Bed-sharing due to child reluctance to sleep independently (i.e. reactive bed-sharing) was a common practice in early childhood with over 1 in 3 parents reporting some bed-sharing and over 1 in 5 reporting nightly bed-sharing. However, prevalence varied significantly by sociodemographic factors, with higher rates in families characterized with lower income and educational attainment, and in families reporting child race and ethnicity of Black and (combined) American Indian, Alaska Native and Asian. Bed-sharing prevalence also decreased over development with lower rates among older compared to younger preschoolers. Cross-sectional associations suggested higher levels of separation anxiety and sleep terrors in children who bed-share nightly, and difficulty maintaining sleep and sleep terrors in children who bed-share weekly. Similar associations were observed in longitudinal models. However, associations attenuated after controlling for sociodemographics, time between interviews, and baseline status of the outcome. Our findings suggest reactive bed-sharing is a common practice in families with young children that varies by sociodemographic factors, declines over time, and is a more meaningful indicator of current problems than a risk factor for later struggles.

Our overall reactive bed-sharing prevalence was slightly lower than the 41–55% reported in some previous studies [5,6,7], but quite similar to the 38% bed-sharing prevelance reported for 4-year-old Swiss children in a 10-year longitudinal study of bed-sharing [12], and the 22% nightly bed-sharing prevalence reported for 3–5 year olds in the United States [37]. We also found a higher percentage of families were bed-sharing nightly than weekly, a result which runs counter to prior reports that intermittent bed-sharing is more common than frequent bed-sharing [6, 8, 9]. The higher rates of nightly than weekly bed-sharing might be due to the diverse nature of our sample and/or emphasis on reactive bed-sharing.

Sociodemographic factors were associated with bed-sharing. Consistent with previous research [4, 6, 10, 11], bed-sharing was more common among families reporting low socioeconomic status such as income below the poverty threshold and educational attainment less than high school. Bed-sharing was also more common in families of Black and (combined) American Indian, Alaska Native and Asian, but not Hispanic, race and ethnicity. Due to our small sample sizes of American Indian, Alaska Native and Asian families, we cannot make any conclusions about these groups individually. Altogether the differences suggest a need to better understand whether potential variation in family cultural beliefs, values, and norms about child sleep reluctance influence bed-sharing prevalence. These findings are consistent with prior work documenting higher bed-sharing rates for any reason for those reporting Black race and ethnicity [5, 6, 28] and add to the mixed results for Hispanic race and ethnicity [7, 8, 10]. These sociodemographic correlates of bed-sharing suggest, as argued by other investigators [12, 38], that this sleep practice is influenced by an interplay of child reluctance, family/parenting and cultural/subcultural factors. Although our assessment explicitly inquired about reactive bed-sharing due to child reluctance to sleep alone, some families in our sample may have been bed-sharing for additional reasons including bed/crib availability, warmth, and protection against neighborhood violence [39, 40] and as a way to preserve a sense of culture and/or as a family tradition which was practiced by parents and grandparents [40, 41]. These reasons for bed-sharing were not assessed in the current study, and further research is needed to better understand additional reasons for bed-sharing. However, taken together, there is likely not a one-size-fits-all recommendation about normative or problematic bed-sharing when working with families from diverse backgrounds.

We were also interested in the clinical significance of preschool-age bed-sharing. At baseline adjusting for co-morbidities, weekly bed-sharing was associated with sleep terrors and difficulty staying asleep, and nightly bed-sharing was associated with separation anxiety and sleep terrors. Our findings are consistent with prior work indicating a fairly robust concurrent link between bed-sharing and sleep problems [5,6,7, 13, 14] and negligible support for associations with internalizing and externalizing disorders [6, 16, 17]. To our knowledge, no prior investigations have linked bed-sharing to separation anxiety or sleep terrors despite the high prevalence of these disorders during early childhood. Our ability to detect these disorder-specific associations may be due to our assessment method (e.g., structured diagnostic interview versus parent-report questionnaires) and multiple bed-sharing definitions (e.g., weekly and nightly).

Cross-sectional examination of bed-sharing does not address developmental trends. In our sample, bed-sharing decreased but did not disappear from the initial assessment when children were on average 3.8 years old to the follow-up assessment approximately 2 years later. At follow-up, only 41.3% of parents who initially reported nightly bed-sharing and only 11.3% of parents who initially reported weekly bed-sharing continued to do so. These findings are commensurate with previous research indicating that bed-sharing increases after infancy [7], is modestly stable from one to three years of age [6, 9, 28] and, then, starts to decline around 4 12 or 5 11 years of age [16, 18, 42, 43]. Additionally, prior studies have shown that bed-sharing is more likely to persist among youngsters who bed-share several times or more per week [6].

Tests of longitudinal associations found no evidence that reactive bed-sharing preceded or followed sleep disturbances and psychopathology. Thus, although bed-sharing in early childhood may be an indicator of sleep disturbances such as sleep terrors and difficulty staying asleep [15] and/or anxiety disorders such as separation anxiety, we found little evidence to suggest that bed-sharing is a cause or consequence of clinically significant problems.

This study had several strengths including a diverse, well-characterized sample, longitudinal design, and use of a structured diagnostic interview. There were also several limitations. First, all information about bed-sharing and psychopathology came from parent report and was derived from a set of items from the PAPA, an instrument which has good psychometric properties overall [44] and good test-retest reliability for bed-sharing frequency. However individual items were not compared to other metrics (bed-sharing questionnaire, direct observation or sleep diaries) for testing of concurrent validity. Second, our assessment of bed-sharing inquired about bed-sharing in response to child reluctance to sleep independently. Although some participating families may have engaged in bed-sharing for additional reasons, other reasons were not asked about in this study. Third, the study sample was ascertained in a single location in the Southeastern US that limits generalizability to the US population. Fourth, this longitudinal study could have been strengthened by assessing reactive and intentional bed-sharing, child sleep problems and psychopathology, parenting perceptions and practices (which might relate to subcultural differences), familial stress and parental psychopathology, and sociodemographics context particularly race and ethnicity in the same manner at multiple time points (e.g. infancy through early childhood) using a multi-method approach (i.e., parent report, direct measurement using actigraphs and/or video). These factors have been identified as central to understanding bed-sharing [24]. Then, guided by the transactional model of child sleep [21, 23], a bed-sharing model accounting for dynamic, bidirectional interactions between proximal child (e.g., child behavior at bedtime, sleep disturbances and anxiety) and parenting (e.g., maternal depression/anxiety, stress and parenting values/style) factors and distal, contextual factors (e.g., social/cultural norms in different raceialand ethnic groups and impact of socioeconomic status) could have been stipulated and tested. Current study findings suggest that future research could model the bidirectional and dynamic interrelations among child sleep disturbances and anxiety, the parenting practice of bed-sharing due to child reluctance to sleep alone, and variations in bed-sharing by race and ethnicity and socioeconomic factors during early childhood.

In many respects, our findings suggest that bed-sharing in early childhood (2–6) is predominantly a normative, transient sleep practice influenced by sociodemographic context. Thus, when parents have questions or concerns about bed-sharing after infancy, pediatric providers can discuss with parents the evidence that bed-sharing is relatively common experience in this developmental period and one that may be influenced by family circumstances and cultural context. They can also note factors that may contribute to this increase in bed-sharing such as an increase in nighttime fears and heightened distress about being alone at night. Finally and perhaps most importantly, clinicians can reassure parents about the lack of association between preschool bed-sharing and clinically significant sleep or mental health problems as well as the likelihood that such bed-sharing will decrease, on its own, with time.