Study variables measured

Based on the theoretical framework described in the section above, all variables to be included in the study were identified (see Table 2.1).

Table 2.1

Variables to be studied and their respective theoretical frameworks

Each of the identified variables presented in Table 2.1 were then explored in relation to existing measures and their psychometric properties and a comprehensive questionnaire was developed including the following sections:

a) Section A: Knowledge

This section consisted of four items that examined women’s knowledge in relation to the purpose and reliability of amniocentesis, the risk for miscarriage associated with invasive tests, and follow-up options. Two of the items were multiple choices and two were ‘true’ or ‘false’. The score scale ranges from zero (no correct answers) to 4 (all correct answers) with higher scores indicating greater awareness in relation to invasive tests. Similar scales to this have previously been used to assess knowledge of prenatal screening tests in general rather than focusing on invasive tests (Brajenovic-Millic et al, 2008; Marteau et al, 1988).

b) Section B: You and amniocentesis / CVS

This section involved the measurement of the following internalised variables:

would be… not at all beneficial-very beneficial / extremely unpleasant-not at all unpleasant / not at all reassuring-very reassuring / not at all frightening-very frightening”. Participants’ responses were measured on a five point Likert scale ranging from 1(very negative attitude) to 5 (very positive attitude).

ii. Attitudes towards amniocentesis/CVS was measured by two items using a 5-point Likert scale ranging from 1(=strongly disagree) to 5(=strongly agree). Higher scores indicate a more negative attitude towards amniocentesis/CVS.

iii. Attitude towards miscarriage as a result of amniocentesis/CVS was measured using a 5-point Likert scale ranging from 1(=extremely bad) to 5(=not at all bad). Higher scores indicate a more negative attitude towards miscarriage.

iv. Perceived severity was measured using a 5-point Likert scale ranging from 1(=strongly disagree) to 5(=strongly agree). Higher scores indicate a higher perceived severity of chromosomal disorders such as Down’s syndrome.

v. Anticipated decision regret was measured using a 5-point Likert scale ranging from 1(=strongly disagree) to 5(=strongly agree). Higher scores indicate higher intentions to use any tests available.

vi. Burden attached to having a child with a serious abnormality was measured using a 5-point Likert scale ranging from 1(=“very good”) to 5(=”very bad”), with higher scores indicating greater burden attached.

vii. Perceived risk of having a child with a serious abnormality was measured using a 5-point Likert scale ranging from 1(“not at all likely”) to 5(“very likely”). Higher scores indicate greater perceived risk.

viii. Perceived behavioural control was measured using a short version of a scale used in a previous study (Berkenstadt et al, 1999). This consisted of three items rated on a 5-point Likert scale and ranging from 1(=strongly disagree) to 5(=strongly agree). Higher scores indicate greater perceived behavioural control.

For all the items above a sixth option (“Don’t know”) was also provided.

c) Section C: Others and amniocentesis / CVS

This section included a scale adapted from a previous study on prenatal screening (van der Berg, 2008) and measured subjective norms by assessing normative beliefs and weighing them for motivation to comply (Ajzen, 1991). Normative beliefs were assessed for the woman’s partner and her midwife/obstetrician by two 5-point items. For example: “If it is offered to me, I think my partner will want me to…” with answer options ranging from

“certainly decline amniocentesis/CVS” to “certainly accept amniocentesis/CVS”. The respondent’s motivation to comply with each of these normative beliefs was measured by a 5-point item as follows: “I find my partner’s opinion about accepting or declining the test…”

and answer options ranging from “very important” to “not at all important”. An overall

subjective norm scale of the two referents together is estimated by calculating the mean of the two products of normative beliefs with motivation to comply and the scale ranging from 1 (=strong subjective norm to decline amniocentesis/CVS) to 5 (=strong subjective norm to accept amniocentesis/CVS)

d) Section D: How you are feeling

This section measured anxiety using the anxiety scale from the Hospital and Anxiety Scale (HADS; Zigmond & Snaith, 1983). This includes 7 items rated on a 4-point likert scale with scores for each item ranging from 0 to 3. A mean score is then calculated across all items, meaning that a respondent can score between 0 and 21, with higher scores indicating greater levels of anxiety. A cut off score of 8 has been established across numerous studies indicating that individuals scoring above this score are clinically anxious (Bjelland, Dahl, Haug, & Neckelmann, 2002).

e) Section E: Attitudes towards doctors and medicine

This is a scale developed by Marteau (1990) and aims to specifically measure attitudes towards effectiveness of medicine in promoting health and attitudes towards the effectiveness of doctors in promoting health. It consists of 19 items rated on a scale from 1(=strongly disagree) to 5(=strongly agree).

This section covered demographic information (i.e. age, ethnicity, religion), socio-economic status (i.e. marital status, level of education, occupation, household annual income) and medical history information (i.e. prior miscarriages or termination of pregnancy, prior history of amniocentesis, etc.). This information is important in order to be able to control for external factors and be able to focus on the specific psycho-social variables under study.

However, the demographics section was strategically placed at the end of the questionnaire so as to ensure that participants gave priority to the actual questionnaire should they return it incomplete.

h) Screening measure

At the end of the demographics section a brief screening measure for mental health issues was included. This includes a mixture of ten health-related issues covering both, mental health, such as depression and schizophrenia, and common health problems, such as migraine and allergies. The aim of the common health problems was to slightly mask the emphasis on asking questions just about mental health. Participants were also asked to state any medication they were taking at the time. The purpose of this screening tool was to allow for exclusion of those who were suffering from any sort of mental health issue, which may have impacted on their responses to the other scales of the questionnaire.

See Appendix 1 for a copy of the original questionnaire.