Abusive head trauma (AHT) warrants particular attention in terms of prevention. One of the key questions asked is how often AHT occurs in infant day care centers compared with private parental or nonparental homes. To investigate this, we studied the caretaking arrangement and child’s location at the time of injury in a cohort of cases involving AHT from the courts.
This multicenter retrospective study covering an 18-year period included all medical and court records of 323 children (2.5 months to 3 years) with AHT, confirmed by the authors acting as medical experts. All markers for abuse and forensic written reports were analyzed by using a standardized data collection tool. The usual child care arrangement and the child’s location at the time of injury were noted. The percentage of day care centers found in the study was compared to the expected rate in the French population (19.5%) by using the χ2 test.
In 317 AHT cases (98.5%), the assault occurred in a private home (4 in other indoor settings and 1 with missing data). In only 1 case, shaking occurred in a day care center when the nurse was alone with the infant for a few minutes. In 317 cases (98.5%), the usual child care arrangement was by a single adult in charge of 1 or more children.
The fact that AHT is an unusual occurrence in day care centers could help social service agencies make decisions in terms of prevention. Recent government policies regarding stay-at-home orders during a pandemic have given this issue new relevance.
Although the focus of some studies has been on the caregiver features associated with physical child abuse, researchers have not specifically addressed how often abusive head trauma occurs in infant day care centers compared with private parental or nonparental homes.
The fact that abusive head trauma is an exceptional occurrence in day care centers could help social service agencies make appropriate decisions in terms of prevention.
Abusive head trauma (AHT) is the leading cause of child abuse–related morbidity and mortality.1–3 The estimated incidence in children aged 1 year or younger is ∼30 per 100 000 per year in different parts of the world.3–7 AHT is diagnosed on the basis of a constellation of findings: the overall clinical picture, the pattern of brain lesions, and the presence of so-called “sentinel” lesions, such as bruising or fractures.6,7 Because this diagnosis has such serious medicolegal implications, the question of whether intracranial bleeding, retinal hemorrhages (RHs), and parenchymal brain lesions can be attributed to abuse is controversial.8,9
Although the focus of some studies has been on caregiver features that are associated with physical child abuse,10,11 researchers have not specifically addressed the child’s location at the time of the injury that results in discovery. We hypothesize that AHT is most likely to occur in specific settings and that private homes might be of major concern. If true, this could have a significant impact on prevention strategies and on the decision to confine populations during pandemics.
One of the key questions addressed in the current study is in what setting does AHT most commonly occur? In particular, how often does AHT occur in infant day care centers compared with private parental or nonparental homes? To investigate this, the caretaking arrangement and child’s location at the time of injury were studied in a cohort of legal cases involving AHT from the courts.
Methods
Study Population
This multicenter retrospective study covered an 18-year period from 2002 to 2020. It is an extension of an earlier study.12
Included were all of the medical and court records of 406 children aged <3 years whom the authors (acting as medical experts for 82 French courts) confirmed as having AHT. Four patients for whom imaging results were unavailable were excluded. Only children aged >2.5 months were considered because this is the minimum age required by law for admission to day care centers and for licensed nanny services in France (Fig 1).
All of the patients were initially diagnosed with AHT at the hospital by the pediatricians who treated the children and reported the cases to the prosecutor. Next, the authors (C.A. and C.R.-S.) confirmed the diagnosis on the basis of the full context, including the pattern of intracranial injuries (parenchymal lesions, ruptured bridging veins, and subdural hematomas [SDHs]), other signs of abuse (concurrently identified injuries, such as fractures, bruising, RHs, etc), and previous injuries.
Data Collection
Clinical data (including the child’s health records from birth), laboratory data, and imaging data were reviewed by a forensic pediatrician and a pediatric radiologist, each having >30 years’ experience. The pediatrician author (C.R.-S.) examined the vast majority of the surviving children at the time of the forensic evaluation.
All markers for abuse (particularly, fractures and concurrently identified injuries) were exhaustively noted. All previous traumatic and nontraumatic events (malformations, infections, etc), signs, and symptoms were noted by using a standardized data collection tool.
As forensic medical experts, the authors analyzed all of the written reports from the police investigations and court hearings. When available, we also analyzed the recordings of emergency calls. Current national imaging guidelines for cases of suspected child abuse include a full-skeletal survey plus a computed tomography scan or MRI of the head. A senior pediatric radiologist (C.A.) reviewed all of the imaging studies performed at the time of diagnosis (computed tomography scan, MRI, standard radiographs, and ultrasound) in addition to the initial radiology report.
The final statements given by the suspected perpetrators in the course of investigation fell into 4 distinct categories characterized by (1) an admission by the suspected perpetrator of a causal relationship between the violence inflicted and the child’s symptoms, (2) a history of shaking after an apparent life-threatening event (ALTE), (3) a traumatic event (playing, a fall, or a head impact), or (4) no event reported by the caretaker and/or parents.
Repeated (≥2) episodes of shaking were considered to have occurred when there was a clear admission by the suspected perpetrator or when there was medical evidence of different-aged intracranial injuries.
The usual child care arrangement for each child was classified into 2 categories: (1) day care centers, meaning multiple licensed caretakers at a time working in a dedicated building and supervised by a director, and (2) any kind of in-home day care, meaning a single caretaker (family member, friend, or nanny) with ≥1 child. In-home child care refers to care in any kind of private home (ie, a nonfamilial home [such as a caretaker’s home]) or the child’s home.
The child’s location at the time of injury was classified as either a private home or somewhere else. The time-of-injury assessment was based on when caretakers and/or parents, including suspected perpetrators, judged that the child’s behavior had changed and when the caretaker decided to request medical services.
The caretaker present at the time of the last injury was categorized as either the mother, father, stepfather, nanny, or other (grandmother, nanny’s husband, occasional baby-sitter, adult brother or sister, etc).
Statistical Analysis
Patient characteristics and injuries were described by using median (range) for continuous variables and frequency (percentage) for categorical variables. The percentage of nonparental child care found in the study was compared to the expected theoretical rate in the general French population (19.5%) by using the χ2 test. All analyses were performed by using SAS 9.4 software (SAS Institute, Inc, Cary, NC).
The study did not require ethics committee approval because the data were anonymized and drawn from a database of forensic expert findings.
No funding was provided for this study.
Results
Population Characteristics (N = 323)
The median age was 5.5 (2.5–32.6) months (Table 1). Only 24 children (7%) were aged >1 year. The vast majority (86%) were term infants. Of the 46 (14%) premature infants, 13 (4%) were born very prematurely (<32 weeks).
Population Characteristics
. | Study Population (N = 323) . |
---|---|
Age, median (range), mo | 5.5 (2.5–32.6) |
Term, n (%), wk | |
<32 | 13 (4) |
32–37 | 33 (10) |
>37 | 277 (86) |
Sex, n (%) | |
Girls | 98 (30) |
Boys | 225 (70) |
Status, n (%) | |
Survived | 258 (80) |
Died | 65 (20) |
SDHs, n (%) | 323 (100) |
RHs, n (%) | 279 (88) |
Parenchymal injuries, n (%) | 162 (51) |
Ruptured bridging veins (197 MRIs), n (%) | 158 (80) |
Skull fractures, n (%) | 28 (9) |
Other fractures (excluding skull or corner fractures), n (%) | 35 (11) |
Corner fractures, n (%) | 19 (7) |
Associated extracranial injuries (RHs, skin, mucosa, fractures, etc), n (%) | 300 (93) |
Previous traumatic injuries noticed by the caregiver (child not referred to a doctor or other health professional at the time), n (%) | 64 (20) |
Previous traumatic injuries noticed by a medical doctor, n (%) | 39 (12) |
Judicial confessions, n (%) | |
Full confessions | 76 (25) |
Shaking after ALTE | 33 (11) |
Fall | 57 (18) |
No confession | 142 (46) |
Repeated shaking (≥2 episodes), n (%) | 172 (53) |
. | Study Population (N = 323) . |
---|---|
Age, median (range), mo | 5.5 (2.5–32.6) |
Term, n (%), wk | |
<32 | 13 (4) |
32–37 | 33 (10) |
>37 | 277 (86) |
Sex, n (%) | |
Girls | 98 (30) |
Boys | 225 (70) |
Status, n (%) | |
Survived | 258 (80) |
Died | 65 (20) |
SDHs, n (%) | 323 (100) |
RHs, n (%) | 279 (88) |
Parenchymal injuries, n (%) | 162 (51) |
Ruptured bridging veins (197 MRIs), n (%) | 158 (80) |
Skull fractures, n (%) | 28 (9) |
Other fractures (excluding skull or corner fractures), n (%) | 35 (11) |
Corner fractures, n (%) | 19 (7) |
Associated extracranial injuries (RHs, skin, mucosa, fractures, etc), n (%) | 300 (93) |
Previous traumatic injuries noticed by the caregiver (child not referred to a doctor or other health professional at the time), n (%) | 64 (20) |
Previous traumatic injuries noticed by a medical doctor, n (%) | 39 (12) |
Judicial confessions, n (%) | |
Full confessions | 76 (25) |
Shaking after ALTE | 33 (11) |
Fall | 57 (18) |
No confession | 142 (46) |
Repeated shaking (≥2 episodes), n (%) | 172 (53) |
Missing data (n): parenchymal injuries (4), RHs (6), corner fractures (36), previous traumatic injuries noticed by the caregiver (2), and confessions (15).
Although there was a predominance of boys (225 of 323, 70%, sex ratio: 2.3), there was no difference in the death rate between boys and girls (n = 65; 20% vs 19%).
All children had SDHs (Table 1). Ruptured bridging veins were observed in 158 of 197 (80%) children with an available brain MRI. RHs were present in 279 (88%) children. Parenchymal injuries were found in 162 children (51%): 55 of 61 (90%) children who died versus 107 of 258 (41%) children who survived, a statistically significant difference (P < .0001).
Previous traumatic injuries were found in 32% (103 of 321) of children.
Shaking was repeated in 172 of 323 (53%) children, meaning that these children suffered ≥2 shaking events.
Full confessions (ie, admission by the perpetrator of a clear causal relationship between the violence inflicted and the child’s symptoms) were available in 25% of AHT cases. In the other cases (75%), the confessions were either nonexistent or inconsistent (history of shaking after an ALTE or history of a fall, most often from a sofa or bed and sometimes on stairs or from the caretaker’s arms).
All those who clearly admitted to being the perpetrator described the causal mechanism as violent shaking followed, or not, by an impact. And all reported an immediate change in the child’s behavior and/or appearance (loss of consciousness, loss of muscle tone, and pallor) and that the child stopped crying during or after shaking.
There was no significant difference (P = .14) in the number of full confessions between the deceased group (n = 20 of 63; 32%) and the survivors (n = 56 of 245; 23%).
Child Care Arrangements and Caretaker Category
Usual Child Care Arrangement (N = 323, 1 Missing Data)
The usual child care arrangement was a day care center in 5 cases (1.5%) of AHT (Table 2). Four of the 5 children for whom the usual child care arrangement was a day care center were not in their usual caretaking arrangement at the time of injury.
Location of the Child and Caretaking Arrangement at the Time of Behavior Change
. | Study Population (N = 323) . |
---|---|
Location of child at time of behavior change, n (%) | |
Day care center | 1 (0.3) |
Private home | 317 (98.5) |
Other location | 4 (1.2) |
Caretaker at time of injury, n (%) | |
Nanny only | 163 (51) |
Father only | 86 (27) |
Mother only | 34 (11) |
Stepfather only | 10 (3) |
Other family member (grandmother, aunt, or adult brother) only | 3 (1) |
2 people at home | 22 (7) |
Day care center professional | 1 (<1) |
. | Study Population (N = 323) . |
---|---|
Location of child at time of behavior change, n (%) | |
Day care center | 1 (0.3) |
Private home | 317 (98.5) |
Other location | 4 (1.2) |
Caretaker at time of injury, n (%) | |
Nanny only | 163 (51) |
Father only | 86 (27) |
Mother only | 34 (11) |
Stepfather only | 10 (3) |
Other family member (grandmother, aunt, or adult brother) only | 3 (1) |
2 people at home | 22 (7) |
Day care center professional | 1 (<1) |
Missing data (n): location (1) and caregiving (4).
The observed ratio (5 of 322; 1.5% [0.2–2.9]) was significantly lower than expected on the basis of the rate in the general population (19.5%) (1.5% vs 19.5%; P < .001). For all other children, the usual child care arrangement was an in-home day care, meaning a single adult in charge of ≥1 child (317 of 322; 98.5%).
Location of the Child at the Time of the Last Injury (N = 323)
Only a single child was injured while in a day care center. The perpetrator was a nurse who admitted in court to losing her temper and shaking the crying child when she was alone with him. That child died.
In 317 AHT cases (98.5%), the assault occurred in a private home. Among the 5 remaining cases, the following was noted: in 1 case, these data were missing; in 2 cases, the shaking occurred in the pool house of a community swimming pool; in 1 case, the shaking occurred in the street; and in 1 case, the shaking occurred at the hospital. In the last case, the suspected perpetrator was the child’s father, who was alone in the room with his son at night.
Caretaker at the Time of Injury
In 93% (n = 297) of AHT cases, the caretaker was alone in a room with the child at the time of injury (Tables 2 and 3). In the remaining 7% (n = 22), 2 caretakers were at home, and it was impossible to determine if the child was alone with one of them or not. The adult pairs were either both parents, the child’s stepfather and mother, the child’s mother and grandmother, or the nanny and her husband.
Distribution of Injury Types and Judicial Confessions by Caretaker Category
. | Nanny Only (n = 163), n (%) . | Father Only (n = 86), n (%) . | Mother Only (n = 34), n (%) . | Other (n = 36), n (%) . | P . |
---|---|---|---|---|---|
Dieda | 29 (18) | 19 (22) | 10 (29) | 7 (11) | .47 |
RHsa | 148 (92) | 69 (82) | 31 (91) | 30 (88) | .15 |
Parenchymal injuries | 74 (46) | 51 (59) | 19 (58) | 18 (50) | .2 |
Ruptured bridging veins (n = 197) | 84 (82) | 41 (82) | 17 (85) | 15 (68) | .46 |
Skull fractures | 7 (4) | 10 (12) | 8 (24) | 2 (6) | <.0001 |
Other fractures | 17 (10) | 11 (13) | 3 (9) | 4 (11) | .93 |
Corner fractures | 4 (3) | 11 (15) | 2 (8) | 2 (7) | .01 |
Confessions | .0001 | ||||
Full confession | 26 (17) | 27 (32) | 17 (50) | 6 (18) | |
Shaking after ALTE | 18 (12) | 9 (11) | 4 (12) | 2 (6) | |
Fall | 22 (14) | 19 (22) | 8 (23) | 8 (23) | |
No confession | 89 (57) | 30 (35) | 5 (15) | 18 (53) |
. | Nanny Only (n = 163), n (%) . | Father Only (n = 86), n (%) . | Mother Only (n = 34), n (%) . | Other (n = 36), n (%) . | P . |
---|---|---|---|---|---|
Dieda | 29 (18) | 19 (22) | 10 (29) | 7 (11) | .47 |
RHsa | 148 (92) | 69 (82) | 31 (91) | 30 (88) | .15 |
Parenchymal injuries | 74 (46) | 51 (59) | 19 (58) | 18 (50) | .2 |
Ruptured bridging veins (n = 197) | 84 (82) | 41 (82) | 17 (85) | 15 (68) | .46 |
Skull fractures | 7 (4) | 10 (12) | 8 (24) | 2 (6) | <.0001 |
Other fractures | 17 (10) | 11 (13) | 3 (9) | 4 (11) | .93 |
Corner fractures | 4 (3) | 11 (15) | 2 (8) | 2 (7) | .01 |
Confessions | .0001 | ||||
Full confession | 26 (17) | 27 (32) | 17 (50) | 6 (18) | |
Shaking after ALTE | 18 (12) | 9 (11) | 4 (12) | 2 (6) | |
Fall | 22 (14) | 19 (22) | 8 (23) | 8 (23) | |
No confession | 89 (57) | 30 (35) | 5 (15) | 18 (53) |
Missing data (n): died (4), RHs (10), parenchymal injuries (8), ruptured bridging veins (3), skull fractures (4), other fractures (4), corner fractures (40), and confessions (15).
It is worth noting that 3 of the suspected perpetrators (1 father and 2 nannies) were responsible for causing AHT in 2 different infants at different times. This included one pair of twins.
Full confessions (n = 76) came more frequently from fathers (27; 36%) than from nannies (26; 34%) or mothers (17; 22%). The 6 remaining confessions (8%) came from 4 stepfathers, one day care worker, and one 17-year-old brother.
There was no difference in the frequency of admission of repeated shaking according to perpetrator type (ie, nanny, father, mother, or other).
Skull fractures were more frequently observed with mother perpetrators. Corner fractures were more frequently observed with father perpetrators. Parents were more likely to give a confession than were nannies.
Discussion
AHT warrants particular attention in terms of early diagnosis and prevention. It is a hotly debated subject, however, because none of the signs are specific in and of themselves, and alternative diagnoses are often proposed, particularly by the defense team in court.13,14 Intracranial injuries can occur in any kind of child care situation and any setting, indoors or outdoors. Our aim for this study was to investigate whether AHT occurs more or less frequently in collective day care settings (ie, day care centers) than in private homes. Recent decisions to confine populations at home during pandemics set the framework for the importance and potential implications of this work.
To answer this question, we closely examined a cohort of cases involving AHT coming from the courts for which we had access to both the medical data and the legal records. In France, the judges appoint public experts to inform them. Public experts have no conflict of interest because, by law, they are independent of all parties, and the judges independently choose one or more of them from a public list.15
Our study population showed the classic demographics for AHT (a predominance of boys, young age, a high mortality rate, and a high percentage of repeated physical violence [at least half of the cases]), as reported in previously published studies.10,12,13
The most striking result is that only 1 case of AHT occurred at a day care center while the caretaker was alone with the infant for a few minutes. Almost all (98.5%) of the hundreds of other AHT cases occurred in private homes. Only 4 AHT cases occurred in other settings: 2 in pool houses (out of the water), 1 in the street, and 1 in a hospital room while the caretaker was alone with the infant. This is a key point to remember when AHT-type signs are attributed to other causes. If unrecognized diseases or routine falls were the cause of such signs, why would they almost always occur in private homes?
One might argue that this is due to selection bias and circular reasoning because the initial reporting by doctors may have only concerned cases occurring in private homes. It is also important to note that in this series, day care centers were rarely the usual child care arrangement; only 1.5% of the children with AHT were placed in day care centers, significantly different (P < .001) than the expected rate in France (19.5%).16 Looking more closely, however, we see that selection bias cannot be the reason because a doctor’s decision to report a case to the authorities is totally independent of the child care arrangement (because the latter is not a diagnostic criterion for suspected AHT). Day care centers likely play a protective role against AHT because they offer parents a respite and are staffed by early childhood professionals.
Although caretaker characteristics were not the primary focus of the study, the results of this series reveal that if we only consider infants aged >2.5 months (ie, those eligible for placement in any sort of nonfamilial day care), nannies represent the largest percentage of confirmed and/or suspected perpetrators. The results also reveal that a large percentage of the confirmed and/or suspected perpetrators are men, as already reported in a number of studies.10,11,17,18 The percentage of full perpetrator confessions in this series was similar to that found in previous reports, and as this study reveals, parents (both fathers and mothers) are more likely to admit to having shaken their infants than are other categories of caretakers.10,12,19
The results of this series also reveal some interesting medical features. First, although SDHs and RHs were common, they were not universal. In fact, the frequency of those 2 findings may be the result of recruitment bias because their presence likely influenced the pediatricians’ decision to report cases of AHT to the prosecutor. Second, ruptured bridging veins on MRI, a sign that is increasingly recognized because of technical advances, were also confirmed in our series as an excellent marker of AHT.14,20,21 More than half of our patients exhibited other concurrent injuries and 20% exhibited previous injuries, which raises the issue of missed opportunities for diagnosis.22,23
The main limitation of this study is its retrospective design, which is typical in child abuse research. We attempted to compensate for this limitation by including cases from a wide variety of courts throughout France. A second concern is that determining the time of injury is not an exact science. We used all available medical and legal data to determine when each child’s behavior changed, given reports of children becoming exhausted and losing consciousness immediately after being shaken.12,24,25 However, caution is required here because if the child was put to bed after the shaking episode, it may have taken the caretaker several hours to recognize the symptoms and call for medical help.12,24,25
Conclusions
The fact that AHT is an unusual occurrence in day care centers could help social service agencies make appropriate decisions in terms of prevention. Recent government policies regarding stay-at-home orders during a pandemic have given this issue new urgency and relevance.
FUNDING: No external funding.
- AHT
abusive head trauma
- ALTE
apparent life-threatening event
- RH
retinal hemorrhage
- SDH
subdural hematoma
References
Competing Interests
POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose.
FINANCIAL DISCLOSURE: The authors have indicated they have no financial relationships relevant to this article to disclose.
Comments
Missing information
The authors observed that among 323 AHT cases collected in France over 18 years, only one occurred in a daycare center while 98.5% occurred in private homes. They consider that this evidence shows that unrecognized diseases or routine falls cannot be common causes of AHT-like symptoms: “If unrecognized diseases or routine falls were the cause of [AHT-related] signs, why would they almost always occur in private homes?”
As readers with a background in statistics, we would like to point out that the authors appear to miss two important points that shed doubt on their conclusions. The first is that the relative amount of time spent by babies in collective daycare centers compared to private homes is extremely small. The authors report that 19.5% of babies under 3 attend daycare, but most of these children are above the age when AHT typically occurs. In the more representative age range 3-9 months, only ~8% attend collective daycare centers [INED 2014], and even these only spend a minority of their time there (~1600 hours/year), which means that in fact only about 1.4% of all baby-hours in France are spent in daycare centers. Therefore, we would statistically expect 4 or 5 cases among 323 cases to occur in daycare centers. The difference between the one observed case as opposed to 4 or 5 expected cases could be a non-significant statistical fluctuation (p-value = 0.06), but in fact it is probably better explained by the second important point missed by the authors, which is the number of children who were brought to hospital with AHT-like symptoms (intracranial and retinal bleeding) but were not included in the study population. This happens very often, since the number of police reports each year is as many as 200 per year whereas far fewer cases reach a trial and become subject to the opinion of medical experts such as the authors. The main reason for not reporting cases, or dismissing them, appears to be the presence of multiple witnesses who saw what happened to the child. Any non-abusive event occurring with multiple witnesses (which encompasses nearly everything that happens in daycare centers) was almost certainly not subject to a police report or a prosecution. To avoid this bias, all children who arrived at the hospital with AHT-findings should have been included, not only those selected as true abuse. Only if we knew the true number of excluded cases could we draw proper conclusions about the prevalence of AHT-events in daycare centers and the probability that unrecognized diseases or routine falls could cause them. These arguments absolutely do not mean that all AHT cases are in fact due to diseases or falls, or that true abuse occurs equally in daycare centers and in private homes. However, they clearly show that the very small number of cases from daycare centers in this study fails to prove that unrecognized diseases or routine falls cannot be causes of AHT-findings.
RE: Statistical error invalidating conclusions
The authors observed that among 323 AHT cases collected in France over 18 years, only one occurred in a daycare center while 98.5% occurred private homes. They consider that this evidence shows that unrecognized diseases or routine falls cannot be common causes of AHT-like symptoms: “If unrecognized diseases or routine falls were the cause of [AHT-related] signs, why would they almost always occur in private homes?”
As readers with a background in medical statistics, we would like to point out that the authors appear to miss two important points that shed doubt on their conclusions. The first is that the relative amount of time spent by babies in collective daycare centers compared to private homes is extremely small. The authors report that 19.5% of babies under 3 attend daycare, but most of these children are above the age when AHT typically occurs. In the more representative age range 3-9 months, only ~8% attend collective daycare centers [https://www.ined.fr/fichier/s_rubrique/21857/population.societes.2014.51..., and even these only spend a minority of their time there (~1600 hours/year), which means that in fact only about 1.4% of all baby-hours in France are spent in daycare centers. Therefore, we would statistically expect only 4 or 5 cases among 323 cases to occur in daycare centers.
The difference between the one observed case as opposed to 4 or 5 expected cases could be a non-significant statistical fluctuation (p-value = 0.06), but in fact it is probably better explained by the second important point missed by the authors, which is the number of children who were brought to hospital with AHT-like symptoms (intracranial and retinal bleeding) but were not included in the study population. This happens very often, since the number of police reports each year is as many as 200 per year whereas far fewer cases reach a trial and become subject to the opinion of medical experts such as the authors. The main reason for not reporting cases, or dismissing them, appears to be the presence of multiple witnesses who saw what happened to the child. Any non-abusive event occurring with multiple witnesses (which encompasses nearly everything that happens in daycare centers) was almost certainly not subject to a police report. To avoid this bias, all children who arrived at the hospital with AHT-findings should have been included, not only those selected as true abuse. Only if we knew the true number of excluded cases could we draw proper conclusions about the prevalence of AHT-events in daycare centers and the probability that unrecognized diseases or routine falls could cause them.
These arguments absolutely do not mean that all AHT cases are in fact due to diseases or falls, or that true abuse occurs equally in daycare centers and in private homes. However, they clearly show that the very small number of cases from daycare centers in this study fails to prove that unrecognized diseases or routine falls are not causes of AHT-findings.