Burak Alsan, MD

All Publications

• Effects of a large-scale social media advertising campaign on holiday travel and COVID-19 infections: a cluster randomized controlled trial. Nature medicine Breza, E., Stanford, F. C., Alsan, M., Alsan, B., Banerjee, A., Chandrasekhar, A. G., Eichmeyer, S., Glushko, T., Goldsmith-Pinkham, P., Holland, K., Hoppe, E., Karnani, M., Liegl, S., Loisel, T., Ogbu-Nwobodo, L., Olken, B. A., Torres, C., Vautrey, P., Warner, E. T., Wootton, S., Duflo, E. 2021

  Abstract

  During the Coronavirus Disease 2019 (COVID-19) epidemic, many health professionals used social media to promote preventative health behaviors. We conducted a randomized controlled trial of the effect of a Facebook advertising campaign consisting of short videos recorded by doctors and nurses to encourage users to stay at home for the Thanksgiving and Christmas holidays ( NCT04644328 and AEARCTR-0006821 ). We randomly assigned counties to high intensity (n=410 (386) at Thanksgiving (Christmas)) or low intensity (n=410 (381)). The intervention was delivered to a large fraction of Facebook subscribers in 75% and 25% of randomly assigned zip codes in high- and low-intensity counties, respectively. In total, 6,998 (6,716) zip codes were included, and 11,954,109 (23,302,290) users were reached at Thanksgiving (Christmas). The first two primary outcomes were holiday travel and fraction leaving home, both measured using mobile phone location data of Facebook users. Average distance traveled in high-intensity counties decreased by -0.993 percentage points (95% confidence interval (CI): -1.616, -0.371; P = 0.002) for the 3 days before each holiday compared to low-intensity counties. The fraction of people who left home on the holiday was not significantly affected (adjusted difference: 0.030; 95%CI: -0.361, 0.420; P = 0.881). The third primary outcome was COVID-19 infections recorded at the zip code level in the 2-week period starting 5 days after the holiday. Infections declined by 3.5% (adjusted 95%CI: -6.2%, -0.7%; P = 0.013) in intervention compared to control zip codes. Social media messages recorded by health professionals before the winter holidays in the United States led to a significant reduction in holiday travel and subsequent COVID-19 infections.

  View details for DOI 10.1038/s41591-021-01487-3

  View details for PubMedID 34413518

• Doctors and Nurses Social Media Ads Reduced Holiday Travel and COVID-19 infections: A cluster randomized controlled trial in 13 States. ArXiv Breza, E., Stanford, F. C., Alsan, M., Alsan, B., Banerjee, A., Chandrasekhar, A. G., Eichmeyer, S., Glushko, T., Goldsmith-Pinkham, P., Holland, K., Hoppe, E., Karnani, M., Liegl, S., Loisel, T., Ogbu-Nwobodo, L., Olken, B. A., Torres, C., Vautrey, P., Warner, E., Wootton, S., Duflo, E. 2021

  Abstract

  During the COVID-19 epidemic, many health professionals started using mass communication on social media to relay critical information and persuade individuals to adopt preventative health behaviors. Our group of clinicians and nurses developed and recorded short video messages to encourage viewers to stay home for the Thanksgiving and Christmas Holidays. We then conducted a two-stage clustered randomized controlled trial in 820 counties (covering 13 States) in the United States of a large-scale Facebook ad campaign disseminating these messages. In the first level of randomization, we randomly divided the counties into two groups: high intensity and low intensity. In the second level, we randomly assigned zip codes to either treatment or control such that 75% of zip codes in high intensity counties received the treatment, while 25% of zip codes in low intensity counties received the treatment. In each treated zip code, we sent the ad to as many Facebook subscribers as possible (11,954,109 users received at least one ad at Thanksgiving and 23,302,290 users received at least one ad at Christmas). The first primary outcome was aggregate holiday travel, measured using mobile phone location data, available at the county level: we find that average distance travelled in high-intensity counties decreased by -0.993 percentage points (95% CI -1.616, -0.371, p-value 0.002) the three days before each holiday. The second primary outcome was COVID-19 infection at the zip-code level: COVID-19 infections recorded in the two-week period starting five days post-holiday declined by 3.5 percent (adjusted 95% CI [-6.2 percent, -0.7 percent], p-value 0.013) in intervention zip codes compared to control zip codes.

  View details for PubMedID 34159223

• Regulation of avian cardiogenesis by Fgf8 signaling DEVELOPMENT Alsan, B. H., Schultheiss, T. M. 2002; 129 (8): 1935-1943

  Abstract

  The avian heart develops from paired primordia located in the anterior lateral mesoderm of the early embryo. Previous studies have found that the endoderm adjacent to the cardiac primordia plays an important role in heart specification. The current study provides evidence that fibroblast growth factor (Fgf) signaling contributes to the heart-inducing properties of the endoderm. Fgf8 is expressed in the endoderm adjacent to the precardiac mesoderm. Removal of endoderm results in a rapid downregulation of a subset of cardiac markers, including Nkx2.5 and Mef2c. Expression of these markers can be rescued by supplying exogenous Fgf8. In addition, application of ectopic Fgf8 results in ectopic expression of cardiac markers. Expression of cardiac markers is expanded only in regions where bone morphogenetic protein (Bmp) signaling is also present, suggesting that cardiogenesis occurs in regions exposed to both Fgf and Bmp signaling. Finally, evidence is presented that Fgf8 expression is regulated by particular levels of Bmp signaling. Application of low concentrations of Bmp2 results in ectopic expression of Fgf8, while application of higher concentrations of Bmp2 result in repression of Fgf8 expression. Together, these data indicate that Fgf signaling cooperates with Bmp signaling to regulate early cardiogenesis.

  View details for Web of Science ID 000175473800013

  View details for PubMedID 11934859