Identifying Young Adults at High Risk for Weight Gain Using Machine Learning

INTRODUCTION

Weight gain among young adults continues to increase. Identifying adults at high risk for weight gain and intervening before they gain weight could have a major public health impact. Our objective was to develop and test electronic health record-based machine learning models to predict weight gain in young adults with overweight/class 1 obesity.

METHODS

Seven machine learning models were assessed, including three regression models, random forest, single-layer neural network, gradient-boosted decision trees, and support vector machine (SVM) models. Four categories of predictors were included: 1) demographics; 2) obesity-related health conditions; 3) laboratory data and vital signs; and 4) neighborhood-level variables. The cohort was split 60:40 for model training and validation. Area under the receiver operating characteristic curves (AUC) were calculated to determine model accuracy at predicting high-risk individuals, defined by ≥ 10% total body weight gain within 2 y. Variable importance was measured via generalized analysis of variance procedures.

RESULTS

Of the 24,183 patients (mean [SD] age, 32.0 [6.3] y; 55.1% females) in the study, 14.2% gained ≥10% total body weight. Area under the receiver operating characteristic curves varied from 0.557 (SVM) to 0.675 (gradient-boosted decision trees). Age, sex, and baseline body mass index were the most important predictors among the models except SVM and neural network.

CONCLUSIONS

Our machine learning models performed similarly and had modest accuracy for identifying young adults at risk of weight gain. Future models may need to incorporate behavioral and/or genetic information to enhance model accuracy.

Association between neighborhood food environments and bariatric surgery outcomes

BACKGROUND

Individual characteristics associated with weight loss after bariatric surgery are well established, but the neighborhood characteristics that influence outcomes are unknown.

OBJECTIVES

The objective of this study was to determine if neighborhood characteristics, including social determinants and lifestyle characteristics, were associated with weight loss after bariatric surgery.

SETTING

Single university healthcare system, United States.

METHODS

In this retrospective cohort study, all patients who underwent primary bariatric surgery from 2008 to 2017 and had at least 1 year of follow-up data were included. Patient-level demographics and neighborhood-level social determinants (area deprivation index, urbanicity, and walkability) and lifestyle factors (organic food use, fresh fruit/vegetable consumption, diet to maintain weight, soda consumption, and exercise) were analyzed. Median regression with percent total body weight (%TBW) loss as the outcome was applied to examine factors associated with weight loss after surgery.

RESULTS

Of the 647 patients who met inclusion criteria, the average follow-up period was 3.1 years, and the mean %TBW loss at the follow-up was 22%. In adjusted median regression analyses, Roux-en-Y gastric bypass was associated with greater %TBW loss (11.22%, 95% confidence interval [8.96, 13.48]) compared to sleeve, while longer follow-up time (-2.42% TBW loss per year, 95% confidence interval [-4.63, -0.20]) and a preoperative diagnosis of diabetes (-1.00% TBW loss, 95% confidence interval [-1.55, -0.44]) were associated with less. None of the 8 neighborhood level characteristics was associated with weight loss.

CONCLUSIONS

Patient characteristics rather than neighborhood-level social determinants and lifestyle factors were associated with weight loss after bariatric surgery in our cohort of bariatric surgery patients. Patients from socioeconomically deprived neighborhoods can achieve excellent weight loss after bariatric surgery.

Obesity and "obesity-related" cancers: are there body mass index cut-points?

BACKGROUND

Despite compelling links between excess body weight and cancer, body mass index (BMI) cut-points, or thresholds above which cancer incidence increased, have not been identified. The objective of this study was to determine if BMI cut-points exist for 14 obesity-related cancers.

SUBJECTS/METHODS

In this retrospective cohort study, patients 18-75 years old were included if they had ≥2 clinical encounters with BMI measurements in the electronic health record (EHR) at a single academic medical center from 2008 to 2018. Patients who were pregnant, had a history of cancer, or had undergone bariatric surgery were excluded. Adjusted logistic regression was performed to identify cancers that were associated with increasing BMI. For those cancers, BMI cut-points were calculated using adjusted quantile regression for cancer incidence at 80% sensitivity. Logistic and quantile regression models were adjusted for age, sex, race/ethnicity, and smoking status.

RESULTS

A total of 7079 cancer patients (mean age 58.5 years, mean BMI 30.5 kg/m2) and 270,441 non-cancer patients (mean age 43.8 years, mean BMI 28.8 kg/m2) were included in the study. In adjusted logistic regression analyses, statistically significant associations were identified between increasing BMI and the incidence of kidney, thyroid, and uterine cancer. BMI cut-points were identified for kidney (26.3 kg/m2) and uterine (26.9 kg/m2) cancer.

CONCLUSIONS

BMI cut-points that accurately predicted development kidney and uterine cancer occurred in the overweight category. Analysis of multi-institutional EHR data may help determine if these relationships are generalizable to other health care settings. If they are, incorporation of BMI into the screening algorithms for these cancers may be warranted.

Association Between Medicaid Status, Social Determinants of Health, and Bariatric Surgery Outcomes

OBJECTIVE

To compare outcomes after bariatric surgery between Medicaid and non-Medicaid patients and assess whether differences in social determinants of health were associated with postoperative weight loss.

BACKGROUND

The literature remains mixed on weight loss outcomes and healthcare utilization for Medicaid patients after bariatric surgery. It is unclear if social determinants of health geocoded at the neighborhood level are associated with outcomes.

METHODS

Patients who underwent laparoscopic sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) from 2008 to 2017 and had ≥1 year of follow-up within a large health system were included. Baseline characteristics, 90-day and 1-year outcomes, and weight loss were compared between Medicaid and non-Medicaid patients. Area deprivation index (ADI), urbanicity, and walkability were analyzed at the neighborhood level. Median regression with percent total body weight (TBW) loss as the outcome was used to assess predictors of weight loss after surgery.

RESULTS

Six hundred forty-seven patients met study criteria (191 Medicaid and 456 non-Medicaid). Medicaid patients had a higher 90-day readmission rate compared to non-Medicaid patients (19.9% vs 12.3%, P < 0.016). Weight loss was similar between Medicaid and non-Medicaid patients (23.1% vs 21.9% TBW loss, respectively; P = 0.266) at a median follow-up of 3.1 years. In adjusted analyses, Medicaid status, ADI, urbanicity, and walkability were not associated with weight loss outcomes.

CONCLUSIONS

Medicaid status and social determinants of health at the neighborhood level were not associated with weight loss outcomes after bariatric surgery. These findings suggest that if Medicaid patients are appropriately selected for bariatric surgery, they can achieve equivalent outcomes as non-Medicaid patients.

Simultaneous spatial smoothing and outlier detection using penalized regression, with application to childhood obesity surveillance from electronic health records

Electronic health records (EHRs) have become a platform for data-driven granular-level surveillance in recent years. In this paper, we make use of EHRs for early prevention of childhood obesity. The proposed method simultaneously provides smooth disease mapping and outlier information for obesity prevalence that are useful for raising public awareness and facilitating targeted intervention. More precisely, we consider a penalized multilevel generalized linear model. We decompose regional contribution into smooth and sparse signals, which are automatically identified by a combination of fusion and sparse penalties imposed on the likelihood function. In addition, we weigh the proposed likelihood to account for the missingness and potential nonrepresentativeness arising from the EHR data. We develop a novel alternating minimization algorithm, which is computationally efficient, easy to implement, and guarantees convergence. Simulation studies demonstrate superior performance of the proposed method. Finally, we apply our method to the University of Wisconsin Population Health Information Exchange database.

Weight Loss for Patients With Obesity: An Analysis of Long-Term Electronic Health Record Data

BACKGROUND

Numerous studies have reported that losing as little as 5% of one's total body weight (TBW) can improve health, but no studies have used electronic health record data to examine long-term changes in weight, particularly for adults with severe obesity [body mass index (BMI) ≥35 kg/m].

OBJECTIVE

To measure long-term weight changes and examine their predictors for adults in a large academic health care system.

RESEARCH DESIGN

Observational study.

SUBJECTS

We included 59,816 patients aged 18-70 years who had at least 2 BMI measurements 5 years apart. Patients who were underweight, pregnant, diagnosed with cancer, or had undergone bariatric surgery were excluded.

MEASURES

Over a 5-year period: (1) ≥5% TBW loss; (2) weight loss into a nonobese BMI category (BMI <30 kg/m); and (3) predictors of %TBW change via quantile regression.

RESULTS

Of those with class 2 or 3 obesity, 24.2% and 27.8%, respectively, lost at least 5% TBW. Only 3.2% and 0.2% of patients with class 2 and 3 obesity, respectively, lost enough weight to attain a BMI <30 kg/m. In quantile regression, the median weight change for the population was a net gain of 2.5% TBW.

CONCLUSIONS

Although adults with severe obesity were more likely to lose at least 5% TBW compared with overweight patients and patients with class 1 obesity, sufficient weight loss to attain a nonobese weight class was very uncommon. The pattern of ongoing weight gain found in our study population requires solutions at societal and health systems levels.

Circannual growth in Wisconsin children and adolescents: Identifying optimal periods of obesity prevention

BACKGROUND

Recent studies suggest kids tend to gain the most weight in summer, but schools are chastised for supporting obesogenic environments. Conclusions on circannual weight gain are hampered by infrequent body mass index (BMI) measurements, and guidance is limited on the optimal timeframe for paediatric weight interventions.

OBJECTIVES

This study characterized circannual trends in BMI in Wisconsin children and adolescents and identified sociodemographic differences in excess weight gain.

METHODS

An observational study was used to pool data from 2010 to 2015 to examine circannual BMI z-score trends for Marshfield Clinic patients age 3 to 17 years. Daily 0.20, 0.50, and 0.80 quantiles of BMI z-score were estimated, stratified by gender, race, and age.

RESULTS

BMI z-scores increased July to September, followed by a decrease in October to December, and another increase to decrease cycle beginning in February. For adolescents, the summer increase in BMI was greater among those in the upper BMI z-score quantile relative to those in the lower quantile (+0.15 units vs +0.04 units). This pattern was opposite in children.

CONCLUSIONS

BMI increased most rapidly in late summer. This growth persisted through autumn in adolescents who were larger, suggesting weight management support may be beneficial for kids who are overweight at the start of the school year.

Patient Engagement and Attitudes Toward Using the Electronic Medical Record for Medical Research: The 2015 Greater Plains Collaborative Health and Medical Research Family Survey

BACKGROUND

Electronic health records (EHRs) are ubiquitous. Yet little is known about the use of EHRs for prospective research purposes, and even less is known about patient perspectives regarding the use of their EHR for research.

OBJECTIVE

This paper reports results from the initial obesity project from the Greater Plains Collaborative that is part of the Patient-Centered Outcomes Research Institute's National Patient-Centered Clinical Research Network (PCORNet). The purpose of the project was to (1) assess the ability to recruit samples of adults of child-rearing age using the EHR; (2) prospectively assess the willingness of adults of child-rearing age to participate in research, and their willingness (if parents) to have their children participate in medical research; and (3) to assess their views regarding the use of their EHRs for research.

METHODS

The EHRs of 10 Midwestern academic medical centers were used to select patients. Patients completed a survey that was designed to assess patient willingness to participate in research and their thoughts about the use of their EHR data for research. The survey included questions regarding interest in medical research, as well as basic demographic and health information. A variety of contact methods were used.

RESULTS

A cohort of 54,269 patients was created, and 3139 (5.78%) patients responded. Completers were more likely to be female (53.84%) and white (85.84%). These and other factors differed significantly by site. Respondents were overwhelmingly positive (83.9%) about using EHRs for research.

CONCLUSIONS

EHRs are an important resource for engaging patients in research, and our respondents concurred. The primary limitation of this work was a very low response rate, which varied by the method of contact, geographic location, and respondent characteristics. The primary strength of this work was the ability to ascertain the clinically observed characteristics of nonrespondents and respondents to determine factors that may contribute to participation, and to allow for the derivation of reliable study estimates for weighting responses and oversampling of difficult-to-reach subpopulations. These data suggest that EHRs are a promising new and effective tool for patient-engaged health research.

Circannual variation in relative weight of children 5 to 16 years of age

BACKGROUND

Summer weight gain in children has been reported; however, this is usually based on two time points. Our objective was to investigate monthly variation in weight status.

METHODS

Cross-sectional, de-identified health records including height, weight and demographics, collected between 2007 and 2012 from South Central Wisconsin in 70 531 children age 5-16 years were analysed. The monthly averages in body mass index (BMI) z-score were analysed cross-sectionally followed by a paired analysis for a subset with one visit each during school and summer months.

RESULTS

BMI z-scores during the summer months (June-August) were lower than values during the school year (September-May). Of note, there was a rapid decrease in BMI z-scores from May to June, with June BMI z-score values being 0.065 units less (95% CI 0.046-0.085) than those in May, little change from June to August and a rapid increase between the August and September BMI z-scores.

CONCLUSION

The monthly pattern does not fully agree with previous two-point school-based studies. Results raise concern that the use of two time point measures of BMIs (early fall and late spring) is suboptimal for evaluation of circannual variation. We suggest that future evaluation of the effect of school-based or summer interventions utilizes additional measures in those periods so that a seasonal analysis can be performed.

Using Electronic Health Records to Examine Disease Risk in Small Populations: Obesity Among American Indian Children, Wisconsin, 2007-2012

Introduction

Tribe-based or reservation-based data consistently show disproportionately high obesity rates among American Indian children, but little is known about the approximately 75% of American Indian children living off-reservation. We examined obesity among American Indian children seeking care off-reservation by using a database of de-identified electronic health records linked to community-level census variables.

Methods

Data from electronic health records from American Indian children and a reference sample of non-Hispanic white children collected from 2007 through 2012 were abstracted to determine obesity prevalence. Related community-level and individual-level risk factors (eg, economic hardship, demographics) were examined using logistic regression.

Results

The obesity rate for American Indian children (n = 1,482) was double the rate among non-Hispanic white children (n = 81,042) (20.0% vs 10.6%, P < .001). American Indian children were less likely to have had a well-child visit (55.9% vs 67.1%, P < .001) during which body mass index (BMI) was measured, which may partially explain why BMI was more likely to be missing from American Indian records (18.3% vs 14.6%, P < .001). Logistic regression demonstrated significantly increased obesity risk among American Indian children (odds ratio, 1.8; 95% confidence interval, 1.6–2.1) independent of age, sex, economic hardship, insurance status, and geographic designation.

Conclusion

An electronic health record data set demonstrated high obesity rates for nonreservation-based American Indian children, rates that had not been previously assessed. This low-cost method may be used for assessing health risk for other understudied populations and to plan and evaluate targeted interventions.

Linking electronic health records with community-level data to understand childhood obesity risk

BACKGROUND

Environmental and socioeconomic factors should be considered along with individual characteristics when determining risk for childhood obesity.

OBJECTIVES

To assess relationships and interactions among the economic hardship index (EHI) and race/ethnicity, age and sex in regard to childhood obesity rates in Wisconsin children using an electronic health record dataset.

METHODS

Data were collected using the University of Wisconsin (UW) Public Health Information Exchange database, which links electronic health records with census-derived community-level data. Records from 53,775 children seen at UW clinics from 2007 to 2012 were included. Mixed-effects modelling was used to determine obesity rates and the interaction of EHI with covariates (race/ethnicity, age, sex). When significant interactions were determined, linear regression analyses were performed for each subgroup (e.g. by age groups).

RESULTS

The overall obesity rate was 11.7% and significant racial/ethnic disparities were detected. Childhood obesity was significantly associated with EHI at the community level (r = 0.62, P < 0.0001). A significant interaction was determined between EHI and both race/ethnicity and age on obesity rates.

CONCLUSIONS

Reducing economic disparities and improving environmental conditions may influence childhood obesity risk in some, but not all, races and ethnicities. Furthermore, the impact of EHI on obesity may be compounded over time. Our findings demonstrate the utility of linking electronic health information with census data to rapidly identify community-specific risk factors in a cost-effective manner.

Roles of Clinician, Patient, and Community Characteristics in the Management of Pediatric Upper Respiratory Tract Infections

PURPOSE

Prior studies have evaluated factors predictive of inappropriate antibiotic prescription for upper respiratory tract infections (URIs). Community factors, however, have not been examined. The aim of this study was to evaluate the roles of patient, clinician, and community factors in predicting appropriate management of URIs in children.

METHODS

We used a novel database exchange, linking electronic health record data with community statistics, to identify all patients aged 3 months to 18 years in whom URI was diagnosed in the period from 2007 to 2012. We followed the Healthcare Effectiveness Data and Information Set (HEDIS) quality measurement titled "Appropriate treatment for children with upper respiratory infection" to determine the rate of appropriate management of URIs. We then stratified data across individual and community characteristics and used multiple logistic regression modeling to identify variables that independently predicted antibiotic prescription.

RESULTS

Of 20,581 patients, the overall rate for appropriate management for URI was 93.5%. Family medicine clinicians (AOR = 1.5; 95% CI 1.31, 1.71; reference = pediatric clinicians), urgent care clinicians (AOR = 2.23; 95% CI 1.93, 2.57; reference = pediatric clinicians), patients aged 12 to 18 years (AOR = 1.44; 95% CI 1.25, 1.67; reference = age 3 months to 4 years), and patients of white race/ ethnicity (AOR = 1.83; 95% CI 1.41, 2.37; reference = black non-Hispanic) were independently predictive of antibiotic prescription. No community factors were independently predictive of antibiotic prescription.

CONCLUSIONS

Results correlate with prior studies in which non-pediatric clinicians and white race/ethnicity were predictive of antibiotic prescription, while association with older patient age has not been previously reported. Findings illustrate the promise of linking electronic health records with community data to evaluate health care disparities.

Electronic health records and community health surveillance of childhood obesity

BACKGROUND

Childhood obesity remains a public health concern, and tracking local progress may require local surveillance systems. Electronic health record data may provide a cost-effective solution.

PURPOSE

To demonstrate the feasibility of estimating childhood obesity rates using de-identified electronic health records for the purpose of public health surveillance and health promotion.

METHODS

Data were extracted from the Public Health Information Exchange (PHINEX) database. PHINEX contains de-identified electronic health records from patients primarily in south central Wisconsin. Data on children and adolescents (aged 2-19 years, 2011-2012, n=93,130) were transformed in a two-step procedure that adjusted for missing data and weighted for a national population distribution. Weighted and adjusted obesity rates were compared to the 2011-2012 National Health and Nutrition Examination Survey (NHANES). Data were analyzed in 2014.

RESULTS

The weighted and adjusted obesity rate was 16.1% (95% CI=15.8, 16.4). Non-Hispanic white children and adolescents (11.8%, 95% CI=11.5, 12.1) had lower obesity rates compared to non-Hispanic black (22.0%, 95% CI=20.7, 23.2) and Hispanic (23.8%, 95% CI=22.4, 25.1) patients. Overall, electronic health record-derived point estimates were comparable to NHANES, revealing disparities from preschool onward.

CONCLUSIONS

Electronic health records that are weighted and adjusted to account for intrinsic bias may create an opportunity for comparing regional disparities with precision. In PHINEX patients, childhood obesity disparities were measurable from a young age, highlighting the need for early intervention for at-risk children. The electronic health record is a cost-effective, promising tool for local obesity prevention efforts.

Sparse modeling of spatial environmental variables associated with asthma

Geographically distributed environmental factors influence the burden of diseases such as asthma. Our objective was to identify sparse environmental variables associated with asthma diagnosis gathered from a large electronic health record (EHR) dataset while controlling for spatial variation. An EHR dataset from the University of Wisconsin's Family Medicine, Internal Medicine and Pediatrics Departments was obtained for 199,220 patients aged 5-50years over a three-year period. Each patient's home address was geocoded to one of 3456 geographic census block groups. Over one thousand block group variables were obtained from a commercial database. We developed a Sparse Spatial Environmental Analysis (SASEA). Using this method, the environmental variables were first dimensionally reduced with sparse principal component analysis. Logistic thin plate regression spline modeling was then used to identify block group variables associated with asthma from sparse principal components. The addresses of patients from the EHR dataset were distributed throughout the majority of Wisconsin's geography. Logistic thin plate regression spline modeling captured spatial variation of asthma. Four sparse principal components identified via model selection consisted of food at home, dog ownership, household size, and disposable income variables. In rural areas, dog ownership and renter occupied housing units from significant sparse principal components were associated with asthma. Our main contribution is the incorporation of sparsity in spatial modeling. SASEA sequentially added sparse principal components to Logistic thin plate regression spline modeling. This method allowed association of geographically distributed environmental factors with asthma using EHR and environmental datasets. SASEA can be applied to other diseases with environmental risk factors.

Estimating Wisconsin asthma prevalence using clinical electronic health records and public health data

OBJECTIVES

We compared a statewide telephone health survey with electronic health record (EHR) data from a large Wisconsin health system to estimate asthma prevalence in Wisconsin.

METHODS

We developed frequency tables and logistic regression models using Wisconsin Behavioral Risk Factor Surveillance System and University of Wisconsin primary care clinic data. We compared adjusted odds ratios (AORs) from each model.

RESULTS

Between 2007 and 2009, the EHR database contained 376,000 patients (30,000 with asthma), and 23,000 (1850 with asthma) responded to the Behavioral Risk Factor Surveillance System telephone survey. AORs for asthma were similar in magnitude and direction for the majority of covariates, including gender, age, and race/ethnicity, between survey and EHR models. The EHR data had greater statistical power to detect associations than did survey data, especially in pediatric and ethnic populations, because of larger sample sizes.

CONCLUSIONS

EHRs can be used to estimate asthma prevalence in Wisconsin adults and children. EHR data may improve public health chronic disease surveillance using high-quality data at the local level to better identify areas of disparity and risk factors and guide education and health care interventions.

The theory and application of UW ehealth-PHINEX, a clinical electronic health record-public health information exchange

BACKGROUND

Electronic health records (EHRs) hold the promise of improving clinical quality and population health while reducing health care costs. However, it is not clear how these goals can be achieved in practice.

METHODS

Clinician-led teams developed EHR data extracts to support chronic disease use cases. EHRs were linked with community-level data to describe disease prevalence and health care quality at the patient, health care system, and community risk factor levels. Software was developed and statistical modeling included multivariate, mixed-model, longitudinal, data mining, and geographic information system (GIS)/spatial regression approaches.

RESULTS

A HIPAA-compliant limited data set was created on 192,201 patients seen in University of Wisconsin Family Medicine clinics throughout Wisconsin in 2007-2009. It was linked to a commercially available database of approximately 6000 variables describing community-level risk factors at the census block group. Areas of increased asthma and diabetes prevalence have been mapped, identified, and compared to economic hardship.

CONCLUSIONS

A comprehensive framework has been developed for clinical-public health data exchange to develop new evidence and apply it to clinical practice and health policy. EHR data at the neighborhood level can be used for future population studies and may enhance understanding of community-level patterns of illness and care.

Relationship of serum levels of individual PCB, dioxin, and furan congeners and DDE with Great Lakes sport-caught fish consumption

Great Lakes (GL) sport fish consumption is a potential route of exposure for environmentally persistent organochlorine contaminants, which may have human health effects. In this report, relationships are explored among individual congeners in a large cohort of frequent and infrequent GL sport fish consumers. Blood samples were obtained in 1993-1995 and analyzed for 1,1-bis(4-chlorophenyl)-2,2-dichloroethene (DDE) and for 62 noncoplanar polychlorinated biphenyls (PCBs), 4 coplanar PCBs, 8 polychlorinated dibenzo-p-dioxin (dioxin), and10 dibenzofuran (furan) congeners. All GL fish eaters and referents had detectable levels of DDE, total noncoplanar PCBs, total coplanar PCBs, total dioxins, and total furans. Noncoplanar PCBs were higher in GL sport fish consumers than in a referent population from the same geographic area, were associated with GL sport-caught fish (GLSCF) consumption, and varied significantly by Great Lake. DDE, lower chlorinated dioxin and furan toxic equivalents (TEQs), and coplanar PCB TEQs were positively associated with noncoplanar PCBs but were not associated with GL sport fish consumption independent of PCB level. Highly chlorinated dioxin and furan congener TEQs were not significantly associated with noncoplanar PCBs or GL sport fish consumption, suggesting that participants were acquiring some of these TEQs from a source other than GLSCF. In epidemiologic studies, it may be important to include populations with higher organochlorine exposures as well as background exposures and to consider the effects of individual congeners or mixtures of congeners on health outcomes.

Medical informatics in population health: building Wisconsin's strategic framework for health information technology

Medicine is increasingly practiced through the application of information sciences. Medical informatics deals with optimal information use within bioinformatics, imaging, clinical, and population health domains. Population health informatics plays an important role in that it critically informs practice in each of the other domains. Proper functioning of health care systems requires an advanced health information network that supports clinical care, personal health management, population health, and research. But this infrastructure does not yet exist in the United States. A number of federal initiatives are underway to address this problem, including the development of a framework for a national health information network and funding for implementation. This network will be facilitated by federal leadership, but public and private partnerships, and state, regional, and local implementation and policy development will play a critical role. In this article, we describe several Wisconsin initiatives that are keys to developing a strategic framework and building the state's electronic health information infrastructure.

Using Web-based reporting systems to evaluate health promotion: the experience of two statewide HIV prevention programs

While Web-based reporting systems are becoming more common in public health for disease surveillance and for tracking interventions such as immunizations, their use for program evaluation is relatively new. This article describes two Web-based reporting systems developed to enable local agencies that conduct health promotion activities to enter process and outcome data for their own use, as well as for analysis by researchers and funders. The systems support the three major uses of evaluation: accountability, program improvement, and generating knowledge for the field. Annually, these programs obtain evaluation information on thousands of clients and individual and group sessions. Developing and introducing the Web-based systems was time-consuming and required significant State Health Department and local agency resources. Involvement of end users in the development process was critical to creating responsive systems that were accepted by staff in local agencies. Staff members from grantee agencies responded well to systems, as evidenced by high rates of user compliance (over 90%) and positive reactions (over 80%) on anonymous surveys. Concerns about resistance from contractors to use of the system, based on fears about breaches in client confidentiality or concerns about the difficulty in using the technology, were not borne out.

Maternal exposure to Great Lakes sport-caught fish and dichlorodiphenyl dichloroethylene, but not polychlorinated biphenyls, is associated with reduced birth weight

Fish consumption may be beneficial for a developing human fetus, but fish may also contain contaminants that could be detrimental. Great Lakes sport-caught fish (GLSCF) are contaminated with polychlorinated biphenyls (PCBs) and dichlorodiphenyl dichloroethylene (DDE), but the effects of these contaminants on birth outcome are not clear. To distinguish potential contaminant effects, we examined (1) whether the decrease over time in contaminant levels in GLSCF is paralleled by an increase in birth weight of children of GLSCF-consuming mothers and (2) the relation between maternal serum concentrations of these contaminants and birth weight. Mothers (n=511) were interviewed from 1993 to 1995, and maternal serum was collected from 1994 to 1995 (n=143). Potential confounders considered were child gender, maternal age at delivery, maternal prepregnancy body mass index, maternal cigarette and alcohol use during pregnancy, maternal education level, maternal parity, and maternal breastfeeding. Children born during 1970-1977, 1978-1984, and 1985-1993 to mothers who ate more than 116 meals of GLSCF before pregnancy were, on average, 164 g lighter, 46 g heavier, and 134 g heavier, respectively, than children of mothers who ate no GLSCF before pregnancy (P trend=0.05). GLSCF-consuming mothers had higher serum PCB and DDE concentrations, but only increased DDE was associated with lower birth weight. The data suggest that fetal DDE exposure (as indicated by maternal serum DDE concentration) may decrease birth weight and that decreased birth weight effects associated with GLSCF consumption have decreased over time.

Wisconsin's environmental public health tracking network: information systems design for childhood cancer surveillance

In this article we describe the development of an information system for environmental childhood cancer surveillance. The Wisconsin Cancer Registry annually receives more than 25,000 incident case reports. Approximately 269 cases per year involve children. Over time, there has been considerable community interest in understanding the role the environment plays as a cause of these cancer cases. Wisconsin's Public Health Information Network (WI-PHIN) is a robust web portal integrating both Health Alert Network and National Electronic Disease Surveillance System components. WI-PHIN is the information technology platform for all public health surveillance programs. Functions include the secure, automated exchange of cancer case data between public health-based and hospital-based cancer registrars; web-based supplemental data entry for environmental exposure confirmation and hypothesis testing; automated data analysis, visualization, and exposure-outcome record linkage; directories of public health and clinical personnel for role-based access control of sensitive surveillance information; public health information dissemination and alerting; and information technology security and critical infrastructure protection. For hypothesis generation, cancer case data are sent electronically to WI-PHIN and populate the integrated data repository. Environmental data are linked and the exposure-disease relationships are explored using statistical tools for ecologic exposure risk assessment. For hypothesis testing, case-control interviews collect exposure histories, including parental employment and residential histories. This information technology approach can thus serve as the basis for building a comprehensive system to assess environmental cancer etiology.

The role of sport-fish consumption advisories in mercury risk communication: a 1998-1999 12-state survey of women age 18-45

BACKGROUND

In 2002, in the United States, 48 states issued advisories for sport-fish consumers that included 39 chemical contaminants. The most commonly identified chemical was methyl mercury, which is linked to reproductive and developmental effects. Advisories to reduce consumption of contaminated fish have been issued by states since the early 1970s. Advisories are being integrated to include both sport and commercial fish.

METHODS

As part of a comprehensive risk-communication project, from December 1998 through August 1999 the Wisconsin Division of Public Health and the State of Maine Bureau of Health conducted a 12-state random-digit-dial telephone survey of 3015 women of childbearing age (ages 18-45). The goal was to assess the prevalence of fish consumption, understanding of mercury toxicity, and awareness of state sport-fish consumption advisories for mercury. We gathered information concerning respondents' demographic characteristics, understanding of mercury toxicity, fish consumption during the preceding 12 months, and sport-fish consumption advisory awareness.

RESULTS

The overall survey completion rate was 57% with a Council of American Survey Research Organizations (CASRO)-calculated response rate of 50%. Completion rates varied from 37% in New Jersey to 73% in Minnesota. Fish consumption during the previous 12 months was reported by 87% of respondents (range by state of 82-90%). Nearly 10% of women reported consuming two or more fish-meals per week over the prior 12 months. Twenty-nine percent reported sport-fish consumption during the same time period, with a greater state-to-state variability (14-43%). Most women (71%) were aware of mercury's toxicity to a developing child (87% among those aware of an advisory and 67% among those unaware of an advisory). However, awareness of state advisories was only 20%, ranging by state from 8% to 32%. Women who were older, had more than a high school education, and had a household member with a fishing license were the most informed about mercury and fish-consumption advisories.

CONCLUSIONS

Most women of childbearing age consume commercial fish and a substantial number also consume sport-caught fish. Despite this potential exposure to dietary mercury, most are unfamiliar with their state's mercury fish-consumption advisory. Most women were aware of the most toxic effects of mercury but less informed about mercury and its relationship to types of fish and fish characteristics. Minorities, women over age 30, family incomes above 25,000 US dollars, and those with some collage education were more likely to be consuming two or more fish-meals per week. Until source control and environmental remediation efforts can reduce the environmental burden of mercury below levels of concern, combined sport and commercial fish consumption advisories will remain the primary means of reducing human exposure to methylmercury. Assuring and assessing the effectiveness of such advisories is paramount. Our survey documents that current efforts to inform vulnerable populations are far from optimal.

Aeroallergens, allergic rhinitis, and sedating antihistamines: risk factors for traumatic occupational injury and economic impact

BACKGROUND

The U.S. workplace injury burden is significant. Our objective was to assess the particular impact of aeroallergen, allergic rhinitis, and antihistamine exposures and side effects on the risk of traumatic work-related injuries, and the associated economic impact.

METHODS

This is an observational case-control study with 1,223 acute traumatic injury cases that are compared to 1,202 chronic back injury controls. Structured telephone interviews were conducted in 1998 and 1999 on Workers' Compensation applicants injured in 1997. Antihistamine use and pollen levels were measured 2 weeks prior to the injury date.

RESULTS

Sedating antihistamine exposures elevated acute injury risk (main effect OR: 2.93). A significant increase in traumatic injury risk was observed for combined sedating antihistamine and high pollen exposures among subjects with physician and self-diagnosed allergic rhinitis (OR: 2.41). Direct medical costs associated with this increased risk were estimated at $143 million in 2001.

CONCLUSIONS

Workers with physician-diagnosed allergic rhinitis have as high a reliance on sedating antihistamines as do self-diagnosed and self-medicating nasal allergy sufferers. High pollen exposures along with sedating antihistamine use may confer significant additional injury risks among allergic rhinitis sufferers. Medical management "best practices" of diagnosed allergic rhinitis should include avoidance of sedating antihistamines to minimize acute, traumatic injury risks.

Decreased sex ratio following maternal exposure to polychlorinated biphenyls from contaminated Great Lakes sport-caught fish: a retrospective cohort study

BACKGROUND

Fish from the Great Lakes are contaminated with polychlorinated biphenyls, which have been found to have several adverse reproductive effects. Several environmental contaminants have been found to alter the sex ratio of offspring at birth, but the evidence of such an effect of polychlorinated biphenyls has been inconsistent.

METHODS

We examined parental serum polychlorinated biphenyl concentration in relation to the sex ratio of 173 children of mothers and 208 children of fathers from the Great Lakes region of the United States between 1970 and 1995. We calculated odds ratios for a male child using logistic regression and generalized estimating equations with adjustment for the year of birth of the child, maternal and paternal age, the mother's parity at the child's birth, and whether the child had an older brother.

RESULTS

The adjusted odds ratio for having a male child among mothers in the highest quintile of serum polychlorinated biphenyl concentration was 0.18 (95% CI: 0.06-0.59) compared to mothers in the lowest quintile. Treating exposure as a continuous variable, the adjusted odds ratio for having a male child was 0.54 per unit increase in the natural log of maternal serum polychlorinated biphenyl concentration (95% CI: 0.33-0.89). There was little evidence of an association with paternal exposure. We found no association between either maternal or paternal serum dichlorodiphenyl-dichloroethene concentration and the sex ratio.

CONCLUSIONS

These findings suggest that maternal exposure to polychlorinated biphenyls may decrease the sex ratio of offspring. These data add to the growing body of evidence that exposure to particular chemicals can alter the sex ratio at birth.

Hazardous ammonia releases: public health consequences and risk factors for evacuation and injury, United States, 1993-1998

Unplanned releases of ammonia lead more often to evacuation and injury than releases of other chemicals, but few studies have systematically investigated ammonia releases. We analyzed Hazardous Substances Emergency Events Surveillance system data for 1993-1998. Evacuation of a total of at least 40,680 persons resulted from 537 ammonia releases, and 248 ammonia releases led to injury of 1434 persons. Equipment failure and operator error were cited as factors contributing to ammonia releases 90% of the time. Eighty-seven percent of releases occurred at fixed facilities. Risk factors for evacuation and injury differed between the food-manufacturing industry and other industries. Indoor release was a consistent risk factor, whereas quantity of ammonia released was not always a risk factor. Preventive maintenance and worker training may be effective tools to reduce the burdens of hazardous ammonia releases.

Heat wave morbidity and mortality, Milwaukee, Wis, 1999 vs 1995: an improved response?

OBJECTIVES

This study examined whether differences in heat alone, as opposed to public health interventions or other factors, accounted for the reduction in heat-related deaths and paramedic emergency medical service (EMS) runs between 1995 and 1999 during 2 heat waves occurring in Milwaukee, Wis.

METHODS

Two previously described prediction models were adapted to compare expected and observed heat-related morbidity and mortality in 1999 based on the city's 1995 experience.

RESULTS

Both models showed that heat-related deaths and EMS runs in 1999 were at least 49% lower than levels predicted by the 1995 relation between heat and heat-related deaths or EMS runs.

CONCLUSIONS

Reductions in heat-related morbidity and mortality in 1999 were not attributable to differences in heat levels alone. Changes in public health preparedness and response may also have contributed to these reductions.

The effects of PCB exposure and fish consumption on endogenous hormones

Previous studies have suggested that exposure to polychlorinated biphenyls (PCBs) may alter thyroid function, but data on effects of PCB exposure on other endogenous hormones has been lacking. The current study is ancillary to a larger investigation of the effects of Great Lakes fish consumption on PCBs and reproductive function. In the current study we examine associations of PCBs, 1,1-bis (4-chlorophenyl)-2,2-dichloroethene (DDE), and fish consumption with thyroid and steroid hormones in 178 men and PCBs, DDE, and fish consumption with thyroid hormones in 51 women from the original study. Serum PCB level and consumption of Great Lakes fish are associated with significantly lower levels of thyroxine (T(4)) and free thyroxine index (FTI) in women and with significantly lower levels of T(4) in men. Fish consumption, but not PCB level, is significantly and inversely associated with triiodothyronine (T(3)) in men. Results for thyroid-stimulating hormone (TSH) are inconsistent. Among men, there are significant inverse associations of both PCB and fish consumption with sex hormone-binding globulin (SHBG)-bound testosterone, but no association with SHBG or free testosterone. There are no significant overall associations of PCB, DDE, or fish consumption with estrone sulfate, follicle-stimulating hormone, luteinizing hormone, or dehydroepiandrosterone sulfate. The results of this study are consistent with previous studies showing effects of fish consumption and PCB exposure on thyroid hormones and suggest that PCBs may also decrease steroid binding to SHBG. Elucidation of specific mechanisms must await future investigations.

The effects of PCB exposure and fish consumption on endogenous hormones

Previous studies have suggested that exposure to polychlorinated biphenyls (PCBs) may alter thyroid function, but data on effects of PCB exposure on other endogenous hormones has been lacking. The current study is ancillary to a larger investigation of the effects of Great Lakes fish consumption on PCBs and reproductive function. In the current study we examine associations of PCBs, 1,1-bis (4-chlorophenyl)-2,2-dichloroethene (DDE), and fish consumption with thyroid and steroid hormones in 178 men and PCBs, DDE, and fish consumption with thyroid hormones in 51 women from the original study. Serum PCB level and consumption of Great Lakes fish are associated with significantly lower levels of thyroxine (T(4)) and free thyroxine index (FTI) in women and with significantly lower levels of T(4) in men. Fish consumption, but not PCB level, is significantly and inversely associated with triiodothyronine (T(3)) in men. Results for thyroid-stimulating hormone (TSH) are inconsistent. Among men, there are significant inverse associations of both PCB and fish consumption with sex hormone-binding globulin (SHBG)-bound testosterone, but no association with SHBG or free testosterone. There are no significant overall associations of PCB, DDE, or fish consumption with estrone sulfate, follicle-stimulating hormone, luteinizing hormone, or dehydroepiandrosterone sulfate. The results of this study are consistent with previous studies showing effects of fish consumption and PCB exposure on thyroid hormones and suggest that PCBs may also decrease steroid binding to SHBG. Elucidation of specific mechanisms must await future investigations.

Fish consumption habits and advisory awareness among Fox River anglers

Eating PCB-contaminated fish caught from the Lower Fox River, northeast Wisconsin, has raised concern about the health risk to consumers, especially to children and unborn babies. The fish advisory published by the state of Wisconsin recommends which fish are safe to eat. However, there is reason to believe that many anglers, especially non-English speaking anglers, are not aware of the advisory and the possible health risks of eating contaminated fish. A face-to-face survey administered to 104 anglers fishing along the Fox River indicates that 17% of anglers eat some or all of the fish they catch and that 83% practice "catch and release." Almost all the anglers were not familiar with Wisconsin's fish advisory but had heard of the health risks from their local newspaper and TV. As a follow-up, a fish health advisory brochure specific to the Fox River was developed.

Asthma hospitalizations in Wisconsin: a missed opportunity for prevention

Asthma is the most common chronic disease of children and the third leading cause of preventable hospitalizations in the United States. To assess the impact of this disease on Wisconsin, we examined 1996-1998 state-wide and county-specific asthma hospitalization rates and compared these rates to Wisconsin 1990-1992 rates, national rates, and United States Healthy People 2010 asthma target objectives. Wisconsin's average asthma hospitalization rate has decreased from 13.4/10,000 during 1990-1992 to 12.1/10,000 during 1996-1998. Wisconsin children 0-4 years of age had the highest asthma-related hospitalization rate (38.0/10,000) of all age groups, during 1996-1998. Wisconsin African American residents had an average asthma hospitalization rate 6.6 times higher than whites (58.5 vs. 8.8 per 10,000, respectively) during 1996-1998. Milwaukee County had the highest county-specific asthma hospitalization rate in the state (26.4/10,000). Unless significant reductions are achieved, Wisconsin will not reach the Healthy People 2010 target objectives. Interventions should be directed to preventing asthma hospitalizations, especially among Wisconsin's youth and African American population.

Hazardous ammonia releases in Wisconsin: trends and risk factors for evacuation and injury

OBJECTIVE

To assess trends in hazardous ammonia releases and risk factors for subsequent evacuation and injury.

METHODS

Analysis of the Wisconsin Hazardous Substances Emergency Events Surveillance system data during 1993 through 1998.

RESULTS

Ammonia releases (291) accounted for 13% of all reported chemical releases, but 26% of all releases that led to evacuations. The majority of non-transportation-related ammonia releases are the result of equipment failure or operator error (85.5%). Few ammonia releases are transportation-related (6.5%) or occur during extreme weather (14.4%). Extreme weather is not a risk factor for evacuation or injury following ammonia releases.

CONCLUSIONS

Ammonia releases are frequently the result of equipment failure or operator error and thus preventable. The majority of ammonia releases that lead to evacuation and injury are not the result of transportation accidents or weather factors beyond human control. Prevention efforts that focus on preventive maintenance, and worker training and awareness could reduce the burden of hazardous ammonia releases.

Wisconsin farmer cancer mortality, 1981 to 1990: selected malignancies

Cancer mortality risks for Wisconsin white male farmers were examined during the years 1981 to 1990. Four malignancies were studied: Non-Hodgkin's lymphoma, melanoma, colon cancer, and rectal cancer. Occupation coded deaths were segmented into farmer and nonfarmer groups and population counts for the groups were estimated from 1980 and 1990 Bureau of the Census data. Standardized mortality ratios (SMRs) were constructed from the ratio of observed farmer deaths and the expected number of farmer deaths. Expected deaths were generated from the underlying statewide nonfarmer rate for the malignancy multiplied into the farmer population at risk. Farmers had significantly lower mortality risks for melanoma (SMR: 0.659; 95% CI: 0.993-0.326) and colon cancer (SMR: 0.763; 95% CI: 0.928-0.599). Farmers also exhibited a nonsignificant decrement for non-Hodgkin's lymphoma (SMR: 0.930; 95% CI: 1.214-0.645). For rectal cancer, farmers experienced a slightly higher but essentially the same risk as nonfarmers (SMR: 1.013; 95% CI: 1.418-0.608)--the SMR was not significant. This study corroborates a number of cancer incidence and mortality investigations demonstrating that farmers generally experience the same or lower mortality risks for these malignancies.

Serum PCB and DDE levels of frequent Great Lakes sport fish consumers-a first look. The Great Lakes Consortium

Great Lakes (GL) sport fish consumption is a potential human exposure route for polychlorinated biphenyls (PCBs) and dichlorodiphenyl dichloroethene (DDE). Because of fish tissue contamination, frequent consumers of Great Lakes sport caught fish (GLSCF) may be at risk for PCB and DDE accumulation. To examine this problem, the Health Departments of Wisconsin, Illinois, Indiana, Ohio, and Michigan formed a health assessment consortium. Participants were contacted by telephone to complete a detailed demographic and fish consumption survey. Frequent and infrequent GLSCF consumers were identified, and a participant subset was then asked to donate blood for PCB and DDE analysis. Analysis of variance (ANOVA) was done to study exposure group mean differences, while correlation and regression analyses were performed to examine relationships between demographic characteristics, GLSCF consumption, PCB, and DDE body burdens. A total of 4206 individuals participated in the study. Of these, 2542 were habitual GLSCF consumers (mean greater than 35 meals/year males; greater than 27 meals/year females), while 1664 did not eat GLSCF. A subset of 538 participants donated blood and included 439 frequent and 99 infrequent GLSCF consumers. PCB levels were significantly higher in the group of GLSCF consumers (geometric mean: 4.8 ppb males, 2.1 ppb females) when compared to their referents (geometric mean: 1.5 ppb males, 0.9 ppb females), while DDE levels were also higher for GLSCF consumers. PCB and DDE body burdens varied by exposure group, gender, and great lake (Michigan, Huron, Erie). PCB and DDE levels were significantly correlated to age, body mass index, and sport fish and Great Lakes sport fish consumption histories. Regression analysis identified years of consuming sport caught fish as the most robust predictor of PCBs (r2=25%), while age was the best predictor of DDE levels (r2=21%). This study corroborated previous findings relating frequent GLSCF consumption to a higher body burden for PCBs and DDE.

Health advisories for consumers of Great Lakes sport fish: is the message being received?

Nationwide, 45 states issue health advisories for sport fish consumers. Chemical contaminants in some Great Lakes (GL) sport fish include compounds suspected of causing adverse reproductive and developmental effects. Although advisories to reduce consumption of contaminated fish, especially by women, have been issued by GL states (i.e., Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin) since the mid-1970s, little is known about advisory awareness and GL sport fish consumption in the general population. To estimate the prevalence of GL sport fish consumption and health advisory awareness, we conducted a population-based telephone survey of 8,306 adult residents of the eight GL states. We gathered information concerning respondents' demographic characteristics, fish consumption during the preceding year, and sport fish consumption advisory awareness. The survey response rate was 69%. GL sport fish were eaten during the preceding year by 8.4% -95% confidence interval (CI), 7.6-9.2- of adults in the GL states, approximately 4.7 million persons. Women accounted for 43.9% (CI,39. 4-48.4) of consumers. Although 49.9% of GL sport fish consumers were aware of a health advisory, awareness varied significantly by sex: 58.2% (CI, 51.7-64.7) of males and 39.1% (CI, 32.6-45.6) of females were aware. Using logistic regression, we found awareness associated with male sex -odds ratio (OR) = 2.3; CI, 1.5-3.5), white race (OR = 4.2; CI, 1.9-9.1), college degree (OR = 3.1; CI, 1.3-7.6), and consuming >=24 GL sport fish meals/year (OR = 2.4; CI, 1.4-4.3). Only half of GL sport fish consumers reported awareness of a health advisory concerning eating GL sport fish. Awareness was especially low among women, suggesting the need of targeted risk communication programs for female consumers.

Osteosarcoma, seasonality, and environmental factors in Wisconsin, 1979-1989

Proxy exposure measures and readily available data from the Wisconsin Cancer Reporting System were used to contrast 167 osteosarcoma cases with 989 frequency-matched cancer referents reported during 1979-1989. Differences in potential exposure to water-borne radiation and fluoridated drinking water, population size for the listed place of residence, and seasonality were assessed. An association was found between osteosarcoma and residence in a population of less than 9,000 (odds ratio = 1.6, 95% confidence interval = 1.1-2.4). In addition, an association between month of birth (May through July versus other months of birth) and osteosarcoma among individuals who were less than 25 y of age (odds ratio = 1.9, 95% confidence interval = 1.1-3.4). Overall, no association was found between potential exposure to fluoridated drinking water and osteosarcoma (odds ratio = 1.0, 95% confidence interval = 0.6-1.5). The association between osteosarcoma and water-borne radiation was weak and was not significant statistically (odds ratio = 1.5, 95% confidence interval = 0.8-2.8).

Mesothelioma among employees with likely contact with in-place asbestos-containing building materials

The occurrence of mesothelioma is a sentinel event in occupational and environmental disease. A mesothelioma surveillance system was established utilizing existing computerized Wisconsin vital statistics data maintained since 1959 and a Cancer Reporting System (CRS) established in 1978. Review of the death certificate listing of usual occupation and industry from 487 mesothelioma deaths in Wisconsin from 1959 to 1989 led to the investigation of 41 persons with likely exposure to inplace asbestos-containing building materials (ACBM): 12 school teachers, 10 school maintenance employees, 7 public building maintenance workers, 5 private building maintenance workers, and 7 commercial and factory workers performing maintenance activities. For 10 (34%) of the 29 maintenance workers the only source of asbestos exposure identified was their maintenance work. For five (17%) histories indicated some prior employment in occupations and industries with probable asbestos exposures. Opportunities for indirect occupational exposure were identified for ten who had been employed in the residential construction industry. One maintenance worker was exposed to asbestos in the household and another had neighborhood exposure. For 9 (75%) of the school teachers, the only identifiable potential source of asbestos exposure was derived from in-place ACBM in schools. One teacher had spent a season in the merchant marine aboard an iron ore-hauling ship and 2 had worked in the residential construction industry. Two of the teachers were sisters, and in two instances, two teachers had taught in the same school facility. We conclude that individuals occupationally exposed to in-place ACBM are at risk for the subsequent development of mesothelioma.

Risk factors for measles in a previously vaccinated population and cost-effectiveness of revaccination strategies

Using data from a large measles outbreak that occurred in Dane County (Wisconsin) in 1986, we conducted a case-control study to evaluate risk factors for vaccine failure and assessed the cost-effectiveness of school-based revaccination strategies. Vaccination before a change in the measles vaccine stabilizer in 1979 (odds ratio, 5.5; 95% confidence interval, 1.05 to 28.9) and vaccination before age 15 months (odds ratio, 13.9; 95% confidence interval, 5.9 to 32.6) were identified as risk factors. Revaccination strategies for all students ($3444 per case prevented), students vaccinated before 1980 ($3166 per case prevented), and students vaccinated before age 15 months ($2546 per case prevented) were evaluated, assuming use of measles-mumps-rubella vaccine after the initial case was detected in a school. However, a large proportion of cases (43% to 53%) may not have been preventable using these strategies. Therefore, revaccination in all schools assessed to be at risk for measles may be necessary to prevent large outbreaks until a two-dose vaccination schedule is fully implemented.

State health department response to disease cluster reports: a protocol for investigation

State health departments are increasingly faced with the task of responding to reports of apparent cancer and other disease clusters. Since 1979, 141 requests for investigation have been received by the Wisconsin Division of Health, with over 60% of these requests occurring since 1985. Mounting public concern and limited resources have resulted in the development of a "disease cluster investigation and analysis protocol." Protocol steps include: 1) circumscribing the cluster; 2) ascertaining cases; 3) assessing risk of the exposed versus a referent population; 4) statistically analyzing disease rates; 5) examining potential exposure; 6) assessing biologic plausibility; 7) determining cluster significance and need for further investigation; and 8) reporting results. To demonstrate the protocol, the authors present a case example of an investigation of an apparent cancer cluster. Since 1979, 62 reports were resolved with initial contact with informant education (step 1), 61 reports required descriptive analysis (steps 1-8) with no site visit, and 18 reports required site visits. None of the reports required further in-depth epidemiologic investigation. This protocol provides a systematic approach to investigation and analysis, prioritizes the need for more in-depth study, and, when necessary, assuages community concerns when a disease cluster is reported.

SMRFIT: a Statistical Analysis System (SAS) program for standardized mortality ratio analyses and Poisson regression model fits in community disease cluster investigations

Increasingly, health departments are being pressed by the public to respond to disease risk with cluster investigations in communities and neighborhoods. This is a direct result of growing concern about the role that the environment may play in disease risk. While extensive analyses directly inputing exposures or numbers at risk are often necessary to thoroughly investigate clusters, it is quite useful to perform an exploratory analysis with existing morbidity and mortality data as a first level of response. To meet this need for timely evaluation, the authors describe a user-friendly Statistical Analysis System (SAS) program called SMRFIT to automate community disease cluster evaluations. The program creates frequency tables for number at risk and number of disease outcomes for the community, balance of parent county, and balance of state. SMRFIT then constructs standardized mortality ratios, with the community compared with balance of county and balance of state referents. Poisson regression is offered as an option for the modeling of community disease rates.

A monitoring system to detect increased rates of cancer incidence

A new method for monitoring occurrences of rare health events is proposed. This proposed method is similar in principle to the sets technique but is shown to have much better expected time to alarm properties. This is illustrated for a number of hypothetical situations, and then both methods are applied to cancer mortality data. The proposed method will allow the use of large monitoring systems consisting of implementations of the method in a number of subregions (i.e., counties) of a larger region (i.e., state) independently, and still maintain reasonable expected times between false alarms.

Sport fish consumption and body burden levels of chlorinated hydrocarbons: a study of Wisconsin anglers

Sport-caught fish consumption is the major source of polychlorinated biphenyls (PCBs) exposure for the general population. To assess this and 2,2'-bis-(p-chlorophenyl)-1,1-dichloroethylene (DDE) exposure, we surveyed 801 Wisconsin anglers for fishing and consumption habits and comprehension of and compliance with the Wisconsin fish consumption health advisory. The mean annual number of sport-caught fish meals was 18. Seventy-two percent of anglers were familiar with the health advisory and 57% had changed their fishing or fish consumption habits as a result of the advisory. The mean PCB serum congener sum level for 192 anglers was 2.2 micrograms/l (range = nondetectable to 27.1 micrograms/l); mean DDE was 6.3 micrograms/l (range = nondetectable to 40.0 micrograms/l). Statistically significant positive Spearman correlations were observed between sport-caught fish meals and PCB and DDE sera levels (R = .21 and .14, respectively) and between kilograms of fish caught and PCB sera levels (R = .25). These results demonstrate that anglers may provide a population for assessment of PCBs and DDE associated morbidity and mortality.