Research paperThe pregnancy-related anxiety scale: A validity examination using Rasch analysis
Introduction
Pregnancy was once regarded as a time of protection from mental health disorders, however, research evidence increasingly points to the common experience of emotional disturbances in pregnancy (Austin, 2003). Symptoms of general anxiety and diagnosed anxiety disorders (Diagnostic and Statistical Manual), for instance, are estimated to affect approximately 35% and 8.5% of pregnant women, respectively (Lee et al., 2007, Sutter-Dallay et al., 2004). These estimations demonstrate the greater prevalence of mood disorders in pregnancy when compared to women of similar age in the general population which has been reported to be 19.8% and 3%, respectively (American Psychiatric Association 2000, Hinz and Brähler, 2011). Moreover, consideration needs to be given to a specific anxiety experienced antenatally, called pregnancy-related anxiety1 (Huizink et al., 2004). Evidence supports the distinction of pregnancy-related anxiety from other anxiety types. This evidence includes (but is not limited to) consistent associations with negative obstetric and paediatric outcome (i.e. preterm birth, postnatal depression, Robertson et al., 2004, Wadhwa et al., 1993). These consistent associations, however, are not regularly reported for other anxiety types (e.g. general anxiety). Pregnancy-related anxiety, which is regarded to affect up to 14.4% of expectant mothers (Poikkeus et al., 2006), is the focus of this paper.
Pregnancy-related anxiety is a contextually tied type of state anxiety characterised by a pregnancy specific fears and worries. These include, for example, childbirth, the wellbeing of the mother and baby and impending motherhood. As stated above, there are various unfavourable outcomes associated with this anxiety type. For the mother, these may include increased nausea, poor psychological adjustment and negative views of motherhood (Hart and McMahon, 2006, Swallow et al., 2004). Furthermore, pregnancy-related anxiety has been shown to predict birth weight and gestational age independent of general anxiety and anxiety disorders (Blackmore et al., 2016; Wadhwa et al., 1993). Pregnancy-related anxiety has also been identified as independently predicting postnatal depression (Austin et al., 2007, Heron et al., 2004, Milgrom et al., 2008, Sutter-Dallay et al., 2004). Postnatal depression, with an estimated prevalence of 13%, has well-documented consequences (Milgrom et al., 2011 provides a review), such as reducing a woman's capacity to care equally for herself and her baby (Beestin et al., 2014, Leigh and Milgrom, 2008). The deleterious effects of postnatal depression are such that Australian perinatal care guidelines recommend routine postnatal depression screening (Australian Health Ministers Advisory Council, 2012). In consideration of all the adverse associations, the importance of prenatal screening for pregnancy-related anxiety cannot be underestimated. Recent calls for pregnancy-related anxiety measures to be included in clinical interventions (Blackmore et al., 2016) highlight that antenatal screening may afford valuable intervention opportunities.
While the need for early screening for pregnancy-related anxiety has been identified in the research literature, (Australian Health Ministers Advisory Council 2012, NSW Department of Health 2009), this need is not reflected in current clinical practice. There are no formal antenatal screening procedures for pregnancy-related anxiety in Australia, the United States of America or the United Kingdom (NICE 2008, Office of Women's Health 2014 ). In Australia, prenatal screening for pregnancy-related anxiety does not tend to take place due to the limitations of current anxiety measures. For instance, some general anxiety scales (e.g., State Trait Anxiety Inventory) have been utilised for pregnancy-related anxiety yet these scales potentially overlook facets of this specific type of anxiety by failing to acknowledge its characteristics, such as fear of childbirth or appearance-related concerns (to name just two). Therefore, any existing psychometric properties of general anxiety scales (such as the State Trait Anxiety Inventory) cannot be assumed to comprehensively cover all the relevant aspects of pregnancy-related anxiety. Moreover, the overlap of many anxiety symptoms and common pregnancy experiences (e.g. poor sleep) further suggest substantial limitations of general measures (Meades & Ayers, 2011).
Other more specific instruments (e.g. Pregnancy Related Anxiety Questionnaire-Revised, PRAQ-R, Pregnancy Related Thoughts (Huizink, 2000, Rini et al., 1999), may specifically target a pregnant woman's concerns and have demonstrated good, and in some cases excellent reliability; but evidence of content and construct validity is lacking. The PRAQ-R has shown evidence of predictive validity (Huizink et al., 2003), yet in the majority of these studies, pregnancy-related anxiety was assessed as a component of prenatal stress (which is considered a different construct to anxiety). Given these specific limitations, the predictive validity of the PRAQ-R may be limited. Furthermore, many existing pregnancy specific scales lack the broadness of scope for this multidimensional construct such as the Pregnancy Specific Anxiety Scale (PSAS, Mancuso et al., 2004). This scale consists of a single item rated in terms of the intensity of panic, concern, anxiety and fear experienced. The lower reliability (a = 0.65–0.72) of the PSAS has been attributed to the exploratory nature of the scale. Therefore, the use of instruments that have limitations related to both validity and reliability to screen for this anxiety may result in some women with pregnancy-related anxiety being misdiagnosed, and/or overlooked (a full and detailed review of existing scales which demonstrates the need for the development of this scale is provided by Brunton, Dryer, Saliba and Kohlhoff, 2015).
The Pregnancy-related Anxiety Scale (PrAS) was developed to fill the abovementioned need (Brunton, Dryer, Saliba & Kohlhoff, 2017a). The PrAS contains 33-items with responses ranging from 1 (not at all) to 4 (very often). Higher scores are indicative of increased pregnancy-related anxiety. The PrAS is multi-dimensional scale with nine subscales. These are: Childbirth Concerns which contains six items consistent with concerns about birth; Body Image Concerns a subscale with five questions about appearance-related concerns; Attitudes Towards Childbirth, three items relating to a women's attitude towards birth; Worry About Motherhood with three items assessing motherhood worry; Acceptance of Pregnancy contains three items about a woman's acceptance of pregnancy; Anxiety Indicators, four anxiety symptoms items; Attitudes Towards Medical Staff, three items concerning attitudes towards the doctors/midwives; Avoidance with three items tapping into avoidance-type behaviour; and Baby Concerns, which asks three questions about the unborn baby's welfare (see, Brunton, Dryer, Saliba and Kohlhoff, 2017a, Brunton, Dryer, Saliba and Kohlhoff, 2017b; for details on the full development and initial validation).
The PrAS improves on existing scales by its development on sound theoretical and psychometric grounds. Theoretically, the scale was derived from a comprehensive literature review ensuring it contains the main fears and worries characteristic of this anxiety (e.g., childbirth, appearance, baby concerns). The PrAS also includes subscales identified as important characteristics/dimensions of pregnancy-related anxiety but not previously considered by existing measures. These include subscales such as Acceptance of Pregnancy, which assesses pregnancy wantedness. Likewise, the inclusion of the Anxiety Indicators subscale provides more depth to the evaluation of this anxiety. Assessment of anxiety symptomology is another facet rarely considered by existing scales, however, is an important consideration given that anxiety is always accompanied by physical symptoms (Healey, 2006). Therefore, the PrAS is a more comprehensive assessment of this unique anxiety than previously offered by other existing scales.
In an initial validation study of the PrAS (Brunton, et al., 2017b), the scale was shown to have good content validity, with the items/subscales found by an Expert Review Panel to be consistent with the key characteristics of pregnancy-related anxiety. The scale's construct validity was confirmed using a variety of statistical techniques (i.e., Principal Components Analysis, correlation, multiple regression). These statistical techniques provided support for the underlying principle of construct validity, i.e., the variable of interest was found to correlate more highly with similar measures than with measures of different traits (Campbell & Fiske, 1959). Finally, the PrAS's ability to predict group membership further supports its concurrent validity (Brunton, Dryer, Saliba and Kohlhoff, 2017a, Brunton, Dryer, Saliba and Kohlhoff, 2017b). The initial validity results and the good to excellent internal consistency reliability both overall and at subscale level (ranging from α 0.80 to 0.93, evaluated on several samples) point to the PrAS as having promising psychometric properties. Notwithstanding this initial validity evidence, to add to the accumulating validity evidence, further examination of the scale's psychometric properties will be done by more thorough statistical techniques. Specifically, Rasch analysis will provide more detailed psychometric data, as described below. This further examination, which is the aim of the current article, means the PrAS will only be one of a few pregnancy specific scales that have been evaluated using Rasch analysis.
Section snippets
Rasch analysis
Rasch analysis, developed by Georg Rasch (1961), was first popular for education and then rehabilitation measures. These included, for example, measures of pain and mobility, quality of life, and personal well-being (Chalmers et al., 2016, Misajon et al., 2016, Tennant et al., 2004). More recently, Rasch analysis has been utilised with other latent traits such as depression and stress (Medvedev et al., 2017a, Siegert et al., 2010) and pregnancy-specific measures (e.g. Wijma Delivery Experience
Participants
Following approval from the author's university ethics committee, participants were recruited online via dedicated Facebook and Instagram pages. The convenience of online recruitment for research purposes has meant increased use of this method of recruitment in research. Further, responses to online surveys do not significantly differ from traditional paper/pencil methods, providing added support for this approach (Weigold et al., 2013). This approach, however, has been shown to produce biased
Rasch analysis
The full 33-item PrAS was subjected to a Rasch analysis. The likelihood-ratio test performed on the initial output confirmed the appropriateness of the unrestricted partial-credit model. Table 2 provides a summary of the overall Rasch model fit statistics. Following the iterative approach of this analysis, the scale data was assessed and modified for each analysis, to achieve a good final Rasch model fit.
The initial analysis displayed a significant item-trait interaction indicated by the
Discussion
The application of the Rasch model in this study provides added support to the validity of the PrAS as a psychometrically sound scale for pregnancy-related anxiety. The final Rasch model achieved a good fit with only minor model modifications. The DIF evident for two subscales resulted in age differentiation scoring which provides a more targeted scale for pregnant women. Moreover, the merging of the subscales, Worry About Motherhood and Anxiety Indicators, meant that the PrAS subscales were
Conclusion
Rasch analysis is increasingly becoming the preferred method in test development. The PrAS represents only one of a few pregnancy specific scales that have been evaluated using Rasch analysis. The Rasch analysis complements previous validation studies for the PrAS by providing further support for the internal validity of the scale. Further, the ordinal to interval conversion brings an added precision to the analysis of the PrAS scores not previously seen with other pregnancy-specific scales in
Acknowledgements
We acknowledge the women who voluntarily gave their time to participate in the online survey. Without their contribution, this study would not be possible.
Conflicts of interest
none
References (59)
- et al.
Examining the relationship between antenatal anxiety and postnatal depression
J. Affective Disord.
(2007) - et al.
Pregnancy Anxiety: A systematic review of current scales
J. Affective Disord.
(2015) - et al.
Pregnancy-related anxiety: Evidence of distinct clinical significance from a prospective longitudinal study
J. Affective Disorders
(2016) - et al.
Using item response theory to optimize measurement of chronic stress in pregnancy
Soc. Sci. Res.
(2017) - et al.
The course of anxiety and depression through pregnancy and the postpartum in a community sample
J. Affective Disord.
(2004) - et al.
Normative values for the Hospital Anxiety and Depression Scale (HADS) in the general German population
J. Psychosomatic Res.
(2011) - et al.
Is pregnancy anxiety a distinctive syndrome
Early Human Development
(2004) - et al.
Anxiety measures validated in perinatal populations: A systematic review
J. Affective Disord.
(2011) - et al.
Antenatal risk factors for postnatal depression: A large prospective study
J. Affective Disord.
(2008) - et al.
Towards parenthood: An antenatal intervention to reduce depression, anxiety and parenting difficulties
J. Affective Disord.
(2011)
Antenatal risk factors for postpartum depression: a synthesis of recent literature
Gen Hosp Psychiatry
Women with anxiety disorders during pregnancy are at increased risk of intense postnatal depressive symptoms: a prospective survey of the MATQUID cohort
Eur. Psychiatry
Application of Rasch analysis in the development and application of quality of life instruments
Value Health
Body image across the adult life span: stability and change
Body Image
The association between prenatal stress and infant birth weight and gestational age at birth: A prospective investigation
Am. J. Obstetrics Gynecol.
A review and psychometric evaluation of pregnancy-specific stress measures
J. Psychosomatic Obstetr. Gynecol.
Diagnostic and Statistical Manual of Mental Disorders
RUMM 2030
Psychosocial assessment and management of depression and anxiety in pregnancy
Aust. Family Phys.
Clinical Practice Guidelines: Antenatal Care - Module
The impact of maternal postnatal depression on men and their ways of fathering: an interpretative phenomenological analysis
Psychol. Health
Convergent and discriminant validation by the multitrait-multimethod matrix
Psychol. Bulletin
Assessing the impact of pelvic pain: development using a patient as expert approach, Rasch analysis, and reliability testing of the Pelvic Pain Impact Questionnaire
Australian New Zealand Continence J.
Critical Values for Yen's Q 3: Identification of Local Dependence in the Rasch Model Using Residual Correlations
Appl. Psychol. Measure.
Mood state and psychological adjustment to pregnancy
Arch. Women's Mental Health
Cited by (35)
Design and development of the trauma informed care beliefs scale-brief
2023, Children and Youth Services ReviewAn interactive childbirth education platform to improve pregnancy-related anxiety: a randomized trial
2023, American Journal of Obstetrics and GynecologyThe role of body dissatisfaction and self-compassion in pregnancy-related anxiety
2022, Journal of Affective DisordersCitation Excerpt :Higher scores indicate greater pregnancy-related anxiety. The PrAS has demonstrated construct, convergent and divergent validity, and excellent internal consistency reliability (α = 0.92, Brunton et al., 2018). The current study obtained a full-scale Cronbach's α of 0.92.
Repetitive negative thinking in the perinatal period and its relationship with anxiety and depression
2022, Journal of Affective DisordersCitation Excerpt :Thus, instruments which measure RNT about concerns that are salient and relevant to pregnant women may be more appropriate for this population. Indeed, a growing number of measures have been developed which index RNT about content specific to the perinatal period, such as the PASS (Somerville et al., 2014, which includes a general worry and specific fears subscale), the Pregnancy Related Anxiety Scale (PrAS; Brunton et al., 2018, 2019, 2021), the Postpartum Worry Scale (Moran et al., 2015), and the Postpartum Specific Anxiety Scale (PSAS; Fallon et al., 2016). That said, measures which index RNT about specific concerns introduce another possibility: that responses are conflated by the extent to which the respondent experiences the specified issue/concern.
Child Sexual Abuse and Pregnancy: A Systematic Review of the Literature
2021, Child Abuse and Neglect