Alex Dahlen
Alex Dahlen
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Clinical Associate Professor of Biostatistics
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Professional overview
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Alex Dahlen, PhD joins GPH as Director of the new Collaborative Statistical Core in the Department of Biostatistics. The goal of the Core is to collaborate widely throughout the School, to bring robust statistical methods and thoughtful study design to public health research, and to train the next generation of data scientists and statisticians in team science and applied statistics. Dr. Dahlen has nearly 10 years of experience working in collaborative statistics, across a variety of settings in and out of academia.
In his previous role as senior statistician in the Quantitative Sciences Unit of the Department of Medicine at Stanford University, Dr. Dahlen collaborated with physicians and clinical researchers on all aspects of research, including acting as lead statistician on grant applications and statistical author on numerous published manuscripts. He devotes a large portion of his time to mentoring junior scientists: providing hands-on coding lessons; overseeing analysis; offering study design and methodology tutorials; and lecturing about healthy research practices. Dr. Dahlen received his PhD in the physics of bubbles from Princeton University in 2011.
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Education
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BA, Theoretical and Mathematical Physics, Harvard University, Cambridge, MAPhD, Theoretical and Mathematical Physics, Princeton University, Princeton, NJ
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Honors and awards
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Pathology Health Equity Research Award at Stanford University (2023)
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Publications
Publications
A public health community health worker-delivered intervention to reduce human trafficking among Denotified Tribes in India: A protocol paper
AbstractDahlen, A., Dank, M., Zhang, S., Abeyta, S., Moton, L., Stoklosa, H., Cuadrado, N., Dahlen, A., & Farabee, D. J. (n.d.).Publication year
2025Journal title
PloS oneVolume
20Issue
3Page(s)
e0317733AbstractThe objective of this study is to evaluate an intervention designed to reduce human trafficking among Denotified Tribes (DNTs) in two regions of India. We will conduct a cluster-randomized controlled trial utilizing a participatory-designed, community health worker (CHW)- delivered public health intervention. CHWs will be trained to conduct anti-human-trafficking advocacy and psychological first aid (humane, supportive and practical assistance to people who are distressed) to DNT community members, and mobilize resources to ensure access to health and mental health services, education, livelihoods, and government benefits. This project leverages known effective, systemic, and sustainable approaches to reducing vulnerabilities to trafficking among DNT communities, through increased economic alternatives, health and mental health services guided by the trafficking-survivor-informed treatment protocols.Author Correction: Quantifying bias introduced by sample collection in relative and absolute microbiome measurements
AbstractDahlen, A., Maghini, D. G., Dvorak, M., Dahlen, A., Roos, M., Doyle, B., Kuersten, S., & Bhatt, A. S. (n.d.).Publication year
2024Journal title
Nature biotechnologyVolume
42Issue
8Page(s)
1313Abstract~Benchmarking commercial healthcare claims data
AbstractDahlen, A., Dahlen, A., Deng, Y., & Charu, V. (n.d.).Publication year
2024Journal title
medRxiv : the preprint server for health sciencesAbstractCommercial healthcare claims datasets represent a sample of the US population that is biased along socioeconomic/demographic lines; depending on the target population of interest, results derived from these datasets may not generalize. Rigorous comparisons of claims-derived results to ground-truth data that quantify this bias are lacking.Implementing adaptive e-learning for newborn care in Tanzania: an observational study of provider engagement and knowledge gains
AbstractDahlen, A., Meaney, P. A., Hokororo, A., Ndosi, H., Dahlen, A., Jacob, T., Mwanga, J. R., Kalabamu, F. S., Joyce, C. L., Mediratta, R., Rozenfeld, B., & others. (n.d.).Publication year
2024Journal title
BMJ OpenVolume
14Issue
2Page(s)
e077834Abstract~Incidence of Pediatric Urinary Tract Infections Before and During the COVID-19 Pandemic
AbstractDahlen, A., Liang, D., Wang, M. E., Dahlen, A., Liao, Y., Saunders, A. C., Coon, E. R., & Schroeder, A. R. (n.d.).Publication year
2024Journal title
JAMA network openVolume
7Issue
1Page(s)
e2350061AbstractUrinary tract infection (UTI) is common in children, but the population incidence is largely unknown. Controversy surrounds the optimal diagnostic criteria and how to balance the risks of undertreatment and overtreatment. Changes in health care use during the COVID-19 pandemic created a natural experiment to examine health care use and UTI diagnosis and outcomes.Point-of-care lung ultrasound for continuous positive airway pressure discontinuation in preterm infants
AbstractDahlen, A., Myers, F., Dasani, R., Tong, J., Vallandingham-Lee, S., Manipon, C., Dahlen, A., De Luca, D., Singh, Y., Davis, A. S., Chock, V. Y., & Bhombal, S. (n.d.).Publication year
2024Journal title
Journal of perinatology : official journal of the California Perinatal AssociationAbstractTo determine if the lung ultrasound score (LUS) is predictive of successful continuous positive airway pressure (CPAP) discontinuation in preterm neonates bornPrescribing Patterns of Nonrecommended Medications for Children With Acute COVID-19
AbstractDahlen, A., Burns, J. E., Dahlen, A., Bio, L. L. L., Chamberlain, L. J., Bassett, H. K., Ramaraj, R., Schwenk, H. T., Teufel, R. J., & Schroeder, A. R. (n.d.).Publication year
2024Journal title
PediatricsAbstractRepurposed medications for acute coronavirus disease 2019 (COVID-19) continued to be prescribed after results from rigorous studies and national guidelines discouraged use. We aimed to describe prescribing rates of nonrecommended medications for acute COVID-19 in children, associations with demographic factors, and provider type and specialty.Quantifying bias introduced by sample collection in relative and absolute microbiome measurements
AbstractDahlen, A., Maghini, D. G., Dvorak, M., Dahlen, A., Roos, M., Doyle, B., Kuersten, S., & Bhatt, A. S. (n.d.).Publication year
2024Journal title
Nature biotechnologyVolume
42Issue
2Page(s)
328-338AbstractTo gain insight into the accuracy of microbial measurements, it is important to evaluate sources of bias related to sample condition, preservative method and bioinformatic analyses. There is increasing evidence that measurement of the total count and concentration of microbes in the gut, or 'absolute abundance', provides a richer source of information than relative abundance and can correct some conclusions drawn from relative abundance data. However, little is known about how preservative choice can affect these measurements. In this study, we investigated how two common preservatives and short-term storage conditions impact relative and absolute microbial measurements. OMNIgene GUT OMR-200 yields lower metagenomic taxonomic variation between different storage temperatures, whereas Zymo DNA/RNA Shield yields lower metatranscriptomic taxonomic variation. Absolute abundance quantification reveals two different causes of variable Bacteroidetes:Firmicutes ratios across preservatives. Based on these results, we recommend OMNIgene GUT OMR-200 preservative for field studies and Zymo DNA/RNA Shield for metatranscriptomics studies, and we strongly encourage absolute quantification for microbial measurements.The Safety of Body Wraps on Skin-to-Skin Care in the Neonatal Population: A Pilot Study
AbstractDahlen, A., Freccero, A., Scala, M., McLeod, K. A. A., Donahue, B., Webb, M., Briggs, M., Najm, I., Sinha, M., Santagata, L., Dahlen, A., & Nasr, A. (n.d.).Publication year
2024Journal title
Advances in neonatal care : official journal of the National Association of Neonatal NursesVolume
24Issue
1Page(s)
E11-E19AbstractDespite well-established benefits of skin-to-skin care (SSC) for preterm infants and parents, standardized guidelines for implementation do not exist. Furthermore, the literature offers little evidence-based information to guide best practice.Therapeutic Hypothermia for Neonatal Hypoxic-Ischemic Encephalopathy: Reducing Variability in Practice through a Collaborative Telemedicine Initiative
AbstractDahlen, A., Leandro, D. M. K., Variane, G. F. T., Dahlen, A., Pietrobom, R. F. R., de Castro, J. A. R. R., Rodrigues, D. P., Magalhães, M., Mimica, M. J., Van Meurs, K. P., & Chock, V. Y. (n.d.).Publication year
2024Journal title
American journal of perinatologyAbstractThis study aimed to assess the viability of implementing a tele-educational training program in neurocritical care for newborns diagnosed with hypoxic-ischemic encephalopathy (HIE) and treated with therapeutic hypothermia (TH), with the goal of reducing practice variation.Analysis of Sampling Bias in Large Health Care Claims Databases
AbstractDahlen, A., Dahlen, A., & Charu, V. (n.d.).Publication year
2023Journal title
JAMA network openVolume
6Issue
1Page(s)
e2249804Abstract~Cerebral oxygen saturation in neonates: a bedside comparison between neonatal and adult NIRS sensors
AbstractDahlen, A., Variane, G. F., Dahlen, A., Noh, C. Y., Zeng, J., Yan, E. S., Kaneko, J. S., Gouveia, M. S., Van, M., & Chock, V. Y. (n.d.).Publication year
2023Journal title
Pediatric ResearchVolume
94Issue
5Page(s)
1810--1816Abstract~Characteristics associated with diagnostic yield of imaging for deep venous thrombosis and pulmonary embolism in the emergency department, hospital, and office settings: An Optum Clinformatics claims database study (2015--2019)
AbstractDahlen, A., Rohatgi, N., Dahlen, A., Berube, C., Weng, Y., Wintermark, M., & Ahuja, N. (n.d.).Publication year
2023Journal title
Thrombosis ResearchVolume
224Page(s)
4--12Abstract~Correction To: Early nitric oxide is not associated with improved outcomes in congenital diaphragmatic hernia
Failed generating bibliography.AbstractPublication year
2023Journal title
Pediatric researchVolume
94Issue
3Page(s)
1250Abstract~Early nitric oxide is not associated with improved outcomes in congenital diaphragmatic hernia
Failed generating bibliography.AbstractPublication year
2023Journal title
Pediatric researchVolume
93Issue
7Page(s)
1899-1906AbstractInhaled nitric oxide (iNO) is widely used for the management of infants with congenital diaphragmatic hernia (CDH); however, evidence of benefit is limited.Effect of vitamin D supplementation on cerebral blood flow in male patients with adrenoleukodystrophy
AbstractDahlen, A., Zhao, M. Y., Dahlen, A., Ramirez, N. J., Moseley, M., Van, H. K., & Zaharchuk, G. (n.d.).Publication year
2023Journal title
Journal of Neuroscience ResearchVolume
101Issue
7Page(s)
1086--1097Abstract~Environmental pollutants are associated with irritable bowel syndrome in a commercially insured cohort of California residents
AbstractDahlen, A., Okafor, P. N., Dahlen, A., Youssef, M., Olayode, A., Sonu, I., Neshatian, L., Nguyen, L., & Charu, V. (n.d.).Publication year
2023Journal title
Clinical Gastroenterology and HepatologyVolume
21Issue
6Page(s)
1617--1626Abstract~High-titer post-vaccine COVID-19 convalescent plasma for immunocompromised patients during the first omicron surge
AbstractDahlen, A., Tayyar, R., Wong, L. K., Dahlen, A., Shu, E., Pandey, S., & Liu, A. Y. (n.d.).Publication year
2023Journal title
Transplant Infectious DiseaseVolume
25Issue
2Page(s)
e14055Abstract~Impact of Repeat Extracorporeal Life Support on Mortality and Short-term In-hospital Morbidities in Neonates With Congenital Diaphragmatic Hernia
Failed generating bibliography.AbstractPublication year
2023Journal title
Annals of surgeryVolume
278Issue
3Page(s)
e605-e613AbstractTo evaluate the impact of repeat extracorporeal life support (ECLS) on survival and in-hospital outcomes in the congenital diaphragmatic hernia (CDH) neonates.Remote Monitoring for Seizures During Therapeutic Hypothermia in Neonates With Hypoxic-Ischemic Encephalopathy
AbstractDahlen, A., Variane, G., Dahlen, A., Pietrobom, R., Rodrigues, D. P., Magalh~aes, M., Mimica, M. J., Llaguno, N. S., Leandro, D., Girotto, P. N., Sampaio, L. B., & others. (n.d.).Publication year
2023Journal title
JAMA Network OpenVolume
6Issue
11Page(s)
e2343429--e2343429Abstract~Retrospective Observational Analysis of Free Serum Retinol in a Cohort of Pediatric Patients with Short Bowel Syndrome and Intestinal Failure
AbstractDahlen, A., Smith, A., Dahlen, A., Diyaolu, M., McDonnell, E., Kerner, J., Dunn, J. C., & Namjoshi, S. (n.d.).Publication year
2023Journal title
SN Comprehensive Clinical MedicineVolume
5Issue
1Page(s)
287Abstract~Association between multi-organ dysfunction and adverse outcome in infants with hypoxic ischemic encephalopathy
AbstractDahlen, A., Yan, E. S., Chock, V. Y., Bonifacio, S. L. L., Dahlen, A., Guimaraes, C. V., Altit, G., Bhombal, S., & Van Meurs, K. (n.d.).Publication year
2022Journal title
Journal of perinatology : official journal of the California Perinatal AssociationVolume
42Issue
7Page(s)
907-913AbstractTo evaluate multi-organ dysfunction (MOD) in newborns treated with therapeutic hypothermia (TH) for hypoxic ischemic encephalopathy (HIE), and to compare MOD in those with normal/mild magnetic resonance imaging (MRI) findings to those with moderate to severe MRI findings or death.Association between obesity and length of COVID-19 hospitalization: unexpected insights from the american heart association national COVID-19 registry
AbstractDahlen, A., Collins, W. J., Chang, A. Y., Weng, Y., Dahlen, A., O’Brien, C. G., Hom, J., Ahuja, N., Rodriguez, F., & Rohatgi, N. (n.d.).Publication year
2022Journal title
Journal of Obesity & Metabolic SyndromeVolume
31Issue
3Page(s)
277Abstract~Design of a population-based longitudinal cohort study of SARS-CoV-2 incidence and prevalence among adults in the San Francisco Bay Area
AbstractDahlen, A., Lindan, C. P., Desai, M., Boothroyd, D., Judson, T., Bollyky, J., Sample, H., Weng, Y., Cheng, Y., Dahlen, A., Hedlin, H., Grumbach, K., Henne, J., Garcia, S., Gonzales, R., Craik, C. S., Rutherford, G., & Maldonado, Y. (n.d.).Publication year
2022Journal title
Annals of epidemiologyVolume
67Page(s)
81-100AbstractWe describe the design of a longitudinal cohort study to determine SARS-CoV-2 incidence and prevalence among a population-based sample of adults living in six San Francisco Bay Area counties.Gastrointestinal symptoms and fecal shedding of SARS-CoV-2 RNA suggest prolonged gastrointestinal infection
AbstractDahlen, A., Natarajan, A., Zlitni, S., Brooks, E. F., Vance, S. E., Dahlen, A., Hedlin, H., Park, R. M., Han, A., Schmidtke, D. T., Verma, R., Jacobson, K. B., Parsonnet, J., Bonilla, H. F., Singh, U., Pinsky, B. A., Andrews, J. R., Jagannathan, P., & Bhatt, A. S. (n.d.).Publication year
2022Journal title
Med (New York, N.Y.)Volume
3Issue
6Page(s)
371-387.e9AbstractCOVID-19 manifests with respiratory, systemic, and gastrointestinal (GI) symptoms. SARS-CoV-2 RNA is detected in respiratory and fecal samples, and recent reports demonstrate viral replication in both the lung and intestinal tissue.2, 3, 4 Although much is known about early fecal RNA shedding, little is known about long-term shedding, especially in those with mild COVID-19. Furthermore, most reports of fecal RNA shedding do not correlate these findings with GI symptoms..