Follow-up of cardiovascular adverse events after smallpox vaccination among civilians in the United States, 2003.

Limited information exists regarding intermediate or long-term consequences of cardiac adverse events (CAEs) after smallpox vaccination. We conducted follow up at 5-12 months after vaccination of 203 US civilian vaccinees who reported a possible CAE. Among 31 of the 33 with confirmed CAEs, at least 1 health-related quality-of-life change persisted for approximately 48%; approximately 87% missed work (average, 11.5 days). Among 168 of the 170 case patients with other reported cardiovascular conditions, at least 1 health-related quality-of-life change persisted for approximately 40%; almost 49% missed work (average, 10.2 days). Almost all vaccinees with possible CAEs were working the same number of hours at follow-up compared with before vaccination. Although intermediate-term consequences among possible postvaccination CAEs were not considered serious, lost days of work and a decline in health-related quality of life at the time of follow-up were common, resulting in personal economic and quality-of-life burden.

Impact of methodological "shortcuts" in conducting public health surveys: results from a vaccination coverage survey.

BACKGROUND: Lack of methodological rigor can cause survey error, leading to biased results and suboptimal public health response. This study focused on the potential impact of 3 methodological "shortcuts" pertaining to field surveys: relying on a single source for critical data, failing to repeatedly visit households to improve response rates, and excluding remote areas. METHODS: In a vaccination coverage survey of young children conducted in the Commonwealth of the Northern Mariana Islands in July 2005, 3 sources of vaccination information were used, multiple follow-up visits were made, and all inhabited areas were included in the sampling frame. Results are calculated with and without these strategies. RESULTS: Most children had at least 2 sources of data; vaccination coverage estimated from any single source was substantially lower than from all sources combined. Eligibility was ascertained for 79% of households after the initial visit and for 94% of households after follow-up visits; vaccination coverage rates were similar with and without follow-up. Coverage among children on remote islands differed substantially from that of their counterparts on the main island indicating a programmatic need for locality-specific information; excluding remote islands from the survey would have had little effect on overall estimates due to small populations and divergent results. CONCLUSION: Strategies to reduce sources of survey error should be maximized in public health surveys. The impact of the 3 strategies illustrated here will vary depending on the primary outcomes of interest and local situations. Survey limitations such as potential for error should be well-documented, and the likely direction and magnitude of bias should be considered.

Unsuspected recent transmission of tuberculosis among high-risk groups: implications of universal tuberculosis genotyping in its detection.

BACKGROUND: The initiation of universal genotyping revealed 3 clusters of 19 patients with tuberculosis (TB) in Wisconsin, with no apparent epidemiologic links among most of them. An epidemiologic investigation was conducted to determine whether genotype clustering resulted from recent transmission. METHODS: We conducted additional interviews with patients and reviewed medical records. Places frequented by the patients while they were infectious were visited to identify contacts. RESULTS: Our investigation revealed several previously unrecognized possible sites of TB transmission: a single-room occupancy hotel, 2 homeless shelters, 1 bar, and 2 crack houses. Seven patients with previously diagnosed TB were added to the clusters. Of 26 patients, we identified epidemiologic links for all but 1. Common risk factors among patients included alcohol abuse, crack cocaine use, homelessness, and unemployment. Additionally, 98 contacts missed during routine contact investigation were identified. CONCLUSIONS: Transmission of TB, particularly among high-risk groups, may go undetected for years. Our investigation demonstrated the value of universal genotyping in revealing unsuspected recent TB transmission and previously unrecognized sites of transmission, which can be targeted for specific TB interventions.

Predictors of age-appropriate receipt of DTaP dose 4.

BACKGROUND: In the United States, the national childhood immunization schedule calls for children to receive four doses of DTaP (diphtheria and tetanus toxoids and acellular pertussis) vaccine administered at 2, 4, 6, and 15 to 18 months. Dose 4 of DTaP is among the most frequently missed vaccines for children who are not adequately immunized. METHODS: Using the 2001 National Immunization Survey, the effect of the timeliness of the first three DTaP doses was assessed on completion of the four-dose series by age 24 months and on time by age 12 to 18 months. RESULTS: Missing Dose 4 was more prevalent among children who received Dose 3 late (but <16 months) than among children who received Dose 3 on time (24% vs 10%). Similarly, receiving Dose 4 late (or not at all) was more prevalent among children who received Dose 3 late (but <9 months) (39% vs 22%). An invalid Dose 4 was administered to 4.6% of those with Dose 3 late but before 9 months and to 10.6% of those with no Dose 3 before 9 months, compared to 1.2% of those with Dose 3 on time. CONCLUSIONS: Physicians and staff can identify children at risk for missing the fourth DTaP dose or receiving it late by assessing timeliness of receipt of DTaP Dose 3 and implementing steps to ensure that at-risk children receive Dose 4 as recommended.

Bayesian Small Area Estimates of Diabetes Incidence by United States County, 2009.

In the United States, diabetes is common and costly. Programs to prevent new cases of diabetes are often carried out at the level of the county, a unit of local government. Thus, efficient targeting of such programs requires county-level estimates of diabetes incidence-the fraction of the non-diabetic population who received their diagnosis of diabetes during the past 12 months. Previously, only estimates of prevalence-the overall fraction of population who have the disease-have been available at the county level. Counties with high prevalence might or might not be the same as counties with high incidence, due to spatial variation in mortality and relocation of persons with incident diabetes to another county. Existing methods cannot be used to estimate county-level diabetes incidence, because the fraction of the population who receive a diabetes diagnosis in any year is too small. Here, we extend previously developed methods of Bayesian small-area estimation of prevalence, using diffuse priors, to estimate diabetes incidence for all U.S. counties based on data from a survey designed to yield state-level estimates. We found high incidence in the southeastern United States, the Appalachian region, and in scattered counties throughout the western U.S. Our methods might be applicable in other circumstances in which all cases of a rare condition also must be cases of a more common condition (in this analysis, "newly diagnosed cases of diabetes" and "cases of diabetes"). If appropriate data are available, our methods can be used to estimate proportion of the population with the rare condition at greater geographic specificity than the data source was designed to provide.

Compliance with recommendations and opportunities for vaccination at ages 11 to 12 years: evaluation of the 2009 national immunization survey-teen.

OBJECTIVES: To determine vaccination coverage at selected ages and by birth cohort and to assess whether all indicated vaccines were administered during vaccination visits. DESIGN: Population-based cross-sectional study. SETTING: National Immunization Survey-Teen 2009 telephone interview. PARTICIPANTS: United States adolescents aged 13 to 17 years with provider-reported vaccination histories (N = 20 066). MAIN OUTCOME MEASURES: Among all adolescents and by birth cohort: coverage estimates for 3 childhood vaccines (measles-containing, hepatitis B, and varicella) and 3 adolescent vaccines (tetanus-diphtheria and/or tetanus-diphtheria-acellular pertussis, meningococcal-containing, and human papillomavirus for girls) at selected ages. RESULTS: By age 11 years, most adolescents had obtained the childhood vaccines. Receipt of a tetanus-diphtheria and/or tetanus-diphtheria-acellular pertussis vaccine at ages 11 to 12 years increased significantly from the 1991 to 1996 birth cohort (33.8% vs 68.2%, P < .001); receipt of meningococcal-containing vaccine at ages 11 to 12 years increased significantly from the 1993 to 1996 birth cohort (8.4% vs 50.0%, P < .001). Among girls, receipt of human papillomavirus vaccine at ages 11 to 12 years increased significantly from the 1994 to 1996 birth cohort (11.1% vs 30.5%, P < .001). Overall, 54.9% of adolescents received at least 1 vaccination visit at ages 11 to 12 years. Among adolescents who made a vaccination visit at ages 11 to 12 years and were eligible for vaccination, 19.5% did not receive tetanus-diphtheria and/or tetanus-diphtheria-acellular pertussis, 60.9% did not receive meningococcal-containing, and 62.4% did not receive human papillomavirus vaccines. CONCLUSIONS: Receipt of vaccines at the recommended ages of 11 to 12 years appears to be increasing; however, providers often do not administer all indicated vaccines during a vaccination visit.

Modeling and public health emergency responses: lessons from SARS.

Modelers published thoughtful articles after the 2003 SARS crisis, but had limited if any real-time impact on the global response and may even have inadvertently contributed to a lingering misunderstanding of the means by which the epidemic was controlled. The impact of any intervention depends on its efficiency as well as efficacy, and efficient isolation of infected individuals before they become symptomatic is difficult to imagine. Nonetheless, in exploring the possible impact of quarantine, the product of efficiency and efficacy was varied over the entire unit interval. Another mistake was repeatedly fitting otherwise appropriate gamma distributions to times to event regardless of whether they were stationary or not, particularly onset-isolation intervals whose progressive reduction evidently contributed to SARS control. By virtue of their unknown biology, newly-emerging diseases are more challenging than familiar human scourges. Influenza, for example, recurs annually and has been modeled more thoroughly than any other infectious disease. Moreover, models were integrated into preparedness exercises, during which working relationships were established that bore fruit during the 2009 A/H1N1 pandemic. To provide the most accurate and timely advice possible, especially about the possible impact of measures designed to control diseases caused by novel human pathogens, we must appreciate the value and difficulty of policy-oriented modeling. Effective communication of insights gleaned from modeling SARS will help to ensure that policymakers involve modelers in future outbreaks of newly-emerging infectious diseases. Accordingly, we illustrate the increasingly timely care-seeking by which, together with increasingly accurate diagnoses and effective isolation, SARS was controlled via heuristic arguments and descriptive analyses of familiar observations.

Prevalence of parental concerns about childhood vaccines: the experience of primary care physicians.

BACKGROUND: Little is known about the effects of increased parental vaccine safety concerns on physicians' vaccine communication attitudes and practices. PURPOSE: To assess among pediatricians and family medicine (FM) physicians: (1) prevalence of parental requests to deviate from recommended vaccine schedules; (2) responses to such requests; and (3) attitudes about the burden and success of vaccine communications with parents. METHODS: Survey of nationally representative samples of pediatricians and FM physicians (N=696) conducted during February to May 2009 with analysis in 2010. RESULTS: Response rates were 88% for pediatricians and 78% for FM physicians. Overall, 8% of physicians reported that ≥10% of parents refused a vaccine and 20% reported that ≥10% of parents requested to spread out vaccines in a typical month. More pediatricians than FM physicians reported always/often requiring parents to sign a form if they refused vaccination (53% vs 31%, p<0.0001); 64% of all physicians would agree to spread out vaccines in the primary series at least sometimes. When talking with parents with substantial concerns, 53% of physicians reported spending 10-19 minutes and 8% spending ≥20 minutes. Pediatricians were more likely than FM physicians to report their job less satisfying because of parental vaccine concerns (46% vs 21%, p<0.0001). Messages most commonly reported as "very effective" were personal statements such as what they would do for their own children. CONCLUSIONS: The burden of communicating with parents about vaccines is high, especially among pediatricians. Physicians report the greatest success convincing skeptical parents using messages that rely on their personal choices and experiences.

Legal basis of consent for health care and vaccination for adolescents.

State law is generally the controlling authority for whether parental consent is required or minors may consent for their own health care, including vaccination. At the federal level, no vaccination consent law exists; however, federal law requires that vaccine information statements be given to the parent or another person who is qualified under state law to consent to vaccination of a minor. All states allow minors to consent for their own health care in some circumstances on the basis of either (1) their status (eg, age, emancipation, marriage) or (2) the kind of health care services they are seeking (eg, family planning services, treatment of sexually transmitted disease). In each state, a specific analysis of laws will be required to determine the circumstances under which a minor can consent for vaccination.

Adolescent immunizations and other clinical preventive services: a needle and a hook?

Advances in technology have led to development of new vaccines for adolescents, but these vaccines will be added to a crowded schedule of recommended adolescent clinical preventive services. We reviewed adolescent clinical preventive health care guidelines and patterns of adolescent clinical preventive service delivery and assessed how new adolescent vaccines might affect health care visits and the delivery of other clinical preventive services. Our analysis suggests that new adolescent immunization recommendations are likely to improve adolescent health, both as a "needle" and a "hook." As a needle, the immunization will enhance an adolescent's health by preventing vaccine-preventable diseases during adolescence and adulthood. It also will likely be a hook to bring adolescents (and their parents) into the clinic for adolescent health care visits, during which other clinical preventive services can be provided. We also speculate that new adolescent immunization recommendations might increase the proportion and quality of other clinical preventive services delivered during health care visits. The factor most likely to diminish the positive influence of immunizations on delivery of other clinical preventive services is the additional visit time required for vaccine counseling and administration. Immunizations may "crowd out" delivery of other clinical preventive services during visits or reduce the quality of the clinical preventive service delivery. Complementary strategies to mitigate these effects might include prioritizing clinical preventive services with a strong evidence base for effectiveness, spreading clinical preventive services out over several visits, and withholding selected clinical preventive services during a visit if the prevention activity is effectively covered at the community level. Studies are needed to evaluate the effect of new immunizations on adolescent preventive health care visits, delivery of clinical preventive services, and health outcomes.

Projected cost-effectiveness of new vaccines for adolescents in the United States.

BACKGROUND: Economic assessments that guide policy making on immunizations are becoming increasingly important in light of new and anticipated vaccines for adolescents. However, important considerations that limit the utility of these assessments, such as the diversity of approaches used, are often overlooked and should be better understood. OBJECTIVE: Our goal was to examine economic studies of adolescent vaccines and compare cost-effectiveness outcomes among studies on a particular vaccine, across adolescent vaccines, and between new adolescent vaccines versus vaccines that are recommended for young children. METHODS: A systematic review of economic studies on immunizations for adolescents was conducted. Studies were identified by searching the Medline, Embase, and EconLit databases. Each study was reviewed for appropriateness of model design, baseline setup, sensitivity analyses, and input variables (ie, epidemiologic, clinical, cost, and quality-of-life impact). For comparison, the cost-effectiveness outcomes reported in key studies on vaccines for younger children were selected. RESULTS: Vaccines for healthy adolescents were consistently found to be more costly than the health care or societal cost savings they produced and, in general, were less cost-effective than vaccines for younger children. Among the new vaccines, pertussis and human papillomavirus vaccines were more cost-effective than meningococcal vaccines. Including herd-immunity benefits in studies significantly improved the cost-effectiveness estimates for new vaccines. Differences in measurements or assumptions limited further comparisons. CONCLUSION: Although using the new adolescent vaccines is unlikely to be cost-saving, vaccination programs will result in sizable health benefits.

Ranking states' immunization coverage: an example from the National Immunization Survey.

The National Immunization Survey (NIS) provides state-level estimates of preschool immunization coverage. These coverages are frequently presented in ranked lists, and ranks are frequently over-interpreted. In this paper, we highlight the difficulty in interpreting ranked point estimates. To demonstrate the uncertainty of ranks, parametric bootstrap methods were used to derive 90 per cent confidence intervals for ranks of state vaccination coverage levels among preschool children. We graphically compared states to a reference state. If NIS data are used to rank states, one should consider presenting confidence intervals for rank and the results of comparisons of one state with another graphically.

Counting the shots: a model for immunization screening and referral in nonmedical settings.

BACKGROUND: Clinics of the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) have become important partners in efforts to improve vaccination coverage in low income children. However, the time required to assess all antigens in each child's vaccination record may exceed the capacity of many of these clinics. Seeking a solution, experts recommended assessing up-to-date (UTD) status only for the diphtheria-tetanus-acellular-pertussis (DTaP) vaccine and treating this as a proxy measure for all vaccines in the childhood schedule. Whether this single vaccine screening method represents an acceptable alternative to the traditional multiple-vaccine method as a basis for improving overall immunization coverage levels in this vulnerable population has not been demonstrated. OBJECTIVE: To evaluate the validity of the proposed simplified method for assessing immunization status in a nationally representative population of infants and children who had ever been enrolled in WIC before 35 months old. METHODS: This was a cross-sectional analysis of the 2000 National Immunization Survey representing children ages 3 to 24 months who had ever been enrolled in WIC. For the 6277 children in the study population, we compared personal records of completion status for DTaP with personal records of completion status for all immunizations appropriate for age in the combination 4:3:1:3 schedule to see which of the 2 (single vs multiple screening) methods would better predict the child's true (provider-reported) status for the 4:3:1:3 series. The main outcome measures were the comparative sensitivity, specificity, and overall test efficiency of the 2 methods in correctly identifying underimmunized WIC children. RESULTS: Completion status for DTaP was less sensitive than completion status for all vaccinations in correctly identifying truly underimmunized children (sensitivity = 70% and 77%, respectively). However, it was more specific in correctly identifying children who were truly UTD for age (specificity = 86% and 82%, respectively). The 2 methods were essentially identical with respect to overall test efficiency (82% and 81% for DTaP assessment and assessment of all vaccines, respectively). CONCLUSIONS: Given limited resources to do immunization screening and referral in nonmedical settings such as WIC, simplifying the process by using DTaP from the personal vaccination record as a proxy for the 4:3:1:3 series is a viable option. Loss in sensitivity may well be offset by gains in the capacity of WIC clinics to screen more children.

Has surveillance been adequate to detect endemic measles in the United States?

Evidence that endemic measles has been eliminated in the United States rests on the performance of the surveillance system. Information from national surveillance data allows us to evaluate the adequacy of national surveillance to detect the circulation of endemic measles. Sources of data include measles report dates, international importation status, and the size of chains of measles transmission. The proportion of chains of measles transmission that can be epidemiologically linked to international importations is high (62%), as would be expected if measles is no longer circulating; the number of imported cases, although lower than estimated expected values, is within a reasonable range of expectation. National surveillance detects even small outbreaks, so larger outbreaks that are the marker for endemic transmission would almost certainly be detected. Few unreported cases of measles are detected when health departments conduct careful investigations in response to reports of an index case. Surveillance appears to be adequate to support the contention that measles is no longer endemic in the United States.

Assessing equivalence: an alternative to the use of difference tests for measuring disparities in vaccination coverage.

Eliminating health disparities in vaccination coverage among various groups is a cornerstone of public health policy. However, the statistical tests traditionally used cannot prove that a state of no difference between groups exists. Instead of asking, "Has a disparity--or difference--in immunization coverage among population groups been eliminated ?," one can ask, "Has practical equivalence been achieved?" A method called equivalence testing can show that the difference between groups is smaller than a tolerably small amount. This paper demonstrates the method and introduces public health considerations that have an impact on defining tolerable levels of difference. Using data from the 2000 National Immunization Survey, the authors tested for statistically significant differences in rates of vaccination coverage between Whites and members of other racial/ethnic groups and for equivalencies among Whites and these same groups. For some minority groups and some vaccines, coverage was statistically significantly lower than was seen among Whites; however, for some of these groups and vaccines, equivalence testing revealed practical equivalence. To use equivalence testing to assess whether a disparity remains a threat to public health, researchers must understand when to use the method, how to establish assumptions about tolerably small differences, and how to interpret the test results.

An economic analysis of the current universal 2-dose measles-mumps-rubella vaccination program in the United States.

To evaluate the economic impact of the current 2-dose measles-mumps-rubella (MMR) vaccination program in the United States, a decision tree-based analysis was conducted with population-based vaccination coverage and disease incidence data. All costs were estimated for a hypothetical US birth cohort of 3803295 infants born in 2001. The 2-dose MMR vaccination program was cost-saving from both the direct cost and societal perspectives compared with the absence of MMR vaccination, with net savings (net present value) from the direct cost and societal perspectives of US dollars 3.5 billion and US dollars 7.6 billion, respectively. The direct and societal benefit-cost ratios for the MMR vaccination program were 14.2 and 26.0. Analysis of the incremental benefit-cost of the second dose showed that direct and societal benefit-cost ratios were 0.31 and 0.49, respectively. Varying the proportion of vaccines purchased and administered in the public versus the private sector had little effect on the results. From both perspectives under even the most conservative assumptions, the national 2-dose MMR vaccination program is highly cost-beneficial and results in substantial cost savings.