determine whether pregnant adolescents are less likely to make informed choices about undertaking this test than adult pregnant women.

DESIGN

Controlled, prospective design.

SETTING

Public hospital antenatal clinics in Victoria, Australia.

PARTICIPANTS

Adolescents up to 20 years of age were recruited at young mothers' clinics before they were offered second trimester maternal screening. They completed self-report questionnaires prior to maternal serum screening and again after the screening result was known.

MAIN OUTCOME MEASURES

A validated measure of informed choice was used to determine whether adolescents made informed choices about undertaking second trimester maternal serum screening.

RESULTS

Complete data were available for 147 adolescents. These data were combined with data from 85 adults which had been collected in an identical way. Ten percent of the adolescents made informed decisions about having the maternal serum screening, compared with 37% of the adult participant group (P < 0.05). Adolescent women were significantly less likely to make an informed choice than adult women, when relevant demographic and reproductive history variables were controlled for (adjusted OR = 0.25; P = 0.004; 95% CI for OR: 0.10, 0.63).

CONCLUSION

Few pregnant adolescents made informed decisions about maternal serum screening. Clinicians face a challenge to improve adolescents' knowledge about maternal serum screening.

Did I really want to know this? Pregnant women's reaction to detection of a soft marker during ultrasound screening

OBJECTIVE

To investigate women's expectations of routine ultrasound and experiences when soft markers were discovered: what the disclosure meant, how it affected them, how they experienced the information given and why they did or did not choose amniocentesis.

DESIGN

Semi-structured, in-depth interviews were conducted with 11 women 25-30 weeks into the pregnancy, 7-13 weeks after the discovery of a soft marker.

FINDINGS

Women lacked knowledge about the potential of the scan and detection of soft markers created strong emotional reactions that women thought could have been alleviated by prior information about potential findings. Information in connection with the scan was perceived as insufficient. Decision about amniocentesis was affected by attitudes to disability, anxiety about fetal loss due to the procedure, need for certainty by a diagnostic test, and partner's opinion.

CONCLUSIONS

Women were shocked by the unexpected and sometimes unwanted information on elevated risk for a chromosomal aberration for which they lacked any preparation. Because this event often has long-lasting effects on the pregnancy, models of information that are efficient in promoting informed decisions are imperative.

PRACTICE IMPLICATIONS

Both women and their partners need relevant information before and in connection with ultrasound scan to be able to make informed choices.

Prenatal testing for Down syndrome: comparison of screening practices in the UK and USA

Prenatal testing for Down Syndrome is a topic covered in every genetic counselor's training as it constitutes the main workload of genetic counselors in prenatal settings. Most Western countries nowadays offer some type of testing for Down Syndrome. However, practices vary according to country with regards to what tests are offered, insurance coverage and the legal situation concerning the option of terminating an affected pregnancy. In view of the growing interest in international genetic counseling issues, this article aims to compare prenatal testing practices in two English-speaking countries: the United Kingdom and the United States of America. A case will be presented to highlight some of the differences in practice. The topic underlines important implications for genetic counseling practice, such as patients' understanding of testing practices, risk perception, counseling provision and impact of prenatal testing results.