Infants develop socioemotional and cognitive skills through attuned interactions with their caregivers (Evans & Porter,
2009; Kim et al.,
2017; Leerkes et al.,
2009). Caregiver mental health problems, such as depression and/or anxiety, affect both caregiver-child interactions in terms of increased caregiver intrusiveness (meta-analysis by Lovejoy et al.,
2000), infant withdrawal (Braarud et al.,
2013; Feldman et al.,
2009; Smith-Nielsen et al.,
2019), lowered maternal sensitivity (meta-analysis by Bernard et al.,
2018), and aspects of long-term child psycho-social development, e.g. cognitive functions and socioemotional development (Murray et al.,
2010). This suggests that poorer caregiver-infant interaction quality may be one of the routes for transmission of risk in general from parent to infant (Erickson et al.,
2019; Stanley et al.,
2004). Early detection of infants at risk with valid instruments for assessing caregiver-child interaction quality is therefore crucial. Although many instruments exist, systematic reviews of their psychometric properties concluded that there was a need for an examination of the theoretical dimensions assumed to underlie the items as the majority of the instruments lacked structural or factorial validity (Gridley et al.,
2019; Lotzin et al.,
2015). Therefore, the aim of the present study is to examine the construct validity of the Coding Interactive Behaviour (CIB; Feldman,
1998), widely used for assessing caregiver-infant interaction. In addition, we examine the effect of maternal depression and co-morbid anxiety on the interaction quality.
Assessment of Caregiver-Child Interactions
It has been proposed that caregiver-child interaction quality is best assessed using observational tools due to less susceptibility to bias associated with parental self-report, e.g. understanding, recall/memory bias, and social desirability (Lotzin et al.,
2015). Following this, attachment and developmental psychology researchers have a long tradition for observing and assessing caregiver-infant interactions (e.g. Ainsworth,
1967; Cohn & Tronick,
1988). For decades, children and their caregivers have been observed in their homes and in the lab, playing freely or in structured tasks, over the course of several minutes up to hours (for reviews see Gridley et al.,
2019; Lotzin et al.,
2015). Typically, interactions are video recorded and coded using one of 24 available coding systems for interactive quality (Lotzin et al.,
2015). Lotzin et al. (
2015) conclude in their systematic review that most tools demonstrate a valid rating procedure, reproducibility, and discriminant validity but lack factorial and predictive validity, meaning the internal structure of the measurement and its capacity to predict later outcomes from caregiver-infant interactions are less established. They recommend future studies improve the quality of caregiver-infant interaction research by examining the theoretically assumed directionality of the tools using factor analysis (Lotzin et al.,
2015). A more recent systematic review of observational measures of interaction quality commonly used in randomised controlled trials (RCT) conclude that for younger children (age 0–3 years), the evidence for validity and reliability was scarce and weak (Gridley et al.,
2019). They argue that this lack of validity evidence is a severe limitation when assessing change in interaction quality in RCTs, as we cannot be sure that the measurement is robust enough to measure the same construct over time.
The assumed theoretical dimensions underlying a range of the widely used observational tools have also been questioned. Mesman and Emmen (
2013) systematically reviewed observational tools measuring parental sensitivity and compared these to Ainsworth et al.’s (
1978) definition of sensitivity, i.e. the ability to (1) notice the child signals, (2) interpret these signals correctly, and (3) respond promptly and appropriately. While the reviewed tools include scales referring to the most salient behaviours from Ainsworth’s definition, many also include parental positive affect, warmth, and affection in their sensitivity composites. Mesman and Emmen (
2013) argue that parental sensitivity and positive affect are two related but distinct dimensions of parenting and that in a subgroup of parents, high levels of positive affect are related to extreme intrusiveness rather than sensitivity. Hence, from a methodological as well as a theoretical point of view, factor analyses examining the theoretical dimensions underlying observational tools are needed.
The CIB is a widely used instrument for assessing caregiver-infant and caregiver-child interaction quality, has been used in many countries (e.g. Denmark, France, United States of America, Germany, Brazil; Feldman,
2012), and it has been shown to capture differences in parent-child interactions related to child biological risk (Feldman et al.,
2002), child socio-emotional risk (Dollberg et al.,
2006), caregiver psychological risk (Feldman et al.,
2009), and change following intervention (Ferber et al.,
2005). For a review of the results from studies using the CIB, see Feldman (
2012). The CIB consists of 33 items; 18 related to the parent’s behaviour (e.g. parental acknowledging), eight to the child’s behaviour (e.g. child initiation), five to the dyad (e.g. dyadic reciprocity), and two represent the lead-lag of the interaction, i.e. child-led versus parent-led (Feldman,
1998). These items mainly focus on the global nature and flow of the interaction (i.e. the involvement and individual style of the two participants in the dyad). Scores reflect the reciprocity and adaptation as well as the affectivity and attention from the partners (Feldman,
1998). The items are coded and then aggregated into constructs based on theory/research in early social development, e.g. sensitivity.
Despite the frequent use of the CIB, to the best of our knowledge, only two previous studies have examined its factor structure. The factor structure proposed by Feldman (see Table
1; hereafter referred to as the original theoretical model), the developer of the CIB, was confirmed in a study of 483 caregiver-child dyads (cited in Feldman,
2012). A recent but smaller study of 52 mothers, 41 fathers, and their 5-year-old children in Denmark failed to confirm the theoretically assumed factor structure for the parental composites (Steenhoff et al.,
2019). Using exploratory factor analysis, this study found different factor structures underlying mother-child and father-child interactions. The factor structure underlying mother-child interaction quality showed resemblance to the original theoretical model in the sense that a sensitivity and an intrusiveness composite were identified, the items included in the composites were overlapping but also different from the original theoretical model. These findings might not be surprising since Feldman (
2012) argues that while some items of the CIB are to be considered core items (see Table
1) and expected to be included in specific composites across contexts, other items may be sensitive to the specific context, e.g. culture or child age. This stresses the importance of examining the factor structure underlying caregiver-infant interactions across cultures and child ages.
Table 1
Original theoretical model
Parent composites: |
Parental sensitivity (10 items) | Acknowledging (core item), Imitating, Elaborating, Parent Gaze, Positive Affect, Vocal Appropriateness, Appropriate Range of Affect, Resourcefulness, Affectionate Touch, and Parent Supportive Presence |
Parental intrusiveness (5 items) | Overriding (core item), Forcing, Parent Negative Affect/Anger, Hostility, and Parent Anxiety |
Child composites |
Child involvement (6 items) | Child Initiation (core item), Child Gaze, Child Positive Affect, Alert, Fatigue (reversed), and Child Vocalisation |
Child withdrawal (2 items) | Negative Emotionality and Withdrawal |
Dyadic composites |
Dyadic reciprocity (3 items) | Reciprocity (core item), Adaptation-Regulation, and Fluency |
Dyadic negative states (2 items) | Constriction and Tension |
Studies using the CIB generally refer to the composites proposed in the original theoretical model, yet with differences in relation to the remaining items included in the composites (e.g. Cordes et al.,
2017; Dollberg et al.,
2010; Egmose et al.,
2017; Feldman et al.,
2002,
2009; Ferber et al.,
2005; van Huisstede et al.,
2019). The composites included in the studies using the CIB generally have high Cronbach’s alpha values (≥0.80), suggesting high internal consistency between items in the composites but, apart from this, studies do not typically detail how decisions were made in relation to which items to include in or exclude from the composites. However, forming composites based on measures of internal consistency is problematic as it only informs on the composite’s reliability, i.e. the items measure something consistently, and not its validity, i.e. the items measure what they are intended to (Tavakol & Dennick,
2011). One of the most basic assumptions in scale validation is unidimensionality, i.e. items measure a single latent construct. Though necessary to establish unidimensionality, high levels of internal consistency are not sufficient (Tavakol & Dennick,
2011). Therefore, it is possible a composite with high levels of internal consistency captures two distinct but related constructs, e.g. parental positive affect and sensitivity. When the multidimensionality of a composite is not recognised, it can potentially limit our understanding of caregiver-child interactions and its effect on child development, especially when two dimensions show differential predictive associations with child development (Mesman & Emmen,
2013). Davidov and Grusec (
2006) found that parental sensitivity to distress was associated with child regulation of negative affect, but parental warmth was associated with child regulation of positive affect. Thus, examination of the factor structure underlying observational tools, such as the CIB, has important implications for research and theory.
Effects of Postnatal Depression and Anxiety on Mother-Infant Interactions
Postnatal depression (PND) and anxiety (PNA) are among the most common psychiatric conditions in the postnatal period and in the population in general. In the postnatal period, meta-analytic evidence shows that about 13% of mothers experience depression (Stephens et al.,
2016), and 15% of mothers experience high levels of anxiety, and 9.9% fulfil criteria for an anxiety disorder (Dennis et al.,
2017). Another meta-analysis shows that co-morbid anxiety and depression diagnosis is present in 9.3% of mothers (Falah-Hassani et al.,
2017).
Research on the effects of PND and PNA on different aspects of mother-infant interactions has yielded mixed results. To our knowledge, only one study has used the CIB to measure the interaction quality in mothers with PND and PNA. Feldman et al. (
2009) used the CIB at 9 months postpartum and compared mothers with PND (
n = 22), PNA (
n = 19), and matched controls (
n = 59). Anxiety and depression status were assessed using self-report questionnaires (State-Trait Anxiety Inventory (Spielberger et al. (
1970)) and Beck Depression Inventory (Beck,
1978), respectively). They found that the PNA-group was more intrusive compared to the other two groups. In contrast, mothers suffering from PND were more withdrawn and less sensitive compared to both the anxious mothers and the control group. Studies using other measurements of mother-infant interaction quality have also found a negative effect of PND and PNA on interaction. Nath et al. (
2019) found that only PND was associated with lower maternal sensitivity while PNA was not, neither in itself nor as comorbid with depression. In contrast, Neri et al. (
2015) found that PNA was associated with lower sensitivity, PND with lower maternal affect, and a combination of the two was associated with lower infant engagement. Finally, Crugnola et al. (
2016) found that only anxiety, and not depression, was associated with more negative infant affect and less positive maternal affect. In conclusion, previous research consistently shows that mother-infant interactions may be negatively affected when mothers suffer from PND and/or PNA, with the interactions being characterised as less sensitive, mothers being more withdrawn and intrusive, as well by more negative affect in either the infant, the mother, or both. At the same time, maternal anxiety and depression have been inconsistently associated with various negative aspects of the mother-child interaction across studies.
The Present Study
The purpose of the present study is twofold: (a) to examine the factor structure of the CIB and (b) to examine the effect of maternal depression and co-morbid anxiety on the derived factors.
We examine the factor structure of the CIB in an at-risk population with mothers and their infants aged 2–6 months. Here, at-risk is defined as a high probability of the mothers having PND (see the Methods section for a further description). We use a combination of exploratory and confirmatory approaches to find the best fitting factor structure. The exploratory approaches are useful when the aim is to uncover complex patterns in the data that can then be hypothesis tested using confirmatory analyses (Yong & Pearce,
2013). We compare the original model developed by Feldman (
1998) with an alternative theoretical model (see the Methods section for how we developed it) and a data-driven model that is based on an exploratory factor analysis.
Finally, we examine the extent to which the best fitting model shows measurement invariance. Ensuring invariance is a prerequisite for investigating possible group differences, because otherwise you cannot be sure whether possible significant differences are due to an actual difference in the populations or to the measurement functioning differently (Putnick & Bornstein,
2016). Measurement invariance is especially important concerning psychological constructs that may have a different meaning in different clinical groups (Putnick & Bornstein,
2016). We examine measurement invariance for mothers with and without a PND diagnosis.
Our second objective is to examine if and how a PND diagnosis and PNA caseness are associated with mother-infant interaction quality as compared with subclinical levels of depression and co-morbid anxiety. We use the composites identified in the best fitting model to measure mother-infant interaction quality. We expect that (a) maternal PND and (b) maternal PNA caseness status is associated with less optimal scores on the CIB composites and (c) co-morbid clinical PND and PNA caseness is associated with less optimal scores on the CIB composites compared to PND a diagnosis alone, PNA caseness alone, and no PND diagnosis or PNA caseness.
Conclusion
In conclusion, the present study confirmed a four factor model of the CIB consisting of the composites ‘Maternal Sensitivity’, ‘Child Engagement’, ‘Maternal Social Withdrawal’, and ‘Maternal Controlling Behaviour’, and configural, metric, and scalar invariance between mothers with and without PND was reached. These results indicate that the CIB using this factor structure is a valid instrument in measuring mother-infant interaction quality regardless of whether the mother is suffering from PND or not. However, we also argue that these parenting items are liable to change due to sample characteristics such as culture or child age, and we would therefore urge users of the CIB to consider the challenges in using such an instrument, both across different cultural contexts as well as in longitudinal studies. Future studies should investigate the latent growth model of the CIB in order to assess invariance across time points. We would, thus, argue that the factor structure of the CIB needs to be validated in more culturally diverse samples before arguing that one sensitivity composite for example is more valid than another. Further, no cut-off scores exist, so the validity of using the composites of the CIB would perhaps also benefit from future research investigating when scores are clinically relevant and when they are just part of the variation in a normal range. Finally, we think that a next step is using item response theory to shorten the CIB to be more applicable in clinical practice. Further, using this method, we can investigate whether some of the items may be more stable across contexts as well as salient for assessing the desired interaction behaviour compared to the use of composites to further ensure the construct validity of the CIB.
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