Gregory J. Martin

Bio: Gregory J. Martin is an academic researcher from Stanford University. The author has contributed to research in topics: Polarization (politics) & Sepsis. The author has an hindex of 8, co-authored 21 publications receiving 570 citations. Previous affiliations of Gregory J. Martin include Emory University.

Bias in Cable News: Persuasion and Polarization

Abstract: We measure the persuasive effects of slanted news and tastes for like-minded news, exploiting cable channel positions as exogenous shifters of cable news viewership. Channel positions do not correlate with demographics that predict viewership and voting, nor with local satellite viewership. We estimate that Fox News increases Republican vote shares by 0.3 points among viewers induced into watching 2.5 additional minutes per week by variation in position. We then estimate a model of voters who select into watching slanted news, and whose ideologies evolve as a result. We use the model to assess the growth over time of Fox News influence, to quantitatively assess media-driven polarization, and to simulate alternative ideological slanting of news channels.

qSOFA does not replace SIRS in the definition of sepsis

Abstract: The recently published consensus definitions for sepsis [1] have raised a lot of discussion and controversy. We had the privilege of being part of this consensus group and fully support the final definitions. We are pleased that a definition has been developed that closely reflects everyday clinical language, recognizing that sepsis is most simply described as a “bad infection” associated with some degree of organ dysfunction, as proposed earlier [2]. The article conveying the consensus definition [1] also emphasizes that sepsis is more often recognized from the associated organ dysfunction than from the more difficult to identify infection, so that sepsis can be defined as “life-threatening organ dysfunction caused by a dysregulated host response to an infection”. The proposition of the 1992 North American consensus document [3] that sepsis be defined by a combination of the systemic inflammatory response syndrome (SIRS) and the presence of an infection raised confusion, because the SIRS criteria (especially fever, tachycardia, and altered white blood cell count) are themselves typical features of infection [3]. As the majority of infected patients will therefore meet the SIRS criteria, they would also be considered to have sepsis by this 1992 definition. This approach to defining sepsis has resulted in a dramatic increase in the number of patients diagnosed with sepsis over the years [4]; however, these patients may have less severe disease so that reported parallel reductions in mortality rates [5] may be deceptive [6]. The recent “new” definitions are not so novel, more a return to the traditional use of the term to indicate patients with a substantial and deleterious response to an infection. We doubt that this will change further over time, exactly as the meaning of other words like pneumonia, peritonitis, or meningitis has not changed. We all agree on the fundamental importance of identifying sepsis early and of applying effective and complete treatment to minimize complications. However, the SIRS criteria were too sensitive and not sufficiently specific for this purpose. Rangel-Frausto et al. [7] reported that 68 % of patients admitted to three intensive care units (ICUs) and three general wards met the SIRS criteria; in 198 ICUs in 24 European countries, Sprung et al. [8] reported that 93 % of ICU patients had at least two SIRS criteria at some point during their ICU stay; and in a database of patients in 23 Australian and New Zealand ICUs, Dulhunty et al. [9] reported that 88.4 % of patients had at least two SIRS criteria on ICU admission. In a recent analysis of a large US database, Churpek et al. [10] reported that almost half of the 270,000 patients hospitalized on regular wards met the SIRS criteria at one time or another. Our consensus definition paper suggested the quick sequential organ failure assessment (qSOFA) as an effective way of raising suspicion of sepsis on the regular floor [1]. Evaluating all six components of the SOFA score can be time consuming, and some require laboratory measurements. By analyzing a large database of hospitalized patients, three clinical elements (hypotension, altered mentation, and tachypnea) were identified that could be used at the bedside to recognize those infected patients who are at risk of deteriorating or having a complicated course (death or ICU stay ≥ 3 days). The presence of two or more of these criteria can be used to prompt clinicians to further evaluate the patient for the presence of infection and/or organ dysfunction, to start or adapt treatment, and to consider transfer to an ICU. Importantly, this approach is designed to be an early warning system, and a patient with less than two qSOFA criteria may still raise concern. Clinical judgment should always supersede tools designed to help improve patient care, such as qSOFA. We would like to stress that, although SIRS was part of the definition of sepsis in 1992 [3], the qSOFA is not part of the new sepsis definitions. This important difference is illustrated in Fig. 1, with panel A showing that infection and sepsis (by the 1992 definition) are virtually the same—infection without SIRS can be found, but it is relatively rare. By contrast, panel B shows that sepsis (by the new SEPSIS-3 definition) represents only a minority of cases of infection. Moreover, panel B illustrates important aspects of the sepsis definition vis-a-vis infection and qSOFA. For example, sepsis can be present without a qSOFA score ≥ 2 because different forms of organ dysfunction may be present than are assessed using the qSOFA, such as hypoxemia, renal failure, coagulopathy, or hyperbilirubinemia. In addition, a patient may have a qSOFA ≥ 2 without infection; for example, in other acute conditions, such as hypovolemia, severe heart failure, or large pulmonary embolism. Further work remains to be done to determine the predictive validity of qSOFA in such patients. Finally, infected patients may have a qSOFA ≥ 2 and not be septic because the degree of hypotension, tachycardia, and/or altered mentation needed to fulfill qSOFA criteria is not the same as that needed to meet the SOFA organ dysfunction criteria necessary for a diagnosis of sepsis; the qSOFA criteria are thus clinically valuable but imperfect markers of sepsis. Nevertheless, in an analysis of a database of more than 74,000 patients, Seymour et al. [11] recently reported that 75 % of patients with suspected infection who had two or more qSOFA points also had at least two SOFA points. Fig. 1 Schematic representation illustrating a the almost complete overlap of sepsis and infection when the SIRS criteria of the 1992 criteria [3] are used and b the differences between qSOFA and sepsis. qSOFA quick sequential organ failure assessment, SIRS ... We hope this editorial will clarify that the qSOFA is meant to be used to raise suspicion of sepsis and prompt further action—it is not a replacement for SIRS and is not part of the definition of sepsis.

Local News and National Politics

Abstract: The level of journalistic resources dedicated to coverage of local politics is in a long-term decline in the US news media, with readership shifting to national outlets. We investigate whether this trend is demand- or supply-driven, exploiting a recent wave of local television station acquisitions by a conglomerate owner. Using extensive data on local news programming and viewership, we find that the ownership change led to (1) substantial increases in coverage of national politics at the expense of local politics, (2) a significant rightward shift in the ideological slant of coverage, and (3) a small decrease in viewership, all relative to the changes at other news programs airing in the same media markets. These results suggest a substantial supply-side role in the trends toward nationalization and polarization of politics news, with negative implications for accountability of local elected officials and mass polarization.

Political Advertising Online and Offline

Abstract: Despite the rapid growth of online political advertising, the vast majority of scholarship on political advertising relies exclusively on evidence from candidates’ television advertisements. The relatively low cost of creating and deploying online advertisements and the ability to target online advertisements more precisely may broaden the set of candidates who advertise and allow candidates to craft messages to more narrow audiences than on television. Drawing on data from the newly released Facebook Ad Library API and television data from the Wesleyan Media Project, we find that a much broader set of candidates advertises on Facebook than television, particularly in down-ballot races. We then examine within-candidate variation in the strategic use and content of advertising on television relative to Facebook for all federal, statewide, and state legislative candidates in the 2018 election. Among candidates who use both advertising media, Facebook advertising occurs earlier in the campaign, is less negative, less issue focused, and more partisan than television advertising.

Does residential sorting explain geographic polarization

Abstract: Political preferences in the United States are highly correlated with population density, at national, state, and metropolitan-area scales. Using new data from voter registration records, we assess the extent to which this pattern can be explained by geographic mobility. We find that the revealed preferences of voters who move from one residence to another correlate with partisan affiliation, though voters appear to be sorting on non-political neighborhood attributes that covary with partisan preferences rather than explicitly seeking politically congruent neighbors. But, critically, we demonstrate through a simulation study that the estimated partisan bias in moving choices is on the order of five times too small to sustain the current geographic polarization of preferences. We conclude that location must have some influence on political preference, rather than the other way around, and provide evidence in support of this theory.

Social Media and Fake News in the 2016 Election

Abstract: Following the 2016 U.S. presidential election, many have expressed concern about the effects of false stories (“fake news”), circulated largely through social media. We discuss the economics of fake news and present new data on its consumption prior to the election. Drawing on web browsing data, archives of fact-checking websites, and results from a new online survey, we find: (i) social media was an important but not dominant source of election news, with 14 percent of Americans calling social media their “most important” source; (ii) of the known false news stories that appeared in the three months before the election, those favoring Trump were shared a total of 30 million times on Facebook, while those favoring Clinton were shared 8 million times; (iii) the average American adult saw on the order of one or perhaps several fake news stories in the months around the election, with just over half of those who recalled seeing them believing them; and (iv) people are much more likely to believe stories that favor their preferred candidate, especially if they have ideologically segregated social media networks.

Prognostic Accuracy of Sepsis-3 Criteria for In-Hospital Mortality Among Patients With Suspected Infection Presenting to the Emergency Department

Abstract: Importance An international task force recently redefined the concept of sepsis. This task force recommended the use of the quick Sequential Organ Failure Assessment (qSOFA) score instead of systemic inflammatory response syndrome (SIRS) criteria to identify patients at high risk of mortality. However, these new criteria have not been prospectively validated in some settings, and their added value in the emergency department remains unknown. Objective To prospectively validate qSOFA as a mortality predictor and compare the performances of the new sepsis criteria to the previous ones. Design, Settings, and Participants International prospective cohort study, conducted in France, Spain, Belgium, and Switzerland between May and June 2016. In the 30 participating emergency departments, for a 4-week period, consecutive patients who visited the emergency departments with suspected infection were included. All variables from previous and new definitions of sepsis were collected. Patients were followed up until hospital discharge or death. Exposures Measurement of qSOFA, SOFA, and SIRS. Main Outcomes and Measures In-hospital mortality. Results Of 1088 patients screened, 879 were included in the analysis. Median age was 67 years (interquartile range, 47-81 years), 414 (47%) were women, and 379 (43%) had respiratory tract infection. Overall in-hospital mortality was 8%: 3% for patients with a qSOFA score lower than 2 vs 24% for those with qSOFA score of 2 or higher (absolute difference, 21%; 95% CI, 15%-26%). The qSOFA performed better than both SIRS and severe sepsis in predicting in-hospital mortality, with an area under the receiver operating curve (AUROC) of 0.80 (95% CI, 0.74-0.85) vs 0.65 (95% CI, 0.59-0.70) for both SIRS and severe sepsis ( P Conclusions and Relevance Among patients presenting to the emergency department with suspected infection, the use of qSOFA resulted in greater prognostic accuracy for in-hospital mortality than did either SIRS or severe sepsis. These findings provide support for the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3) criteria in the emergency department setting. Trial Registration clinicaltrials.gov Identifier:NCT02738164