DETERMINANTS OF THE INTENTION OF PREGNANT WOMEN AND THEIR PHYSICIANS TO SHARED DECISIONS REGARDING PRENATAL SCREENING OF DOWN SYNDROME: AN APPLICATION OF THE THEORY OF PLANNED BEHAVIOUR

Purpose
To compare the determinants of the intention of pregnant women and their physicians to shared decisions regarding prenatal screening for Down syndrome based on the Theory of Planned Behaviour (TPB).
Methods
Between May 2007 and April 2008, we conducted a descriptive study which main objective was to assess shared decision making in dyads of family physicians and pregnant women regarding prenatal screening for Down syndrome. We conducted this study in three family practice teaching units (FPTU) in Québec city, Canada. Family physicians agreed to have their pregnant patients contacted by a research assistant before their first routine prenatal care clinical encounter. Data were collected by means of a self-administered questionnaire. A clinical vignette was used to elicit participants’ opinions on their intention to share decisions regarding prenatal screening for Down syndrome. The following TPB variables were assessed in both physicians and patients: attitude, subjective norm and perceived behavioural control. Additional variables (moral norm and sociodemographics) were also assessed. A general linear regression was used to assess which variables were associated with the intention to shared decisions regarding prenatal screening for Down syndrome. Family physicians and women were compared to each other.
Results
A total of 108 pregnant women and 26 family physicians are included in the present study. Mean age for pregnant women was 28.6 ± 3.4. Intention of women and of family physicians to share decisions regarding prenatal screening for Down syndrome was 2.1 ± 1.4 and 2.65 ± 0.43 ( on a scale of -3 [strongly disagree] to + 3 [strongly agree]), respectively. In the regression model for women, attitude (p=0.02), subjective norm (p=0.03) , perceived behavioural control (p=0.49) and moral norm (p=0.02) explained 42% of the variance in their intention to shared decisions regarding prenatal screening for Down syndrome with their physicians. In the regression model for family physicians, subjective norm (p=0.0007) and perceived behavioural control (p=0.005) explained 65% of the variance in their intention to shared decisions regarding prenatal screening for Down syndrome with their patients.
Conclusion
Both family physicians and pregnant women have high positive intention to share decisions regarding prenatal screening for Down syndrome. However, theory-based intervention to foster shared decision making in this area will need to be tailored to the each group.