A macrophage-cell model of HIV latency reveals the unusual importance of the bromodomain axis.

BACKGROUND: Although macrophages are now recognized as an essential part of the HIV latent reservoir, whether and how viral latency is established and reactivated in these cell types is poorly understood. To understand the fundamental mechanisms of viral latency in macrophages, there is an urgent need to develop latency models amenable to genetic manipulations and screening for appropriate latency-reversing agents (LRAs). Given that differentiated THP-1 cells resemble monocyte-derived macrophages in HIV replication mechanisms, we set out to establish a macrophage cell model for HIV latency using THP-1 cells. METHODS: We created single-cell clones of THP-1 cells infected with a single copy of the dual-labeled HIVGKO in which a codon switched eGFP (csGFP) is under the control of the HIV-1 5' LTR promoter, and a monomeric Kusabira orange 2 (mKO2) under the control of cellular elongation factor one alpha promoter (EF1α). Latently infected cells are csGFP-, mKO2+, while cells with actively replicating HIV (or reactivated virus) are csGFP+,mKO2+. After sorting for latently infected cells, each of the THP-1 clones with unique integration sites for HIV was differentiated into macrophage-like cells with phorbol 12-myristate 13-acetate (PMA) and treated with established LRAs to stimulate HIV reactivation. Monocyte-derived macrophages (MDMs) harboring single copies of HIVGKO were used to confirm our findings. RESULTS: We obtained clones of THP-1 cells with latently infected HIV with unique integration sites. When the differentiated THP-1 or primary MDMs cells were treated with various LRAs, the bromodomain inhibitors JQ1 and I-BET151 were the most potent compounds. Knockdown of BRD4, the target of JQ1, resulted in increased reactivation, thus confirming the pharmacological effect. The DYRK1A inhibitor Harmine and lipopolysaccharide (LPS) also showed significant reactivation across all three MDM donors. Remarkably, LRAs like PMA/ionomycin, bryostatin-1, and histone deacetylase inhibitors known to potently reactivate latent HIV in CD4 + T cells showed little activity in macrophages. CONCLUSIONS: Our results indicate that this model could be used to screen for appropriate LRAs for macrophages and show that HIV latency and reactivation mechanisms in macrophages may be distinct from those of CD4 + T cells.

HTLV-1 infected T cells cause bone loss via small extracellular vesicles.

Adult T cell leukemia (ATL), caused by infection with human T cell leukemia virus type 1 (HTLV-1), is often complicated by hypercalcemia and osteolytic lesions. Therefore, we studied the communication between patient-derived ATL cells (ATL-PDX) and HTLV-1 immortalized CD4+ T cell lines (HTLV/T) with osteoclasts and their effects on bone mass in mice. Intratibial inoculation of some HTLV/T lead to a profound local decrease in bone mass similar to marrow-replacing ATL-PDX, despite the fact that few HTLV/T cells persisted in the bone. To study the direct effect of HTLV/T and ATL-PDX on osteoclasts, supernatants were added to murine and human osteoclast precursors. ATL-PDX supernatants from hypercalcemic patients promoted formation of mature osteoclasts, while those from HTLV/T were variably stimulatory, but had largely consistent effects between human and murine cultures. Interestingly, this osteoclastic activity did not correlate with expression of osteoclastogenic cytokine RANKL, suggesting an alternative mechanism. HTLV/T and ATL-PDX produce small extracellular vesicles (sEV), known to facilitate HTLV-1 infection. We hypothesized that these sEV also mediate bone loss by targeting osteoclasts. We isolated sEV from both HTLV/T and ATL-PDX, and found they carried most of the activity found in supernatants. In contrast, sEV from uninfected activated T cells had little effect. Analysis of sEV (both active and inactive) by mass spectrometry and electron microscopy confirmed absence of RANKL and intact virus. Viral proteins Tax and Env were only present in sEV from the active, osteoclast-stimulatory group, along with increased representation of proteins involved in osteoclastogenesis and bone resorption. sEV injected over mouse calvaria in the presence of low dose RANKL caused more osteolysis than RANKL alone. Thus, HTLV-1 infection of T cells can cause release of sEV with strong osteolytic potential, providing a mechanism beyond RANKL production that modifies the bone microenvironment, even in the absence of overt leukemia.

Racial and Ethnic Disparities in Length of Stay for Common Pediatric Diagnoses: Trends From 2016 to 2019.

BACKGROUND AND OBJECTIVES: Inequities in pediatric illness include unequal treatment and outcomes for children of historically marginalized races/ethnicities. Length of stay (LOS) is used to assess health care quality and is associated with higher costs/complications. Studies show LOS disparities for Black and Hispanic children in specific diagnoses, but it is unclear how broadly they exist or how they change over time. We examined the association between race/ethnicity and LOS longitudinally for the most common pediatric inpatient diagnoses. METHODS: We used the 2016 and 2019 Kids' Inpatient Databases. The 10 most frequent diagnoses in 2016 were determined. For each diagnosis in each year, we assessed the association between race and LOS by fitting a generalized linear mixed effects model with a negative binomial distribution, accounting for clustering and confounding. Using descriptive statistics, we compared associations between the 2 years for trends over time. RESULTS: Our analysis included >450 000 admissions and revealed significantly longer LOS for Black, Hispanic, and/or Asian American or Pacific Islander, Native American, and other children in 8 of the 10 diagnoses in 2016, with mixed changes over time. Three new disparities emerged in 2019. The largest disparities were for Black children in most diagnoses. CONCLUSIONS: Kids' Inpatient Database data showed longer LOS for children of historically marginalized race/ethnicity with common pediatric inpatient diagnoses, which largely persisted from 2016 to 2019. There is no plausible biological explanation for these findings, and inequities in social needs, access to care, and quality of care likely contribute. Future directions include further study to understand and address contributing factors.

Employment trajectories of young women with breast cancer: an ongoing prospective cohort study in Italy and Switzerland.

PURPOSE: Despite extensive research on cancer and work-related outcomes, evidence from longitudinal cohort studies is limited, especially in young women with breast cancer (BC). We aimed to investigate employment trajectories in young BC survivors and to identify potential factors associated with changes in work activity. METHODS: The HOHO European prospective multicenter cohort study enrolled 300 young women (≤ 40 years) with newly diagnosed BC. Women completed surveys at baseline and every 6 months for 3 years, then yearly for up to 10 years to assess, among other variables, employment status, sociodemographic, medical, and treatment data. Symptoms were assessed by the Breast Cancer Prevention Trial symptom scales and single items from the Cancer Rehabilitation Evaluation System. Univariable and multivariable multinomial logistic regression analyses identified factors associated with changes in employment status. RESULTS: Among the 245 women included in this analysis, 85% were employed at the last individual post-baseline assessment (1 to 10 years). At 5 years, women had a 29.4% probability (95% CI: 23.6-35.5) of experiencing any reduction and a 14.9% probability (95% CI: 10.6-19.9) of experiencing any increase in work activities. Being enrolled in Switzerland (vs. Italy) and reporting more trouble in performing daily activities were significantly associated with work reduction. CONCLUSION: Our results suggest that most young BC survivors remain employed in the long-term. IMPLICATIONS FOR CANCER SURVIVORS: Regular evaluation of symptoms which may interfere with daily life and identification of financial discomfort is critical in providing timely and individually tailored interventions and in limiting unwanted reductions in work activities.

Guidance for Structuring a Pediatric Intermediate Care Unit.

The purpose of this policy statement is to update the 2004 American Academy of Pediatrics clinical report and provide enhanced guidance for institutions, administrators, and providers in the development and operation of a pediatric intermediate care unit (IMCU). Since 2004, there have been significant advances in pediatric medical, surgical, and critical care that have resulted in an evolution in the acuity and complexity of children potentially requiring IMCU admission. A group of 9 clinical experts in pediatric critical care, hospital medicine, intermediate care, and surgery developed a consensus on priority topics requiring updates, reviewed the relevant evidence, and, through a series of virtual meetings, developed the document. The intended audience of this policy statement is broad and includes pediatric critical care professionals, pediatric hospitalists, pediatric surgeons, other pediatric medical and surgical subspecialists, general pediatricians, nurses, social workers, care coordinators, hospital administrators, health care funders, and policymakers, primarily in resource-rich settings. Key priority topics were delineation of core principles for an IMCU, clarification of target populations, staffing recommendations, and payment.

Reviewer Feedback for Abstract Submissions to the Pediatric Academic Societies Meeting: A Pilot Project.

PURPOSE: To describe and evaluate a pilot project to provide reviewer comments to authors who submitted abstracts to the Hospital-based medicine topic area for the Pediatric Academic Societies (PAS) 2021 annual meeting METHODS: Abstract reviewers were encouraged via email to include reviewer comments for authors in their abstract reviews. Unedited comments were emailed to authors shortly after the abstract decision notifications were sent. We quantified the number of reviewers who commented per abstract. Additionally, we surveyed authors and reviewers to evaluate the perceived impact of the pilot project. RESULTS: For 123 abstracts submitted to the Hospital-based medicine topic area, every abstract received comments from at least one reviewer, and a median (IQR) of 4 (3-5) reviewers commented per abstract. The response rates for the author and reviewer surveys were 61/114 (54%) and 54/84 (64%), respectively, and both groups of respondents generally favored the pilot program. The majority of authors (59%) made changes to their project based on the feedback provided and 96% reported that they would like to continue to receive reviewer feedback for future PAS abstract submissions. Reviewers reported spending a mean of 11 minutes reviewing each abstract. Most (85%) felt that they spent the same or slightly more (1%-25%) time reviewing than in prior years. Multiple open-ended comments were provided, largely positive. CONCLUSION: A pilot program to incorporate reviewer feedback into abstract decision notification for a large national research meeting was successful. This approach should be considered for future meetings to enhance this integral component of academic development.

Adult T-Cell Leukemia-Lymphoma Presenting Concurrently with Myelopathy.

Human T-cell leukemia virus type 1 (HTLV-1) is an oncogenic retrovirus. Of the approximate ten to twenty million people currently infected worldwide, 4-9% of infected individuals develop adult T-cell leukemia/lymphoma (ATLL) or HTLV-associated myelopathy/tropical spastic paresis (HAM/TSP) in their lifetime. The current report is based on a patient who presented concurrently with CD30+ lymphoma subtype ATLL and HAM/TSP. The patient's ATLL responded to brentuximab-vedotin-based chemotherapy; however, HAM/TSP did not improve. The patient's peripheral blood mononuclear cells were cultured and injected into immunodeficient mice, and the mice developed massive organ involvement and chronic lymphocytic leukemia-subtype ATLL. This case study is novel in the findings of concurrent development of ATLL and HAM/TSP, the response to brentuximab-vedotin chemotherapy, and the use HTLV-1 helix basic zipper protein-targeted probe for RNAscope for diagnosis.

Contemporary treatment patterns and survival of cervical cancer patients in Ethiopia.

BACKGROUND: Cervical cancer is the second commonly diagnosed cancer and the second leading cause of cancer death in women in Ethiopia, with rates among the highest worldwide. However, there are limited data on cervical cancer treatment patterns and survival in the country. Herein, we examine treatment patterns and survival of cervical cancer patients treated in Tikur Anbessa Hospital Radiotherapy Center (TAHRC), the only hospital with radiotherapy facility in the country. METHODS: Women with histologically verified cervical cancer who were seen in 2014 (January 1, 2014 to December 31, 2014) at TAHRC were included. Information about clinical characteristics and treatments were extracted from the patients' medical record files. The information on vital status was obtained from medical chart and through telephone calls. RESULT: Among 242 patients included in the study, the median age at diagnosis was 48 years. The median waiting time for radiotherapy was 5.6 months (range 2 to 9 months). Stage migration occurred in 13% of patients while waiting for radiotherapy. Consequently, the proportion of patients with stage III or IV disease increased from 66% at first consultation to 74% at the initiation of radiotherapy. Among 151 patients treated with curative intent, only 34 (22.5%) of the patients received concurrent chemotherapy while the reaming patients received radiotherapy alone. The 5-year overall survival rate was 28.4% (20.5% in the worst-case scenario). As expected, survival was lower in patients with advanced stage at initiation of radiotherapy and in those treated as palliative care. CONCLUSION: The survival of cervical cancer patients remains low in Ethiopia because of late presentation and delay in receipt of radiotherapy, leading to stage migration in substantial proportion of the cases. Concerted and coordinated multisectoral efforts are needed to promote early presentation of cervical cancer and to shorten the unacceptable, long waiting time for radiotherapy.

Combined, patient-level, analysis of two randomised trials evaluating the addition of denosumab to standard first-line chemotherapy in advanced NSCLC - The ETOP/EORTC SPLENDOUR and AMGEN-249 trials.

INTRODUCTION: The efficacy of adding denosumab to standard first-line chemotherapy for advanced NSCLC patients has been evaluated in two separate randomised trials (SPLENDOUR and AMGEN-249). In this pooled analysis, we will assess the combination-treatment effect in the largest available population, in order to conclude about the potential impact of denosumab in NSCLC. METHODS: Both trials included in this combined analysis, were randomised (SPLENDOUR 1:1, AMGEN-249 2:1) multi-centre trials stratified by histology, bone metastasis, geographical region and for SPLENDOUR only, ECOG PS. Cox proportional hazards models, were used to assess the treatment effect with respect to overall survival (OS; primary endpoint) and progression-free survival (PFS; secondary endpoint). Heterogeneity between trials was assessed, and subgroup analyses were performed. RESULTS: The pooled analysis was based on 740 randomised patients (SPLENDOUR:514; AMGEN-249:226), with 407 patients in the chemotherapy-denosumab arm and 333 in the chemotherapy-alone arm. In the chemotherapy-denosumab arm, at a median follow-up of 22.0 months, 277 (68.1%) deaths were reported with median OS 9.2 months (95%CI:[8.0-10.7]), while in the chemotherapy-alone arm, with similar median follow-up of 20.3 months, 230 (69.1%) deaths with median OS 9.9 months (95%CI:[8.2-11.2]). No significant denosumab effect was found (HR = 0.98; 95%CI:[0.82-1.18]; P = 0.85). Among subgroups, interaction was found between treatment and histology subtypes (P = 0.020), with a statistically significant benefit in the squamous group (HR = 0.70; 95%CI:[0.49-0.98]; P = 0.038), from 7.6 to 9.0 months median OS. With respect to PFS, 363 (89.2%) and 298 (89.5%) events were reported in the chemotherapy-denosumab and chemotherapy-alone arms, respectively, with corresponding medians 4.8 months (95%CI:[4.4-5.3]) and 4.9 months (95%CI:[4.3-5.4]). HR for PFS was 0.97(95%CI:[0.83-1.15]; P = 0.76), indicating that no significant denosumab benefit existed for PFS. CONCLUSION: In this pooled analysis, no statistically significant improvement was shown in PFS/OS with the combination of denosumab and chemotherapy for advanced NSCLC and no meaningful benefit in any of the subgroups.

Targeting NF-κB with Nanotherapy in a Mouse Model of Adult T-Cell Leukemia/Lymphoma.

Adult T-cell leukemia/lymphoma (ATLL) is an aggressive, clonal malignancy of mature T cells caused by human T-cell leukemia virus type 1. Although it is a rare tumor type, it serves as an excellent model of a virus driven process that transforms cells and engenders a highly malignant tumor that is extraordinarily difficult to treat. The viral transcriptional transactivator (Tax) in the HTLV-1 genome directly promotes tumorigenesis, and Tax-induced oncogenesis depends on its ability to constitutively activate NF-κB signaling. Accordingly, we developed and evaluated a nano-delivery system that simultaneously inhibits both canonical (p65) and noncanonical (p100) NF-κB signaling pathways locally in tumors after systemic administration. Our results demonstrate that siRNA is delivered rapidly to ATLL tumors after either i.p. or i.v. injection. The siRNA treatment significantly reduced both p65 and p100 mRNA and protein expression. Anti-NF-κB nanotherapy significantly inhibited tumor growth in two distinct tumor models in mice: a spontaneous Tax-driven tumor model, and a Tax tumor cell transplant model. Moreover, siRNA nanotherapy sensitized late-stage ATLL tumors to the conventional chemotherapeutic agent etoposide, indicating a pleiotropic benefit for localized siRNA nanotherapeutics.

Availability of Pediatric Inpatient Services in the United States.

OBJECTIVES: We sought to evaluate trends in pediatric inpatient unit capacity and access and to measure pediatric inpatient unit closures across the United States. METHODS: We performed a retrospective study of 4720 US hospitals using the 2008-2018 American Hospital Association survey. We used linear regression to describe trends in pediatric inpatient unit and PICU capacity. We compared trends in pediatric inpatient days and bed counts by state. We examined changes in access to care by calculating distance to the nearest pediatric inpatient services by census block group. We analyzed hospital characteristics associated with pediatric inpatient unit closure in a survival model. RESULTS: Pediatric inpatient units decreased by 19.1% (34 units per year; 95% confidence interval [CI] 31 to 37), and pediatric inpatient unit beds decreased by 11.8% (407 beds per year; 95% CI 347 to 468). PICU beds increased by 16.0% (66.9 beds per year; 95% CI 53 to 81), primarily at children's hospitals. Rural areas experienced steeper proportional declines in pediatric inpatient unit beds (-26.1% vs -10.0%). Most states experienced decreases in both pediatric inpatient unit beds (median state -18.5%) and pediatric inpatient days (median state -10.0%). Nearly one-quarter of US children experienced an increase in distance to their nearest pediatric inpatient unit. Low-volume pediatric units and those without an associated PICU were at highest risk of closing. CONCLUSIONS: Pediatric inpatient unit capacity is decreasing in the United States. Access to inpatient care is declining for many children, particularly those in rural areas. PICU beds are increasing, primarily at large children's hospitals. Policy and surge planning improvements may be needed to mitigate the effects of these changes.

Epigenomic regulation of human T-cell leukemia virus by chromatin-insulator CTCF.

Human T-cell leukemia virus type 1 (HTLV-1) is a retrovirus that causes an aggressive T-cell malignancy and a variety of inflammatory conditions. The integrated provirus includes a single binding site for the epigenomic insulator, CCCTC-binding protein (CTCF), but its function remains unclear. In the current study, a mutant virus was examined that eliminates the CTCF-binding site. The mutation did not disrupt the kinetics and levels of virus gene expression, or establishment of or reactivation from latency. However, the mutation disrupted the epigenetic barrier function, resulting in enhanced DNA CpG methylation downstream of the CTCF binding site on both strands of the integrated provirus and H3K4Me3, H3K36Me3, and H3K27Me3 chromatin modifications both up- and downstream of the site. A majority of clonal cell lines infected with wild type HTLV-1 exhibited increased plus strand gene expression with CTCF knockdown, while expression in mutant HTLV-1 clonal lines was unaffected. These findings indicate that CTCF binding regulates HTLV-1 gene expression, DNA and histone methylation in an integration site dependent fashion.

The Future of Inpatient Community Hospital Care: Is There One?

Community hospital inpatient pediatric programs face a variety of challenges including financial instability, variable censuses, difficulty maintaining qualified staff, and a lack of focus for the hospital. With the addition of new payment models, such as bundled payments and global budgets, along with a global pandemic, the future of community hospital pediatric inpatient care is uncertain at best. In this article we summarize the challenges, opportunities, and potential solutions to maintaining high-quality care for hospitalized children in community hospitals.

Prolonged rituximab maintenance in follicular lymphoma patients: long-term results of the SAKK 35/03 randomized trial.

The Swiss Group for Clinical Cancer Research (SAKK) conducted the SAKK 35/03 randomized trial (NCT00227695) to investigate different rituximab monotherapy schedules in patients with follicular lymphoma (FL). Here, we report their long-term treatment outcome. Two-hundred and seventy FL patients were treated with 4 weekly doses of rituximab monotherapy (375 mg/m2); 165 of them, achieving at least a partial response, were randomly assigned to maintenance rituximab (375 mg/m2 every 2 months) on a short-term (4 administrations; n = 82) or a long-term (up to a maximum of 5 years; n = 83) schedule. The primary end point was event-free survival (EFS). At a median follow-up period of 10 years, median EFS was 3.4 years (95% confidence interval [CI], 2.1-5.5) in the short-term arm and 5.3 years (95% CI, 3.5-7.5) in the long-term arm. Using the prespecified log-rank test, this difference is not statistically significant (P = .39). There also was not a statistically significant difference in progression-free survival or overall survival (OS). Median OS was 11.0 years (95% CI, 11.0-NA) in the short-term arm and was not reached in the long-term arm (P = .80). The incidence of second cancers was similar in the 2 arms (9 patients after short-term maintenance and 10 patients after long-term maintenance). No major late toxicities emerged. No significant benefit of prolonged maintenance became evident with longer follow-up. Notably, in symptomatic patients in need of immediate treatment, the 10-year OS rate was 83% (95% CI, 73-89%). These findings indicate that single-agent rituximab may be a valid first-line option for symptomatic patients with advanced FL.

Interferon regulatory factor 4 as a therapeutic target in adult T-cell leukemia lymphoma.

BACKGROUND: Adult T-cell leukemia lymphoma (ATLL) is a chemotherapy-resistant malignancy with a median survival of less than one year that will afflict between one hundred thousand and one million individuals worldwide who are currently infected with human T-cell leukemia virus type 1. Recurrent somatic mutations in host genes have exposed the T-cell receptor pathway through nuclear factor κB to interferon regulatory factor 4 (IRF4) as an essential driver for this malignancy. We sought to determine if IRF4 represents a therapeutic target for ATLL and to identify downstream effectors and biomarkers of IRF4 signaling in vivo. RESULTS: ATLL cell lines, particularly Tax viral oncoprotein-negative cell lines, that most closely resemble ATLL in humans, were sensitive to dose- and time-dependent inhibition by a next-generation class of IRF4 antisense oligonucleotides (ASOs) that employ constrained ethyl residues that mediate RNase H-dependent RNA degradation. ATLL cell lines were also sensitive to lenalidomide, which repressed IRF4 expression. Both ASOs and lenalidomide inhibited ATLL proliferation in vitro and in vivo. To identify biomarkers of IRF4-mediated CD4 + T-cell expansion in vivo, transcriptomic analysis identified several genes that encode key regulators of ATLL, including interleukin 2 receptor subunits α and ß, KIT ligand, cytotoxic T-lymphocyte-associated protein 4, and thymocyte selection-associated high mobility group protein TOX 2. CONCLUSIONS: These data support the pursuit of IRF4 as a therapeutic target in ATLL with the use of either ASOs or lenalidomide.

Prospective long-term follow-up after first-line subcutaneous cladribine in hairy cell leukemia: a SAKK trial.

Hairy cell leukemia (HCL) remains an incurable disease. However, first-line treatment with either intravenous or subcutaneous cladribine generally leads to long-lasting remissions. Although there are excellent long-term data for intravenous application, similar data regarding subcutaneous administration are lacking. We therefore analyzed the long-term outcome of 3 prospective multicenter clinical trials on subcutaneous cladribine performed by the Swiss Group for Clinical Cancer Research (SAKK), which recruited 221 patients with classical HCL between 1993 and 2005. Median overall survival from start of treatment was not reached. Pretreatment anemia, higher Eastern Cooperative Oncology Group score, and higher age were associated with poorer overall survival in multivariable analysis, whereas early progression at 24 and 36 months had no significant impact on overall survival. Second-line treatment was necessary in 53 (23.7%) patients after a median of 5 (range, 0.2-20.4) years, and first retreatment was mainly monotherapy with cladribine (66%) or rituximab (15.1%) or a combination of these drugs (15.1%). A total of 44 (19.9%) patients developed second primary malignancies with a median time to occurrence of 5.7 (range, 0.01-17.5) years. Second primary malignancies were the main cause for death (14; 27.5%). Compared with a matched normal Swiss population, the incidence of second primary malignancies was not increased. However, survival of patients with HCL was slightly inferior by comparison (P = .036). In conclusion, the outcome of HCL patients treated with subcutaneous cladribine is excellent, and in most patients, 1 cycle of subcutaneous cladribine is sufficient for long-term disease control.

Developing Content for Pediatric Hospital Medicine Certification Examination Using Practice Analysis.

OBJECTIVES: The American Board of Pediatrics (ABP) and the Pediatric Hospital Medicine (PHM) subboard developed a content outline to serve as a blueprint for the inaugural certification examination through practice analysis. The systematic approach of practice analyses process is described in the study. METHODS: A diverse, representative panel of 12 pediatric hospitalists developed the draft content outline using multiple resources (publications, textbooks, PHM Core Competencies, PHM fellow's curriculum, etc). The panel categorized practice knowledge into 13 domains and 202 subdomains. By using the ABP database self-defined practicing pediatric hospitalists were identified. Participants rated the frequency and criticality of content domains and subdomains along with providing open-ended comments. RESULTS: In total, 1449 (12.1%) generalists in the ABP database self-identified as pediatric hospitalists, and 800 full-time pediatric hospitalists responded. The content domains that were rated as highly critical and frequently required in practice were weighted more heavily (ie, the percentage of examination questions associated with a domain) than the less critical and less frequently rated. Both community and noncommunity pediatric hospitalists rated domains similarly (P = .943). Subdomain and preliminary weights were rated with similar means and SDs in the majority of topics. CONCLUSIONS: There was concordance in the rating of domain and universal tasks among both community and noncommunity hospitalists. The areas of significant differences, although minor, could be explained by difference in practice settings. The practice analysis approach was structured, engaged the PHM community, reflected the breadth and depth of knowledge required for PHM practice, and used an iterative process to refine the final product.