Regression Analysis Of Time Series Data Research Articles

When the President Speaks…

The theory of presidential influence over public opinion is used to predict the impact of presidential rhetoric on the public’s concern regarding drug use as “the most important problem (MIP) facing the nation.” It is hypothesized that the more attention presidents give to the policy area of drugs in their state of the union (SOTU) addresses, the more concerned the public becomes with drug use. Using a time-series regression analysis of data collected from a content analysis of presidents’SOTU speeches regressed on the Gallup Poll’s MIP series from 1946 to 2010, the findings suggest that presidential mentions of drugs in the SOTU addresses influence public concern for illicit drugs in America.

Blood Culture Contamination Rates after Skin Antisepsis with Chlorhexidine Gluconate versus Povidone-Iodine in a Pediatric Emergency Department

To determine blood culture contamination rates after skin antisepsis with chlorhexidine, compared with povidone-iodine. Retrospective, quasi-experimental study. Emergency department of a tertiary care children's hospital. Children aged 2-36 months with peripheral blood culture results from February 2004 to June 2008. Control patients were children younger than 2 months with peripheral blood culture results. Blood culture contamination rates were compared using segmented regression analysis of time-series data among 3 patient groups: (1) patients aged 2-36 months during the 26-month preintervention period, in which 10% povidone-iodine was used for skin antisepsis before blood culture; (2) patients aged 2-36 months during the 26-month postintervention period, in which 3% chlorhexidine gluconate was used; and (3) patients younger than 2 months not exposed to the chlorhexidine intervention (ie, the control group). Results from 11,595 eligible blood cultures were reviewed (4,942 from the preintervention group, 4,274 from the postintervention group, and 2,379 from the control group). For children aged 2-36 months, the blood culture contamination rate decreased from 24.81 to 17.19 contaminated cultures per 1,000 cultures (P < .05) after implementation of chlorhexidine. This decrease of 7.62 contaminated cultures per 1,000 cultures (95% confidence interval, -0.781 to -15.16) represented a 30% relative decrease from the preintervention period and was sustained over the entire postintervention period. No change in contamination rate was observed in the control group (P = .337). Skin antisepsis with chlorhexidine significantly reduces the blood culture contamination rate among young children, as compared with povidone-iodine.

The Determinants of Heat-Related Mortality in England and Wales

MAA1-O-08 Introduction: Much uncertainty remains about the groups of people who are most at risk from exposure to high ambient temperature and, also, therefore, in who should be targeted by any government interventions. We determine here the subgroups of the population most vulnerable to heat-related mortality in England and Wales. Methods: A regression analysis of time-series data of daily mortality between 1993 and 2003 was undertaken, with postcode-linkage of individual deaths to the CHIC database of care and nursing homes and the 2001 U.K. census. Each series was examined in relation to daily temperature using Poisson generalized linear models allowing for overdispersion and controlling for season, trend, air pollution (PM10 and O3), and any day-of-week effects. Results were obtained separately for all regions of England and Wales and also as a combined effect across regions estimated from a fixed-effect meta-analysis. Results: An increased risk of mortality was observed with heat exposure in all regions, with the strongest heat effects in London: relative risk 1.05 (95% confidence interval 1.04–1.06) for every 1°C increase in mean temperature above the heat threshold (defined as the 95th percentile of daily mean temperature). The combined risk from the meta-analysis was 1.03 (95% confidence interval 1.02–1.03) for each degree increase. Elderly people and those in nursing and care homes were particularly vulnerable, and a greater risk of heat-mortality was observed in women which remained after control for age. Effects were strongest in urban settings and for respiratory disease and deaths from external causes. Vulnerability to heat was not modified by quintiles of deprivation, the proportion of people living in flats, or the proportion of elderly (65+) people living alone. Discussion: Our results indicate that interventions to reduce vulnerability to hot weather should target elderly people and, in particular, those living in nursing or care homes. In addition, in a country where very few households have air-conditioning units, risks are not restricted to the most deprived populations. “

The Pied Piper of Crime in America: An Analysis of the Presidents’ and Public’s Agenda on Crime

The theory of presidential influence over public opinion is used to predict the impact of presidential rhetoric on crime over the public’s concern for crime being “the most important problem facing the nation.” It is hypothesized that the more attention presidents give to the policy area of crime in the their State of the Union Addresses, the more concerned the public becomes with crime. Utilizing a time-series regression analysis of data collected from a content analysis of presidents’ State of the Union addresses on the Gallup Poll’s Most Important Problem series from 1946 to 1996, the analysis demonstrates that presidential mention of crime seems to elicit a public response, thus influencing public opinion of crime with a decay effect of approximately 1 year.

Presidential Rhetoric on Crime and Public Opinion

The theory of presidential influence over public opinion is used to predict the impact of presidential rhetoric on the public's concern for crime as the "most important problem facing the country." The more attention presidents give to the issue of crime, the more concerned the public becomes with crime. Utilizing a time-series regression analysis of data collected from the Public Papers of the President of the United States and the Gallup poll's "Most Important Problem" series from 1945 to 1994 and controlling for crime rates, unemployment rates, and media influence, presidential attention to crime is found to influence the public's perception that crime is an important issue.

Arms and Aggression in the Middle East

The authors' understanding of the relationship between the cold war and enduring rivalry in the Third World has been hampered by a tendency to view international conflicts as relatively isolated phenomena. The authors address this question by analyzing the impact of superpower arms transfers on armed interventions in the Middle East from 1948 to 1991. The evidence suggests that arms transfers from the United States to Israel restrained the level of military aggression in the region, on the part of both Israel and its Arab rivals. Soviet arms transfers, however, had the opposite effect. This latter pattern is attributed more to the Soviet Union's inability to restrain its clients than to its active promotion of regional conflict. The authors' conclusions are based on a Poisson regression analysis of time-series data derived from the Overt Military Interventions database and the arms trade registers compiled by the Stockholm International Peace Research Institute.

Presidential Rhetoric and the Public Agenda

Theory: The theory of presidential influence over agenda setting is used to predict the impact of presidential rhetoric over the public's agenda. Hypotheses: The more attention presidents give to policy areas in their State of the Union Addresses, the more concerned the public becomes with those policy areas. Methods: Time-series regression analysis of data collected from content analyses of presidents' State of the Union Addresses on the Gallup Poll's MostImportant Problem Series from 1953-89. Results: Increases in presidential attention to economic, foreign, and civil rights policy lead to increases in public concern with those policies. These results hold with controls for past public concern and objective conditions. Mere presidential mentions of a policy area seem to elicit a public response, thus, presidents do not have to resort to substantive arguments to sway public opinion. But popular presidents seem no more influential than unpopular ones and these presidential leadership effects decay within a year, except for foreign policy, which shows effects lasting across the year.

Evidence of Structural Change in Preferences for Seafood

The results from graphical and regression analyses of time-series data on seafood consumption and prices suggest that preferences for seafood have strengthened in response to medical evidence that seafood promotes nutrition and health. The graphical analysis reveals a trend of increased per capita consumption of seafood since the late 1960s despite concurrent increases in the relative price of seafood. The two-phase regression analyses of per capita consumption and of the relative price of seafood identified the mid-1960s and the mid-1970s as possible times of accelerated change in preferences. These results, which match those reported for consumption of poultry and red meats, have important implications for modeling derived demand in landings markets, for estimating welfare, and for managing fishing effort and multiple uses of fish stocks.

Australian mineral export forecasts to 2000

Mineral exports are now about 35% of Australia's total export earnings. The authors consider the prospects to 2000 for the main export-earning commodities. Forecasts are arrived at using a variety of approaches, including regression analysis of time-series data, but the final assessment reflects specialists' personal judgments. It is argued that economic resources (reserves) already identified can, for most commodities, sustain forecast exports until the end of the century.