Urban and Rural Child Deaths from Motor Vehicle Crashes: United States, 2015-2019.

OBJECTIVE: The objective of the study was to examine child deaths in motor vehicle crashes by rurality, restraint use, and state child passenger restraint laws. STUDY DESIGN: 2015-2019 Fatality Analysis Reporting System data were analyzed to determine deaths and rates by passenger and crash characteristics. Optimal restraint use was defined using age and the type of the restraint according to child passenger safety recommendations. RESULTS: Death rates per 100 000 population were highest for non-Hispanic Black (1.96; [1.84, 2.07]) and American Indian or Alaska Native children (2.67; [2.14, 3.20]) and lowest for Asian or Pacific Islander children (0.57; [0.47, 0.67]). Death rates increased with rurality with the lowest rate (0.88; [0.84, 0.92]) in the most urban counties and the highest rate (4.47; [3.88, 5.06]) in the most rural counties. Children who were not optimally restrained had higher deaths rates than optimally restrained children (0.84; [0.81, 0.87] vs 0.44; [0.42, 0.46], respectively). The death rate was higher in counties where states only required child passenger restraint use for passengers aged ≤6 years (1.64; [1.50, 1.78]) than that in those requiring child passenger restraint use for passengers aged ≤7 or ≤8 years (1.06; [1.01, 1.12]). CONCLUSIONS: Proper restraint use and extending the ages covered by child passenger restraint laws reduce the risk for child crash deaths. Additionally, racial and geographic disparities in crash deaths were identified, especially among Black and Hispanic children in rural areas. Decision makers can consider extending the ages covered by child passenger restraint laws until at least age 9 to increase proper child restraint use and reduce crash injuries and deaths.

Chronic Disease Disparities by County Economic Status and Metropolitan Classification, Behavioral Risk Factor Surveillance System, 2013.

INTRODUCTION: Racial/ethnic disparities have been studied extensively. However, the combined influence of geographic location and economic status on specific health outcomes is less well studied. This study's objective was to examine 1) the disparity in chronic disease prevalence in the United States by county economic status and metropolitan classification and 2) the social gradient by economic status. The association of hypertension, arthritis, and poor health with county economic status was also explored. METHODS: We used 2013 Behavioral Risk Factor Surveillance System data. County economic status was categorized by using data on unemployment, poverty, and per capita market income. While controlling for sociodemographics and other covariates, we used multivariable logistic regression to evaluate the relationship between economic status and hypertension, arthritis, and self-rated health. RESULTS: Prevalence of hypertension, arthritis, and poor health in the poorest counties was 9%, 13%, and 15% higher, respectively, than in the most affluent counties. After we controlled for covariates, poor counties still had a higher prevalence of the studied conditions. CONCLUSION: We found that residents of poor counties had a higher prevalence of poor health outcomes than affluent counties, even after we controlled for known risk factors. Further, the prevalence of poor health outcomes decreased as county economics improved. Findings suggest that poor counties would benefit from targeted public health interventions, better access to health care services, and improved food and built environments.

Improving blood pressure control in a large multiethnic California population through changes in health care delivery, 2004-2012.

The Kaiser Permanente Southern California (Kaiser) health care system succeeded in improving hypertension control in a multiethnic population by adopting a series of changes in health care delivery. Data from the Healthcare Effectiveness Data and Information Set (HEDIS) was used to assess blood pressure control from 2004 through 2012. Hypertension control increased overall from 54% to 86% during that period, and 80% or more in every subgroup, regardless of race/ethnicity, preferred language, or type of health insurance plan. Health care delivery changes improved hypertension control across a large multiethnic population, which indicates that health care systems can achieve a clinical target goal of 70% for hypertension control in their populations.

Tuberculosis Disease Among Nonimmigrant Visa Holders Reported to US Quarantine Stations, January 2011-June 2016.

US-bound immigrants and refugees undergo a mandatory overseas medical examination that includes tuberculosis screening; this exam is not routinely required for temporary visitors applying for non-immigrant visas (NIV) to visit, work, or study in the United States. US health departments and foreign ministries of health report tuberculosis cases in travelers to Centers for Disease Control and Prevention Quarantine Stations. We reviewed cases reported to this passive surveillance system from January 2011 to June 2016. Of 1252 cases of tuberculosis in travelers reported to CDC, 114 occurred in travelers with a long-term NIV. Of these, 83 (73%) were infectious; 18 (16%) with multidrug-resistant tuberculosis (MDR TB) and one with extensively drug-resistant tuberculosis (XDR TB). We found evidence that NIV holders are diagnosed with tuberculosis disease in the United States. Given that long-term NIV holders were over-represented in this data set, despite the small proportion (4%) of overall non-immigrant admissions they represent, expanding the US overseas migration health screening program to this population might be an efficient intervention to further reduce tuberculosis in the United States.

Minority Health Social Vulnerability Index and COVID-19 vaccination coverage - The United States, December 14, 2020-January 31, 2022.

INTRODUCTION: In 2021, HHS Office of Minority Health and CDC developed a composite measure of social vulnerability called the Minority Health Social Vulnerability Index (MHSVI) to assess the needs of communities most vulnerable to COVID-19. The MHSVI extends the CDC Social Vulnerability Index with two new themes on healthcare access and medical vulnerability. This analysis examines COVID-19 vaccination coverage by social vulnerability using the MHSVI. METHODS: County-level COVID-19 vaccine administration data among persons aged ≥18 years reported to CDC from 12/14/20 to 01/31/22 were analyzed. U.S. counties from 50 states and DC were categorized into tertiles of vulnerability (low, moderate, and high) for the composite MHSVI measure and each of the 34 indicators. Vaccination coverage (≥1 dose, primary series completion, and receipt of a booster dose) was calculated by tertiles for the composite MHSVI measure and each indicator. RESULTS: Counties with lower per capita income, higher proportion of individuals with no high school diploma, living below poverty, ≥65 years of age, with a disability, and in mobile homes had lower vaccination uptake. However, counties with larger proportions of racial/ethnic minorities and individuals speaking English less than "very well" had higher coverage. Counties with fewer primary care physicians and greater medical vulnerabilities had lower ≥ 1 dose vaccination coverage. Furthermore, counties of high vulnerability had lower primary series completion and receipt of a booster dose. There were no clear patterns in COVID-19 vaccination coverage by tertiles for the composite measure. CONCLUSION: Results from the new components in the MHSVI identify needs to prioritize persons in counties with greater medical vulnerabilities and limited access to health care, who are at greater risk for adverse COVID-19 outcomes. Findings suggest that using a composite measure to characterize social vulnerability might mask disparities in COVID-19 vaccination uptake that would have otherwise been observed using specific indicators.

Does geographic location matter for transportation risk behaviors among U.S. public high school students?

Introduction: Teen motor vehicle crash fatality rates differ by geographic location. Studies assessing teen transportation risk behaviors by location are inconclusive. Therefore, we explored the role of census region and metropolitan status for driving prevalence and four transportation risk behaviors among U.S. public high school students. Methods: Data from 2015 and 2017 national Youth Risk Behavior Surveys were combined and analyzed. Multivariable models controlled for sex, age, race/ethnicity, grades in school, and school socioeconomic status. Results: Overall, 41% of students did not always wear a seat belt. Students attending schools in the Northeast were 40% more likely than those in the Midwest to not always wear a seat belt. Among the 75% of students aged ≥16 years who had driven during the past 30 days, 47% texted/e-mailed while driving. Students in the Northeast were 20% less likely than those in the Midwest to text/e-mail while driving, and students attending suburban or town schools were more likely to text/e-mail while driving (20% and 30%, respectively) than students attending urban schools. Nineteen percent of students rode with a driver who had been drinking alcohol, and 7% of drivers aged ≥16 years drove when they had been drinking alcohol, with no significant differences by location for either alcohol-related behavior. Conclusions: We found few differences in teen transportation risk behaviors by census region or metropolitan status. Age at licensure, time since licensure, driving experience, and the policy and physical driving environment might contribute more to variation in teen fatal crashes by location than differences in transportation risk behaviors. Regardless of location, teen transportation risk behaviors remain high. Future research could address developing effective strategies to reduce teen cell phone use while driving and enhancing community implementation of existing, effective strategies to improve seat belt use and reduce alcohol consumption and driving after drinking alcohol.

Compliance with vaccination recommendations for U.S. children.

BACKGROUND: Official recommendations for the routine vaccination of U.S. children, made by the Advisory Committee on Immunization Practices (ACIP), specify the vaccines for administration, the number of doses that should be given, the age ranges for administration, the minimum ages at which doses are considered valid, the minimum intervals between doses within a series, and several additional vaccine-specific adjustments and exceptions. Federally reported estimates of vaccination coverage measure only compliance with the required number of doses; other recommendations are not routinely evaluated. METHODS: Analysis of vaccination histories for 17,563 U.S. children aged 19-35 months from the 2005 National Immunization Survey. MAIN OUTCOME MEASURES: Compliance with, and incremental impact of, each vaccination recommendation. RESULTS: Estimated coverage was 72% for the standard vaccination series accounting for all recommendations, 9 percentage points lower than coverage based solely on counting doses. Overall, 19% of children were missing one or more doses, while 8% had received an invalid dose, and 9% were affected by other recommendations. The proportion of noncompliance due to missed doses versus other recommendations varied by state and by antigen. CONCLUSIONS: Approximately 28% of children were not in compliance with the official vaccination recommendations. Missed doses accounted for approximately two thirds of noncompliance, with the remainder due to mis-timed doses and other requirements. Measuring compliance with all ACIP recommendations provides a valuable tool to assess and improve the quality of healthcare delivery and ensure that children and communities are optimally protected from vaccine-preventable diseases.

Trends in colorectal cancer screening disparities in people aged 50-64 years, 2000-2005.

BACKGROUND: Colorectal cancer (CRC) screening rates are low, and racial, ethnic, and economic disparities have been reported. Whether disparities in CRC screening have decreased over time is unknown. This study aimed to determine whether progress was made between 2000 and 2005 in reducing CRC screening disparities by race, ethnicity, income, and insurance status. METHODS: Age-adjusted percentages of participants aged 50-64 who reported CRC screening (home fecal occult blood test in the past year or endoscopy in the past 10 years) were estimated from the 2000 (n=6,020 participants) and 2005 (n=6,706) cancer control supplements of the National Health Interview Survey, with analysis in 2007. RESULTS: Screening rates did not increase between 2000 and 2005 for Hispanic women or uninsured women. Only for high-income participants did screening exceed 50%. For both men and women, the uninsured had the lowest levels of screening (19.1% and 19.3%, respectively, in 2005), and the greatest disparities were observed among groups defined by health insurance status. For women, disparities by ethnicity, income, and insurance status increased over time, whereas among men, disparities in 2005 were similar to those in 2000. For Hispanic women, growing disparities were present at all income and insurance levels and persisted after additional adjustment. CONCLUSIONS: No progress was made in reducing most CRC screening disparities between 2000 and 2005. Methods are needed to increase CRC screening among everyone, but in particular Hispanic women and uninsured men and women.

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.

Asian and Pacific Islander childhood vaccination coverage: National Immunization Survey, 2002-2004.

OBJECTIVE: Public health data on Asian/Pacific Islanders are most often collected and reported as one aggregated group. This aggregation of data can mask potential differences among the many ethnic/national/cultural groups classified as Asian/Pacific Islanders. We used data from the National Immunization Survey (NIS) to examine immunization status for all US children and four mutually exclusive groups: Asian only, Native Hawaiian only, Pacific Islander only, and other. METHODS: We included information from 64,718 US children 19-35 months of age who had adequate vaccination histories from provider(s) for 2002 to 2004; among these, 2673 (4.3%) were Asian only, Native Hawaiian only, or Pacific Islander only. The sample sizes reported are unweighted, while results are based on weighted analyses. RESULTS: Vaccination coverage estimates for children in the Native Hawaiian only group were consistently higher than estimates for all US children, whereas those in the Asian only group were nearly the same. Children in the Pacific Islander only group had vaccination coverage estimates that were lower than estimates for all US children. CONCLUSION: The results of this study indicated that although overall the Asian/Pacific Islander group had similar childhood vaccination coverage to all US children, the group does not have homogeneous coverage, with Pacific Islanders having lower coverage. Public health researchers should, whenever possible, examine individual groups of Asian/Pacific Islanders to more accurately measure the health status of this growing population.

Diabetes is associated with increased prevalence of latent tuberculosis infection: Findings from the National Health and Nutrition Examination Survey, 2011-2012.

AIMS: We aim to determine the association between prediabetes and diabetes with latent TB using National Health and Nutrition Examination Survey data. METHODS: We performed a cross-sectional analysis of 2011-2012 National Health and Nutrition Examination Survey data. Participants ≥20 years were eligible. Diabetes was defined by glycated hemoglobin (HbA1c) as no diabetes (≤5.6% [38 mmol/mol]), prediabetes (5.7-6.4% [39-46 mmol/mol]), and diabetes (≥6.5% [48 mmol/mol]) combined with self-reported diabetes. Latent TB infection was defined by the QuantiFERON®-TB Gold In Tube (QFT-GIT) test. Adjusted odds ratios (aOR) of latent TB infection by diabetes status were calculated using logistic regression and accounted for the stratified probability sample. RESULTS: Diabetes and QFT-GIT measurements were available for 4958 (89.2%) included participants. Prevalence of diabetes was 11.4% (95%CI 9.8-13.0%) and 22.1% (95%CI 20.5-23.8%) had prediabetes. Prevalence of latent TB infection was 5.9% (95%CI 4.9-7.0%). After adjusting for age, sex, smoking status, history of active TB, and foreign born status, the odds of latent TB infection were greater among adults with diabetes (aOR 1.90, 95%CI 1.15-3.14) compared to those without diabetes. The odds of latent TB in adults with prediabetes (aOR 1.15, 95%CI 0.90-1.47) was similar to those without diabetes. CONCLUSIONS: Diabetes is associated with latent TB infection among adults in the United States, even after adjusting for confounding factors. Given diabetes increases the risk of active TB, patients with co-prevalent diabetes and latent TB may be targeted for latent TB treatment.

United States Notifications of Travelers from Ebola-Affected Countries.

The International Health Regulations (IHR), an international law under the auspices of the World Health Organization (WHO), mandates that countries notify other countries of "travelers under public health observation." Between November 10, 2014, and July 12, 2015, the US Centers for Disease Control and Prevention (CDC) made 2,374 notifications to the National IHR Focal Points in 114 foreign countries of travelers who were monitored by US health departments because they had been to an Ebola-affected country in West Africa. Given that countries have preidentified focal points as points of contacts for sharing of public health information, notifications could be made by CDC to a trusted public health recipient in another country within 24 hours of receipt of the traveler's information from a US health department. The majority of US health departments used this process, offered by CDC, to notify other countries of travelers intending to leave the United States while being monitored in their jurisdiction.

Impact of state vaccine financing policy on uptake of heptavalent pneumococcal conjugate vaccine.

OBJECTIVE: We examined heptavalent pneumococcal conjugate vaccine (PCV7) uptake among children aged 19 to 35 months in the United States and determined how uptake rates differed by state vaccine financing policy. METHODS: We analyzed data from the 2001-2003 National Immunization Survey. States that changed their vaccine financing policy between 2001 and 2003 (n=17) were excluded from analysis. Logistic regression was performed to identify the association between state vaccine financing policy and receipt of 3 or more doses of PCV7 after control for demographic characteristics. RESULTS: The proportion of children receiving 3 or more doses increased from 6.7% in 2001 to 69.0% in 2003. After controlling for demographic characteristics, children residing in states that provided all vaccines except PCV7 to all children had lower odds of receiving 3 or more doses compared to children residing in states that provided PCV7 only to children eligible for the Vaccines for Children program (odds ratio=0.58; 95% confidence interval=0.51, 0.66). CONCLUSION: It is essential that we continue to monitor the effect that state vaccine financing policy has on the delivery of PCV7 and future vaccines, which are likely to be increasingly expensive.

Disparities between white and African-American children in immunization coverage.

INTRODUCTION: A recent study has shown that the national-scale difference in immunization coverage between non-Hispanic white (abbreviated "white") and non-Hispanic African-American (abbreviated "African-American") children aged 19-35 months in the United States has increased by about 1 percentage point annually. We examined how this widening gap differs with geography and income. METHODS: We used data from the National Immunization Survey, 1998-2003, a national telephone survey. We examined differences between white and African-American children in immunization coverage within income groups (at or above versus below the federal poverty level) for each census region (northeast, south, midwest and west). We tested the hypothesis of constant disparity over time. RESULTS: Among households at or above the federal poverty level in the northeast census region, disparity is widening (white coverage minus African-American coverage was -0.5 in 1998 but 15.5 in 2003). Among household at or above the federal poverty level in the midwest census region, disparity is narrowing (white coverage minus African-American coverage was 13.9 in 1998 but 2.5 in 2003). We found no significant evidence of a trend in other groups. CONCLUSIONS: Widening national-level disparity in immunization coverage is primarily attributable to trends in the northeast census region. Addressing the widening disparity in coverage requires new strategies that consider current social and economic contexts.

Parental vaccine safety concerns: results from the National Immunization Survey, 2001-2002.

BACKGROUND: According to the 2002 National Immunization Survey (NIS), vaccination coverage with recommended vaccines among U.S. children aged 19 to 35 months remained near all-time highs. Sustaining this high coverage requires significant effort, including consideration of parental vaccine safety concerns that have led to decreasing coverage in other countries. METHODS: The Parental Knowledge and Experiences module was administered to a random subset of NIS respondents from July 2001 to December 2002. The module included questions regarding attitudes toward vaccine safety and side effects, simultaneous vaccine administration, and acceptance of new vaccines. Multivariate logistic regression analyses examined associations between attitudes and up-to-date (UTD) vaccination coverage (four or more doses of diphtheria and tetanus toxoids and pertussis vaccine, three or more doses of poliovirus vaccine, one or more doses of any measles-containing vaccine, three or more doses of Haemophilus influenzae type b vaccine, and three or more doses of hepatitis B vaccine), while controlling for demographics. RESULTS: Ninety-three percent of parents rated vaccines as safe, 6% as neither safe nor unsafe, and 1% as unsafe. After adjusting for demographics, parental safety belief was significantly associated with the child's vaccination status. For children whose parents believed vaccines are safe, the odds of being UTD were 2.9 times the odds of being UTD for children of parents who believed vaccines are unsafe (75% vs 53%, respectively). Children whose parents were neutral about the safety of vaccines had vaccination coverage similar to children whose parents believed vaccines are unsafe. CONCLUSIONS: A significant association with vaccine coverage was found for a small group of parents with high vaccine safety concerns. Strategies focused on safety concerns may yield better protection for these children.

Measurement of vaccination coverage at age 24 and 19-35 months: a case study of multiple imputation in public health.

AIM: Childhood immunization coverage in the United States (US) is often measured at age 24 months or, in the National Immunization Survey (NIS) at age of interview, which is between 19 and 35 months. This paper compares these standards. METHODS: Data from the NIS is used to compare immunization coverage at time of interview, retrospectively among all children aged 24 or more months at time of interview, and obtained via multiple imputation (with 10 imputations) for all children, both nationally, by state, and by demographic groups. RESULTS: At the national level, the difference between the 19-35 month estimate and the 24 month complete-case estimate was 1.9 percentage points. For most but not all states and subgroups, the 19-35 month estimate was higher than the 24 month complete-case estimate. The difference between vaccination coverage measured at 19-35 months and 24 months ranged from -2.3 to 7.5 percentage points among states. For three states, the difference between the 19-35 month and 24 month complete-case estimate was more than 6 percentage points, in twelve states there was a 4-6 percentage point difference, and in sixteen states a 2-4 percentage point difference. Conversely, five states had higher 24 month complete-case estimates than 19-35 month estimates. CONCLUSION: We found that the coverages at 19-35 and 24 months differ such that they would rarely be adequate surrogates for one another, particularly at a state level. Multiple imputation, which is easily implemented, increases precision of estimates of coverage at age 24 months.

How do caregivers know when to take their child for immunizations?

BACKGROUND: Childhood vaccinations help reduce and eliminate many causes of morbidity and mortality among children. The objective of this study was to compare 4:3:1:3:3 (4+ doses of diphtheria and tetanus toxoids and pertussis vaccine, 3+ doses of poliovirus vaccine, 1+ doses of measles-containing vaccine, 3+ doses of Haemophilus influenzae type b vaccine, and 3+ doses of hepatitis B vaccine) coverage among children whose caregivers learned by different methods when their child's most recent immunization was needed. METHODS: Between July 2001 and December 2002, a portion of households receiving the National Immunization Survey were asked how they knew when to take the child in for his/her most recent immunization. Responses were post-coded into several categories: 'Doctor/nurse reminder at previous immunization visit', 'Shot card/record', 'Reminder/recall', and 'Other'. Respondents could give more than one answer. Children who did not receive any vaccines, had < or = 1 visits for vaccinations, or whose caregiver did not provide an answer to the question were excluded from analyses. Chi-square analyses were used to compare 4:3:1:3:3 coverage among 19-35 month old children. RESULTS: Children whose caregivers indicated that a doctor/nurse told them at a previous immunization visit when to return for the next immunization had significantly greater 4:3:1:3:3 coverage than those who did not choose the response (77.2% vs. 70.1%, p < 0.01). However, no significant difference in coverage was found between households that did/did not indicate that reminder/recalls (71.0% vs. 75.5%, p = 0.24) helped them remember when to take their child for their most recent immunization visit; only borderline significance was found between those that did/did not choose shot cards (70.6% vs. 76.2%, p = 0.07). CONCLUSION: A doctor or nurse's reminder during an immunization visit of the next scheduled immunization visit effectively encourages caregivers to bring children in for immunizations, providing an inexpensive and easy way to effectively increase immunization coverage.

Timeliness of childhood vaccinations in the United States: days undervaccinated and number of vaccines delayed.

CONTEXT: Only 18% of children in the United States receive all vaccinations at the recommended times or acceptably early. OBJECTIVE: To determine the extent of delay of vaccination during the first 24 months of life. DESIGN, SETTING, AND PARTICIPANTS: The 2003 National Immunization Survey was conducted by random-digit dialing of households and mailings to vaccination providers to estimate vaccination coverage rates for US children aged 19 to 35 months. Data for this study were limited to 14,810 children aged 24 to 35 months. MAIN OUTCOME MEASURES: Cumulative days undervaccinated during the first 24 months of life for each of 6 vaccines (diphtheria and tetanus toxoids and acellular pertussis; poliovirus; measles, mumps, and rubella; Haemophilus influenzae type b; hepatitis B; and varicella) and all vaccines combined, number of late vaccines, and risk factors for severe delay of vaccination. RESULTS: Children were undervaccinated a mean of 172 days (median, 126 days) for all vaccines combined during their first 24 months of life. Approximately 34% were undervaccinated for less than 1 month and 29% for 1 to 6 months, while 37% were undervaccinated for more than 6 months. Vaccine-specific undervaccination of more than 6 months ranged from 9% for poliovirus vaccine to 21% for Haemophilus influenzae type b vaccine. An estimated 25% of children had delays in receipt of 4 or more of the 6 vaccines. Approximately 21% of children were severely delayed (undervaccinated for more than 6 months and for > or vaccines). Factors associated with severe delay included having a mother who was unmarried or who did not have a college degree, living in a household with 2 or more children, being non-Hispanic black, having 2 or more vaccination providers, and using public vaccination provider(s). CONCLUSIONS: More than 1 in 3 children were undervaccinated for more than 6 months during their first 24 months of life and 1 in 4 children were delayed for at least 4 vaccines. Standard measures of vaccination coverage mask substantial shortfalls in ensuring that recommendations are followed regarding age at vaccination throughout the first 24 months of life.

Best (but oft-forgotten) practices: checking assumptions concerning regression residuals.

The residuals of a least squares regression model are defined as the observations minus the modeled values. For least squares regression to produce valid CIs and P values, the residuals must be independent, be normally distributed, and have a constant variance. If these assumptions are not satisfied, estimates can be biased and power can be reduced. However, there are ways to assess these assumptions and steps one can take if the assumptions are violated. Here, we discuss both assessment and appropriate responses to violation of assumptions.