Preconceptional ancestry-based carrier couple screening for cystic fibrosis and haemoglobinopathies: what determines the intention to participate or not and actual participation?

This paper explores determinants of the intention to participate or not and of actual participation in preconceptional ancestry-based carrier couple screening for cystic fibrosis (CF) and haemoglobinopathies (HbPs). In total, 9453 individuals from a multi-ethnic population were invited. Invitees who had a partner and who were planning a pregnancy were the target population (33-36%). Test participation was conditional on survey participation. Those who refrained from test participation were asked to participate in the survey only. The questionnaire was based on the Theory of Planned Behaviour, which explains behaviour through intention. It was completed by 418 survey participants: 171 who intended to participate in the testing, and 247 who refrained from test participation. Both test intenders and offer decliners generally had a positive attitude towards test participation, and perceived high behavioural control. This applied to Western and non-Western survey participants equally. Offer decliners, however, perceived less control in terms of the time and effort needed for participation. Still, 68% of them intended to participate in the future if the screening would be offered routinely. Test intenders more often would draw reproductive consequences from test results, perceived a higher risk of being a carrier, more benefits and less adverse psychological outcomes. Feelings of stigmatisation were not an important issue, but 14% thought that there would be discrimination against carriers: among them more were non-Western survey participants. Preconceptional ancestry-based CF and HbPs carrier screening was evaluated as positive and desirable among Western and non-Western survey participants. The effort and time needed for participation were important reasons for declining participation, which might be overcome by improving access to the screening.

Developing and optimizing a decisional instrument using self-reported ancestry for carrier screening in a multi-ethnic society.

PURPOSE: To develop a decisional instrument for ancestry-based cystic fibrosis and/or hemoglobinopathies carrier couple screening in The Netherlands. METHODS: A flowchart (Instrument A) and a questionnaire with maps of geographical areas with originally high cystic fibrosis and hemoglobinopathies carrier frequencies (Instrument B), were developed to support participants in self-assessing their eligibility as a couple for carrier screening for cystic fibrosis and/or hemoglobinopathies. The outcome was compared to the self-reported origin of both partners' ancestors during an in-depth interview. Furthermore, preference for Instrument A or B was determined. RESULTS: Of the 112 participants, 88% (99/112, 95% CI 82-94%) (Instrument A) and 91% (102/112, 95% CI 86-96%) (Instrument B), respectively, arrived at a decision in accordance with their ancestral origin, and 57% (64/112, 95% CI 48-66%) preferred Instrument B. A false negative proportion of 5.5% suggests that some carriers will exclude themselves from screening. Results might improve with minor changes in the instruments with regard to geographic specification, and availability of translated versions. CONCLUSION: A decisional instrument to assess ancestry-based eligibility for cystic fibrosis and/or hemoglobinopathies carrier screening, is now available and can with slight adaptations be used in other countries. The instrument also takes into account the possibility of mixed ancestry.