Development and evaluation of a novel knowledge assessment tool for pediatric emergency medicine clerkships.

Objectives: This study seeks to determine validity evidence for a newly developed multiple-choice examination (MCE) tool to assess retention and application of medical knowledge of students enrolled in a pediatric emergency medicine (PEM) clerkship. Methods: A team of PEM physicians created a 110-item MCE covering the range of clinical topics in PEM relevant for medical students. The researchers determined examination content using the report of Clerkship Directors in Emergency Medicine and PEM Interest Group of the Society for Academic Emergency Medicine (SAEM). The authors administered the MCE to fourth-year medical students at the end of their PEM rotation from May 2020 to April 2023 at four institutions and then analyzed the examination using four of Messick's five sources of validity evidence: content, response process, internal structure, and relation to other variables. Results: A total of 158 students took the test. In academic year (AY)20-21, 47 students took the test and scored, on average, 81%. After revision of poor and indeterminate questions, the 111 medical students who took the revised version of the test in AY21-AY23 scored on average 77.3% with a standard deviation of 5.7% with a normal distribution in scores. The revised questions were rated as excellent (10.0%), good (26.4%), fair (34.5%), poor (24.5%), or indeterminate (4.5%) based on test item discrimination. There was a positive correlation between MCE scores and students' clinical evaluations but no correlation between MCE scores and scores that students received on their clinical notes or patient presentations during case conference. Conclusions: This novel PEM clerkship examination is a reliable test of medical knowledge. Future directions involve evaluating consequences of the MCE and offering the test to medical students in a dedicated PEM rotation at the national level.

Patient-centered or population-centered? How epistemic discrepancies cause harm and sow mistrust.

Medical distrust is often conceived of as a problem of misinformation or ignorance. In this paper, I depart from this framework, attributing distrust instead to epistemic divergence between lay people and experts. Using data from a contraceptive side effects Facebook group and in-depth physician interviews, I find that providers employ a "body-as-subject" lens informed by population-health goals, while group members employ a "body-as-agent" lens that privileges individuality and bodily autonomy. Provider epistemologies are privileged, creating epistemic injustice and harm for patients. Ultimately, this erodes trust in providers and the medical community more broadly.

A multicenter evaluation of pediatric emergency department injury visits during the COVID-19 pandemic.

BACKGROUND: Injuries, the leading cause of death in children 1-17 years old, are often preventable. Injury patterns are impacted by changes in the child's environment, shifts in supervision, and caregiver stressors. The objective of this study was to evaluate the incidence and proportion of injuries, mechanisms, and severity seen in Pediatric Emergency Departments (PEDs) during the COVID-19 pandemic. METHODS: This multicenter, cross-sectional study from January 2019 through December 2020 examined visits to 40 PEDs for children < 18 years old. Injury was defined by at least one International Classification of Disease-10th revision (ICD-10) code for bodily injury (S00-T78). The main study outcomes were total and proportion of PED injury-related visits compared to all visits in March through December 2020 and to the same months in 2019. Weekly injury visits as a percentage of total PED visits were calculated for all weeks between January 2019 and December 2020. RESULTS: The study included 741,418 PED visits for injuries pre-COVID-19 pandemic (2019) and during the COVID-19 pandemic (2020). Overall PED visits from all causes decreased 27.4% in March to December 2020 compared to the same time frame in 2019; however, the proportion of injury-related PED visits in 2020 increased by 37.7%. In 2020, injured children were younger (median age 6.31 years vs 7.31 in 2019), more commonly White (54% vs 50%, p < 0.001), non-Hispanic (72% vs 69%, p < 0.001) and had private insurance (35% vs 32%, p < 0.001). Injury hospitalizations increased 2.2% (p < 0.001) and deaths increased 0.03% (p < 0.001) in 2020 compared to 2019. Mean injury severity score increased (2.2 to 2.4, p < 0.001) between 2019 and 2020. Injuries declined for struck by/against (- 4.9%) and overexertion (- 1.2%) mechanisms. Injuries proportionally increased for pedal cycles (2.8%), cut/pierce (1.5%), motor vehicle occupant (0.9%), other transportation (0.6%), fire/burn (0.5%) and firearms (0.3%) compared to all injuries in 2020 versus 2019. CONCLUSIONS: The proportion of PED injury-related visits in March through December 2020 increased compared to the same months in 2019. Racial and payor differences were noted. Mechanisms of injury seen in the PED during 2020 changed compared to 2019, and this can inform injury prevention initiatives.

The Epidemiology of Violence Exposure in Children.

Exposure to violence remains a significant issue for children in the United States. The COVID-19 pandemic exacerbated many of these exposures. Violence unequally impacts children of color and lesbian, gay, bisexual, transgender, and questioning youth. Pediatricians can and must continue to advocate and intervene to decrease pediatric violence exposure and its effects.

Violent Injury as a Predictor of Subsequent Assault-Related Emergency Department Visits Among Adolescents.

PURPOSE: To measure the risk of a subsequent assault-related emergency department (ED) visit in assault injured adolescents as compared to those who initially presented for non-assault related injuries. METHODS: This was a historical cohort study of youth (ages 10-18 years) seen at two pediatric EDs between 2016 and 2019. Participants were included if their visit had an International Classification of Diseases-10 code for assaultive injury or accidental injury (motor vehicle collisions (MVC) and sports injuries). We calculated the rate of a subsequent ED visit for an assault-related injury, and then used survival analysis to compare time to subsequent ED visit with an assault-related injury between study and comparison groups. RESULTS: A total of 6125 adolescents met inclusion criteria (Assault: n = 2782, 45.4%; MVC: n = 1834, 29.9%; Sports n = 1509, 24.6%). The overall rate per 100 person years of a subsequent assault-related ED visit was 5.6 (n = 344). Patients who initially presented with an assault-related injury had an increased adjusted relative risk (aRR) of return for a subsequent ED visit for an assault-related injury when compared to MVC patients (aRR 17.6 [95% CI: 9.6, 32.2]). Kaplan-Meier time to event analysis found that patients in the assault injury group have a higher probability of a subsequent ED visit for an assault-related injury compared to patients in the MVC injury group (adjusted hazard ratio (aHR): 17.7 [95% CI: 9.67, 32.42]). DISCUSSION: Adolescents injured by assault are more likely to return to the ED for a subsequent assault-related injury compared to adolescents who initially present with non-assault-related injuries.

The Current State of Pediatric Emergency Medicine Training in Emergency Medicine Residencies.

BACKGROUND: Several studies show that emergency medicine (EM) physicians are less comfortable caring for pediatric patients than adults. The state of pediatric training has not been comprehensively evaluated since 2000. OBJECTIVES: We sought to describe current pediatric education in EM residencies and to evaluate EM Program Director (PD) confidence in graduating trainees' abilities to care for pediatric patients. METHODS: We conducted an anonymous, cross-sectional survey study of EM PDs in August 2020. We collected program demographics, clinical rotations, and didactic methods. We used Likert scales to measure PD confidence in graduating residents' competence to care for pediatric and adult patients. RESULTS: We found e-mail addresses for 249 (93%) of 268 EM programs. One hundred nineteen (48%) PDs completed the survey. We include denominators to account for unanswered questions. Sixty-eight (59%) of 116 programs spend 10% to 20% of clinical time seeing pediatric patients. One hundred ten (91%) of 119 require a pediatric emergency medicine (PEM) rotation, 88/119 (83%) require pediatric intensive care, and 34/119 (29%) require neonatal intensive care. Seventy (62%) of 113 have curricula designed by PEM-trained faculty, 96/113 (85%) have PEM attendings teach lectures, and 77/113 (68%) spend 10% to 20% of didactic time on pediatric topics. Twenty-three (23%) of 106 PDs stated not all residents graduate with competence in pediatric resuscitation compared with 2/106 (2%) for adult resuscitation ( P < 0.05). CONCLUSIONS: Program directors report less confidence in graduating residents' competence in caring for pediatric patients compared with adult patients. We propose ideas to strengthen the quality of pediatric education in EM residencies.

Variations in Safe Sleep Practices and Beliefs: Knowledge is not Enough.

OBJECTIVES: Sleep-related infant deaths in the District of Columbia (DC) varies, with rates in certain geographical areas three times higher than DC and seven times higher than the national average. We sought to understand differences in infant sleep knowledge, beliefs, and practices between families in high-risk infant mortality and low-risk infant mortality areas in DC. METHODS: Caregivers of infants presenting to the emergency department were surveyed. The associations between location and safe sleep knowledge, beliefs, and practices were analyzed. RESULTS: Two hundred and eighty-four caregivers were surveyed; 105 (37%) were from the high-risk infant mortality area. The majority (68%) of caregivers reported placing their infant to sleep on their backs, sleeping in a crib, bassinet, or pack and play (72%), and were familiar with the phrase "safe sleep" (72%). Caregivers from the high-risk infant mortality area were more likely to report that their infants sleep in homes other than their own (aOR 1.53; 95% CI 1.23, 2.81) and other people took care of their infants while sleeping (aOR 1.76; 95% CI 1.17, 3.19), adjusting for race/ethnicity, education, marital status, and help with childcare. No differences in safe sleep knowledge, beliefs, and practices were present. CONCLUSIONS FOR PRACTICE: Infants from the high-risk infant mortality area were more likely to sleep in homes other than their own and have other caretakers while sleeping. Lack of differences in caregiver awareness of safe sleep recommendation or practices suggests effective safe sleep messaging. Outreach to other caregivers and study of unmet barriers is needed.

Experiencing Bullying Is Associated With Firearm Access, Weapon Carriage, Depression, Marijuana Use, and Justice Involvement in Adolescents.

OBJECTIVES: The aims of this study were to assess whether bullying experience among youths is associated with firearm access and to evaluate assault perpetration risk factors between bullied and nonbullied adolescents. METHODS: This was a secondary analysis of a cross-sectional survey designed to measure self-reported social determinants of health and behavioral health risks among adolescents (13-21 years) in a pediatric emergency department between July 2017 and August 2019. Participants were included in this subanalysis if they responded to a survey item that assessed bullying. Multivariable logistic regression was used to measure the association of firearm access, weapon carriage, and assault perpetration factors (violence, mental health, substance abuse, and justice involvement) with bullying after adjustment for sex, race/ethnicity, and insurance status. RESULTS: Of the 369 participants meeting inclusion criteria, 147 adolescents (40.5%) reported experiencing bullying. Bullied teenagers had higher odds of a gun in the home (adjusted odds ratio [aOR], 3.0; 95% confidence interval [CI], 1.2-7.8]), weapon carriage (aOR, 5.6; 95% CI, 1.6-18.8), witnessing an assault (aOR, 3.0; 95% CI, 1.6-5.6), negative experience with law enforcement (aOR, 4.5; 95% CI, 2.2-9.2), mental health diagnosis (aOR, 3.9; 95% CI, 2.3-6.7), and marijuana use (aOR, 2.7; 95% CI, 1.1-7.0]). CONCLUSIONS: More than 1 in 3 adolescents presenting to the emergency department report having ever experienced bullying. Bullied teenagers have a higher likelihood of firearm access, weapon carriage, and violent injury perpetration risk factors compared with nonbullied youths. Further studies are needed to understand the relationship between bullying and assault perpetration.

Determining Intentionality of Pediatric Firearm Injuries by International Classification of Disease Code.

OBJECTIVE: Firearm injuries are a leading cause of serious injury and death in childhood. The accuracy of International Classification of Disease (ICD) codes to assign intent is unclear. The objective of this study was to assess the validity of documented ICD codes for firearm injury intent compared with chart review. METHODS: We performed a retrospective cohort study of children (<= 18 years) presenting to a tertiary care level 1 pediatric trauma center with firearm injuries between 2006 and 2017. We compared agreement between ICD codes and intent of injury determined by medical record review using Cohen κ. Intent for medical record review was assigned via the injury spectrum of intentionality (suicide attempt, accidental firing, mistaken target, firearm assault and unknown). For comparison with ICD codes, all medical record review cases marked as mistaken target were classified as accidental. A sensitivity analysis was then performed, coding all mistaken targets as assault. RESULTS: There were 122 cases identified over the study period. The most common intent by ICD code was assault (n = 80, 65.6%). Medical record review categorized most injuries as mistaken targets. When mistaken target was categorized as accidental, most firearm injuries were coded as accidental (n = 89, 72.9%) Similar results were seen when mistaken target was categorized as assault, most injuries were categorized as assault (n = 79, 79.5%) Cohen κ was 0.15 when mistaken targets were categorized as accident and 0.30 when categorized as assault. CONCLUSIONS: The ICD codes do not fully describe the intent of firearm injury. Revising ICD codes to account for mistaken targets could help to improve the validity of ICD codes for intent.

Metrics of shock in pediatric trauma patients: A systematic search and review.

INTRODUCTION: Shock-index (SI) and systolic blood pressure (SBP) are metrics for identifying children and adults with hemodynamic instability following injury. The purpose of this systematic review was to assess the quality of these metrics as predictors of outcomes following pediatric injury. MATERIALS AND METHODS: We conducted a literature search in Pubmed, SCOPUS, and CINAHL to identify studies describing the association between shock metrics on the morbidity and mortality of injured children and adolescents. We used the data presented in the studies to calculate the sensitivity and specificity for each metric. This study was registered with Prospero, protocol CRD42020162971. RESULTS: Fifteen articles met the inclusion criteria. seven studies evaluated SI or SIPA score, an age-corrected version of SI, as predictors of outcomes following pediatric trauma, with one study comparing SIPA score and SBP and one study comparing SI and SBP. The remaining eight studies evaluated SBP as the primary indicator of shock. The median sensitivity for predicting mortality and need for blood transfusion was highest for SI, followed by SIPA, and then SBP. The median specificity for predicting these outcomes was highest for SBP, followed by SIPA, and then SI. CONCLUSIONS: Common conclusions were that high SIPA scores were more specific than SI and more sensitive than SBP. SIPA score had better discrimination for severely injured children compared to SI and SBP. An elevated SIPA was associated with a greater need for blood transfusion and higher in-hospital mortality. SIPA is specific enough to exclude most patients who do not require a blood transfusion.

Firearms Injuries Involving Young Children in the United States During the COVID-19 Pandemic.

OBJECTIVES: Increased rates of firearm ownership, school closures, and a suspected decrease in supervision during the coronavirus disease 2019 (COVID-19) pandemic place young children at increased risk of firearm injuries. We measured trends in firearm injuries in children and inflicted by children discharging a firearm during the pandemic and correlated these changes with a rise in firearm acquisition. METHODS: In this cross-sectional study with an interrupted time series analysis, we used multiyear data from the Gun Violence Archive. We compared trends in (1) firearm injuries in children younger than 12 years old and (2) firearm injuries inflicted by children younger than 12 years old during the pre-COVID-19 period (March to August in the years 2016-2019) and during the first 6 months of the COVID-19 pandemic (March 2020 to August 2020). Linear regression models were developed to evaluate the relationship between firearm injuries and new firearm acquisitions. RESULTS: There was an increased risk of (1) firearm injuries in young children (relative risk = 1.90; 95% confidence interval 1.58 to 2.29) and (2) firearm injuries inflicted by young children (relative risk = 1.43; 95% confidence interval 1.14 to 1.80) during the first 6 months of the COVID-19 pandemic as compared to the pre-COVID-19 study period. These increased incidents correlate with an increase in new firearm ownership (P < .03). CONCLUSIONS: There has been a surge in firearm injuries in young children and inflicted by young children during the first 6 months of the COVID-19 pandemic. There is an urgent and critical need for enactment of interventions aimed at preventing firearm injuries and deaths involving children.

Prescription Drug Shortages: Pediatric Emergency and Critical Care Medications.

OBJECTIVES: Drug shortages have been increasing over the past 2 decades. There are limited data on drug shortages and their effect on pediatric emergency and critical care. Our objective was to describe pediatric emergency and critical care drug shortages. METHODS: Drug shortage data from January 2001 to December 2015 were obtained from the University of Utah Drug Information Services. Shortages were reviewed, identifying agents used in pediatric emergency and critical care. Shortage data were analyzed for the type of drug, formulation, shortage reason, duration, marketing status (generic vs brand name), or if it was a pediatric-friendly formulation, used for a high-acuity condition, or a single-source product. The availability of a substitute was also described. RESULTS: Of 1883 products on shortage, 779 were used in pediatric emergency or critical care. The annual number of shortages decreased from 2001 to 2004, but then increased, reaching a high in 2011. The median duration for resolved shortages was 7.6 months (interquartile range, 3.0-17.6 months). The most common category affected was infectious disease drugs. High-acuity agents were involved in 27% of shortages and in 11% of pediatric-friendly formulations. An alternative agent was available for 95% of drugs, yet 43% of alternatives were also affected at some time during the study period. The most common reported reason for a shortage was manufacturing problems. CONCLUSIONS: From 2001 to 2015, drug shortages affected a substantial number of agents used in pediatric emergency and critical care. This has had implications to the medications available for use and may impact patient outcomes. Providers must be aware of current shortages and implement mitigation strategies to optimize patient care.

Never Just a Shot in the Dark: Pediatric Firearm Advocacy.

Firearms remain a common cause of injury in children. Advocacy is a tool that can be useful in effecting systemic change. Yet for firearm injury prevention, traditional methods of effecting change face unique barriers not experienced in other areas of pediatric injury prevention. As pediatric emergency medicine physicians, we are on the front lines, and as part of the receiving end of the trauma inflicted on our communities by firearms, ours is a powerful voice well suited to overcome these barriers. Current firearm advocacy efforts include raising awareness via social media or editorials, organizing larger advocacy groups for support, challenging legislation, and implementing hospital-based violence intervention programs. Future advocacy directions should include collaborating with unique partners, teleadvocacy, direct action, and finding common ground with gun regulation opposition. Physician advocacy is essential to firearm injury prevention. Continuing to innovate around our advocacy efforts will be vital to the health and safety of our patients.

Barriers to Firearm Injury Research.

INTRODUCTION: Firearm injuries and motor vehicle injuries are 2 leading causes of fatal injury in the U.S., each accounting for approximately 35,000 deaths annually. Research on firearm injuries is under-represented compared with research on motor vehicle collisions. This study seeks to identify perceived barriers to firearm injury research versus motor vehicle injury research. METHODS: This was a mixed-methods survey of corresponding authors of a minimum of 1 study, archived in PubMed, related to firearm injury or motor vehicle injury between 2014 and 2018. Analyses were performed in 2019. Electronic surveys included both closed- and open-ended questions to assess barriers to research. Bivariable and multivariable logistic regression was performed to identify differences in perceptions to barriers between the 2 groups. Qualitative analysis of free-text responses was performed through inductive derivation of themes. RESULTS: Surveys were distributed to 113 firearm injury researchers (42% response rate) and 241 motor vehicle injury researchers (31.5% response rate). After adjustment, firearm injury researchers were less likely to cite institutional support (AOR=0.3, 95% CI=0.1, 0.8) as a factor contributing to their success, than motor vehicle injury researchers. Firearm injury researchers were more likely to report fear of personal threats (AOR=10.4, 95% CI=2.4, 44.4) and experiencing personal threats (AOR=16.1, 95% CI=1.6, 165.4). Thematic analysis revealed 4 themes: career, political, funding, and harassment. CONCLUSIONS: When compared with motor vehicle injury researchers, firearm injury researchers are significantly more likely to report limited support and threats to personal safety as barriers to research. Further research to understand the impact of these barriers and methods to overcome them is needed.

Patients at High Risk of Intervention for Pediatric Traumatic Liver Injury.

OBJECTIVES: Nonoperative management of hemodynamically stable liver lacerations in pediatric trauma patients is a safe and effective management strategy for pediatric patients; approximately 90% will be successfully managed nonoperatively. No study has specifically identified risk criteria for the need for intervention versus observation alone. Our objective for this study was to determine risk factors from the physical examination, computed tomography scan, and laboratory results associated with intervention for liver laceration. METHODS: We performed a retrospective cohort study using data from the Pediatric Emergency Care Applied Research Network Intra-abdominal Injuries Study public use data set. Data were collected prospectively at the time of enrollment; a limited data set was released for public use in 2014. Patients were included if they were diagnosed with a liver laceration by computed tomography scan. We used bivariable and multivariable analyses to determine associations of specific risk factors with intervention, defined as laparotomy, angiographic embolization, blood transfusion, death, or return to emergency department for any reason within 30 days. RESULTS: Of the 12,044 patients in the Intra-abdominal Injuries Study, 282 were diagnosed with a liver laceration. All patients were hospitalized, and 99 (35.1%) underwent an intervention. Variables were then eliminated if more than 10% of cases were missing data. Multivariable logistic regression identified the following independent risk factors for intervention: white blood cell count greater than 15 K/mcl (adjusted odds ratio [adjOR], 2.83; 95% confidence interval [CI], 1.43-5.63), pelvic fracture (adjOR, 2.50; 95% CI, 1.02-6.10), liver injury greater than grade 2 (adjOR, 2.16; 95% CI, 1.06-4.40), Glasgow Coma Scale score less than 15 (adjOR, 4.77; 95% CI, 2.27-7.63), and hematocrit less than 32% (adjOR, 4.79; 95% CI, 2.00-11.46). CONCLUSIONS: We identified 5 high-risk criteria associated with intervention for traumatic liver laceration in pediatric patients. Prospective studies are necessary to validate these results before using them to determine disposition of pediatric patients with traumatic liver injuries.

Prescription Drug Shortages: Implications for Ambulatory Pediatrics.

OBJECTIVE: To describe contemporary drug shortages affecting general ambulatory pediatrics. STUDY DESIGN: Data from January 2001 to December 2015 were obtained from the University of Utah Drug Information Service. Two pediatricians reviewed drug shortages and identified agents used in ambulatory pediatrics. Shortage data were analyzed by the type of drug, formulation, reason for shortage, duration, marketing status, if a pediatric friendly-formulation was available, or if it was a single-source product. The availability of an alternative, and whether that alternative was affected by a shortage, also was noted. RESULTS: Of 1883 products in shortage during the study period, 314 were determined to be used in ambulatory pediatrics. The annual number of new pediatric shortages decreased initially but then increased to a high of 38 in 2011. Of the 314 pediatric shortages, 3.8% were unresolved at the end of the study. The median duration of resolved shortages was 7.6 months. The longest shortage was for ciprofloxacin 500-mg tablets. The most common class involved was infectious disease drugs. Pediatric-friendly dosage forms were affected in 19.1% of shortages. An alternative agent was available for 86% drugs; however, 29% of these also were affected. The most common reason for shortage was manufacturing problems. CONCLUSIONS: Drug shortages affected a substantial number of agents used in general ambulatory pediatrics. Shortages for single-source products are a concern if a suitable alternative is unavailable. Providers working in the ambulatory setting must be aware of current shortages and implement mitigation strategies to optimize patient care.

Structural systematics and conformational analyses of a 3 × 3 isomer grid of fluoro-N-(pyridyl)benzamides: physicochemical correlations, polymorphism and isomorphous relationships.

An isomer grid of nine fluoro-N-(pyridyl)benzamides (Fxx) (x = para-/meta-/ortho-) has been examined to correlate structural relationships between the experimental crystal structure and ab initio calculations, based on the effect of fluorine (Fx) and pyridine N-atom (x) substitution patterns on molecular conformation. Eight isomers form N-H⋅⋅⋅N hydrogen bonds, and only one (Fom) aggregates via intermolecular N-H⋅⋅⋅O=C interactions exclusively. The Fpm and Fom isomers both crystallize as two polymorphs with Fpm_O (N-H⋅⋅⋅O=C chains, P-syn) and Fpm_N (N-H⋅⋅⋅N chains, P-anti) both in P2(1)/n (Z' = 1) differing by their meta-N atom locations (P-syn, P-anti; N(pyridine) referenced to N-H), whereas the disordered Fom_O is mostly P-syn (Z' = 6) compared with Fom_F (P-anti) (Z' = 1). In the Fxo triad twisted dimers form cyclic R(2)(2)(8) rings via N-H⋅⋅⋅N interactions. Computational modelling and conformational preferences of the isomer grid demonstrate that the solid-state conformations generally conform with the most stable calculated conformations except for the Fxm triad, while calculations of the Fox triad predict the intramolecular N-H⋅⋅⋅F interaction established by spectroscopic and crystallographic data. Comparisons of Fxx with related isomer grids reveal a high degree of similarity in solid-state aggregation and physicochemical properties, while correlation of the melting point behaviour indicates the significance of the substituent position on melting point behaviour rather than the nature of the substituent.

2-Fluoro-N-(2-fluoro-benzo-yl)-N-(2-pyrid-yl)benzamide.

The title compound, C(19)H(12)F(2)N(2)O(2), a 2:1 product of the reaction of 2-fluoro-benzoyl chloride and 2-amino-pyridine, crystallizes with a disordered 2-fluoro-benzene ring adopting two conformations [ratio of occupancies = 0.930 (4):0.070 (4)] in one of the two independent mol-ecules (differing slightly in conformation) comprising the asymmetric unit. In the crystal structure, C-H⋯O and C-H⋯π(arene) inter-actions are present.

Assembling an isomer grid: the isomorphous 4-, 3- and 2-fluoro-N'-(4-pyridyl)benzamides.

The three title isomers, 4-, (I), 3-, (II), and 2-fluoro-N'-(4-pyridyl)benzamide, (III), all C12H9FN2O, crystallize in the P2(1)/c space group (No. 14) with similar unit-cell parameters and are isomorphous and isostructural at the primary hydrogen-bonding level. An intramolecular C-H...O=C interaction is present in all three isomers [C...O = 2.8681 (17)-2.884 (2) A and C-H...O117-118 degrees ], with an additional N-H...F [N...F = 2.7544 (15) A] interaction in (III). Intermolecular amide-pyridine N-H...N hydrogen bonds link molecules into one-dimensional zigzag chains [graph set C(6)] along the [010] direction as the primary hydrogen bond [N...N = 3.022 (2), 3.049 (2) and 3.0213 (17) A]. These are augmented in (I) by C-H...pi(arene) and cyclic C-F...pi(arene) contacts about inversion centres, in (II) by C-F...F-C interactions [C...F = 3.037 (2) A] and weaker C-H...pi(arene)/C-H...F contacts, and in (III) by C-H...pi(arene) and C=O...O=C interactions, linking the alternating chains into two-dimensional sheets. Typical amide N-H...O=C hydrogen bonds [as C(4) chains] are not present [N...O = 3.438 (2) A in (I), 3.562 (2) A in (II) and 3.7854 (16) A in (III)]; the C=O group is effectively shielded and only participates in weaker interactions/contacts. This series is unusual as the three isomers are isomorphous (having similar unit-cell parameters, packing and alignment), but they differ in their interactions and contacts at the secondary level.

3-Fluoro-N-(3-fluoro-benzo-yl)-N-(2-pyrid-yl)benzamide.

The title compound, C(19)H(12)F(2)N(2)O(2), a 2:1 product of the reaction of 3-fluoro-benzoyl-chloride and 2-amino-pyridine crystallizes with a disordered 3-fluoro-benzene ring adopting two conformations [ratio of occupancies 0.959 (4):0.041 (4)]. In the crystal structure, there are no classical hydrogen bonds and inter-actions comprise C-H⋯O in the form 2(C-H)⋯O=C [with motif R(2) (1)(5)]; C-H⋯π(arene) inter-actions are also present.