Medical diagnoses among infants at entry in out‐of‐home care: A Swedish population‐register study

Abstract Background and aims Identification of child abuse involves a medical investigation and assessment of problems related to social environment and upbringing and might necessitate out‐of‐home care. The objective of this study was to analyse infants placed in out‐of‐home care in Sweden by incidence, medical diagnoses, and perinatal factors. Methods This was a population‐based register study of infants born in Sweden 1997 to 2014. Data were retrieved from registers at the Swedish National Board of Health and Welfare and Statistics Sweden. Outcome measures were out‐of‐home care categories: (a) “Problems Related to Social Environment/Upbringing”, (b) “Abuse diagnoses without SDH (subdural haemorrhage), RH (retinal haemorrhage), rib fracture, or long bone fracture”, and (c) “SDH, RH, rib fracture, or long bone fracture.” As a reference population, we randomly selected infants without medical diagnoses born the same year. Results Overall incidence of out‐of‐home care was 402 per 100 000. For subcategories (a), (b), and (c), the incidences were 14.8 (n = 273), 3.77 (n = 70), and 9.83 (n = 182) per 100 000, respectively. During the study period, the first remained unchanged; the latter two have been increasing. Compared with other reasons for out‐of‐home care, children in category (c), “SDH, RH, rib fracture, or long bone fracture”, had increased odds of being boys (adjusted odds ratio [aOR] 1.60; 95% confidence interval [CI], 1.08‐2.38) and decreased odds of having a mother being single (aOR 0.49; 95% CI, 0.32‐0.75) and a smoker (aOR 0.60; 95% CI, 0.37‐0.96). Compared with the reference population, children in this category were more often twin born (7.7% versus 2.8%), preterm (18.5% versus 5.5%), and small‐for‐gestational age (5.2% versus 2.1%). Conclusion SDH, RH, rib fracture, or long bone fracture constitute a minor part of medical diagnoses for infants entered in out‐of‐home care, but have been increasing, both in numbers and proportion. Overdiagnosis of abuse might be a possible reason but cannot be ascertained by this study design.


| INTRODUCTION
Child health and child protection policy in Sweden has a long history, from the building of Child Care Centres from the 1930s, the forming of the Child Accident Prevention Committee in the 1950s, and prohibiting corporal punishment and emotional humiliation in 1979 to instituting the Children's Ombudsman in 1993. 1 In 2001, the governmental committee for the "Child Abuse-Prevention and Protection" inquiry recommended establishment in all municipalities of a multisectoral and multidisciplinary agency, Barnahus (Children's House), linking the services of the police, social services, public prosecutor, children's and youth psychiatry, paediatrics, and forensic medicine. 2 Further, a section of the Child Maltreatment division of the Swedish Paediatric Society promoted the establishment of Child Protection Teams in paediatric university departments, starting in 2007. 3 In addition, clinical guidelines on shaken baby syndrome/abusive head trauma (SBS/AHT) were adapted for use in some parts of Sweden the same year, 4,5 and child care centres recommended informing parents about the dangers of shaking a baby. 5,6 Swedish welfare law mandates any professional to report to social services any harmful domestic condition that may expose a child to risks. For child maltreatment welfare, interventions involve out-ofhome care in foster families or residential care; such measures can be voluntary (Social Service Act) or compulsory (Compulsory Care Act).
The incidence of out-of-home care for infants in Sweden during the years 1998 to 2009 was 275.7 per 100 000, while incidences in England, the United States, and Manitoba (Canada) were much higher: 696.4, 631.4, and 2913.1, respectively. 1 For preschool children (0-6 y) born in Sweden between 1992 and 1996, increased odds of out-ofhome care were associated with the mother giving birth in her teens, single, less educated, unemployed, and with psychosocial adversity, but not with being a second-generation immigrant. 7 For Swedish children aged 1 to 6 years during the 1990s and early 2000s, trends in maltreatment indicated a decrease in parental reports of severe child abuse, admissions for maltreatment or assault, violent deaths, or adolescents reporting severe beating by parents. 1 Yet, until 2009, little change was noted in rates of infant (aged 0-1 y) maltreatment, out-of-home care, or deaths. 1 However, this trend was broken by a doubling of infant abuse diagnoses from the period 1997 to 2007 to 2008 to 2014. 8 The following diagnoses, subdural haemorrhage (SDH), retinal haemorrhage (RH), skull fracture, rib fracture, classic metaphyseal lesions (CMLs), long bone shaft fracture, apnoea, and seizures, are claimed to be specific for the diagnosis of abuse. [9][10][11][12][13][14][15] However, the scientific solidity of the SBS/AHT diagnosis has been questioned. [16][17][18][19][20][21] A systematic literature review of the Swedish Agency for Health Technology Assessment and Assessment of Social Service (SBU) concluded that there is limited scientific evidence to explain the triad or its components (subdural haematoma, RHs, and encephalopathy) by isolated shaking. 22 Moreover, there is insufficient evidence on which to assess the diagnostic accuracy of the triad in identifying SBS/AHT, irrespective of presumed injury mechanisms. 22 This systematic literature review has been criticized, commented on, and answered by the SBU expert group. [23][24][25][26][27][28][29] We have provided evidence of perinatal risk factor profiles of infants with abuse diagnosis and SDH, 30 rib, or long bone fractures, 31 risk profiles that are similar to those having a medical cause of SDH or fractures.
To our knowledge, out-of-home care, specifically among infants aged 0 to 1 years, has not been studied in Sweden with respect to medical diagnoses. It might be hypothesized that the observed increase in the diagnosis of abuse is not real but due to an overdiagnosis of abuse (false positives). 8,22,23 The objective of this study was to analyse the following epidemiological aspects for out-of-home care for infants: • the incidence of entries in out-of-home care, overall and by medical diagnoses, prior to or at the time of out-of-home care; • perinatal and parental factors associated with the infants' entry into out-of-home care by medical diagnoses. A flow chart of the study design is presented in Figure S1. Out of 1 855 267 children born, 395 812 had an entry in NPR. From those, a selection of 119 diagnoses was made (n = 182 974 children). 8 For analysis of perinatal and parental factors, four controls were selected for each included infant; these were born the same year and had no diagnoses in NPR during the first year of life. 8 Information from the T A B L E 1 Specified infant diagnoses (ICD-10) before or at time of out-of-home care (±15 d) according to the Social Service Act or Compulsory Care of Young Persons Act by superficial body or head injury and fall accidents for children aged 0- Of the final sample, 1514 infants had an entry in the Out-of-home

| Selection and description of participants
Care Register ( Figure S1).
To calculate the overall incidence of entries into out-of-home care, the number of all infants that had an entry in the Register of Children and Young Persons Subjected to Child Welfare Measures was retrieved as aggregated data without personal identity number or linkage to other registers within this study design ( Figure S1).

| Exposures
We selected a total of 51 diagnoses of abuse, adverse social and parental circumstances, and specific diagnoses that might be associated with infant abuse according to the literature (Table S1) 0.97 for severe RH, 9 0.67 to 1.0 for rib fracture, 10,15,34 and 0.57 for long bone fracture. 11 Those diagnoses were combined in different categories and finally as one category, "SDH, RH, rib fracture, or long bone fracture" ( Table 1).
Incidences of out-of-home care were estimated for all infants and following subcategories: (a) "Problems Related to Social Environment/Upbringing", (b) "Abuse diagnoses without SDH, RH, rib fracture, or long bone fracture", and (c) "SDH, RH, rib fracture, or long bone fracture".
To analyse differences in perinatal and parental characteristics, the following categories of infants with entry into out-of-home care were selected: (1) infants with any medical diagnosis, (2) infants with "Problems Related to Social Environment/Upbringing", and (3) infants with "SDH, RH, rib fracture, or long bone fracture". These were compared with the reference population (see Table 2). To analyse risk factors, the categories "Problems Related to Social Environment/Upbringing" and "SDH, RH, rib fracture, or long bone fracture" were compared with out-of-home care children without those diagnoses (see Table 3).
We defined the following perinatal (for the index pregnancy and birth) and parental variables according to current knowledge: 7

| Ethics
The Regional Ethical Committee in Uppsala approved the study

| Out-of-home care by medical diagnoses
In our sample, 782 of all infants in out-of-home care (51.6%) had any of the 51 prespecified diagnoses (see Section 2- Figure S1 and Median ages at entry into out-of-home care for infants in "Problems Related to Social Environment/Upbringing", "Abuse diagnoses without SDH, RH, rib fracture, or long bone fracture", or "SDH, RH, rib fracture, or long bone fracture" were 1, 3.3, and 4 months, respectively.

| Incidence and time trend by diagnosis category
The incidences during the study period for the out-of-home care categories "Problems Related to Social Environment/Upbringing," "Abuse diagnoses without SDH, RH, rib fracture, or long bone fracture," and "SDH, RH, rib fracture, or long bone fracture" were 14.8, 3.77, and 9.83 per 100 000, respectively. The annual incidence for "Problems Related to Social Environment/Upbringing" remained stable during the study period, whereas it increased for "Abuse diagnoses without SDH, RH, rib fracture, or long bone fracture" (P value 0.002) and "SDH, RH, rib fracture, or long bone fracture" (P value < 0.001) (chisquare for trend); see Figure 1.

| DISCUSSION
The overall incidence of out-of-home care for infants was 402 per 100 000 during the study period (1997-2014). For the category "Problems Related to Social Environment/Upbringing", the incidence was 14.8 per 100 000, with no increase during this period; for categories "Abuse diagnosis without subdural haemorrhage, retinal haemorrhage, rib fracture, or long bone fracture" and "SDH, RH, rib fracture, or long bone fracture", the incidences were 3.77 and 9.83 per 100 000, respectively, and both increased during the study period. In the category "SDH, RH, rib fracture, or long bone fracture", 37% of the infants had a reported fall accident. Parents of infants in the total out-of-home care sample had a typically adverse perinatal and socioeconomic profile compared with the population, while parents to infants in the "SDH, RH, rib fracture, or long bone fracture" group were better educated, more often living together, and the mothers smoked less than mothers of other infants in out-of-home care.
The overall incidence of all infants with first entry into out-ofhome care, although increasing during the study period, was comparable with that in Western Australia 1994 to 2005, 35 slightly lower than that in England 1995 to 2008, and higher than that in Denmark, where the incidence has been declining. 36 This is the first Swedish study addressing medical diagnoses and   30 and in addition to these, obesity is associated with infant metabolic bone disease. 31 Thus, biological risk factors might, at least to some extent, account for the relative overrepresentation of low socioeconomic status in the SBS/AHT criteria sample, compared with the reference population. There is also a possibility of selection bias related to doctors' inclination to interpret findings as being related to physical abuse among socially underprivileged carers. 43 Our finding of an increase over time in out-of-home care associated with SBS/AHT criteria is intriguing in view of the fact that information about the dangers of shaking was introduced to parents during the study period 6 and parental reports of shaking decreased from 18% in 2006 to 0% in 2011. 8 The risk factors for infants in out-of-home care in association with SDH, RH, rib fracture, or long bone fracture have similarities with previously reported risk factors for SBS/AHT, such as preterm, 8,33 male preponderance, 9 and multiple birth. 8,33,44 This might be interpreted that having a boy, caring of a preterm, or having twins are potential predictors of provoking violence. An alternative explanation is that these characteristics are associated with medical conditions that predispose to the spontaneous occurrence of physical findings that are also included in the SBS/AHT criteria. Given that only a small proportion (1.8%) of the infants had superficial injuries of the body indicating violence, it is possible that a considerable proportion of those infants had such underlying medical conditions. This assumption is further supported by the fact that diagnoses of SDH, long bone, and rib fracture that were associated with abuse only constituted a minor part of all those fractures found in the population, as shown in our previous studies. 30,31 Only one case had the triad (SDH, RH, and encephalopathy), and rather few had a combination of diagnoses. The number of infants with "SDH, RH, rib fracture, or long bone fracture" in this study might be interpreted as correctly indicating infant abuse and proper out-of-home care intervention, provided that the prevailing SBS/AHT paradigm employs evidence-based practice. 3,[9][10][11][12][13]33 However, the scientific solidity of the SBS/AHT paradigm has been challenged. [17][18][19][20][21][22]45 Further, the claimed high predictivity of long bone and rib fractures for diagnosing SBS/AHT 11,12 has been challenged by previous reviews and described "to be of low quality (high risk of bias)" because of circular reasoning. 22 If the parents cannot provide a plausible trauma history that explains the medical findings, this is believed 33

| Strengths and weaknesses of the study
The strength of this study is the population design: The diagnoses were retrieved nationally, on the basis of a uniform ICD-10 version. The reference population was representative, containing 39.4% of all children born during the study period. The reliability of the data drawn from the out-of-home care entries in the register has previously been reported to be satisfactory. 7 The validity of the Swedish health registers is considered to be high, both with respect to the SBMR 50 and the NPR. 51

| CONCLUSIONS
Diagnoses of SDH, RH, rib fracture, or long bone fracture constitute a minor part of the overall sample of infants in out-of-home care but have increased considerably over the recent years. Overdiagnosis of abuse might be possible but cannot be ascertained by this study design. Overdiagnosis of abuse is not according to the ethical principles of beneficence, nonmaleficence, and justice.

FUNDING
This study was supported by a grant from the Grieg Foundation, Bergen, Norway, to K.W. The funding source had no involvement in the research process of this study. The funding source had no involvement in the study design; collection, analysis, and interpretation of data; writing of the report; or the decision to submit the report for publication.

CONFLICTS OF INTEREST
None declared.