Data collection and source: the CVM

The various stages undertaken to conduct the CVM are presented in this section. The

data collection techniques are presented in the first instance and outlined in section

4.3.3.1. The data source is described in section 4.3.3.2. Descriptive statistics on

response rates and participant characteristics are presented in this section also.

4.3.3.1 Survey distribution and data collection: the CVM

Identical data collection techniques are followed for the CVM as the DCE since both

SP techniques are included in the MAMS booklet. However, a larger sample is

recruited for the CVM (see Figure 4.2 for breakdown of sample across the CVM and

DCE). Women receiving antenatal care across six different maternity units are invited

to participate in the study, representing the six hospital groups spread across the

country (CUMH, Galway University Hospital, the NMH, Cavan General Hospital

(CGH), Our Lady of Lourdes (OLOL) Hospital, Drogheda, and St. Luke’s Hospital) (Higgins 2013). Two maternity units declined to participate, but were replaced by

other willing participants.

Selecting an appropriate sample size is complex for the CVM also. There currently

exists no standard guideline on what the minimum sample size should be, especially

when the results are intended for use within a formal CBA. Mitchell and Carson (1989)

maintain that, using a simple statistical tolerance formula, a sample size between 200

and 2,500 is usually sufficient. To protect against a poor response rate, 900 women

are invited to participate in the study, sampling 150 women from each maternity unit

in the first instance. The study was conducted at different times across the various

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the maternity units. Ethical approval for this study was granted by the Clinical

Research Ethics Committee, Division of Obstetrics and Gynaecology in CUMH; the

Health Service Executive (HSE) Mid-Western Regional Hospital Research Ethics

Committee; the HSE South-Eastern Regional Hospital Research Ethics Committee;

the Research Ethics Committee in University Hospital Galway (UHG); and the

Research Ethics Committee in the NMH, Dublin.

4.3.3.2 Response rate and participant characteristics: the CVM

Of the six maternity units invited to participate in the study, data were used for five

units only; UHG was excluded from the analysis due to a sampling error.37

Fortunately, there was no loss of data arising from the error as MAMS was distributed

to an additional 200 women in CUMH, and an additional 50 women in the NMH.38

The total number of women invited to participate in the study was 1,000.39

Of the 1,000 surveys distributed to women across the five maternity units, 367

questionnaires were returned, yielding a response rate of 36.7 per cent. The response

rate differed across the five maternity units. The highest response rate was from

CUMH with 46 per cent of surveys returned. 42 per cent of the sample from CGH

returned their questionnaire. 34 and 35.3 per cent of the sample from OLOL hospital

and St. Luke’s hospital returned their surveys, respectively. The lowest response rate came from the NMH. However, women in this group did not receive any reminder

about the study whereas in each of the other four maternity units women received three

37 _{Local investigators mistakenly distributed the surveys to a randomly selected group of women who}

had been identified from the unit’s postnatal database records, rather than antenatal database records.

38 _{This group comprises the sample for the DCE.} 39 _{This excludes surveys distributed to UHG.}

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postal reminders. 15.1 per cent of women (151) opted-out of the study after the initial

invitation letter was distributed.

A number of participants were removed from the sample due to the high risk status of

their pregnancy. Five women were removed due to advanced maternal age. A further

31 participants were removed due to a history of Caesarean section. There were 331

women in the final sample.

The average age of participants was 31.2, with a median age of 32 (Table 4.9). The

mean age of first-time mothers was 30.5, with a median age of 31. Forty-six point

eight per cent of the sample was expecting their first child. The average number of

children per woman was 1.6, with a median number of 1. The majority of participants

were married (67.6 per cent), with 10.6 per cent of the sample comprising of single

people, while 21.5 per cent were cohabitating with their partner. Approximately three-

quarters of the sample were Irish. Other ethnicities included other white (19.1 per

cent), African (1.2 per cent), and Asian backgrounds (1.2 per cent). 23.6 per cent of

women were in receipt of some form of the medical card, while 45.0 per cent reported

having PHI. The majority of participants were concentrated in the top three income

brackets (63.5 per cent).

There were some differences in demographics across the five maternity units. The

average age of women in OLOL hospital was 32.5, which differs considerably from

the youngest average age of 30.6 in CGH, and the overall average age of 31.2. In St. Luke’s hospital, the sample consisted largely of multiparous women who accounted for 65.3 per cent of the group. 60.4 per cent of the sample in OLOL hospital consisted

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Table 4.9: Demographic characteristics of the CVM sample.

Variable CUMH n (%) Cavan n (%) OLOL n (%) Luke’s n (%) NMH n (%) All n (%)

Age in years, mean (SD) 30.9 (3.9) 30.6 (4.7) 32.5 (3.1) 31.2 (3.8) 31.5 (4.8) 31.2 (4.1)

First baby (%) 73 (51.1) 29 (49.2) 19 (39.6) 17 (34.7) 17 (53.1) 155 (46.8)

Age of first-time mothers, mean (SD)

30.4 (4.2) 29.2 (4.5) 32 (3.6) 30.7 (3.4) 31.0 (4.8) 30.5 (4.2)

Number of children, mean (SD) 1.5 (3.5) 1.7 (0.9) 1.6 (0.8) 1.6 (0.7) 1.5 (0.72) 1.6 (0.82)

Marital status (%) Single 14 (9.8) 7 (11.9) 4 (8.3) 3 (6.1) 7 (22.6) 35 (10.6) Married 96 (67.1) 43 (72.9) 30 (62.5) 38 (77.6) 16 (51.6) 223 (67.6) Cohabitating 32 (22.4) 9 (15.2) 14 (29.2) 8 (16.3) 8 (25.8) 71 (21.5) Separated 1 (0.70) - - - - 1 (0.3) Education status (%) Some primary/primary/junior 5 (3.4) 3 (5.1) 6 (12.5) 2 (4.1) 1 (3.1) 17 (5.1) Leaving certificate 17 (11.9) 6 (10.2) 9 (18.8) 5 (10.2) 3 (9.4) 40 (12.1) Diploma 47 (32.9) 19 (32.2) 20 (41.7) 13 (26.5) 7 (21.9) 106 (32.0) Primary degree 30 (20.9) 7 (11.8) 7 (14.6) 16 (32.6) 5 (15.6) 65 (19.6) Higher degree 44 (30.8) 24 (40.7) 6 (12.5) 13 (26.6) 16 (50.0) 103 (31.1) Ethnicity (%) Irish background 110 (77.5) 49 (83.1) 40 (83.3) 37 (77.1) 22 (68.8) 258 (78.4)

Other white background 30 (21.1) 9 (15.2) 8 (16.7) 7 (14.6) 9 (28.1) 63 (19.1)

African background 1 (0.7) - - 3 (6.3) - 4 (1.2) Asian background 1 (0.7) 1 (1.7) - 1 (2.0) 1 (3.1) 4 (1.2) Employment status (%) Self-employed 7 (4.9) 1 (1.7) 1 (2.1) - - 9 (2.7) Employee 94 (65.7) 42 (71.2) 29 (60.4) 39 (79.6) 25 (78.1) 229 (69.1) Homemaker 26 (18.2) 6 (10.2) 12 (25.0) 6 (12.3) 5 (15.6) 55 (16.6) Unemployed 10 (7.0) 8 (13.5) 5 (10.4) 2 (4.1) 1 (3.1) 26 (7.6) Student 2 (1.4) 1 (1.7) 1 (2.1) 1 (2.0) 1 (3.1) 5 (1.5) Unable to work 4 (2.8) 1 (1.7) - 1 (2.0) - 7 (2.1)

Medical card status (%)

Full card 33 (23.1) 17 (28.8) 15 (31.2) 10 (20.4) 3 (9.4) 78 (23.6)

GP card only 5 (3.5) 4 (6.8) 3 (6.2) 2 (4.1) 3 (9.4) 17 (5.1)

Not covered 105 (73.4) 38 (64.4) 30 (62.5) 37 (75.5) 26 (81.3) 236 (71.3)

Private health insurance (%)

Yes 68 (47.5) 24 (40.7) 19 (39.6) 24 (49.0) 14 (43.7) 149 (45.0) No 75 (52.5) 35 (59.3) 29 (60.4) 25 (51.0) 18 (56.3) 182 (55.0) Household income (%) < €834 per month 1 (0.7) 5 (8.6) - 3 (6.5) - 9 (2.8) €834 - €1,667 per month 14 (10.1) 9 (15.5) 9 (19.6) 4 (8.7) 2 (6.3) 38 (11.9) €1,668 - €2,500 per month 37 (26.8) 13 (22.4) 6 (13.0) 10 (21.7) 4 (12.5) 70 (21.9) €2,501 - €3,333 per month 27 (19.6) 10 (17.2) 18 (39.1) 7 (15.2) 8 (25.0) 70 (21.9) €3,334 - €4,167 per month 25 (18.1) 10 (17.2) 4 (8.7) 9 (19.6) 8 (25.0) 56 (17.5) > €4,167 per month 34 (24.6) 11 (19.0) 9 (19.6) 13 (28.3) 10 (31.2) 77 (24.1) Observations 143 59 48 49 32 331

Notes:Abbreviations: CUMH, Cork University Maternity Hospital; NMH, the National Maternity Hospital, Dublin; CGH, Cavan

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of multiparous women, while in each of the other units the division between

nulliparous and multiparous women was evenly distributed across the two groups.

This concludes the description of the data collection techniques used for the DCE and

sample obtained therein (Figure 4.2). The results of the CVM are presented in Chapter

6. Section 4.4 compares the sample obtained for the CVM with the DCE and

qualitative research and draws comparisons across these groups of women with

available data on the general obstetric population.