Michael Chang is a Clinical Instructor in Stanford's Department of Otolaryngology - Head & Neck Surgery and currently completing a fellowship in Rhinology & Endoscopic Skull Base Surgery as part of a 2-year track dedicated to both clinical training and research. He completed his residency in Otolaryngology - Head & Neck Surgery at Stanford, where he was awarded Resident Teacher of the Year. His main research interests include outcomes in endoscopic sinus and skull base surgery, new surgical technologies, and video and social media applications in healthcare.
- Skull Base
Clinical Instructor, Otolaryngology - Head & Neck Surgery Divisions
Internship: Stanford University Dept of General Surgery (2017) CA
Residency: Stanford University Otolaryngology Residency (2021) CA
Medical Education: Yale University Office of the Registrar (2016) CT
M.D., Yale University School of Medicine (2016)
B.S., Brown University (2011)
Oral Corticosteroids Following Endoscopic Sinus Surgery for Chronic Rhinosinusitis Without Nasal Polyposis: A Randomized Clinical Trial.
JAMA otolaryngology-- head & neck surgery
Although oral corticosteroids are commonly prescribed following endoscopic sinus surgery (ESS) for chronic rhinosinusitis (CRS) without nasal polyposis, there are little data to suggest that this is a beneficial practice.To assess the efficacy of oral corticosteroids following ESS in CRS without polyps.This prospective double-blinded, placebo-controlled, randomized noninferiority clinical trial conducted in a single academic tertiary rhinology practice included adults with CRS without polyps undergoing ESS. Of 81 patients recruited, 72 completed the study.Patients were randomized into 2 treatment groups: a 12-day postoperative taper of oral prednisone vs matched placebo tablets. All study patients also received a uniform 2-week postoperative regimen of oral antibiotics, fluticasone nasal spray, and saline rinses.The primary outcome measures were Sinonasal Outcome Test-22 (SNOT-22) scores and Lund-Kennedy endoscopy scores, collected preoperatively and postoperatively at 1 week, 1 month, 3 months, and 6 months. Scores were compared between treatment groups at each time point using longitudinal difference between treatment groups and analyzed using 2-way, repeated measures analysis of variance. Secondary outcome measures included treatment-related adverse effects.Overall, 72 patients (mean [SD] age, 49.4 [14.9] years; 36 men, 36 women) completed the study, with 33 in the prednisone arm and 39 in the placebo arm. When comparing longitudinal differences between treatment groups, there was no clinically meaningful difference observed in SNOT-22 total (F = 1.71, η2 = 0.01 [95% CI, 0.00-0.05]) or Lund-Kennedy scores (F = 1.23, η2 = 0.02 [95% CI, 0.00-0.50]). In SNOT-22 subdomain analyses, there was no clinically meaningful difference between treatment groups for rhinologic, extranasal rhinologic, ear/facial, or sleep subdomains. However, the prednisone group had worse longitudinal scores for psychological dysfunction compared with the placebo group (F = 3.18, η2 = 0.05 [95% CI, 0.02-0.09]). Reported adverse effects were similar between the 2 treatment groups.In this randomized clinical trial of patients with CRS without polyps, oral prednisone following ESS conferred no additional benefit over placebo in terms of SNOT-22 total scores, SNOT-22 rhinologic subscores, or Lund-Kennedy endoscopy scores up to 6 months after surgery. Patients receiving prednisone, however, did demonstrate worse SNOT-22 psychologic subdomain scores. These results suggest that the risks of oral corticosteroids may outweigh the benefits; thus use of oral corticosteroids after ESS for CRS without polyps should be carefully considered.ClinicalTrials.gov Identifier: NCT02748070.
View details for DOI 10.1001/jamaoto.2021.0011
View details for PubMedID 33662124
Hemodynamic changes in patients undergoing office-based sinus procedures under local anesthesia.
International forum of allergy & rhinology
2020; 10 (1): 114–20
The objective of this study is to characterize changes in hemodynamics, pain, and anxiety during office-based endoscopic sinus procedures performed under local anesthesia.We conducted a prospective study of adults undergoing in-office endoscopic sinus procedures under local anesthesia. Patients with American Society of Anesthesiologists (ASA) Physical Status Classification System class 1 or 2 were included. Anesthesia was administered by topical 4% lidocaine/oxymetazoline and submucosal injection of 1% lidocaine/1:200,000 epinephrine. Vital signs and pain were measured at baseline, postinjection, and 5-minute intervals throughout the procedure. Anxiety levels were scored using the State-Trait Anxiety Inventory (STAI). Univariate and multivariate regression analyses were performed to identify factors significantly associated with changes in each hemodynamic metric.Twenty-five patients were studied. This cohort was 52% male, mean age of 57.8 ± 14.4 years, and Charlson Comorbidity Index (CCI) median of 2. Mean procedure duration was 25.0 ± 10.3 minutes. Mean maximal increase in systolic blood pressure (SBP) was 24.6 ± 17.8 mmHg from baseline. Mean maximal heart rate increase was 22.8 ± 10.8 beats per minute (bpm) from baseline. In multivariate regression analysis, when accounting for patient age, cardiac comorbidity, CCI, and ASA, older age was significantly associated with an increase of >20 mmHg in SBP (p = 0.043). Mean pain score during procedures was 1.5 ± 1.3 with a mean maximum of 4.0 ± 2.6. STAI anxiety scores did not change significantly from preprocedure to postprocedure (32.8 ± 11.6 to 31.0 ± 12.6, p = 0.46). No medical complications occurred.Although patients appear to tolerate office procedures well, providers should recognize the potential for significant fluctuations in blood pressure during the procedure, especially in older patients.
View details for DOI 10.1002/alr.22460
View details for PubMedID 31899857
The Effect of Endoscopic Sinus Surgery on Eustachian Tube Dysfunction Symptoms.
Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery
We assessed how eustachian tube dysfunction (ETD) changed with endoscopic sinus surgery (ESS) and identified factors associated with improvement.Retrospective chart review.Academic center.Patients undergoing ESS for chronic rhinosinusitis with and without nasal polyposis (CRSwNP, CRSsNP) or recurrent acute rhinosinusitis (RARS) completed the Eustachian Tube Dysfunction Questionnaire 7 (ETDQ-7) preoperatively and postoperatively at 2 weeks, 6 weeks, 3 months, and 6 months. Included in analyses were demographics, comorbidities, Sinonasal Outcome Test 22 (SNOT-22), radiographic score, endoscopy score, procedure, and medication use. Regression analysis identified factors associated with improvement, defined as ΔETDQ-7 >3.5.In total, 302 patients were studied. ETD prevalence was 68% in CRSsNP, 48% in CRSwNP, and 88% in RARS. Patients with ETD had a mean baseline ETDQ-7 of 25.8 ± 8.0 and improved postoperatively at 2 weeks (19.9 ± 8.1, P < .001), 6 weeks (17.8 ± 9.3, P < .001), 3 months (16.8 ± 8.5, P < .001), and 6 months (16.4 ± 7.9, P < .001). At 6 months, ETD improved in 89% of patients with CRSsNP, 68% with CRSwNP, and 78% with RARS. On multivariate analysis, ETD improvement was associated with higher preoperative ETDQ-7 score (adjusted odds ratio [aOR], 1.12; 95% confidence interval [CI], 1.04-1.22; P = .030), higher preoperative SNOT-22 score (aOR, 1.02; 95% CI, 1.02-1.08; P = .001), higher preoperative SNOT-22 ear subscore (aOR, 1.27; 95% CI, 1.02-1.65; P = .034), posterior ethmoidectomy (aOR, 1.59; 95% CI, 1.22-4.92; P = .025), and postoperative corticosteroid spray use (aOR, 1.57; 95% CI, 1.17-1.66; P = .008).ETD symptoms often improve following ESS. Factors associated with improvement include higher preoperative disease burden, posterior ethmoidectomy, and postoperative corticosteroid spray.4.
View details for DOI 10.1177/0194599820917396
View details for PubMedID 32343633
Update on long-term outcomes for chronic rhinosinusitis in cystic fibrosis.
Current opinion in otolaryngology & head and neck surgery
PURPOSE OF REVIEW: This article reviews the existing body of literature regarding long-term outcomes of various treatments for chronic rhinosinusitis (CRS) in the cystic fibrosis population.RECENT FINDINGS: The management of CRS in cystic fibrosis involves a multitude of medical and surgical therapies. Despite their high usage amongst clinicians, corticosteroids and antibiotics currently have little outcome data supporting their use. There is emerging evidence demonstrating beneficial outcomes for DNAse mucolytics and molecular modulators of cystic fibrosis transmembrane conductor regulator (CFTR). Endoscopic sinus surgery (ESS) improves sinonasal outcomes in cystic fibrosis CRS; however, the benefit on pulmonary outcomes remains unclear.SUMMARY: Successful management of CRS in cystic fibrosis requires multimodal and multidisciplinary care. The long-term outcome data is variable for different treatment modalities. There is recent evidence supporting the role of DNAse mucolytics, CFTR-targeting therapies, and ESS in management of cystic fibrosis CRS.
View details for DOI 10.1097/MOO.0000000000000596
View details for PubMedID 31815863
Cryosurgical ablation for treatment of rhinitis: A prospective multicenter study.
To assess the efficacy and safety of cryoablation of the posterior nasal nerve (PNN) for treatment of chronic rhinitis.This was a prospective single-arm trial of 98 adult patients at six U.S. centers with chronic allergic and nonallergic rhinitis. PNN cryoablation was performed in-office under local anesthesia using a handheld device. Patients discontinued use of intranasal ipratropium 3 days prior to treatment and throughout the study period. Reflective Total Nasal Symptom Score (rTNSS) was measured at pretreatment baseline and posttreatment at 1 month, 3 months, 6 months, and 9 months. The Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) was completed at pretreatment and 3 months posttreatment. Adverse effects and postprocedure medication usage were recorded.Ninety-eight procedures (100%) were successfully completed. rTNSS significantly improved over pretreatment baseline (6.1 ± 1.9) at 1 month (2.9 ± 1.9, P < 0.001), 3 months (3.0 ± 2.3, P < 0.001), 6 months (3.0 ± 2.1, P < 0.001), and 9 months (3.0 ± 2.4, P < 0.001) postprocedure. Nasal congestion and rhinorrhea subscores improved significantly at all time points (P < 0.001). Both allergic and nonallergic rhinitis subcohorts showed improvement (P < 0.001), with a comparable degree of improvement between groups. RQLQ significantly improved over pretreatment baseline (3.0 ± 1.0) at 3 months (1.5 ± 1.0, P < 0.001), and all RQLQ subdomains demonstrated improvement. Of 54 patients using intranasal medication at baseline, 19 (35.2%) were able to discontinue use. Twenty-nine adverse effects were reported, including headache, epistaxis, and sinusitis.Cryoablation of the PNN for chronic rhinitis is safe and can result in relief of nasal symptoms and improvements in quality of life.4 Laryngoscope, 2019.
View details for DOI 10.1002/lary.28301
View details for PubMedID 31566744
- Challenging our assumptions: oral corticosteroids and chronic rhinosinusitis without nasal polyposis. International forum of allergy & rhinology 2021
Long-Term Outcomes of Inferior Meatus Augmentation Procedure to Treat Empty Nose Syndrome.
OBJECTIVES/HYPOTHESIS: We sought to report the long-term, symptom-focused, prospective outcomes in empty nose syndrome (ENS) patients after undergoing inferior meatus augmentation procedure (IMAP) through use of four validated questionnaires: Empty Nose Syndrome 6-Item Questionnaire (ENS6Q), 22-item Sino-Nasal Outcome Test (SNOT-22), Generalized Anxiety Disorder 7-Item Scale (GAD-7), and Patient Health Questionnaire-9 (PHQ-9).STUDY DESIGN: Prospective case series.METHODS: A single-center prospective case series was performed for patients diagnosed with ENS who underwent IMAP between July 2017 and February 2020. Diagnosis of ENS was based on the following criteria: 1) reported discomfort with nasal breathing and/or paradoxical nasal obstruction after inferior turbinate reduction, 2) a positive ENS6Q score of at least 11, and 3) a positive cotton test. Questionnaire responses were recorded prior to surgery as well as 1, 3, 6, and 12months postoperatively.RESULTS: Seventeen eligible patients were included. Mean ENS6Q scores were significantly reduced at all postoperative time points (p<.0001, p<.0001, p<.0001, p=.0003). Of the six ENS6Q subdomains, five (suffocation, dryness, sense of diminished airflow, nasal crusting, and nasal burning) were significantly reduced 1-year postoperatively (p<.0001, p=.0004, p=.0136, p=.0114, p=.0080, respectively). SNOT-22 scores were significantly reduced at all time points (p=.0021, p=.0227, p=.0004, and p=.0025). Of the SNOT-22 subdomains, the sleep subdomain was significantly reduced 1-year postoperatively (p=.0432). Low baseline GAD-7 and PHQ-9 scores were recorded at 7 and 9.4, respectively, and although scores at all postoperative time points were reduced, there was no statistical significance.CONCLUSION: IMAP via implant of cadaveric rib cartilage provides significant, long-term improvements in ENS-specific and general sinonasal symptoms.LEVEL OF EVIDENCE: IV Laryngoscope, 2021.
View details for DOI 10.1002/lary.29593
View details for PubMedID 33991117
International Consensus Statement on Rhinology and Allergy: Rhinosinusitis.
International forum of allergy & rhinology
BACKGROUND: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR-RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR-RS-2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence-based findings of the document.METHODS: ICAR-RS presents over 180 topics in the forms of evidence-based reviews with recommendations (EBRRs), evidence-based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary.RESULTS: ICAR-RS-2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence-based management algorithm is provided.CONCLUSION: This ICAR-RS-2021 executive summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS. This article is protected by copyright. All rights reserved.
View details for DOI 10.1002/alr.22741
View details for PubMedID 33236525
Retrograde parotidectomy under local anesthesia for benign, malignant, and inflammatory lesions.
American journal of otolaryngology
OBJECTIVE: To report the patient selection, surgical technique, and outcomes of parotidectomy using local anesthesia under monitored anesthesia care (MAC).METHODS: A retrospective chart review was performed for patients undergoing parotidectomy under local anesthesia at an academic head and neck surgery center.RESULTS: Six patients deemed high risk for general anesthesia (GA) due to medical comorbidities or with a strong preference to avoid GA underwent parotidectomy using local anesthesia and MAC. Parotidectomy was performed for several indications, including benign tumors, malignant tumors, and chronic sialadenitis. Mean age of patients was 78.0 ± 7.9 years, and all had an American Society of Anesthesia score ≥ 2 and Charlson comorbidity index ≥4. Mean operative time was 102.8 ± 38.3 min, comparable to that of parotidectomy under general anesthesia. No major complications occurred. Minor complications included three cases of temporary postoperative facial nerve weakness limited to 1-2 lower division branches. At most recent follow up (10 to 48 months), all patients were medically stable and disease free.CONCLUSION: In carefully selected patients, parotidectomy under local anesthesia is a viable treatment alternative that can be offered to patients. Successful outcomes require preoperative counseling, meticulous technique, and close collaboration with anesthesia colleagues.
View details for PubMedID 30691973
Operative Management of Vocal Fold Avulsion Following Pediatric Laryngotracheal Separation.
Ear, nose, & throat journal
Laryngotracheal disruption in children is rare but life-threatening, and endolaryngeal injuries may go overlooked. We present the case of a 10-year-old boy who sustained near-complete laryngotracheal separation, multiple laryngeal fractures, and arytenoid and vocal fold avulsion following blunt cervical trauma. These injuries were not identified radiographically and only became apparent intraoperatively. Following surgical repair, the patient was successfully decannulated, eating a normal diet, and had a serviceable speaking voice within 2 months. In children, the diagnosis of severe endolaryngeal injuries may be elusive and therefore require high degree of clinical suspicion. Surgical success requires accurate diagnosis and prompt intervention.
View details for DOI 10.1177/0145561319866821
View details for PubMedID 31558058
The 50 Most Cited Articles in Facial Plastic Surgery.
Aesthetic plastic surgery
2017; 41 (5): 1202-1207
Bibliometric analysis is a common method to determine the most influential articles in medical specialties, as it is an objective measure of peer recognition of scientific work. This study is the first bibliometric analysis of the literature in facial plastic surgery, to determine the most cited papers in the field. Bibliometric analysis was performed using the Science Citation Index from the Institute for Scientific Information, accessed through the Web of Science™. Filter terms relevant to the field of facial plastic surgery were used to identify the 50 most cited journal articles between 1900 and 2016. The median number of citations was 150 (range 116-1091). The articles spanned a wide range of topics in the field, with the most common topics being free flap reconstruction (n = 10), nasal surgery (n = 9), and rhytidectomy (n = 6). The majority of these articles (n = 29) presented findings supported by level IV or V evidence. This analysis provides an overview of the most cited articles in facial plastic surgery, many of which introduced some of the most fundamental principles and techniques in the field. These landmark articles represent important educational points that should be reviewed by all clinicians and trainees in this field. Level of Evidence III This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
View details for DOI 10.1007/s00266-017-0908-x
View details for PubMedID 28634701
Clinical and molecular insights into adenoid cystic carcinoma: Neural crest-like stemness as a target.
Laryngoscope investigative otolaryngology
2016; 1 (4): 60-77
This review surveys trialed therapies and molecular defects in adenoid cystic carcinoma (ACC), with an emphasis on neural crest-like stemness characteristics of newly discovered cancer stem cells (CSCs) and therapies that may target these CSCs.Articles available on Pubmed or OVID MEDLINE databases and unpublished data.Systematic review of articles pertaining to ACC and neural crest-like stem cells.Adenoid cystic carcinoma of the salivary gland is a slowly growing but relentless cancer that is prone to nerve invasion and metastases. A lack of understanding of molecular etiology and absence of targetable drivers has limited therapy for patients with ACC to surgery and radiation. Currently, no curative treatments are available for patients with metastatic disease, which highlights the need for effective new therapies. Research in this area has been inhibited by the lack of validated cell lines and a paucity of clinically useful markers. The ACC research environment has recently improved, thanks to the introduction of novel tools, technologies, approaches, and models. Improved understanding of ACC suggests that neural crest-like stemness is a major target in this rare tumor. New cell culture techniques and patient-derived xenografts provide tools for preclinical testing.Preclinical research has not identified effective targets in ACC, as confirmed by the large number of failed clinical trials. New molecular data suggest that drivers of neural crest-like stemness may be required for maintenance of ACC; as such, CSCs are a target for therapy of ACC.
View details for DOI 10.1002/lio2.22
View details for PubMedID 28894804
View details for PubMedCentralID PMC5510248
NOTCH1 and SOX10 are Essential for Proliferation and Radiation Resistance of Cancer Stem-Like Cells in Adenoid Cystic Carcinoma.
Clinical cancer research : an official journal of the American Association for Cancer Research
2016; 22 (8): 2083-95
Although the existence of cancer stem cells (CSC) in adenoid cystic carcinoma (ACC) has been proposed, lack of assays for their propagation and uncertainty about molecular markers prevented their characterization. Our objective was to isolate CSC from ACC and provide insight into signaling pathways that support their propagation.To isolate CSC from ACC and characterize them, we used ROCK inhibitor-supplemented cell culture, immunomagnetic cell sorting, andin vitro/in vivoassays for CSC viability and tumorigenicity.We identified in ACC CD133-positive CSC that expressed NOTCH1 and SOX10, formed spheroids, and initiated tumors in nude mice. CD133(+)ACC cells produced activated NOTCH1 (N1ICD) and generated CD133(-)cells that expressed JAG1 as well as neural differentiation factors NR2F1, NR2F2, and p27Kip1. Knockdowns ofNOTCH1, SOX10, and their common effectorFABP7had negative effects on each other, inhibited spheroidogenesis, and induced cell death pointing at their essential roles in CSC maintenance. Downstream effects ofFABP7knockdown included suppression of a broad spectrum of genes involved in proliferation, ribosome biogenesis, and metabolism. Among proliferation-linked NOTCH1/FABP7 targets, we identified SKP2 and its substrate p27Kip1. A γ-secretase inhibitor, DAPT, selectively depleted CD133(+)cells, suppressed N1ICD and SKP2, induced p27Kip1, inhibited ACC growthin vivo, and sensitized CD133(+)cells to radiation.These results establish in the majority of ACC the presence of a previously uncharacterized population of CD133(+)cells with neural stem properties, which are driven by SOX10, NOTCH1, and FABP7. Sensitivity of these cells to Notch inhibition and their dependence on SKP2 offer new opportunities for targeted ACC therapies.
View details for DOI 10.1158/1078-0432.CCR-15-2208
View details for PubMedID 27084744
View details for PubMedCentralID PMC4834904
Severe epistaxis due to aberrant vasculature in a patient with STAT-1 mutation.
Head & neck
2016; 38 (3): E68-70
Signal transducer and activator 1 (STAT-1) mutations are rare and have been implicated in combined immunodeficiency, enhanced tumorigenesis, and vascular defects.A 60-year-old woman with a novel STAT-1 mutation and resulting immunodeficiency, squamous cell carcinoma, and vascular disease presented with profuse epistaxis secondary to rupture of an aberrant artery that she developed in part because of this mutation. After unsuccessful posterior packing, embolization was initiated but subsequently aborted because of a bovine origin carotid artery and a history of multiple carotid dissections.After repeat posterior packing, hemostasis was achieved. No additional episodes of epistaxis occurred in the subsequent 13 months.Vascular anomalies can present challenges in epistaxis management. In patients with conditions known to cause vascular anomalies, it is critical to obtain vascular imaging before intervention.
View details for DOI 10.1002/hed.24165
View details for PubMedID 26445901
- Applications of 3-Dimensional Printing in Facial Plastic Surgery. Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons 2016; 74 (3): 427-8
High rate of bilaterality in internal auditory canal metastases.
American journal of otolaryngology
2015; 36 (6): 798-804
Presentation of three cases of metastatic carcinoma to the internal auditory canal bilaterally, as well as a systematic review of the literature regarding the characteristics of these lesions.Using a MEDLINE Ovid search (1946-2015), we identified and reviewed 102 cases of metastatic carcinoma to the internal auditory canal. Metrics recorded include: patient age, sex, tumor type, laterality, past oncologic history, co-occurring metastatic sites, clinical findings, radiographic findings, therapy received, and outcome. Cases of unilateral versus bilateral IAC were compared.Remarkably, 52.9% reported cases of internal auditory canal metastases have bilateral occurrence. The most common primary tumor sites for internal auditory canal metastases were lung (21.2%), skin (18.6%), and breast (16.7%), with lung and skin cancers having the highest rates of bilateral metastasis. Meningeal metastasis occurred at a much higher rate in bilateral cases (47.2%) versus unilateral cases (8.5%). Brain parenchymal metastasis also occurred at a higher rate in bilateral cases (38.2%) versus unilateral cases (19.2%). Outcomes for cases of internal auditory canal metastases are generally poor, with 56.3% of unilateral cases and 86.1% of bilateral cases reporting patient death within 5 years from diagnosis.In cases of internal auditory canal metastasis, clinicians should carefully assess for not only contralateral disease but also additional metastatic disease of the central nervous system. Rapid-onset hearing loss, tinnitus, vertigo, or facial palsy should raise suspicion for internal auditory canal metastasis, particularly in patients with a known oncologic history.
View details for DOI 10.1016/j.amjoto.2015.06.002
View details for PubMedID 26545474
Quantifying interhospital patient sharing as a mechanism for infectious disease spread.
Infection control and hospital epidemiology
2010; 31 (11): 1160-9
Assessments of infectious disease spread in hospitals seldom account for interfacility patient sharing. This is particularly important for pathogens with prolonged incubation periods or carrier states.We quantified patient sharing among all 32 hospitals in Orange County (OC), California, using hospital discharge data. Same-day transfers between hospitals were considered "direct" transfers, and events in which patients were shared between hospitals after an intervening stay at home or elsewhere were considered "indirect" patient-sharing events. We assessed the frequency of readmissions to another OC hospital within various time points from discharge and examined interhospital sharing of patients with Clostridium difficile infection.In 2005, OC hospitals had 319,918 admissions. Twenty-nine percent of patients were admitted at least twice, with a median interval between discharge and readmission of 53 days. Of the patients with 2 or more admissions, 75% were admitted to more than 1 hospital. Ninety-four percent of interhospital patient sharing occurred indirectly. When we used 10 shared patients as a measure of potential interhospital exposure, 6 (19%) of 32 hospitals "exposed" more than 50% of all OC hospitals within 6 months, and 17 (53%) exposed more than 50% within 12 months. Hospitals shared 1 or more patient with a median of 28 other hospitals. When we evaluated patients with C. difficile infection, 25% were readmitted within 12 weeks; 41% were readmitted to different hospitals, and less than 30% of these readmissions were direct transfers.In a large metropolitan county, interhospital patient sharing was a potential avenue for transmission of infectious agents. Indirect sharing with an intervening stay at home or elsewhere composed the bulk of potential exposures and occurred unbeknownst to hospitals.
View details for DOI 10.1086/656747
View details for PubMedID 20874503
View details for PubMedCentralID PMC3064463