II. Definitions
- Child Abuse (Child Maltreatment, U.S. Health and human services definition)
- Recent act or failure to act on part of parent or caretaker
- Results in death, serious physical or emotional harm, sexual abuse or exploitation or
- Imminent risk of serious harm
- Nonaccidental Trauma
- Any non-accidental physical injury (e.g. biting, hitting, kicking burning) or
- A non-accidental action that results in a physical Impairment of a child
- Neglect
- Parental omissions in care that results in actual or potential harm to a child
- Child's basic physical, emotional, educational or medical needs are not met in a consistent pattern
III. Epidemiology
- Third leading U.S. cause of death age 1 to 4 years old in 2009
- Annual U.S. Incidence estimated at 3.5 deaths per 100,000 children age <4 years
-
Incidence: 4 to 6 million alleged maltreatment cases referred to U.S. child protection per year
- Evidence of maltreatment found in 9 of 1000 children (0.9%) after investigation
- Demographics of Child Abuse (based on 1995 data, National Child Abuse and Neglect Data Systems)
- Offenders
- Parents: 80% of cases
- Caretakers at daycare, or nursery school: 2%
- Abuse is rarely a single event, but rather one of repeated and increasing Violence
- Perpetrators cross all socioeconomic , ethnic, racial, gender and setting boundaries
- Types of abuse
- Neglect: 52%
- Physical abuse: 25%
- Ages of abused children
- Most abused children are under age 6 months
- Age 7 years old or younger: 50%
- Offenders
IV. Types: Abuse
- Neglect
- Most common form of Child Maltreatment, and accounts for 73% of child fatalities
- Physical neglect includes inadequate hygiene, nutrition, shelter and clothing
- Includes environmental hazard exposure (e.g. ingestions)
- Includes inadequate supervision (e.g. abandonment, expulsion)
- Includes malnourishment or Failure to Thrive (also impacted by poverty, food insecurity)
- Medical neglect is refusing or delaying appropriate medical care
- Includes presentations with advanced medical or dental disease (also with low health literacy)
- Emotional neglect is inadequate nurturing or affection
- Includes exposure to Violence (e.g. Intimate Partner Violence)
- Includes permission to abuse Alcohol or drugs
- Includes delayed mental health care
- Physical abuse (Nonaccidental Trauma)
- Any non-accidental physical injury (e.g. biting, hitting, kicking burning) or
- A non-accidental action that results in a physical Impairment of a child
- Psychological Maltreatment or Emotional Abuse
- Repeated patterns of Caregiver behavior or extreme incidents
- Children interpret that they are worthless, unloved, unwanted or flawed
- Sexual Abuse
V. Precautions
- Child Abuse is a commonly missed diagnosis with potentially devestating consequences
- Initially missed abusive Head Injury: 30% of cases
- Initially missed abusive Fractures: 20% of cases
- Identify Child Abuse early, when it is still associated with minor injury
- Consider every injury and illness in a child in the context of the reported history, mechanism and developmental stage
- Persistent Vomiting without Diarrhea despite >1-3 days of illness (consider Head Injury)
- Falls in under age 3 years old (and especially under age 6 months) should be considered carefully
- Consider Consultation with a Child Abuse expert if a presentation raises a red flag
- Cardiac Arrest in young children (or BRUE)
VI. Pathophysiology
- Negative Parenting Behaviors are at risk of progressing to abuse
- Emotional abuse is a precursor to physical abuse
- Child Maltreatment may significantly impact physical, neurologic and intellectual development
VII. Risk Factors
- Child
- Chronic illness
- Behavioral Disorder
- Physical Disability
- Preterm Infant
- Unplanned Pregnancy
-
Caregiver
- Alcohol or Substance Abuse
- Victim of abuse (e.g. Intimate Partner Violence)
- Mental Illness (e.g. Major Depression)
- Criminal History
- Young parental age
- Low self esteem
- Low educational level
- Poverty
- Poor impulse control
- Single parent home
- Non-biologically related adult living in the same home
VIII. History: Questions
- History of event or injury
- Ask a careful history and document specific details
- What happened?
- Where were you and the child when this happened?
- Who else was there?
- When did this happen?
- What made you concerned?
- Why did you not come in sooner?
- Last known well time of the child?
- How did the child appear before and after event?
- What was the child wearing at the time of the injury?
- What objects were around the child when injured?
- Ask the patient (if old enough) what happened without parents present in the room
- Abusive parents may blame an older sibling or family dog for the injury
- Avoid asking leading questions that supply the potential abuser with an excuse
- Record the history with specific quotes from children and parents or Caregivers
- Ask a careful history and document specific details
- Perform a Trauma-informed history of the child
- Stay seated for the interview
- Discuss confidentiality, trust, safety
- Ask open-ended questions in a nonjudgemental manner
- Explain why sensitive questions (e.g. sex) are asked
- Medical History
- Maternal pregnancy, perinatal and birth history
- Prior injuries or Trauma
- Congenital disorders or hospitalizations
- Developmental history (milestones met?)
-
Family History
- Bleeding Disorders
- Bone disorders (e.g. osteogenesis imperfecta)
- Genetic disorders
- Social history
- Discipline techniques
- Child fussiness or hyperactivity
- Abuse history in child, siblings or parent (Domestic Violence)
- Substance Abuse by others in the same home
- Financial or social stressors
- Violent Behavior in the home
- Criminal history of others in home
- Mental health problems of family members
IX. History: Red Flags
X. Screening: Tools
-
SPUTOVAMO-R2 Checklist
- Any positive answer of 5 questions suggests higher suspicion injury
- History consistent with injury, interaction appropriate, parents responded with appropriate measures without delay
-
Pediatric Hurt Insult Threaten Scream Sex Questionnaire (PedHITSS)
- Evaluates for abuse exposure
XI. Symptoms: Behavior Indicators of Abuse
- Wary of adult contact
- Brief Resolved Unexplained Event (ALTE, BRUE)
- Apprehensive when others cry
- Concerned that the crying is their fault
- Fear that punishment is occurring and they are next
- Behavior extremes
- Introverted, isolated, and social withdrawal
- Out of control anger, aggressive, violent or oppositional
- Unconsolable Crying or Fussy Infant (broad differential)
- Unexplained Developmental Delay
- Speech Delay
- Motor skill delay
- Comorbidity
- Emotional Abuse Indicators
- Speech disorders such as Stuttering or slurred speech
- Delayed Physical growth
- Failure to Thrive
XII. Exam: Approach
- Perform exam with a chaperone present
- Documentation of exam
- Obtain consent if possible (optional)
- Photograph all injuries in color
- Use a ruler in the photograph to document size
- Take two or more pictures (e.g. AP and lateral) each from three different orientations
- Full body
- Medium range
- Close-up
- Photograph injuries before treatment
- Repeat photographs hours or days later
- Patient's face should be included in 1 or more photos
- Label each photo with name, date, date of injury
- Also record photographer and those present at exam
- Seal photos in envelope marked confidential
- Maintain chain of custody
- Background color
- Photograph skin against a blue background
- Photograph other areas against a neutral background
- Consider ultraviolet light
- Accentuates bite wounds
- Avoid interfering with formal evidence exam when indicated
- Sexual Assualt Nurse Examiner (SANE) exam
- Child Abuse specialist
XIII. Exam: Key Regions
- See Child Sexual Abuse
- Perform a head to toe exam with the patient in a gown
- Height, weight and Head Circumference
- Alertness
- Decreased Glasgow Coma Scale requires immediate evaluation for serious Head Injury
- Scalp exam
- Traction Alopecia
- Bulging Fontanelle
- Ear exam
- Bruising or hemotympanum
-
Mouth Exam
- Dental Caries may suggest neglect
- Oral Lesion such as torn frenulum, chipped teeth or mucosal lesion (e.g. forced feeding in a Fussy Infant)
- Mandible injury associated with grabbing the face or holding the child down
- Fundoscopic exam (typically performed by ophthalmology with images obtained)
- Retinal Hemorrhages
- Specific for abusive Head Injury
- Not associated with CPR or accidental injury (except possibly at posterior pole)
- Retinal Hemorrhages
- Palpate for tenderness or deformity
- Scalp, neck, and torso
- Extremities
-
Neurologic Exam
- Assess for Closed Head Injury and Spinal Cord Injury
- Assess for Altered Level of Consciousness (e.g. Abusive Head Trauma of Infancy)
- Skin exam
- Bruising or marks
XIV. Signs: Physical Abuse Indicators
- Most common sentinel injuries in pre-mobile infants
- Bruising (50% of cases will be found concerning for abuse)
- Oral injuries (esp. frenulum injury)
- Subconjunctival Hemorrhage
- Traumatic in nearly all causes (contrast with spontaneous in adults)
- Predicts concurrent Bruising (27%), Fractures (up to 46%), Intracranial Hemorrhage (up to 15%)
- Lesions show unusual distribution, location, pattern
- Red Flag presentations
- Significant delay in seeking care
- Story inconsistent with the injury
- Infants under 3-4 months of age should not be able to "roll off the bed"
- Bruising in infants <6 months old or to Abdomen, ear, neck or in an organized pattern
- See TEN-4 Rule below
- Atypical Fractures as listed below
- Oropharyngeal injury in non-mobile infant (e.g. something shoved in mouth to pacify a Crying Infant)
- Torn Tongue frenulum injury
- Chipped teeth in a non-mobile infant
- Oral Mucosal injury
- Significant Closed Head Injury
- Red Flag Fractures
- Fractures in various stages of healing
- Scapula Fracture
- Sternum Fracture
- Spinous process Fracture or Vertebral body Fracture
- Rib Fractures (especially posterior Rib Fractures)
- Rib Fractures under age 3 years, 82% are Child Abuse
- Posterior Rib Fractures occur with anterior-posterior chest compression (squeezing of chest)
- Barsness (2003) J Trauma 54(6): 1107-10 [PubMed]
- Metaphyseal avulsion Fractures (Bucket-Handle Fracture, metaphyseal Corner or chip Fracture)
- Long bone Fractures in Children age <2 years (especially non-ambulatory infant)
- Exception: MVA or other serious witnessed injury
- Long bone Fractures in infants are associated with a 20% Incidence of Child Abuse
- Bilateral long bone Fractures are higher risk for abuse
- Femur Fractures
- Femur Fractures under age 12 months are associated with abuse in 33% of cases
- Femur Fractures over age 12-18 months are associated with abuse in 1.5 to 6.0% of cases
- Metaphyseal Fractures are associated with abuse in 50-75% of cases
- Wood (2004) BMC Pediatr 14:169 [PubMed]
- Red Flag Bruising or Marks
XV. Signs: Injury Locations
XVI. Signs: Injury Types
- Welts
- Lacerations
- Burns
- Consider burn specialist Consultation to discuss burn pattern and circumstances
- Take pictures of Burn Injury
-
Fractures
- See Red Flag injuries listed above
- Spiral Fractures may not be as pathognomonic for Child Abuse as previously thought
- Toddler's Fracture of the tibia are spiral and seen in typical Trauma
- Consider repeat xrays in 10-14 days after suspected injury if initial xrays are non-diagnostic
- Fractures (aside from Skull Fractures) heal at predictable times and offer forensic evidence
- Acute Fractures evident within 4 days of injury
- Subperiosteal new bone forms by days 5 to 14
- Callus forms by days 10 to 14
- Red Flags (see above)
- Complex Skull Fractures
- Scapula or Sternum Fractures
- Rib Fractures (esp. posterior Fractures)
- Spinous process Fractures
- Metaphyseal avulsion Fractures (Bucket-handle Fractures), esp. around the knees and ankles
- Non-ambulatory infant with long bone Fractures
- Abrasions
- Hour 0-6: Raw surface, oozing blood or clear fluid
- Hour 6-24: Dry, erythematous lesion
- Hour >24: Scab formation
-
Bruises
- Undress the child for exam (Bruises are commonly missed)
- Red Flags (see signs above)
- Bilaterally symmetric Bruising, with clear pattern (especially central, e.g, over Abdomen)
- Buttocks and back are not typically injured accidentally (even in older children)
- Non-ambulatory infants (especially under age 6 months)
- Isolated Bruising without other signs of injury
- Associated with brain or Abdominal Injury in 50% of cases
- Those who don't cruise, rarely Bruise
- Isolated Bruising without other signs of injury
- Bruising on Abdomen, neck, ear, under chin
- Color (listed for historical purpose, it is however unreliable as an indicator of injury timing)
- Days 0-2: Swelling and tenderness
- Days 2-5: Red, blue or purple coloration
- Days 5-7: Greenish hue
- Days 7-10: Yellow appearance
- Days 10-14: Brown discoloration
- Days 14-32: Clear appearance
XVII. Labs
- Coagulation studies (for concerning Bruising, Intracranial Hemorrhage)
- Complete Blood Count, Platelets
- Prothrombin Time (INR)
- Partial thromboplastic time
- Von Willebrand Factor Antigen and activity
- Factor 8 and Factor 9 Levels
-
Altered Level of Consciousness or signs CNS Trauma
- Coagulation studies as above
- Consider additional testing for DIC (e.g. Fibrinogen, D-Dimer)
- Glutaric Aciduria Type 1 screen
- Urine organic acids profile
- Serum Amino Acids
-
Abdominal Trauma labs
- Fecal Occult Blood Testing (Abdominal Trauma)
- Liver Function Tests, especially AST and ALT (Abdominal Trauma)
- Lipase or amylase (Abdominal Trauma)
- Urinalysis with microscopic exam (Abdominal Trauma)
- Unexplained Fractures
- Serum Calcium
- Serum Phosphorus
- Serum Alkaline Phosphatase
- Parathyroid Hormone
- 25-Hydroxyvitamin D
- Consider Vitamin C Level
- Consider osteogenesis imperfecta testing (e.g. COL1A1, COL1A2)
- Considder Menkes Syndrome testing (e.g. Ceruplasmin, serum Copper)
- Toxicology
- Urine toxicology
- Other evaluation to consider
- Comprehensive Metabolic Panel
- Neonatal Sepsis evaluation
- Newborn Screening
XVIII. Imaging
- Red Flags
-
Skeletal Survey
XRays
- Avoid single view whole-body XRay or "babygram" (inadequate and not helpful)
- Consider transfer to a center skilled in Skeletal Surveys to perform these 20-21 images
- See Skeletal Survey for Indications and XRay protocol
- Perform in all suspected cases under age 2 years (positive in up to 20% of cases)
- Consider in ages 2-5 years old (per AAP guidelines)
- Consider repeating in 10-14 days for occult Fracture
- Also indicated for unexplained Fracture or Rib Fracture <2 years old
- Exceptions: Toddler's Fracture, Distal radius or ulna buckle Fracture
- Indicated for any Fracture in <1 year old
- Exception: Simple linear Skull Fracture attributable to fall
-
Rib Fractures
- Oblique rib films may better demonstrate posterior Rib Fractures
- Rib Fractures overall are unusual in younger children, esp. age <2 years (aside from major Trauma)
- Children have very compliant chest walls making Rib Fractures uncommon
- Probability of Non-accidental Trauma 71% for Rib Fractures without major Trauma
- Posterior or posteromedial Rib Fractures (without history of MVA or metabolic bone disease)
- Seen especially in infants related to compression from assailant's fingers wrapped around chest
- Highly predictive of Nonaccidental Trauma in age <3 years (PPV 95%)
- Head Imaging
- Abusive Head Injury has 20% mortality and serious neurologic sequelae in 60-80%
- Indications
- Head imaging is indicated in most cases of suspected Child Abuse in younger children (esp. <12 months)
- Obtain if suspected Head Injury (e.g. Altered Mental Status, bulging Fontanelle)
- Obtain in high risk cases
- Age < 6 months
- Facial Bruising
- Rib Fractures
- Multiple Fractures
- Imaging Modalities
- Skull XRay is not adequate
- CT Head
- Emergency department in Unstable Patients (e.g. Altered Level of Consciousness)
- Ask for 3-D reconstructions of CT for evaluation of Skull Fractures
- MRI Brain
- MRI Cervical Spine
- Evaluate for ligamentous Cervical Spine Injury if head imaging demonstrates intracranial injury
-
Abdominal CT Indications (Ultrasound alone is insufficient)
- Increased AST or ALT >80 IU/L (associated with 20% positive Abdominal CT) or
- History of being struck in Abdomen or
- Exam with abdominal Bruising or tenderness
- Other imaging to consider
- Bone scan
- Demonstrate occult Fracture up to 2 weeks after injury
- Bone scan
XIX. Differential Diagnosis: Mimics
- Precautions
- Mimics are identified in <5% of Child Abuse investigations
- Evaluation for mimics should occur in parallel with Child Abuse evaluation (rather than defer it)
- Identifying a Child Abuse mimic does not rule-out concurrent abuse
- See Inconsolable Crying in Infants
-
Altered Mental Status and Intracranial Injury Mimics
- See Abusive Head Trauma of Infancy (Shaken Baby Syndrome)
- See Seizure Causes
- Neonatal Sepsis
- Benign subarachnoid space enlargement
- Associated with subarachnoid fluid collections and Macrocephaly
- Asymptomatic and typically incidental finding
- Skull Fracture from Birth Trauma
- Increased risk with instrumentation
- Associated Intracranial Hemorrhage may be asymptomatic and resolve by 4 months of age
- Metabolic Disorders (e.g. Inborn Errors of Metabolism)
- Glutaric Aciduria Type 1 (Autosomal Recessive)
- Associated with cerebral atrophy, widened fissures, Basal Ganglia lesions
- Subdural and arachnoid space widening with tearing of bridging veins
- Associated with subdural and Retinal Hemorrhage
- Menkes Syndrome (X-Linked)
- Copper transport mutation resulting in friable vessels
- Associated with Intracranial Hemorrhage (and intraabdominal Hemorrhage)
- Presents with Seizure Disorder, hypotonia and brittle hair
- Glutaric Aciduria Type 1 (Autosomal Recessive)
- Abusive Fracture mimics
- Osteogenesis imperfecta
- Osteopenia of prematurity or chronic illness
- Vitamin D Dependent Rickets
- Vitamin C Deficiency (Scurvy)
- Menkes Syndrome (kinky hair syndrome)
- Birth Trauma
- Congenital Syphilis
- Abusive Bruise mimics
- Dermal Melanocytes (Mongolian Spot)
- Idiopathic Thrombocytopenic Purpura
- Henoch-Schonlein Purpura
- Ehlers-Danlos Syndrome
- Leukemia
- Hematologic Disorders (e.g. Hemophilia, Von Willebrand Disease)
- Abusive Burn Mimics
- Phytophotodermatitis
- May result in a patterned Sunburn (in regions of sensitized skin)
- King (2024) Pediatr Dermatol 41(2): 215-20 [PubMed]
- Diaper Dermatitis
- Ingested irritants may cause diaper-region burn-like injury (similar to immersion burn)
- Examples: Citric acid, senna Laxatives
- Bullous Impetigo
- Ecthyma (Group A Beta Hemolytic Streptococcus)
- Deeper Skin Infections that complicate minor Skin Trauma
- May appear similar to a Cigarette burn
- Phytophotodermatitis
- Sexual Abuse Mimics
- Vulvar Lichen Sclerosus
- Irritant dermatitis or Irritant Vaginitis
- Local infections (e.g. Perianal Streptococcal Dermatitis)
- Normal anal dilation
- Normal skin variants and growths
- Perianal Skin Tag
- Hymenal tags
- Periurethral bands
- Intravaginal ridges
- Anogenital Hyperpigmentation
XX. Prognosis
- Undiagnosed Child Abuse is associated with 25% mortality rate in 2 years
- Child Abuse strong risk factor for adult crime behavior
- 908 cases of Child Abuse 1967-1971 in midwest
- followed arrest record through mid-1994
- Significantly higher rate of crime and of Violence
- African American Males had much higher risks
- Maxfield (1996) Arch Pediatr Adolesc Med 150:390-5 [PubMed]
- 908 cases of Child Abuse 1967-1971 in midwest
- Investigation Results
- 58% of investigations were found not substantiated
- 36% were found substantiated or maltreatment present
- National Child Abuse and Neglect Data Systems [PubMed]
- Protective Factors
- Child with above average cognition
- Child's belief in own ability to control their destiny
- Child's self impulse control and modulation
- Child's high self esteem and sense of self worth
- Child involvement in extracurricular activities or hobbies
- Spirituality or involvement in religious community
- Caregiver Support network
XXI. Evaluation: Age Based
- Age <6 to 12 months
- Complete Skin Exam
- Skeletal Survey (initial and repeated 1-2 weeks later)
- Neuroimaging
- Age 12 to 24 months
- Complete Skin Exam
- Skeletal Survey (initial and repeated 1-2 weeks later)
- Age >=24 months
- Complete Skin Exam
- Focused imaging based on careful exam
XXII. Evaluation: Injury Based
-
Bruising
- Evaluate differential diagnosis (esp. Bleeding Disorders)
- Evaluate for occult Abdominal Trauma (see labs and imaging above)
-
Fractures
- Evaluate differential diagnosis (esp. metabolic bone disease)
- Evaluate for occult Abdominal Trauma (see labs and imaging above)
- Abusive Head Trauma
- Evaluate differential diagnosis (esp. Bleeding Disorders)
- Evaluate for occult Abdominal Trauma (see labs and imaging above)
- MRI Brain and MRI Spine
- Dilated Eye Exam (ophthalmology)
XXIII. Management
- Report all cases of suspected Child Abuse (medical providers are mandated reporters)
- Contact local social services
-
Consultations
- Ophthalmology for dilated Eye Exam (all cases age<2 years)
- Evaluate for Retinal Hemorrhages, typically with Retinal images obtained
- Significant Retinal Hemorrhages are extremely rare with accidental Trauma
- Dental Consultation (if bite present to find source)
- Burn specialist (if Burn Injury present)
- Ophthalmology for dilated Eye Exam (all cases age<2 years)
- Keep careful and accurate documentation
- See Exam above
- Consider hospitalization for evaluation and treatment of Child Abuse or neglect
- Consult tertiary Child Abuse resources
- Approach to accompanying adult with child
- Develop initial rapport with child and adults
- State role as the advocate of the child, and mandated duty to report concerns
- Avoid confrontational tone
- Ask adults accompanying child to step out for child's interview (if age allows a history)
- Describe the Non-accidental Trauma concern
- "When I see injuries like this, without a clear mechanism, I worry someone may have harmed your child"
- "We do not want to miss Trauma that you are unaware of, or that someone is trying to harm your child"
- "Have you worried that someone may be harming your child?"
- Describe the red flags: "This injury is more severe than what we would expect from this fall"
- Describe the medical reasons for evaluation
- "We do not want to miss a serious underlying cause for brittle bones"
- Describe the evaluation
- "We need to check XRays and CT to look for other injuries and to check blood tests to look for other disorders"
- Explain the need to involve other agencies to ensure safety (mandated reporting)
- Notify accompanying adults when involving police or child protection
- Do not notify adults if child is returning home with them (may put the child in danger of escalating injury)
XXIV. Complications
- High Risk Behaviors
- High risk sexual behavior (Sexually Transmitted Infection, Unplanned Pregnancy)
- Substance Abuse
- Revictimization
- Secondary medical conditions
- Secondary mental health conditions
XXV. Prevention
- Inquire about social history at clinic visits
- Teach Positive Parenting Techniques
- Positive Parenting Program (Triple-P)
- Home Visitation Programs for high risk parents (e.g. Nurse Family Partnership, Healthy Families America, MESCH)
- Discipline Without Shouting or Spanking (book by Unell and Wyckoff)
- Address parental frustrations
- Discuss parental coping skills
- Offer anticipatory guidance for challenges at each developmental stage
- Discuss response and coping with child crying
- Discuss Discipline techniques
- Anticipate children at higher risk for abuse
- Discuss respite care for children with disabilities
- Be alert for parental risk factors for abuse
- Early intervention if emotional abuse suspected
XXVI. Resources
- Child Welfare Information Gateway
- ChildHelp USA
- Tennyson Center for Children
- Child Abuse Evaluation and Treatment Medical Providers
XXVII. References
- Gardiner (2018) Crit Dec Emerg Med 37(5): 3-14
- Canto and Moreno (2026) Crit Dec Emerg Med 40(8): 30-7
- Claudius, Behar and Lindberg in Herbert (2014) EM:Rap 14(1):14-16
- Johnson (2024) Mayo Clinic Pediatric Days, attended lecture 1/16/2024
- Pomeranz (2015) Crit Dec Emerg Med 29(7): 2-9
- Pomeranz (2021) Crit Dec Emerg Med 35(1): 3-10
- Swaminathan and Horowitz in Herbert (2019) EM:Rap 19(6):16
- (2000) Pediatrics 105:1345-8 [PubMed]
- Kocher (2000) J Am Acad Orthop Surg 8:10-20 [PubMed]
- Kodner (2013) Am Fam Physician 88(10): 669-75 [PubMed]
- Lane (2003) Clin Fam Pract 5:493-514 [PubMed]
- McDonald (2007) Am Fam Physician 75:221-8 [PubMed]
- Suniega (2022) Am Fam Physician 105(5): 521-8 [PubMed]