Demographics, health literacy and health locus of control beliefs of Australian women who take complementary medicine products during pregnancy and breastfeeding: A cross‐sectional, online, national survey

Abstract Background Pregnant and breastfeeding women's use of complementary medicine products (CMPs) is common, and possibly associated with autonomous health care behaviours. However, the health literacy levels and health locus of control (HLOC) beliefs of women who use CMPs in pregnancy and lactation have not been previously assessed in a large Australian sample. Aim The aim of this study is to determine the health literacy levels and HLOC beliefs of women who use CMPs in pregnancy and lactation and determine the types of CMPs used. Methods A cross‐sectional, national, online survey of Australian pregnant or breastfeeding women aged 18 years and older, and currently using CMPs was conducted. Results A total of 810 completed surveys (354 pregnant and 456 breastfeeding women) were analysed. Most had adequate functional health literacy levels (93.3%). Health care practitioners (HCPs) HLOC mean scores were the highest for the sample, followed by Internal HLOC beliefs mean scores. Almost all (n = 809) took at least one dietary supplement, the most popular being pregnancy and breastfeeding multivitamins, iron supplements and probiotics. Use was generally in line with clinical recommendations, except for low rates of iodine supplementation. Herbal medicine use was lower for the total sample (57.3%, n = 464), but significantly higher (p < .0001) for the breastfeeding cohort, with consumers taking one to four herbal medicines each. The most popular herbs were raspberry leaf, ginger, peppermint and chamomile (pregnant respondents) and chamomile, ginger and fenugreek (breastfeeding respondents). Conclusions Respondents were health literate, with high scores for Internal and HCP HLOC scales, suggesting that they are likely to demonstrate self‐efficacy, positive health behaviours and work well in partnership with HCPs. HCPs can facilitate discussions with pregnant and breastfeeding women using CMPs, while considering women's health literacy levels, health beliefs and goals.


,40 measures
Internal, Doctors (operationalized as health care practitioners [HCPs] in this study), Other People or Chance Locus of Control beliefs, 40,41 with results indicating where a respondent believes control of her health, and in respect to pregnancy and lactation, where responsibility for the health of her unborn or breastfeeding children, lies. 41 Studies focusing on Health Locus of Control (HLOC) beliefs 39,42 in pregnancy 43,44 and breastfeeding 45 have found that higher Internal HLOC beliefs are associated with several different aspects of health and self-efficacy, including positive self-care behaviours in mothers with gestational diabetes 46 ; choosing to birth in midwifery-led, lowintervention birthing units over obstetrician-led medical wards 44 ; breastfeeding self-efficacy and success 45 ; and positive mental health pre- 47 and postnatally. 45 In general populations, higher Internal HLOC beliefs in healthy adults have been associated with increased use of CM therapies and CMPs, [48][49][50][51] and healthy behaviours including regular exercise. 48 Previous research 9,52-56 has revealed that pregnant and breastfeeding women's use of CMPs is linked to beliefs that CMP use is health-promoting for both themselves and their babies; however, the HLOC beliefs of mothers using CMPs have not been measured before. Measuring HLOC beliefs in women who use CMPs during pregnancy and lactation could help confirm the type/s of control beliefs associated with this use, and confirm whether selfefficacy, or dependence on others, chance or HCPs influences women's CMP use during pregnancy. This would help and inform the practices of HCPs working in maternity care around the use of CMPs.
Maternal health literacy can be described as 'the cognitive and social skills that determine the motivation and ability of women to gain access to, understand and use information in ways that promote and maintain their health and that of their children'. 57 Good health literacy encourages healthy pregnancy and postpartum behaviours, and is a vital component of understanding and using the information to make health-promoting decisions, including decisions about medicines used. 9,58 Despite the potential impact that poor health literacy could have on many aspects of health and health care choices during pregnancy and lactation, 58 the effects of maternal health literacy on women's reproductive health and CMP use is under-researched. 9 Previous research has confirmed the high prevalence of CMP use in pregnancy and lactation 7,8,10,23,24,26,59 and raised concerns regarding maternal health literacy and the ability to make safe decisions regarding CMP use in pregnancy and lactation. 1,[60][61][62] Nevertheless, this previous research has not included measurements of health literacy in pregnant and breastfeeding respondents with respect to the use of CMPs.
As part of a larger, national cross-sectional study investigating factors influencing women's decision-making regarding the use of CMPs in pregnancy and lactation, this paper reports on the women's health literacy levels, HLOC beliefs and the types of CMPs used and compares the use of CMPs by the pregnant and breastfeeding cohorts.

| Ethical approval
Ethical approval for the study was obtained from The University of Sydney Human Research Ethics Committee, approval number 2018/1010. The survey questionnaire was completed and submitted online, and completion of the questionnaire was taken as consent to participate. The survey questionnaires were completed anonymously, and no identifying data such as name or date of birth were collected. The Participant Information Statement (PIS) informed participants of these considerations. Additionally, the PIS clearly stated that participants could withdraw their consent to participate in the study at any time before submitting their completed surveys, but that because all the data were collected anonymously, it would not be possible to extract submitted data once completed surveys had been submitted. The PIS also outlined an incentive to participate: At the end of the survey, respondents were given the option of entering their email addresses to go into the draw to win an iPad mini ® and/or to receive a summary of the overall results of the study. If they chose either of these options, they were automatically redirected to a separate survey so that their email addresses were not linked to the information gathered in the study survey.

| Survey design
A national, cross-sectional, online, anonymous, self-administered questionnaire was designed and set up using the Qualtrics 63

| Inclusion criteria
The inclusion criteria for the study were aged 18 years or over, currently pregnant and/or breastfeeding, currently taking one or more CMPs and living in Australia. Three eligibility screening questions were used at the beginning of the survey.

| Patient or public contribution
This study was designed by a multidisciplinary team of HCPs and researchers without direct public involvement. However, the survey items were informed by data from earlier qualitative research with the same population. 22,31,32 The pilot questionnaire was designed by the research team, all of whom have experience of pregnancy and motherhood, and three of whom have the clinical experience of working with pregnant or breastfeeding women as a naturopath (L. A. J. B.), pharmacist (P. A.) and midwife (L. B.), respectively. The questionnaire was piloted by several lay-women volunteers who fulfilled the study inclusion criteria. Volunteers piloted the questionnaire on tablets, mobile telephones and laptops. Each volunteer trialled the questionnaire twice (once as a pregnant participant and once as a breastfeeding participant). They were invited to comment on its usability and relevance, and their data were not included in the final data analysis. Volunteers were asked to comment on the ease and usability of the questionnaire, as well as their understanding of the questions, which helped confirm face validity. 66 Feedback was generally positive, with volunteers reporting that the survey made sense and was easy to understand, flowed well and covered topics they expected in a survey on CMP use in pregnancy and breastfeeding (content validity). The participants did not suggest any wording changes to the questions, nor did they suggest any additional questions. Furthermore, their understanding of the questions and purpose of the study was aligned with our understanding. It took between 17 and 25 min for each of the volunteers to complete the questionnaire. The first 20 completed questionnaires were also examined to ascertain how long it took for respondents to complete the survey. The Qualtrics data showed that the minimum length of time taken was 14 min and the maximum time was 30 min (average time was 22 min).

| Measures
The complete survey is presented in File S1. The following sections outline the specific sections relevant to this paper.

| Demographic characteristics
Demographic questions included age, smoking status, pregnancy or breastfeeding status, number of children, gestational age of the child (pregnant participants), age of the breastfeeding child (breastfeeding participants), marital status, postcode of residence (to assess rurality), weekly household income, education levels, country of birth of the respondent and countries of birth of her parents and the main language spoken at home.

| CMP use
The operational definition of CMPs (see Section 1) was provided to respondents at several points in the survey. Respondents were asked to indicate the dietary supplements and/or the herbal medicines that they currently consumed from lists of CMPs commonly reported as being used in pregnancy or lactation. 22 People, or Chance Locus of Control health beliefs influenced respondents' CMP use decision-making in pregnancy and lactation. The MHLC-C was developed to be adapted for use with people living with any disease-or health-related condition. 39,41 For the purposes of this study, 'health and well-being during pregnancy' and 'health and wellbeing as a breastfeeding mother' were substituted for the word 'condition' in the MHLC-C for the pregnant and breastfeeding participants, respectively.

| Data analysis
Data were analysed using IBM SPSS Statistics V24 and Excel. Data were screened and incomplete surveys were removed as per the protocol, which outlined that incomplete surveys would be removed before analysis, pending the receipt of at least 768 complete surveys to enable meaningful data analysis 73 (see sample size calculations).
Surveys marked 'complete' in Qualtrics, indicating that the respondent had progressed through all 70 survey items, were included in analyses, provided that at least 75% of the items were completed.
Descriptive analyses, followed by χ 2 tests, were carried out for all demographic, health literacy and CMP use data to examine differences between the pregnant and breastfeeding respondents. Missing data were not included in the statistical analyses. Statistical significance was defined as a p < .05.
The research hypotheses tested were that there would be no statistically significant differences between the two cohorts (pregnant and breastfeeding women) in the total number of dietary supplements or herbal medicines taken; that both cohorts would be similar in their functional health literacy levels and that there would be no differences between the two groups in the numbers of women at risk of inadequate health literacy; and that both cohorts would have similar HLOC scores for all four subscales. Poisson regression analysis was performed to model the count data for dietary supplements and herbal medicines, respectively, to observe whether there were significant differences in the numbers taken between the pregnant and breastfeeding respondents.

| Health literacy levels
For the single-item health literacy screening question How confident are you filling out medical forms by yourself?, 71 respondents answering 'somewhat' or 'a little bit' or 'not at all' were considered to be at risk of inadequate health literacy. Those answering 'extremely' or 'quite a bit' confident were not considered to be at risk of inadequate health literacy. 71 For the Newest Vital Sign, respondents who scored 0-1 correct (out of six questions) were considered to have a high likelihood of limited functional health literacy skills. 72,74 Those who scored 2-3 were considered to be at risk of inadequate functional health literacy skills, and those who scored 4-6 correct were considered to have adequate functional health literacy skills. 72,74

| Health locus of control beliefs
Means for each subscale of the MHLC-C were calculated for the two cohorts, hence providing scores on the original 1-6 subscales. To examine differences between the results for the breastfeeding and pregnancy cohorts, and calculate estimated marginal means of measure, a repeated-measures analysis of variance analysis was performed for the four HLOC subscales.

| Responses collected
A total of 1418 women were enroled in the survey. Of these, 168 respondents were excluded as they did not fulfil the eligibility criteria, and a further 440 incomplete surveys were removed. A total of 810 completed surveys (57.1%) were collated for analysis.
Respondents ranged in age from 19 to 53 years, with the mean age being 33.8 years (SD = 4.6) and the median age being 34.0 years.
Other demographic data are summarized in Table 2
Respondents who reported using herbs were taking between 1 and 15 herbal medicines each, with most taking between one and four (File S3,

| Health literacy
Results from the single-item health literacy question 71

| Health locus of control
For the whole sample, HCPs HLOC had the highest mean scores (above 4.0 for both cohorts), followed by Internal HLOC, scoring above 3.5 for both cohorts (  (Table 5 and File S3, Figure AF3.1). and high health literacy were found in the qualitative research that informed the survey. 32 The respondents were somewhat similar in language background and age to the general population of Australian pregnant and breastfeeding women. 67,82 However, apart from English being the main language spoken at home, their cultural and ethnic diversity did not reflect that of the wider Australian population. Similarly, the sample's country of birth was not reflective of the wider Australian population as 79.6% reported being born in Australia, which is around 13% higher than the 2016 census data. 82 That said, a few interesting parallels with previous work can be seen. Higher levels of education, 7,10,23-29 and income or employment, 10,23,25,28,30 and being nonsmokers 26,29,30 have previously been significantly associated with CM use in pregnancy and lactation. One pregnancy study found that living in urban areas was significantly associated with herbal medicine use in pregnancy. 10 However, in the wider Australian community, mixed results have been shown, with some studies noting higher use of CM in rural areas, 3,83-85 and others showing higher use in urban areas. 86 There were not enough participants from outer regional, remote or very remote Australia areas in this study to examine differences in rural and urban participation and CMP use, but the results did show that CMP use in pregnancy and lactation occurs throughout all Australian regions.

| Use of dietary supplements
Women's use of dietary supplementation was generally in line with recommendations that aim to ensure optimal health of the mother and baby pre-and postnatally, 6  if pathology testing shows deficiencies, to prevent low vitamin D levels in the neonate and decrease the mother's risk of developing osteoporosis. 6 It may also be recommended postnatally as vitamin D deficiency has been associated with postpartum depression in some mothers. 88,89 Iodine supplementation by the sample was low, with only 9.2% of the total sample reporting taking iodine. These low rates are of concern, and are much lower than the 23% adherence noted in Malek et al.'s 87 South Australian study. Iodine is necessary for the physical and mental health of the pre-and postnatal mother, 88 and to prevent some forms of delayed cognitive function in infants. 13,87 Mild iodine deficiency in Australia is common due to low iodine levels in our soils, low uptake of fortified foods and reduced use of iodized salt, 13

| Use of herbal medicines
Respondents reported using far fewer herbal medicines in compar-  104,105 as is good health literacy. 106 As the sample cannot be seen to be a representative sample, it is difficult to infer whether the respondents' health literacy levels are likely to be present across all Australian women who use CMPs in pregnancy or lactation, or are just characteristic of those motivated to participate in this study. However, previous research has noted that women's use of CM, including CMPs, is to facilitate self-determination, autonomy and control over their health during pregnancy and lactation. 33 Good maternal health literacy may also help explain the sample's positive health behaviours during pregnancy and the postpartum period, including the majority being nonsmokers, 110 their use of prenatal folic acid supplements, 58,111 higher than average breastfeeding rates 58 and breastfeeding self-efficacy. 112

| HLOC beliefs
The HLOC results yielded new insights into the health beliefs of Australian pregnant and breastfeeding mothers using CMPs. These results are valuable for HCPs working in maternity care to consider, especially considering that the multidimensional HLOC scales and theory are also often used to predict health behaviours. 41 Internal HLOC beliefs may be considered to be somewhat stable over a lifetime, 44,116 but HCPs can have significant impacts on the health outcomes of women in pregnancy, birth and the postnatal period. 43,44,81,117 In the medical arena, pregnancy and birth are commonly viewed within a 'risk' model, and the samples' high HCP HLOC beliefs may reflect a reliance on their HCPs to reduce the perceived risks associated with pregnancy and birth, and reflect a recognition that HCPs play an essential role in their health pre-and postnatally. 43,44 High Internal HLOC beliefs are considered predictive of positive mother-baby attachment pre-and postnatally, as well as positive, autonomous, self-care behaviours. 46,[118][119][120] This attachment is considered fundamental to both a woman's psychological adjustment to motherhood and the psychological health and development of the baby after birth and throughout early childhood. 118 and/or breastfeeding mothers. 66 However, the use of purposeful sampling was intentional. The survey did not aim to be representative, or to assess population prevalence of CMP use in pregnancy and lactation. 39,41,42 The focus of recruitment was to ensure adequate numbers of respondents from the pregnant and breastfeeding cohorts across a broad range of regions to enable meaningful data analysis.
The homogeneity across the sample regarding education, income, English-language proficiency and health literacy levels is