Sibling profiles, including sibling status (only-child or sibling) and sibling characteristics (sibling size, birth order, and sex), can impact on lived experiences and social interactions, and operate as protective or risk factors for a wide range of health and well-being indicators and outcomes. Using population-based data linkage to disability-specific databases, sibling profiles were compared between families of children with and without neurodevelopmental conditions. Families of children with neurodevelopmental conditions were more likely to contain siblings than only-children, and be larger families, with children more likely to have shorter gestational age, lower birthweight, younger mothers, and lower socioeconomic status than other children. The context of unique sibling experiences may be important for understanding how sibling well-being may be influenced by different family circumstances.

INTRODUCTION: The Rett Syndrome Behaviour Questionnaire (RSBQ) describes behavioural and emotional features. This study investigated total RSBQ score trajectories and their clustering, and for trajectory groups, relationships with genotype and mobility, weight-for-age z scores, and seizure frequency. METHODS: Females in the Australian Rett Syndrome Database who were genetically confirmed with RSBQ data collected between 2000 and 2019 were included. The age trend was modelled with mixed-effects linear regression. Unique trajectory classes for total RSBQ scores and time-varying predictors (mobility, weight-for-age z scores, seizure frequency) were identified with group-based trajectory modelling. Associations between genotype, time-varying predictors and RSBQ total score class memberships were assessed with multinomial logistic regression. RESULTS: There were 1,034 questionnaires collected from 298 individuals (age range 1.7-37.9 years) with a median of 3 (range 1-7) per person. For individuals aged 5 to 20 years at first RSBQ response, the mean (95% CI) scores were 43.9 (40.7, 47.1) at age 5 and 42.0 (39.9, 44.2) at age 20. Total score trajectories clustered into low and middle groups where scores decreased steadily, and a high group which decreased after age 20. Compared to independent walking, assisted walking increased the probability of being in the high-scoring RSBQ group. Very low weight (<-6 z score) increased the probability of being in the medium or high-scoring group. Weak associations were found with seizure frequency and genotype. CONCLUSION: RSBQ total scores declined with increasing age suggesting improvement in the behavioural and emotional phenotype with age and time. There were few relationships between RSBQ scores and indicators of clinical severity. These natural history data form a baseline for comparison as new treatments become available.

BackgroundIn children with Rett syndrome, this study aimed to (1) describe gross motor skill trajectories; and (2) analyse the influences of genetic variant and comorbidities.MethodsThis was a prospective longitudinal study conducted at the Danish National Center for Rett Syndrome 2008 to 2022. The Rett Syndrome Gross Motor Scale (RSGMS) was administered, and clinical data collected at each visit. Mixed-effects linear regression models were used to analyze the effects of age, genetic variant and comorbidities on gross motor skills. Clinical records data were reviewed.ResultsData for 33 children with a mean age of 7.3 years (SD 1.2) at first visit were followed for a mean duration of 6.8 years (SD 2.1). The mean RSGMS score was 24.0 (SD 13.2, total of 45) at baseline. Adjusting for age and genetic variant, all severity levels of epilepsy, autonomic breathing dysfunction and scoliosis, except for surgically corrected scoliosis, were associated with a 4-point decrease in RSGMS score every 5 years. Acute escalation of seizures, change in muscle tone, orthopedic surgeries and bone fracture could be associated capacity to maintain gross motor skills.ConclusionWe identified decline in gross motor skills during childhood. This novel natural history data can assist with interpretation of changes in gross motor skills following the administration of new therapeutics.

This article discusses the important issue of the need for a stable definition of intellectual disability in order to allow comparisons by place and over time such as in the monitoring of this population’s health needs and utilization. The aim of the new Australian National Centre for Intellectual Disability Health, established in 2023, is to ensure that all Australian children and adults with intellectual disability receive high-quality healthcare that meets their needs. Monitoring changes in this regard requires accurate identification of the number of people with intellectual disability within a population which itself is inherently dependent on how intellectual disability is defined. We have used a definition which is relatively easy to operationalize through different sources i.e. a full-scale IQ of less than 70, a condition known to be consistent with intellectual disability or documentation of intellectual disability in medical records; through education a level of intellectual disability defined as either mild/moderate or greater, and through the National Disability Insurance Scheme an International Classification of Diseases (ICD-10-CM) diagnostic code associated with intellectual disability. In contrast the definition required by Inclusion Australia “a lifelong condition that affects a person’s intellectual skills and their behavior in different situations” is much more difficult to operationalize. We discuss this challenge within the context of historical changes and the range of sources possibly able to provide this information today. We present two case studies from different Australian states and conclude with some suggestions for a multi-source approach using data linkage.

Sleep disturbance is a common and significant issue for individuals with CDKL5 Deficiency Disorder (CDD) and their families. The study aimed to investigate experiences of sleep disturbance in CDD and associated factors. Data were sourced from the baseline and follow-up questionnaires completed by caregivers of 258 individuals in the International CDKL5 Disorder Database. Outcome variables were scaled scores for selected domains of the Sleep Disturbance Scale for Children: Disorders of Maintaining Sleep (DIMS), Disorders of Excessive Somnolence (DOES), Sleep Breathing Disorders (SBD), and Sleep-Wake Transition Disorders (SWTD). For DIMS and SBD, t scores were calculated and dichotomised into high (≥ 70) and low (< 70) groups. Through univariable and multivariable Poisson and logistic regression analyses, the relationships between the sleep disturbance domains and covariates, including sex, age group, genetic variant, motor skills, seizure frequency and patterns, medication use and side effects, constipation, and emotional behaviours, were examined. Caregivers also provided qualitative data on their children’s sleep abnormalities. Content analysis assessed caregivers’ responses to the prompt, “Is there anything about your child’s sleeping that you consider unusual or problematic?”. Individuals ≥18 years old had an adjusted mean DIMS scaled score 6.49 (95

Oral DiseasesEarly View LETTER TO THE EDITOR “What about us?”- the drawbacks of current bruxism assessment criteria in evaluating vulnerable groups Yvonne Y. L. Lai, Corresponding Author Yvonne Y. L. Lai [email protected] [email protected] orcid.org/0000-0001-9737-1294 The University of Queensland School of Dentistry, UQ Oral Health Centre, Herston, Queensland, Australia Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia Correspondence Yvonne Y. L. Lai, Child Disability, Telethon Kids Institute, Level 6E, Perth Children's Hospital, PO Box 855, West Perth, Western Australia, 6872, Australia. Email: [email protected]; [email protected] Contribution: Conceptualization, Writing - review & editingSearch for more papers by this authorJenny Downs, Jenny Downs orcid.org/0000-0001-7358-9037 Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia School of Physiotherapy and Exercise Science, Curtin University, Perth, Western Australia, Australia Contribution: Supervision, Writing - review & editingSearch for more papers by this authorSobia Zafar, Sobia Zafar orcid.org/0000-0001-5551-8147 The University of Queensland School of Dentistry, UQ Oral Health Centre, Herston, Queensland, Australia Contribution: Supervision, Writing - review & editingSearch for more papers by this authorKingsley Wong, Kingsley Wong orcid.org/0000-0001-5178-6080 Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia Contribution: Writing - review & editingSearch for more papers by this authorLaurence Walsh, Laurence Walsh orcid.org/0000-0001-5874-5687 The University of Queensland School of Dentistry, UQ Oral Health Centre, Herston, Queensland, Australia Contribution: Supervision, Writing - review & editingSearch for more papers by this authorHelen Leonard, Helen Leonard orcid.org/0000-0001-6405-5834 Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia Contribution: Supervision, Writing - review & editingSearch for more papers by this author Yvonne Y. L. Lai, Corresponding Author Yvonne Y. L. Lai [email protected] [email protected] orcid.org/0000-0001-9737-1294 The University of Queensland School of Dentistry, UQ Oral Health Centre, Herston, Queensland, Australia Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia Correspondence Yvonne Y. L. Lai, Child Disability, Telethon Kids Institute, Level 6E, Perth Children's Hospital, PO Box 855, West Perth, Western Australia, 6872, Australia. Email: [email protected]; [email protected] Contribution: Conceptualization, Writing - review & editingSearch for more papers by this authorJenny Downs, Jenny Downs orcid.org/0000-0001-7358-9037 Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia School of Physiotherapy and Exercise Science, Curtin University, Perth, Western Australia, Australia Contribution: Supervision, Writing - review & editingSearch for more papers by this authorSobia Zafar, Sobia Zafar orcid.org/0000-0001-5551-8147 The University of Queensland School of Dentistry, UQ Oral Health Centre, Herston, Queensland, Australia Contribution: Supervision, Writing - review & editingSearch for more papers by this authorKingsley Wong, Kingsley Wong orcid.org/0000-0001-5178-6080 Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia Contribution: Writing - review & editingSearch for more papers by this authorLaurence Walsh, Laurence Walsh orcid.org/0000-0001-5874-5687 The University of Queensland School of Dentistry, UQ Oral Health Centre, Herston, Queensland, Australia Contribution: Supervision, Writing - review & editingSearch for more papers by this authorHelen Leonard, Helen Leonard orcid.org/0000-0001-6405-5834 Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia Contribution: Supervision, Writing - review & editingSearch for more papers by this author First published: 04 August 2022 https://doi.org/10.1111/odi.14337Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. Early ViewOnline Version of Record before inclusion in an issue RelatedInformation

Abstract Introduction Rett syndrome (RTT) is a rare neurodevelopmental disorder with developmental impairments, comorbidities, and abnormal behaviours such as hand stereotypies and emotional features. The Rett Syndrome Behaviour Questionnaire (RSBQ) was developed to describe the behavioural and emotional features of RTT. Little is known how RSBQ scores are associated with genetic and clinical characteristics in RTT. This study investigated relationships between genotype, age, walking, hand function, sleep, and RSBQ total and subscale scores in RTT. Methods This is a cross-sectional analysis of data collected in the Australian Rett Syndrome Database and the International Rett Syndrome Phenotype Database. Parent caregivers completed the RSBQ and Sleep Disturbance Scale for Children [subscales for disorders of initiating and maintaining sleep (DIMS), disorders of excessive somnolence (DOES)], and provided information on age, variant type, functional abilities (mobility, hand function), seizure frequency and gastrointestinal problems. Associations between the RSBQ scores and the independent variables were modelled using linear regression. Results Data were available for 365 individuals with RTT [median (range) age 17.8 (2.9–51.9) years, 2 males]. Compared to adults, 2- to 12-year-old children had higher mean Total, Night-time Behaviour and Fear/Anxiety scores. Compared to individuals with a C-terminal deletion, individuals with the p.Arg255* variant had higher mean Total and Night-time Behaviours scores, whereas the p.Arg294* variant had higher mean Mood scores. Individuals with intermediate mobility and hand function abilities had a higher mean Total score. Total RSBQ and subscale scores were similar across categories for seizures, constipation, and reflux, but were higher with abnormal DIMS and abnormal DOES scores. Conclusion Except for associations with sleep, the RSBQ measures the behavioural phenotype rather than clinical severity in RTT, as traditionally conceptualised in terms of functional abilities and comorbidities. When designing clinical trials, the RSBQ needs to be complemented by other outcome measures to assess specific core functions and associated comorbidities in RTT.

Background Australian Aboriginal and Torres Strait Islander women with diabetes in pregnancy (DIP) are more likely to have glycaemic levels above the target range, and their babies are thus at higher risk of excessive fetal growth. Shoulder dystocia, defined by failure of spontaneous birth of fetal shoulder after birth of the head requiring obstetric maneuvers, is an obstetric emergency that is strongly associated with DIP and fetal size. The aim of this study was to investigate the epidemiology of shoulder dystocia in Aboriginal babies born to mothers with DIP. Methods Stratifying by Aboriginal status, characteristics of births complicated by shoulder dystocia in women with and without DIP were compared and incidence and time-trends of shoulder dystocia were described. Compliance with guidelines aiming at preventing shoulder dystocia in women with DIP were compared. Post-logistic regression estimation was used to calculate the population attributable fractions (PAFs) for shoulder dystocia associated with DIP and to estimate probabilities of shoulder dystocia in babies born to mothers with DIP at birthweights > 3 kg. Results Rates of shoulder dystocia from vaginal births in Aboriginal babies born to mothers with DIP were double that of their non-Aboriginal counterparts (6.3% vs 3.2%, p < 0.001), with no improvement over time. Aboriginal mothers with diabetes whose pregnancies were complicated by shoulder dystocia were more likely to have a history of shoulder dystocia (13.1% vs 6.3%, p = 0.032). Rates of guideline-recommended elective caesarean section in pregnancies with diabetes and birthweight > 4.5 kg were lower in the Aboriginal women (28.6% vs 43.1%, p = 0.004). PAFs indicated that 13.4% (95% CI: 9.7%-16.9%) of shoulder dystocia cases in Aboriginal (2.7% (95% CI: 2.1%-3.4%) in non-Aboriginal) women were attributable to DIP. Probability of shoulder dystocia among babies born to Aboriginal mothers with DIP was higher at birthweights > 3 kg. Conclusions Aboriginal mothers with DIP had a higher risk of shoulder dystocia and a stronger association between birthweight and shoulder dystocia. Many cases were recurrent. These factors should be considered in clinical practice and when counselling women.

BACKGROUND:Information on the hospital service use among individuals with CDKL5 Deficiency Disorder, an ultrarare developmental epileptic encephalopathy, is limited, evidence of which could assist with service planning. Therefore, using baseline and longitudinal data on 379 genetically verified individuals in the International CDKL5 Disorder Database, we aimed to investigate rates of seizure-related and other hospitalizations and associated length of stay in this cohort. METHODS:Outcome variables were lifetime count of family-reported hospitalizations and average length of stay both for seizure- (management and/or investigative) and non-seizure-related causes. These variables were examined according to gender, age group, genetic variant group, and lifetime number of antiseizure medications. Using negative binomial regression associations were expressed as incidence rate ratios and geometric mean ratios for hospitalization rates and length of stay, respectively. RESULTS:There were 2880 hospitalizations over 2728.4 person-years with two thirds seizure related. Infants were much more likely to be hospitalized than older individuals, with decreasing effect sizes with increasing age. Males had slightly higher rates of hospitalizations for seizure-related management and for non-seizure-related admissions. Lifetime use of six or more antiseizure medications was associated with a higher hospitalization rate for seizure management than use of three or fewer medications. The median length of stay was five days for seizure and nonseizure reasons. CONCLUSION:There is an urgent need for much better seizure management in CDKL5 deficiency disorder given the hospitalization burden especially in the preschool age group and the multiplicity of antiseizure medications being used.

IntroductionEstimates of the prevalence of intellectual disability or autism spectrum disorder (ASD) may vary depending on the methodology, geographical location, and sources of ascertainment. The National Disability Insurance Scheme (NDIS) in Australia was introduced progressively from 2016 to provide individualized funding for eligible people with a significant and permanent disability.MethodsIts recent inclusion as a source of ascertainment in the population-based Intellectual Disability Exploring Answers (IDEA) database in Western Australia has allowed comparisons of the prevalence of intellectual disability and ASD before and after its introduction.ResultsPrevalence of intellectual disability in 2020 was 22.5 per 1,000 (/1,000) live births compared with previous estimates in 2010 of 17/1,000, and for ASD, the estimate was 20.7/1,000 in 2020 compared with 5.1 /1,000 in 2010. Whilst the prevalence of ASD in Aboriginal individuals was about two-thirds that of non-Aboriginals, there was an increased prevalence of ASD in Aboriginal children under 10 years compared with non-Aboriginal children.DiscussionThe concurrent relaxation of ASD diagnostic practice standards in Western Australia associated with the administration of access to the NDIS and the release of the National Guidelines empowering single diagnosticians to determine the appropriateness of engaging additional diagnosticians to form a multidisciplinary team on ASD diagnosis, appear to be important factors associated with the increase in ASD diagnoses both with and without intellectual disability.

CDKL5 deficiency disorder presents as a challenging condition with early-onset refractory seizures, severe developmental delays, and a range of other neurological symptoms. Our study aimed to explore the benefits and side effects of anti-seizure medications (ASMs) in managing seizures among individuals with CDKL5 deficiency disorder, drawing on data from the International CDKL5 Disorder Database. Data for this retrospective cohort study were obtained from the International CDKL5 Disorder Database, which contains responses from a baseline questionnaire administered between 2012 and 2022 and a follow-up questionnaire administered between 2018 and 2019. Families of eligible individuals were asked to provide information on ASMs that were previously and currently taken, the dose prescribed, the age at starting the medications, and the age at discontinuation for past medications. The outcome variables of interest were perceived seizure-related benefits for the current and past use of ASMs and caregiver-reported side effects. Rescue medications and infrequently used ASMs were excluded from the analysis. Descriptive statistics were used to summarise the characteristics of the study population. The study included 399 children and adults with CDKL5 deficiency disorder, descriptively analysing the perceived benefits and side effects of 23 unique ASMs based on caregiver reports. The study identified levetiracetam, topiramate, sodium valproate, vigabatrin, phenobarbital and clobazam as the most used ASMs. Notably, cannabidiol showed highly beneficial outcomes with few side effects, whereas levetiracetam and phenobarbital exhibited less favourable benefit-to-side-effect ratios. Dual therapy involving sodium valproate and levetiracetam was only used a small number (n = 5) of times but appeared effective in reducing seizure activity with relatively few side effects. Compared with monotherapy, polytherapy had a relatively higher likelihood of reported side effects than benefits. The study, leveraging a large sample size that exceeds that of previous research, emphasises the complex nature of seizure management in CDKL5 deficiency disorder. Our findings underscore the necessity of ongoing research to optimise treatment strategies, considering both the efficacy of seizure control and the potential for adverse effects. The study also points to the need for future investigations into the therapeutic potential of emerging treatments such as ganaxolone and the unresolved efficacy of cannabis products in seizure management.

OBJECTIVE:To evaluate the associations between complex hip surgery and subsequent hospitalizations in children with intellectual disability, including a subset of children with cerebral palsy. STUDY DESIGN:We conducted a retrospective cohort study using linked administrative, health, and disability data from Western Australia. Children born between 1983 and 2009 who underwent complex hip surgery by end 2014 were included (intellectual disability, n = 154; subset with cerebral palsy, n = 91). A self-controlled case series analysis using Poisson regression was used to estimate the age-adjusted associations of complex hip surgery on all-cause hospitalizations and when the principal diagnosis was lower respiratory tract infection or epilepsy, for periods following the individual's first major hip surgery, compared with the year before surgery. RESULTS:Age adjusted incidence of all-cause hospitalizations decreased after surgery (year 1: incidence rate ratio [IRR] 0.87 [95% CI, 0.74-1.02]; year 6: IRR 0.57 [95% CI, 0.46-0.72]). The incidence of hospitalizations for lower respiratory tract infection increased (year 1: IRR, 1.03 [95% CI, 0.72-1.51]; year 6: IRR 2.08 [95% CI, 1.18-3.68]). The incidence of hospitalizations for epilepsy decreased (year 1: IRR 0.93 [95% CI, 0.57, 1.54]; year>6: IRR 0.72 [95% CI, 0.34-1.55]) after surgery. A similar pattern was observed for the subset of children with or without cerebral palsy. CONCLUSION:Complex hip surgeries are associated with fewer hospitalizations overall but not respiratory hospitalizations for children with intellectual disability. Fewer hospitalizations suggest benefits for better musculoskeletal alignment.

BackgroundSiblings of children with intellectual disability have unique family experiences, varying by type of disability.MethodsParents of children with Down syndrome (156) or with Rett syndrome (149) completed questionnaires relating to sibling advantages and disadvantages, experiences of holidays and recreation, and perceived availability of parental time. Qualitative responses were analysed using thematic analysis.ResultsPositive personality traits, an optimistic outlook, enhanced skills, and rich relationships were strong and consistent parental perceptions for siblings in both disability groups. Parents of children with Rett syndrome were more likely to rank themselves lower on time availability, and to report sibling difficulties with social engagement and family holidays.ConclusionsParental responses appeared to be influenced by disability type, and reflective of child capabilities. Perceptions of sibling experience should be supplemented by data collected directly from siblings to fully understand their unique perspective, and the ways in which their experiences could be enhanced.

BACKGROUND:Aboriginal and Torres Strait Islander (hereafter Aboriginal) women have a high prevalence of diabetes in pregnancy (DIP), which includes pre-gestational diabetes mellitus (PGDM) and gestational diabetes mellitus (GDM). We aimed to characterize the impact of DIP in babies born to Aboriginal mothers.METHODS:A retrospective cohort study, using routinely collected linked health data that included all singleton births (N = 510 761) in Western Australia between 1998 and 2015. Stratified by Aboriginal status, generalized linear mixed models quantified the impact of DIP on neonatal outcomes, estimating relative risks (RRs) with 95% CIs. Ratio of RRs (RRRs) examined whether RRs differed between Aboriginal and non-Aboriginal populations.RESULTS:Exposure to DIP increased the risk of adverse outcomes to a greater extent in Aboriginal babies. PGDM heightened the risk of large for gestational age (LGA) (RR: 4.10, 95% CI: 3.56-4.72; RRR: 1.25, 95% CI: 1.09-1.43), macrosomia (RR: 2.03, 95% CI: 1.67-2.48; RRR: 1.39, 95% CI: 1.14-1.69), shoulder dystocia (RR: 4.51, 95% CI: 3.14-6.49; RRR: 2.19, 95% CI: 1.44-3.33) and major congenital anomalies (RR: 2.14, 95% CI: 1.68-2.74; RRR: 1.62, 95% CI: 1.24-2.10). GDM increased the risk of LGA (RR: 2.63, 95% CI: 2.36-2.94; RRR: 2.00, 95% CI: 1.80-2.22), macrosomia (RR: 1.95, 95% CI: 1.72-2.21; RRR: 2.27, 95% CI: 2.01-2.56) and shoulder dystocia (RR: 2.78, 95% CI: 2.12-3.63; RRR: 2.11, 95% CI: 1.61-2.77). Birthweight mediated about half of the DIP effect on shoulder dystocia only in the Aboriginal babies.CONCLUSIONS:DIP differentially increased the risks of fetal overgrowth, shoulder dystocia and congenital anomalies in Aboriginal babies. Improving care for Aboriginal women with diabetes and further research on preventing shoulder dystocia among these women can reduce the disparities.

Aim To investigate developmental trajectories in early childhood and predictors of class assignment. Methods Data were available for Gen2 infants at 12 (n = 2275), 24 (n = 1845) and 36 (n = 2110) months of age in the Raine Study. Latent growth class analysis was used to identify developmental trajectories based on the Ages and Stages Questionnaire. Multivariate logistic regression analyses were used to estimate associations between foetal growth restriction, gestational age, child biological sex, breast feeding, parental age, socioeconomic factors and developmental trajectories. Results Two groups of infants were identified, one typically performing and one poorer performing. Being born early-term, pre-term and male were associated with poorer development. Not exposed to breastfeeding was associated with the lower trajectories in the adaptive and personal-social domains. Conclusions Developmental surveillance and advice for early-term infants should be considered. Findings highlight the continued need to support and promote breastfeeding as a protective mechanism for child development.

CDKL5 deficiency disorder (CDD) results in early-onset epilepsy and lifelong cognitive and motor impairments. With no validated measure for communication in CDD, this study evaluated the psychometric properties of the Communication and Symbolic Behavior Scales-Developmental Profile Infant Toddler Checklist (CSBS–DP ITC). Caregivers (n = 150; affected individuals aged 1–29 years) completed the CSBS-DP ITC. Distribution of scores indicated a floor effect. There was poor divergent validity for the three-factor model but goodness of fit and convergent validity data were satisfactory for the one-factor model. Individuals with poorer overall functional abilities scored lower on the CSBS-DP ITC. Test–retest reliability was excellent. The floor effect could explain the very high reliability, suggesting problems as a sensitive outcome measure in clinical trials for CDD.

Objective To describe trends, age-specific patterns, and factors influencing hospitalizations for 5 rare craniofacial anomalies (CFAs). Methods Data on livebirths (1983-2010; n = 721 019) including rare CFA (craniofacial microsomia, mandibulofacial dysostosis, Pierre Robin sequence, Van der Woude syndrome, and frontonasal dysplasia), episodes of death, and demographic and perinatal factors were identified from the Western Australian Register of Developmental Anomalies, Death Registrations and Midwives Notification System. Information on incident craniofacial and noncraniofacial related admissions, length of hospital stay, and intensive care and emergency-related admissions were identified using principal diagnosis and procedural codes were extracted from the Hospital Morbidity Data Collection and linked to other data sources. Associations of hospitalizations by age groups as well as demographic and perinatal factors were expressed as incidence rate ratio (IRR). Results The incident hospitalizations were 3 times as high for rare CFA (IRR 3.22-3.72) throughout childhood into adolescence than those without. Children with rare CFA had 3-4 times as many potentially preventable hospitalizations until 18 years of age than those without. Specifically, respiratory infections (IRR 2.13-2.35), ear infections (IRR 7.92-26.28), and oral health-related conditions contributed for most noncraniofacial admissions until the adolescence period. A greater incidence of noncraniofacial related hospitalizations was observed among Indigenous children, births with intrauterine growth restrictions, and families with high socioeconomic disadvantage. Conclusions Throughout childhood, individuals with rare CFA had greater hospital service use, specifically for potentially preventable conditions, than those without. These population-level findings can inform new preventive strategies and early disease management targeted toward reducing preventable hospitalizations.

Understanding hospital service use among children with a diagnosis of craniosynostosis (CS) is important to improve services and outcomes. This study aimed to describe population-level trends, patterns, and factors influencing hospitalizations for craniosynostosis in Western Australia. Data on live births (1990–2010; n = 554,624) including craniosynostosis, episodes of death, demographic, and perinatal factors were identified from the midwives, birth defects, hospitalizations, and death datasets. Information on craniosynostosis and non-craniosynostosis-related admissions, cumulative length of hospital stay (cLoS), intensive care unit, and emergency department–related admissions were extracted from the hospitalization dataset and linked to other data sources. These associations were examined using negative binomial regression presented as annual percent change and associations of hospitalizations by age groups, demographic, and perinatal factors were expressed as incidence rate ratio (IRR). We found an increasing trend in incident hospitalizations but a marginal decline in cLoS for craniosynostosis over the observed study period. Perinatal conditions, feeding difficulties, nervous system anomalies, respiratory, and other infections contributed to majority of infant non-CS-related admissions.Respiratory infections accounted for about twice the number of admissions for individuals with CS (IRRs 1.94–2.34) across all observed age groups. Higher incidence of non-CS hospitalizations was observed among females, with associated anomalies, to families with highest socioeconomic disadvantage and living in remote areas of the state. Conclusion : Marginal reduction in the cLoS for CS-related admissions observed over the 21-year period are potentially indicative of improved peri-operative care. However, higher incidence of respiratory infection-related admissions for syndromic synostosis is concerning and requires investigation.