De criteria voor KMdF zijn gericht op de conditie van het kind en het gedrag, de handelingen en opvattingen van de ouder(s)/verzorger(s) met betrekking hiertoe. De criteria zijn niet gericht op de intenties, resp. de mentale conditie van ouder(s)/verzorger(s). Deze zijn van belang voor vervolgbeleid, gericht op duurzaam herstel van gezondheid en veiligheid, maar vormen geen onderdeel van de criteria voor KMdF.

De huidige criteria zijn voortgekomen uit gepubliceerde casestudies, en Guidelines en uit eigen ervaring van vertrouwensartsen en kinderartsen; en zijn bedoeld voor de besluitvorming door vertrouwensartsen binnen het multidisciplinair team.

De criteria voor het vaststellen van KMdF zijn in deze richtlijn gebaseerd op het vaststellen of weerleggen van een vermoeden van falsificatie van de (medische) conditie van het kind en het gedrag van de ouder(s) met betrekking hiertoe; zoals bij elke andere vorm van kindermishandeling. Besluitvorming op basis van de criteria gebeurt op basis van zo feitelijk mogelijke informatie uit het onderzoek van de vertrouwensarts (zie module Onderzoek en opstellen van een veiligheidsplan). Bij het onderzoek is het verloop van de medische voorgeschiedenis van het kind(eren) belangrijk en bepalend voor de zorgvuldige weging van de criteria. De besluitvorming heeft tot doel een vermoeden van KMdF vast te stellen of te weerleggen en dit besluit te onderbouwen. Het bevestigen maar ook het weerleggen van een vermoeden van KMdF is van groot belang om (verdere) ernstige schade aan de gezondheid en ontwikkeling van het kind te voorkomen.

Recognition and determination of abuse by PCF

The recognition and determination of Munchausen’s Syndrome by Proxy (MSbP), now known as abuse by PCF is difficult, as no single characteristic or profile of the carer or child is sufficient for confirmation, while also large differences between situations exist (Parrish, 2004; Shaw, 2008; Siegel, 2001). Fabrication of child illness is proven by circumstantial evidence rather than direct evidence (Shaw, 2008). However, there are still several characteristics which are more common in either the carer or the child, although diagnosis rather applies to the carer compared to the child (Parrish, 2004). Likewise, several warning signs and criteria have been reported in order to give guidance for establishing the presence of abuse by PCF.

Characteristics of carer and child

It is known that the carer is usually female, with in large majority of cases the mother of the child (American Professional Society on the Abuse of Children, 2017; Korpershoek, 2004; Shaw, 2008; Siegel, 2001). Likewise, the Royal College of Paediatrics and Child Health (RCPCH) mentions that the mother of the child is nearly always involved, while the father is less often involved (or absent), and when involved, he rarely acts solely (RCPCH, 2021). The non-perpetrating parent is rarely present during the treatments (Parrish, 2004). The carer usually has a coexisting personality disorder, including mostly cluster B disorders, like borderline, sociopathy (American Professional Society on the Abuse of Children (APSAC), 2017; Korpershoek, 2004) or depression (Korpershoek, 2004; Shaw, 2008). Commonly, the carer also has knowledge on or even a background and interest in medical care (Ayoub, 2002; Korpershoek, 2004; Parrish, 2004; Shaw, 2008). The carer is often hypervigilant, insisting on participating in the procedures, with for example bringing medicines from home and not leaving the hospital, and contrary to expectation, the carer’s level of anxiety may actually increase with the child’s medical improvement (Parrish, 2004). Furthermore, the carer often tries to maintain a(n unusual) close relationship with the medical staff (Siegel, 2001; Parrish, 2004).

Several other possible characteristics of the carer include family histories with psychological disorders or sudden childhood deaths, difficult relations with the spouses, reporting of dramatic/unrealistic events, describing experience with rare medical conditions in the past, similar to the current condition of the child, and reporting prior medical records which could confirm or preclude diagnostic impressions either as missing or somehow unavailable. The carer may become defensive or hostile if the information s/he provides is questioned or proven inaccurate. With respect to the relationship with the child, the carer demonstrates either an absence of responsibility or expression of concern for the child, welcoming even invasive or painful diagnostic or surgical procedures for the child (Ayoub, 2002; Korpershoek 2004; Parrish, 2004; Shaw, 2008), or demonstrates overprotection of and strong attachment to the child (Parrish, 2004; Shaw, 2008; Siegel, 2001).

Korpershoek (2004) mentions that Libow and Schreier (1986) developed a classification system by which the carers (phrased as ‘perpetrators’ in the review) can be divided into three categories: active inducers, help seekers and doctor addicts. The first group actively induces illness by poisoning, suffocating or else. The carer is seen as trustworthy and cooperative, although they may respond with denial and anger if confronted with their behavior. Often, they tend to not show up for an intervention. A common characteristic is a disturbed marital status. Siegel (2001) reports this type of abuse as ‘extreme PCF’. Help seekers differ from active inducers in terms of less severe and less frequent symptoms; they present with fictious child illness. The motivation of help seekers is seen as driven by a need to communicate exhaustion, distress, or feelings of inadequacy. They don’t show a strong attachment to the medical system. Doctor addicts are seen as looking for treatment for fictious child illness, with presenting themselves as unable to acknowledge their behavior or motivation when treatments are presented. They are often older, tend to lack insight and often appear as less cooperative and being more suspicious compared to active inducers. Doctor addicts tend to react much more to the child’s medical condition compared to the emotional status. Shaw (2008) mentions only the categories ‘active inducers’ and ‘doctor addicts’ as subgroups. Ayoub (2002) also mentions these subgroups, though not explicitly.

The child is in most cases the biological child of the carer, with a mean age of less than six years (Korpershoek, 2004). There is no overrepresentation of one gender (Korpershoek, 2004; Siegel, 2001). Symptoms in children are mostly related to the gastrointestinal or genitourinary system; fictious psychiatric symptoms are less common (Parrish, 2004). Siegel (2001) also reports mostly symptoms related to the gastrointestinal system, including diarrhea and vomiting, but also bleeding, seizures and fever. Shaw (2008) mentions a much wider range of clinical manifestations, including respiratory, hematologic, and neurological manifestations, as well as allergies and infections. Apnea is also a common presentation form of abuse by PCF (Galvin, 2005; Siegel, 2001). This can mimic an apparent life-threatening event (ALTE) or sudden infant death syndrome (SIDS; Galvin, 2005).

Alerting signs

Several recent reviews and guidelines described lists of alerting signs indicating the possibility of abuse by PCF. Some, like the RCPCH, distinguish between alerting signs concerning the child and its condition and alerting signs regarding the behavior of the carer. Following this distinction, these are all alerting signs combined as mentioned by the APSAC (2017), Glaser (2019), the RCPCH (2021), and Tully (2021):

Alerting signs concerning the child’s condition:

• Symptoms not observed independently in their reported context: Reported symptoms or behaviors that are not congruent with observations. For example, the carer says the child cannot eat, and yet the child is observed eating without the adverse symptoms reported by the abuser.
• Discrepancy between the carer’s reports of the child’s medical history and the medical record.
• Symptoms not corroborated by the child.
• Reported symptoms or observed signs not explained by child’s known medical condition.
• Some characteristics of the child’s illness may be physiologically impossible e.g., persistent negative fluid balance, large blood loss without drop in hemoglobin.
• Physical examination and results of investigations do not explain reported symptoms or signs.
• Unusual results of investigations. Laboratory findings that do not make medical sense, are clinically impossible or implausible, or identify chemicals, medications, or contaminants that should not be present. An example is a serum sodium level that is not clinically within reason.
• Inexplicably poor response to medication or procedures.
• Unexplained worsening of symptoms or new symptoms that correlate with abuser’s visitation or shortly thereafter.
• Symptoms disappear or improve when carer is absent.
• Conditions or illnesses significantly improve or disappear in one child and then appear in another child, such as when another child is born, and the new child begins to have similar or other unexplained symptoms.
• Restriction of child’s daily life, including school attendance, social isolation, and activities that are not justified by any known disorder, possibly including the use of wheelchairs and other aids.
• Repeated or unexplained changes of school (including home schooling), of general practitioner (GP) or of pediatrician/health team.

Alerting signs concerning the carer:

• Carer(s) insistent on more, clinically unwarranted, investigations, referrals, continuation of or new treatments (sometimes based on internet searches) instead of focusing on symptom alleviation when results of examination and investigations have already shown not to explain the reported symptoms or signs.
• Pressing for irreversible or drastic treatment options where the clinical need for this is in doubt or based solely on parental reporting.
• Not able to accept reassurance or recommended management.
• Repeated reporting of new symptoms.
• Frequent presentations of the child to and attendance at medical settings including Emergency Departments.
• Seeking opinions from multiple doctors.
• Insists on referral to "top" experts.
• Carer flatters doctors who comply but angry, threatening and disengages if challenged.
• Frequent vexatious complaints about professionals.
• May become litigious or threaten to report doctor to the medical disciplinary committee.
• One carer is the sole source of information.
• Not letting the child be seen on their own. Talking for the child/child repeatedly referring or deferring to the parent.  
• Another carer is absent.
• Reports that the other carer is not involved, does not want to be involved, and is not reachable.
• Reluctance to provide medical records, claims that past records are not available.
• Refuses permission to medical providers to discuss care or share information about child with previous or concurrently treating medical providers.
• Providing reports by doctors from abroad which conflict with national medical practice.
• Often paradoxically poor compliance with medical advice and multiple failed appointments, often due to cancellations.
• Factual discrepancies in statements that the parent makes to professionals or others about their child’s illness.
• A parent, child, or other family member expresses concern about possible falsification or high-healthcare utilization.
• Observations of clear falsification or induction by the carer. This may take the form of false recounting of past medical recommendations, test or exam results, conditions, or diagnoses.

In addition to the above, APSAC (2017) mentions the following alerting signs, not observed in either the child or the reporting carer:

• Other individuals in the home or the carer have or have had unusual or unexplained illnesses or conditions.
• Animals in the home have unusual or unexplained illnesses or conditions, possibly similar to the child’s presentation (e.g., seizure disorder).

Another specific alerting sign mentioned by Siegel (2001) that needs to be considered, is that abused children can become tolerant for the painful procedures carried out by the carer/parent. Furthermore, older children might even collude with the carer as they cannot distinguish the reality of their symptoms anymore, or they fear abandonment if not ‘helping’ the carer with the fabrication of the symptoms (Siegel, 2001).

A single alerting sign unlikely indicates possible abuse by PCF. It is important to look for other signs and their severity as well (Glaser, 2019; RCPCH, 2021). Alerting signs by themselves do not amount to fabrication but mandate further investigation to establish the actual state of health of the child (RCPCH, 2021; Siegel, 2001). Glaser suggests to initially regard alerting signs as a perplexing presentation instead of indication of abuse by PCF. However, if alerting signs are accompanied by indicators of deception, possible induction of illness by the parent/carer or indicators of other significant harm, a referral to children’s social care is required, according to the safeguarding procedures (Glaser, 2019).

Criteria

As said earlier, alerting signs themselves are no evidence for the presence of abuse by PCF. Criteria for establishing the presence of abuse by PCF have been suggested but are still under debate and the most recent criteria in the Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 (American Psychiatric Association (APA), 2013) are meant to diagnose persons (carers) with “Factitious Disorder Imposed on Another” (FDIA; APA, 2013; in APSAC, 2017; Mart, 2002; Shaw, 2008), not criteria for establishing the presence of abuse of a child by PCF.

Rosenberg (1987) developed the following criteria for abuse by PCF (or rather MSbP), with the need of all of them to be present (in Frye, 2012; Korpershoek, 2004; Mart, 2004; Meadow, 2002; Shaw, 2008):

1. Illness in a child which is simulated (faked) and/or produced by a parent or someone who is in loco parentis.
2. Presentation of the child for medical assessment and care, usually persistently, often resulting in multiple medical procedures.
3. Denial of knowledge by the perpetrator as to etiology of the child’s illness.
4. Acute symptoms and signs of the abate when the child is separated from the perpetrator.

Rosenberg excluded cases of physical abuse only, sexual abuse only, and nonorganic failure to thrive only. Furthermore, Rosenberg rejected the idea that a psychiatric or motivational component should be part of MSbP, stating the difficulty in differentiating between MSbP and intentional poisoning, infanticide, pathological doctor shopping, extreme parental anxiety, or thought disorder, and considering the probability that the underlying psychology overlapped (Mart, 2004; Meadow, 2002).

Mart (2002) mentions that Morley (1995) criticized the criteria as they are subject to misinterpretation. The example given here is that a patient (and carer) might visit a doctor frequently due to inexperience and anxiety or due to actual medical problems. This is supported by Korpershoek (2004), who reports that it is essential to distinguish between a concerned parent, a delusional parent and abuse by PCF. Shaw (2008) reports that abuse by PCF is on the extreme end of parental behavior surrounding illness of child(ren). Simple anxiety, neglection of the child or keeping the child dependent at home are situations in which abuse PCF does not take place (Shaw, 2008). It has been argued that leaving out the motivational component hampers the correct identification of cases and adequate management, including treatment choices for both victim and abuser, and possible legal steps to be taken (Frye, 2012; Korpershoek, 2004; Mart, 2004; Meadow, 2002; Roesler, 2018). Even though the motivation of the carer may be difficult to determine, these authors agree that the use of abuse by PCF/MSBP should be limited to the precise form of abuse in which active deception is involved and the primary motive of emotional gratification can be established (Meadow, 1995, and Rand and Feldman, 1999; in Frye, 2012). Including a motivational component as a fourth criterium and combining Rosenberg’s criteria two and three, Meadow redefined the MSbP criteria (Meadow, 2002):

1. Illness fabricated (faked or induced) by the parent or someone in loco parentis.
2. The child is presented to doctors, usually persistently; the perpetrator (initially) denies causing the child’s illness.
3. The illness goes when the child is separated from the perpetrator.
4. The perpetrator is considered to be acting out of a need to assume the sick role by proxy or as another form of attention seeking behavior.

However, according to the DSM-5 (APA, 2013), specification of a certain type of internal motivation (attention, sick role, or other) is not required to diagnose FDIA, but it must be clear that the psychological needs of the perpetrator have taken precedence over the needs of the victim to pave the way for them to harm their victim in order to have those needs met. DSM-5 criteria for FDIA:

1. Falsification of physical or psychological signs or symptoms, or induction of injury or disease, in another, associated with identified deception.
2. The individual presents another individual (victim) to others as ill, impaired, or injured.
3. The deceptive behavior is evident even in the absence of obvious external rewards.
4. The behavior is not better explained by another mental disorder, such as delusional disorder or another psychotic disorder.

While disregarding the motivational component, the DSM-5 did increase the emphasis on deception (which is conscious, carefully planned and concealed) as the cornerstone of the disorder and subsequently, a need to identify deception as part of the FDIA evaluation process (APSAC, 2017).

Rosenberg (2003; in Shaw, 2008) labels four possible categories of criteria to establish abuse by PCF, depending on the level of confidence in the diagnosis/determination of abuse by PCF. When inclusion diagnostic criteria are met, there is undeniable evidence of abuse by PCF, such as a videotape of an act in the hospital, or clear proof of a change of laboratory specimens. With exclusion diagnostic criteria met, abuse by PCF is established because all other explanations of the child’s condition have been considered and set as not possible. When there are possible diagnostic criteria present, this means that PCF is one of multiple diagnoses that could explain the symptoms of the child. Further diagnostic processes are required in this case. Lastly, inconclusive diagnostic criteria indicate the inability to either eliminate or establish abuse by PCF, even though all possible investigations and tests have been performed (Shaw, 2008).

Glaser proposes to revise the current procedures in order to recognize a wider range of cases as PP or fabricated or induced illness (FII). Glaser suggests that the following criteria (adapted from the International Classification of Disease, Eleventh Revision (ICD-11)) could be used to redefine the characteristics of PP/FII. These criteria were proposed for ‘bodily distress disorder’ to replace somatoform disorders. The overall intention is that these would be mostly pediatric criteria focused on the presented illness in the child and not a label to refer to the carer:

• Presence of child symptoms that are distressing to the carer.
• The carer’s response to the symptoms appears excessive and disproportionate in relation to the nature, impact and progression of the child’s symptoms or any confirmed physical illness in the child.
• Excessive carer attention is focused on these symptoms, manifested by repeated contact with doctors, including tests and treatments that may be unnecessary and harmful to the child.
• The carers’ excessive responses to the child’s symptoms are not alleviated by appropriate examination of the child, reassurance, tests or treatments where needed (however, tests and treatments should not usually be carried out purely to provide reassurance to the carer).
• The child’s symptoms (whether reported by the carer or observed due to induced illness) are persistent or relapsing and remitting, and lead to significant functional impairment. There is a risk of harm caused either directly by the carer or indirectly by the doctor.
• The symptoms may be multiple and may vary over time. On the resolution of one symptom another may appear. Different children in the same family may be presented at different times.
• There may or may not be evidence of the carer causing or creating the child’s illness through apparently deliberate action (if present this would always require statutory intervention).
• The child may continue to exhibit emotional and physical consequences of the condition even after separation from the carer.

Process of assessing possible abuse by PCF

The process establishing abuse by PCF (after suspicion) has been described by several papers. The RCPCH (2021) focusses specifically on the precursing PP and reports that the essence of management is to establish the child’s current physical and psychological health as quickly as possible, as well as the family context. Glaser (2019) adds to this that also all involvement with health services needs to be determined. Several steps need to be taken by the pediatric consultant after suspicion of PP (RCPCH, 2021):

• Obtain the medical history of the child, including from other consultants, general practitioners, with a request for clarification of what wat has been reported and observed.
• Ascertain who has given the reported diagnoses and on what basis they have been made.
• Consider admission of the child for direct observations, including the child’s input and output where relevant (stool, feeding, administration of medication, pain level, sleep et cetera).
• Determine whether further referrals and/or investigations by others specialist are needed.
• Obtain information from the child’s state and activity, including school attendance, emotional and behavioral state, mobility, and any use of aids. It is preferred to explain the parents the need for obtaining this information.

With respect to the parents, the RCPCH (2021) mentions that the pediatric consultant should obtain history and observations form all caregivers of the child, including the parents as well as others who had an important caregiving role. Their views (fears, hopes et cetera) for their child’s health, as well as sources of support should be explored. Significant history surrounding the birth of the child should be verified from the relevant clinician (if applicable). Also, the wellbeing of potential siblings should be ascertained. The pediatric consultant should determine whether early help services or children’s social care is already involved or has been in the past. These professionals should then be involved in the discussion around the health concerns. Lastly, it should be explored whether early help and/or referral to children’s social care (by means of a Child in Need basis) is needed (RCPCH, 2021).

The RCPCH (2021) also mentions that, with respect to the child, the pediatric consultant should explore the views of the child with the child alone (RCPCH, 2021). This may be done using specific tools, including feelings posters and top tips for doctors, developed by the RCPCH in order to let children express their feelings more easily. The views on symptoms, but also the belief of the child about the nature of the illness as well as worries, wishes and the overall mood can be determined independently from the parents in these consultations. Differences in communication (verbal and non-verbal) between consultants with or without the parent can be observed (RCPCH, 2021).

According the RCPCH (2021), consensus about the child’s health status needs to be reached by all health professionals that are involved with the child and his/her family, after the medical and psychosocial review. This also includes professionals who have observations about the child in educational and children’s social care setting, if applicable. The consensus meeting should be chaired by a doctor or clinician with no direct involvement to preserve objectivity. The parents need to be informed about the meeting and they should receive the conclusions of the meeting. Besides, they should be able to discuss these conclusions and contribute to the next steps (RCPCH, 2021).

The APSAC (2017) has a largely comparable recommendation, but specifically points out to regularly communicate with the caregivers about findings and recommendations. Furthermore, they mention that all history of symptoms or disability reported by the family of the child should be considered as possibly inaccurate (APSAC, 2017). Caution is also needed with respect to medical investigations, as the child’s family cannot be relied upon in preparation of these investigations. The APSAC (2017) mentions a toxicology screen before manometry as an example, to test for ingestion of gut-altering compounds.

Furthermore, the APSAC (2017) mentions that video surveillance of hospitalized children could support and act as evidence for diagnosis. This has also been mentioned by Shaw (2008) and Siegel (2001), although they also report that this type of surveillance might be unethical. The more recent guideline of the RCPCH (2021) mentions that covert video surveillance is now rarely used in the United Kingdom (UK). In contrast, Abeln (2018) mentions that audio and video surveillance are commonly used in the United States of America (USA).

According to Siegel (2001), hospitalization in general as part of the diagnosis is an option for diagnostic separation, by which the child is temporarily placed in foster care. This ‘separation test’ was proposed by Jones (1986; in Pankratz, 2010). He stated that the test would be essential in order to check for the fourth criterium of Rosenberg (disappearance of symptoms in the child after separation from the carer). However, the test is disputed.

Problems with assessing possible abuse by PCF

The alerting signs and defining criteria for abuse by PCF are still evolving, but tests for specificity and sensitivity have not been carried out in a prospective way. Glaser (2019) mentions that epidemiological studies are urgently needed to understand the recognition of abuse by PCF. Mart (2002), Rogers (2004), Shaw (2008) and Pankratz (2010) warn that the symptoms and characteristics are so nonspecific that the amount of ‘false positives’ is likely to be quite high. Rogers (2004) also stresses that it is a research priority to establish the symptoms and other characteristics that reliably differentiate FDIA (or abuse by PCF) from other disorders. A prototypical analysis in which experts are asked to quantify the salience and representativeness of different criteria in relationship to FDIA/abuse by PCF is suggested as a useful method to identify the core symptoms of FDIA/abuse by PCF that differentiate it from (a) other forms of child abuse, (b) other types of dysfunctional parents, and (c) other genuine conditions that imitate FDIA (Rogers, 2004). 

Apart from the difficulty that abuse by PCF cannot be established easily by means of large heterogeneity in situations and characteristics and lack of scientific support for defining criteria, several other practical problems are present. One problem is that many professionals only see a few cases throughout their career, which limits learning and understanding the syndrome (Siegel, 2001). Furthermore, doctors and other people involved can be susceptible to the carers. It might be hard for them to believe that a parent would fabricate or induce illness in their own child, but also because of the difficulty in accepting their own inability to solve their patient’s disorder (Shaw, 2008; Siegel, 2001). Besides, they are trained to trust the histories given by their patients (Shaw, 2008; Siegel, 2001). On the other hand, the label of abuse by PCF might also be used too early when no other satisfactory medical explanation of the condition is found. Mart (2002) warns that alerting signs are not supported by evidence and are often confused and treated by doctors as diagnostic signs instead of as an indication for further thorough investigation. An extra problem is that establishing abuse by PCF usually requires agreement and collaboration of multiple physicians and other specialists, and the involvement of multiple facilities (Siegel, 2001). This all results in a time-consuming process of up to a year or even longer (Korpershoek, 2004; Siegel, 2001). In addition, the medical staff often experiences extreme stress due to high emotional situations, difficult interactions, and disagreements with patients’ carers or even with colleagues (Siegel, 2001). Still, cooperation of the health care, protective services and legal systems is crucial with respect to diagnosis and treatment of PCF (Shaw, 2008; Siegel, 2001).

That methods to gather “hard evidence” of abuse by PCF, such as the separation test, have been criticized for being unethical poses another problem. According to Pankratz (2010), the separation test is problematic as children must be removed from their carers (as check for the fourth criterium) before abuse by PCF is actually established. Pankratz (2010) says that it is important that the medical work-up should be finished before accusing a carer of child abuse. Moreover, she says the test is “seldom used to evaluate alternative hypotheses”, often leads to false accusations, and is “often nothing more than seriously contaminated evidence that should have no standing in court.” According to Pankratz, the test has been misused in many cases in a way that makes the mother appear not worthy to regain custody of the child while the goal should be to protect children and not to punish parents. To protect the parent-child relationship and to obtain unbiased information, she, just as the RCPCH and APSAC, stresses the importance of the involvement of a multidisciplinary team in the assessment of possible abuse by PCF “to provide independent perspectives from the viewpoint of different professional domains” as well as the early involvement of patient and carers, informing them and express concerns instead of working ‘secretly’ (Pankratz, 2010).

Lastly, no specific screening tools for abuse by PCF have been mentioned in literature, although there are still some screening tools for child abuse in general. A review by McTavish (2020) investigated to what extent child abuse was falsely suspected or missed by two different screening tools, including the SPUTOVAMO (Soort letsel, Plaats, Uiterlijke kenmerken, Tijd, Oorzaak, Veroorzaker, Andere aanwezigen, Maatregelen genomen en Oude letsels) checklist and the Escape instrument. McTavish concludes, although with low certainty evidence, that both screening tools result in a high number of cases in which child abuse is falsely suspected as well as a high number of cases of child abuse being missed.

In conclusion, the literature stresses the importance of awareness of the possibility of abuse by PCF, including it in the differential diagnosis when noticing alerting signs, and when suspected, the necessity of rigorous investigation, including information from all angles, medical files and input from all relevant parties involved. However, the literature also reveals that although many alerting signals have been presented by multiple authors, definite criteria for the determination of abuse by PCF are still under debate and evidence for these criteria is missing. Furthermore, reliable screening tools or conclusive diagnostic tests to aid in the investigation process are not yet available.

The databases Medline (via OVID) and Embase (via Embase.com) were searched with relevant search terms from the year 2000 until May 24th, 2022. The detailed search strategy is depicted under the tab Methods. This broad literature search resulted in 659 unique hits. Studies already found in the orientational literature search for module Definities in de literatuur were subtracted resulting in 523 new unique hits. Studies were selected based on the following criteria:

• They should be published since the year 2000 until May 24th, 2022.
• Be in line with our research questions pertaining to the modules about signs and symptoms (recognition of abuse by pediatric condition falsification, PCF) and criteria (determination of the presence of abuse by PCF) of this guideline, primarily module Signalen en symptomen – herkennen van KMdF and module Criteria voor het vaststellen van KMdF (current module).
• And add to the relevant information found in the previous literature search for module Definities in de literatuur.

A total of 7 publications were selected based on title and abstract screening. After reading the full text, 3 were selected and 4 were excluded (see the table with reasons for exclusion under the tab Methods). After scanning the reference lists of the included publications, 1 additional publication was added (McTavish, et al. 2020). In the end, 4 publications adding to the previous search were included.