K. Michael Peddecord

A middle school immunization law rapidly and substantially increases immunization coverage among adolescents.

OBJECTIVES This study assessed the effectiveness of a middle school vaccination requirement for raising second-dose measles, mumps, and rubella vaccine and hepatitis B vaccine coverage among adolescents. METHODS Random-digit-dialed telephone surveys were conducted before (1998) and after (1999) the implementation of a vaccination requirement for entry into the seventh grade in San Diego, Calif. RESULTS Vaccination coverage was higher among children subject to the vaccination requirement (seventh-grade students; 60%) than among fifth- and sixth-grade students 1 year before the requirement (13%, P <.001), and 8th- through 12th-grade students not subject to the requirement (27%, P <.0001). CONCLUSIONS Middle school-entry vaccination requirements can rapidly and substantially raise vaccination coverage among students subject to the law.

Prevalence of alcohol consumption among older persons

Percent prevalences of alcohol consumption were determined in a cross-sectional study of randomly chosen residents of San Diego County, California aged 45 years and over. The study sample (N=2,105) showed statistically significant drinking differences between Whites (n=819), Blacks (n=629), and Mexican-Americans (n=657). Overall, the highest prevalence of drinking occurred among the White elderly. The common belief that socioeconomic conditions are inversely associated with a high prevalence of drinking was not supported in this sample. Statistically significant differences in age-specific and sex-specific percent prevalences of alcohol intake were also found. There was a generally decreasing prevalence of alcohol consumption with advancing age, which existed regardless of ethnicity. Initial empirical measures and a better understanding of drinking correlates will identify those elderly persons at risk and provide the basis for future interventions in the areas of applied epidemiology and health promotion.

The Complex Relationship of Realspace Events and Messages in Cyberspace: Case Study of Influenza and Pertussis Using Tweets

Background Surveillance plays a vital role in disease detection, but traditional methods of collecting patient data, reporting to health officials, and compiling reports are costly and time consuming. In recent years, syndromic surveillance tools have expanded and researchers are able to exploit the vast amount of data available in real time on the Internet at minimal cost. Many data sources for infoveillance exist, but this study focuses on status updates (tweets) from the Twitter microblogging website. Objective The aim of this study was to explore the interaction between cyberspace message activity, measured by keyword-specific tweets, and real world occurrences of influenza and pertussis. Tweets were aggregated by week and compared to weekly influenza-like illness (ILI) and weekly pertussis incidence. The potential effect of tweet type was analyzed by categorizing tweets into 4 categories: nonretweets, retweets, tweets with a URL Web address, and tweets without a URL Web address. Methods Tweets were collected within a 17-mile radius of 11 US cities chosen on the basis of population size and the availability of disease data. Influenza analysis involved all 11 cities. Pertussis analysis was based on the 2 cities nearest to the Washington State pertussis outbreak (Seattle, WA and Portland, OR). Tweet collection resulted in 161,821 flu, 6174 influenza, 160 pertussis, and 1167 whooping cough tweets. The correlation coefficients between tweets or subgroups of tweets and disease occurrence were calculated and trends were presented graphically. Results Correlations between weekly aggregated tweets and disease occurrence varied greatly, but were relatively strong in some areas. In general, correlation coefficients were stronger in the flu analysis compared to the pertussis analysis. Within each analysis, flu tweets were more strongly correlated with ILI rates than influenza tweets, and whooping cough tweets correlated more strongly with pertussis incidence than pertussis tweets. Nonretweets correlated more with disease occurrence than retweets, and tweets without a URL Web address correlated better with actual incidence than those with a URL Web address primarily for the flu tweets. Conclusions This study demonstrates that not only does keyword choice play an important role in how well tweets correlate with disease occurrence, but that the subgroup of tweets used for analysis is also important. This exploratory work shows potential in the use of tweets for infoveillance, but continued efforts are needed to further refine research methods in this field.

The Reliability of Tweets as a Supplementary Method of Seasonal Influenza Surveillance

Background Existing influenza surveillance in the United States is focused on the collection of data from sentinel physicians and hospitals; however, the compilation and distribution of reports are usually delayed by up to 2 weeks. With the popularity of social media growing, the Internet is a source for syndromic surveillance due to the availability of large amounts of data. In this study, tweets, or posts of 140 characters or less, from the website Twitter were collected and analyzed for their potential as surveillance for seasonal influenza. Objective There were three aims: (1) to improve the correlation of tweets to sentinel-provided influenza-like illness (ILI) rates by city through filtering and a machine-learning classifier, (2) to observe correlations of tweets for emergency department ILI rates by city, and (3) to explore correlations for tweets to laboratory-confirmed influenza cases in San Diego. Methods Tweets containing the keyword “flu” were collected within a 17-mile radius from 11 US cities selected for population and availability of ILI data. At the end of the collection period, 159,802 tweets were used for correlation analyses with sentinel-provided ILI and emergency department ILI rates as reported by the corresponding city or county health department. Two separate methods were used to observe correlations between tweets and ILI rates: filtering the tweets by type (non-retweets, retweets, tweets with a URL, tweets without a URL), and the use of a machine-learning classifier that determined whether a tweet was “valid”, or from a user who was likely ill with the flu. Results Correlations varied by city but general trends were observed. Non-retweets and tweets without a URL had higher and more significant (P<.05) correlations than retweets and tweets with a URL. Correlations of tweets to emergency department ILI rates were higher than the correlations observed for sentinel-provided ILI for most of the cities. The machine-learning classifier yielded the highest correlations for many of the cities when using the sentinel-provided or emergency department ILI as well as the number of laboratory-confirmed influenza cases in San Diego. High correlation values (r=.93) with significance at P<.001 were observed for laboratory-confirmed influenza cases for most categories and tweets determined to be valid by the classifier. Conclusions Compared to tweet analyses in the previous influenza season, this study demonstrated increased accuracy in using Twitter as a supplementary surveillance tool for influenza as better filtering and classification methods yielded higher correlations for the 2013-2014 influenza season than those found for tweets in the previous influenza season, where emergency department ILI rates were better correlated to tweets than sentinel-provided ILI rates. Further investigations in the field would require expansion with regard to the location that the tweets are collected from, as well as the availability of more ILI data.

The Association between Cerebrovascular Disease and Smoking: A Case-Control Study

A retrospective case-control study was carried out to examine the relationship between cigarette smoking and cerebrovascular disease occurrence. Cases were obtained from the University of California-American Heart Association, San Diego Stroke Data Bank, and controls from selected Veterans Administration and University of California, San Diego, outpatient departments. When cigarette smoking was dichotomously coded into categories of low and high lifetime exposure, consistent significant positive associations were found with cerebrovascular disease occurrence in both bivariate and multivariate analysis when controlling for blood pressure. These associations, however, were not found when smoking was categorized as smoker, ex-smoker, and non-smoker. No association was found between passive smoking and cerebrovascular disease. The results indicate that a cumulative lifetime exposure to active cigarette smoking is directly associated with cerebrovascular disease.

Implementing a seventh grade vaccination law: school factors associated with completion of required immunizations.

OBJECTIVES We investigated school factors associated with successful implementation of a seventh grade vaccination requirement. METHODS The proportion of students vaccinated with hepatitis B vaccine and measles containing vaccine was determined from records of schools in San Diego County, California. A school survey identified compliance strategies. Analysis identified factors associated with coverage. RESULTS In October 1999, 67.2% of 38,875 students had received the required vaccine doses. Of 315 schools, coverage was less than 40% in 60 schools and exceeded 80% in 111 schools. Factors associated with high coverage included private schools, early and frequent notice to parents, and, for public schools, higher overall socioeconomic status of students. CONCLUSIONS In preparation for a middle school vaccination requirement, early and frequent notification of parents improves coverage. Schools with a high percentage of low socioeconomic status students may require extra resources to support implementation.

Can Movie Theater Advertisements Promote Health Behaviors? Evaluation of a Flu Vaccination Pilot Campaign

As part of a multimedia campaign to promote annual influenza vaccination, three slides were shown as part of the slide show of advertisements prior to the beginning of previews in movie theaters in San Diego County. Intercept surveys were conducted following the movie. The primary target groups for the campaign were adults with children 6 months to 2 years of age and adults over 50 years of age. Overall, 88% of exposed patrons reported seeing some type of movie ad. Among those who recalled any ad, 24% recalled the flu advertisement. In contrast, recall of flu-related news coverage was high, with over 95% of exposed and comparison interviewees recalling news stories during the campaign period. While 56% of those interviewed remembered one or more specific flu-related news items, individuals within this group who also had also been exposed to the movie ads were not more likely to recall flu campaign advertisements. We describe a method for estimating valid recalls and cost per valid exposure. Further research that compares movie ads with public service announcements (PSAs) in other venues is necessary to solidify our conclusions that movie advertising is a highly cost-effective medium for health communication.

Early Retirement and Functional Impairment from a Multi-Ethnic Perspective:

The overall purpose of the present study was to identify differences between the early retired and the nonretired among three ethnic groups: Whites, Blacks, and Mexican Americans. Analysis focused on a community-based sample of 1,146 residents of San Diego County aged 45 to 64 years. Three categories of variables that were hypothesized to contribute to early retirement were examined: demographic characteristics, self-reported health measures, and Older American Resource and Service (OARS)based objective summary ratings of functional impairment. Results were consistent with the literature and indicated that functional impairment was higher for the early retired within each of the ethnic groups. For both retirement status groups, Mexican Americans reported the most impairment of the three ethnic groups. Discriminant analysis was used to identify the predictive value of the three categories of variables for early retirement status and yielded the following results: age, gender, and the mental health OARS objective functional-impairment score were the only significant discriminators for all groups. Mexican Americans appeared to have the greatest variety of factors contributing to early retirement status, with fewer variables involved for Blacks and fewer still for Whites.

Use of the CES-D among a community sample of older Mexican-Americans

This study is a descriptive and comparative analysis of the Center for Epidemiologic Studies Depression (CES-D) scale as administered to a sample of Mexican-Americans (n = 455) age 45 years and older. This sample was part of a cross-sectional survey (Health and Lifestyles After 45) carried out in 1985–1987 by the University Center on Aging at San Diego State University. Results indicate that CES-D mean scores (overall = 11.3) and caseness rates (overall = 25.9%) are comparable with depression data reported from other studies among samples of Mexican-Americans. Factor analysis provided evidence indicating cultural response preferences among Mexican-Americans, particularly immigrants, who tend to somatize dysphoric complaints. A re-examination of an often cited CES-D ethnic validation study is included. Implications for construct validity of the CES-D among older Mexican-Americans are discussed.

Universal rapid screening for methicillin-resistant Staphylococcus aureus in the intensive care units in a large community hospital

BACKGROUND Health care-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) infections constitute a significant risk for hospitalized patients. This study evaluates the costs and effects of comprehensive and state-mandated MRSA screening for intensive care unit (ICU) patients and subsequent contact precautions on the rate of HA-MRSA. METHODS A pre- and postimplementation study was conducted in a 24-bed medical intensive care unit (MICU) and a 15-bed surgical intensive care unit (SICU) at an acute care 536-bed community hospital. This study used computerized records for all patients admitted to ICUs. Costs were estimated from financial records. RESULTS HA-MRSA infection rates did not decline after implementation of ICU screening. Regression analysis demonstrated that patients admitted from skilled nursing facilities, assisted living, and similar facilities were 12 times more likely to screen positive for MRSA as compared with patients admitted from home. The costs to identify each MRSA positive patient were