Improving the Efficiency of Inferences From Hybrid Samples for Effective Health Surveillance Surveys: Comprehensive Review of Quantitative Methods.

BACKGROUND: Increasingly, survey researchers rely on hybrid samples to improve coverage and increase the number of respondents by combining independent samples. For instance, it is possible to combine 2 probability samples with one relying on telephone and another on mail. More commonly, however, researchers are now supplementing probability samples with those from online panels that are less costly. Setting aside ad hoc approaches that are void of rigor, traditionally, the method of composite estimation has been used to blend results from different sample surveys. This means individual point estimates from different surveys are pooled together, 1 estimate at a time. Given that for a typical study many estimates must be produced, this piecemeal approach is computationally burdensome and subject to the inferential limitations of the individual surveys that are used in this process. OBJECTIVE: In this paper, we will provide a comprehensive review of the traditional method of composite estimation. Subsequently, the method of composite weighting is introduced, which is significantly more efficient, both computationally and inferentially when pooling data from multiple surveys. With the growing interest in hybrid sampling alternatives, we hope to offer an accessible methodology for improving the efficiency of inferences from such sample surveys without sacrificing rigor. METHODS: Specifically, we will illustrate why the many ad hoc procedures for blending survey data from multiple surveys are void of scientific integrity and subject to misleading inferences. Moreover, we will demonstrate how the traditional approach of composite estimation fails to offer a pragmatic and scalable solution in practice. By relying on theoretical and empirical justifications, in contrast, we will show how our proposed methodology of composite weighting is both scientifically sound and inferentially and computationally superior to the old method of composite estimation. RESULTS: Using data from 3 large surveys that have relied on hybrid samples composed of probability-based and supplemental sample components from online panels, we illustrate that our proposed method of composite weighting is superior to the traditional method of composite estimation in 2 distinct ways. Computationally, it is vastly less demanding and hence more accessible for practitioners. Inferentially, it produces more efficient estimates with higher levels of external validity when pooling data from multiple surveys. CONCLUSIONS: The new realities of the digital age have brought about a number of resilient challenges for survey researchers, which in turn have exposed some of the inefficiencies associated with the traditional methods this community has relied upon for decades. The resilience of such challenges suggests that piecemeal approaches that may have limited applicability or restricted accessibility will prove to be inadequate and transient. It is from this perspective that our proposed method of composite weighting has aimed to introduce a durable and accessible solution for hybrid sample surveys.

Prevalence of COVID-19 Mitigation Behaviors in US Adults (August-December 2020): Nationwide Household Probability Survey.

BACKGROUND: COVID-19 mitigation behaviors, such as wearing masks, maintaining social distancing, and practicing hand hygiene, have been and will remain vital to slowing the pandemic. OBJECTIVE: This study aims to describe the period prevalence of consistent mask-wearing, social distancing, and hand hygiene practices during the peak of COVID-19 incidence (August-December 2020) and just before COVID-19 vaccine availability, overall and in demographic subgroups. METHODS: We used baseline survey data from a nationwide household probability sample to generate weighted estimates of mitigation behaviors: wearing masks, maintaining social distancing, and practicing hand hygiene. Weighted logistic regression explored differences in mitigation behaviors by demographics. Latent class analysis (LCA) identified patterns in mitigation behaviors. RESULTS: Among 4654 participants, most (n=2727, 58.6%) were female, were non-Hispanic White (n=3063, 65.8%), were aged 55 years or older (n=2099, 45.1%), lived in the South (n=2275, 48.9%), lived in metropolitan areas (n=4186, 89.9%), had at least a bachelor's degree (n=2547, 54.7%), had an income of US $50,000-$99,000 (n=1445, 31%), and were privately insured (n=2734, 58.7%). The period prevalence of consistent mask wearing was 71.1% (sample-weighted 95% CI 68.8-73.3); consistent social distancing, 42.9% (95% CI 40.5-45.3); frequent handwashing, 55.0% (95% CI 52.3-57.7); and frequent hand sanitizing, 21.5% (95% CI 19.4-23.8). Mitigation behaviors were more prevalent among women, older persons, Black or Hispanic persons, those who were not college graduates, and service-oriented workers. LCA identified an optimal-mitigation class that consistently practiced all behaviors (n=2656, 67% of US adults), a low-mitigation class that inconsistently practiced all behaviors (n=771, 20.6%), and a class that had optimal masking and social distancing but a high frequency of hand hygiene (n=463, 12.4%). CONCLUSIONS: Despite a high prevalence of COVID-19 mitigation behaviors, there were likely millions who did not consistently practice these behaviors during the time of the highest COVID-19 incidence. In future infectious disease outbreak responses, public health authorities should also consider addressing disparities in mitigation practices through more targeted prevention messaging.

Use of COVIDTests.gov At-Home Test Kits Among Adults in a National Household Probability Sample - United States, 2022.

At-home rapid antigen COVID-19 tests were first authorized by the Food and Drug Administration in late 2020 (1-3). In January 2022, the White House launched COVIDTests.gov, which made all U.S. households eligible to receive free-to-the-user at-home test kits distributed by the U.S. Postal Service (2). By May 2022, more than 70 million test kit packages had been shipped to households across the United States (2); however, how these kits were used, and which groups were using them, has not been reported. Data from a national probability survey of U.S. households (COVIDVu), collected during April-May 2022, were used to evaluate awareness about and use of these test kits (4). Most respondent households (93.8%) were aware of the program, and more than one half (59.9%) had ordered kits. Among persons who received testing for COVID-19 during the preceding 6 months, 38.3% used a COVIDTests.gov kit. Among kit users, 95.5% rated the experience as acceptable, and 23.6% reported being unlikely to have tested without the COVIDTests.gov program. Use of COVIDTests.gov kits was similar among racial and ethnic groups (42.1% non-Hispanic Black or African American [Black]; 41.5% Hispanic or Latino [Hispanic]; 34.8% non-Hispanic White [White]; and 53.7% non-Hispanic other races [other races]). Use of other home COVID-19 tests differed by race and ethnicity (11.8% Black, 44.4% Hispanic, 45.8% White, 43.8% other races). Compared with White persons, Black persons were 72% less likely to use other home test kits (adjusted relative risk [aRR] = 0.28; 95% CI = 0.16-0.50). Provision of tests through this well-publicized program likely improved use of COVID-19 home testing and health equity in the United States, particularly among Black persons. National programs to address availability and accessibility of critical health services in a pandemic response have substantial health value.

Cumulative Incidence of SARS-CoV-2 Infections Among Adults in Georgia, United States, August to December 2020.

BACKGROUND: Reported coronavirus disease 2019 (COVID-19) cases underestimate true severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Data on all infections, including asymptomatic infections, are needed. To minimize biases in estimates from reported cases and seroprevalence surveys, we conducted a household-based probability survey and estimated cumulative incidence of SARS-CoV-2 infections adjusted for antibody waning. METHODS: From August to December 2020, we mailed specimen collection kits (nasal swabs and blood spots) to a random sample of Georgia addresses. One household adult completed a survey and returned specimens for virus and antibody testing. We estimated cumulative incidence of SARS-CoV-2 infections adjusted for waning antibodies, reported fraction, and infection fatality ratio (IFR). Differences in seropositivity among demographic, geographic, and clinical subgroups were explored with weighted prevalence ratios (PR). RESULTS: Among 1370 participants, adjusted cumulative incidence of SARS-CoV-2 was 16.1% (95% credible interval [CrI], 13.5%-19.2%) as of 16 November 2020. The reported fraction was 26.6% and IFR was 0.78%. Non-Hispanic black (PR, 2.03; 95% confidence interval [CI], 1.0-4.1) and Hispanic adults (PR, 1.98; 95% CI, .74-5.31) were more likely than non-Hispanic white adults to be seropositive. CONCLUSIONS: As of mid-November 2020, 1 in 6 adults in Georgia had been infected with SARS-CoV-2. The COVID-19 epidemic in Georgia is likely substantially underestimated by reported cases.

Severe Acute Respiratory Syndrome Coronavirus 2 Cumulative Incidence, United States, August 2020-December 2020.

BACKGROUND: Reported coronavirus disease 2019 (COVID-19) cases underestimate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. We conducted a national probability survey of US households to estimate cumulative incidence adjusted for antibody waning. METHODS: From August-December 2020 a random sample of US addresses were mailed a survey and self-collected nasal swabs and dried blood spot cards. One adult household member completed the survey and mail specimens for viral detection and total (immunoglobulin [Ig] A, IgM, IgG) nucleocapsid antibody by a commercial, emergency use authorization-approved antigen capture assay. We estimated cumulative incidence of SARS-CoV-2 adjusted for waning antibodies and calculated reported fraction (RF) and infection fatality ratio (IFR). Differences in seropositivity among demographic, geographic, and clinical subgroups were explored. RESULTS: Among 39 500 sampled households, 4654 respondents provided responses. Cumulative incidence adjusted for waning was 11.9% (95% credible interval [CrI], 10.5%-13.5%) as of 30 October 2020. We estimated 30 332 842 (CrI, 26 703 753-34 335 338) total infections in the US adult population by 30 October 2020. RF was 22.3% and IFR was 0.85% among adults. Black non-Hispanics (Prevalence ratio (PR) 2.2) and Hispanics (PR, 3.1) were more likely than White non-Hispanics to be seropositive. CONCLUSIONS: One in 8 US adults had been infected with SARS-CoV-2 by October 2020; however, few had been accounted for in public health reporting. The COVID-19 pandemic is likely substantially underestimated by reported cases. Disparities in COVID-19 by race observed among reported cases cannot be attributed to differential diagnosis or reporting of infections in population subgroups.

SARS-CoV-2 Cumulative Incidence and Period Seroprevalence: Results From a Statewide Population-Based Serosurvey in California.

BACKGROUND: California has reported the largest number of coronavirus disease 2019 (COVID-19) cases of any US state, with more than 3.5 million confirmed as of March 2021. However, the full breadth of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission in California is unknown as reported cases only represent a fraction of all infections. METHODS: We conducted a population-based serosurvey, utilizing mailed, home-based SARS-CoV-2 antibody testing along with a demographic and behavioral survey. We weighted data from a random sample to represent the adult California population and estimated period seroprevalence overall and by participant characteristics. Seroprevalence estimates were adjusted for waning antibodies to produce statewide estimates of cumulative incidence, the infection fatality ratio (IFR), and the reported fraction. RESULTS: California's SARS-CoV-2 weighted seroprevalence during August-December 2020 was 4.6% (95% CI, 2.8%-7.4%). Estimated cumulative incidence as of November 2, 2020, was 8.7% (95% CrI, 6.4%-11.5%), indicating that 2 660 441 adults (95% CrI, 1 959 218-3 532 380) had been infected. The estimated IFR was 0.8% (95% CrI, 0.6%-1.0%), and the estimated percentage of infections reported to the California Department of Public Health was 31%. Disparately high risk for infection was observed among persons of Hispanic/Latinx ethnicity and people with no health insurance and who reported working outside the home. CONCLUSIONS: We present the first statewide SARS-CoV-2 cumulative incidence estimate among adults in California. As of November 2020, ~1 in 3 SARS-CoV-2 infections in California adults had been identified by public health surveillance. When accounting for unreported SARS-CoV-2 infections, disparities by race/ethnicity seen in case-based surveillance persist.

Protocol for a national probability survey using home specimen collection methods to assess prevalence and incidence of SARS-CoV-2 infection and antibody response.

PURPOSE: The U.S. response to the SARS-CoV-2 epidemic has been hampered by early and ongoing delays in testing for infection; without data on where infections were occurring and the magnitude of the epidemic, early public health responses were not data-driven. Understanding the prevalence of SARS-CoV-2 infections and immune response is critical to developing and implementing effective public health responses. Most serological surveys have been limited to localities that opted to conduct them and/or were based on convenience samples. Moreover, results of antibody testing might be subject to high false positive rates in the setting of low prevalence of immune response and imperfect test specificity. METHODS: We will conduct a national serosurvey for SARS-CoV-2 PCR positivity and immune experience. A probability sample of U.S. addresses will be mailed invitations and kits for the self-collection of anterior nares swab and finger prick dried blood spot specimens. Within each sampled household, one adult 18 years or older will be randomly selected and asked to complete a questionnaire and to collect and return biological specimens to a central laboratory. Nasal swab specimens will be tested for SARS-CoV-2 RNA by RNA PCR; dried blood spot specimens will be tested for antibodies to SARS-CoV-2 (i.e., immune experience) by enzyme-linked immunoassays. Positive screening tests for antibodies will be confirmed by a second antibody test with different antigenic basis to improve predictive value of positive (PPV) antibody test results. All persons returning specimens in the baseline phase will be enrolled into a follow-up cohort and mailed additional specimen collection kits 3 months after baseline. A subset of 10% of selected households will be invited to participate in full household testing, with tests offered for all household members aged ≥3 years. The main study outcomes will be period prevalence of infection with SARS-CoV-2 and immune experience, and incidence of SARS-CoV-2 infection and antibody responses. RESULTS: Power calculations indicate that a national sample of 4000 households will facilitate estimation of national SARS-CoV-2 infection and antibody prevalence with acceptably narrow 95% confidence intervals across several possible scenarios of prevalence levels. Oversampling in up to seven populous states will allow for prevalence estimation among subpopulations. Our 2-stage algorithm for antibody testing produces acceptable PPV at prevalence levels ≥1.0%. Including oversamples in states, we expect to receive data from as many as 9156 participants in 7495 U.S. households. CONCLUSIONS: In addition to providing robust estimates of prevalence of SARS-CoV-2 infection and immune experience, we anticipate this study will establish a replicable methodology for home-based SARS-CoV-2 testing surveys, address concerns about selection bias, and improve positive predictive value of serology results. Prevalence estimates of SARS-CoV-2 infection and immune experience produced by this study will greatly improve our understanding of the spectrum of COVID-19 disease, its current penetration in various demographic, geographic, and occupational groups, and inform the range of symptoms associated with infection. These data will inform resource needs for control of the ongoing epidemic and facilitate data-driven decisions for epidemic mitigation strategies.

Parental awareness and utilization of meningococcal serogroup B vaccines in the United States.

BACKGROUND: Meningococcal serogroup B (MenB) is the most common cause of invasive meningococcal disease (IMD) in the United States. The US Advisory Committee on Immunization Practices (ACIP) recommends vaccination of healthy adolescents against MenB based on shared clinical decision-making (Category B recommendation). This survey assessed factors associated with MenB vaccine awareness, utilization, and interest among parents/guardians of US adolescents. METHODS: Survey participants were identified in 2016 through KnowledgePanel®, an online random sample of US households; population-based weighting methodology was used to ensure data reflected a demographically representative population sample. Adults with ≥1 dependent aged 16-19 years were eligible and completed an online questionnaire. Respondents were grouped in terms of MenB vaccination of their child as: 1) vaccinated, 2) intending to vaccinate, 3) MenB vaccine-unaware, or 4) vaccine-aware but not intending to vaccinate. Univariate and multivariate analyses were used to identify factors influencing MenB vaccine awareness and utilization; univariate analyses used the weighted proportion of each group or weighted means, and multivariate analyses used logistic regression models based on the weighted study sample of each group. RESULTS: Six hundred nineteen parents/guardians participated, corresponding to 26,266,700 members of the US population after weighting. MenB vaccine awareness was significantly associated with parent race and sex. Specifically, 57% of parents were unaware of MenB vaccines, and there was significantly higher lack of awareness among males and those of Hispanic or non-White ethnicity. In addition, 36% of unaware parents/guardians were interested in and seeking MenB vaccine information from their healthcare provider (HCP), and there was higher interest among parents of Hispanic ethnicity. 'Vaccinated/intending to vaccinate' versus 'not intending to vaccinate' and 'vaccinated' versus 'intending to vaccinate' were both strongly associated with whether an HCP had recommended vaccination (odds ratios, 4.81 [95% CI 2.46, 9.35] and 5.66 [95% CI 2.46, 12.87], respectively). CONCLUSIONS: Racial and socioeconomic disparities exist in the awareness and utilization of MenB vaccines among parents/guardians of US adolescents. HCP discussion and recommendation are critical catalysts for MenB vaccination and underscore the need to accurately interpret and implement the shared clinical decision-making (Category B) recommendation.

Recruiting and retaining youth and young adults: challenges and opportunities in survey research for tobacco control.

INTRODUCTION: Evaluation studies of population-based tobacco control interventions often rely on large-scale survey data from numerous respondents across many geographic areas to provide evidence of their effectiveness. Significant challenges for survey research have emerged with the evolving communications landscape, particularly for surveying hard-to-reach populations such as youth and young adults. This study combines the comprehensive coverage of an address-based sampling (ABS) frame with the timeliness of online data collection to develop a nationally representative longitudinal cohort of young people aged 15-21. METHODS: We constructed an ABS frame, partially supplemented with auxiliary data, to recruit this hard-to-reach sample. Branded and tested mail-based recruitment materials were designed to bring respondents online for screening, consent and surveying. Once enrolled, respondents completed online surveys every 6 months via computer, tablet or smartphone. Numerous strategies were utilized to enhance retention and representativeness RESULTS: Results detail sample performance, representativeness and retention rates as well as device utilization trends for survey completion among youth and young adult respondents. Panel development efforts resulted in a large, nationally representative sample with high retention rates. CONCLUSIONS: This study is among the first to employ this hybrid ABS-to-online methodology to recruit and retain youth and young adults in a probability-based online cohort panel. The approach is particularly valuable for conducting research among younger populations as it capitalizes on their increasing access to and comfort with digital communication. We discuss challenges and opportunities of panel recruitment and retention methods in an effort to provide valuable information for tobacco control researchers seeking to obtain representative, population-based samples of youth and young adults in the U.S. as well as across the globe.

Epilepsy or seizure disorder? The effect of cultural and socioeconomic factors on self-reported prevalence.

Self-reported epilepsy may be influenced by culture, knowledge, and beliefs. We screened 6420 residents of the District of Columbia (DC) for epilepsy to investigate whether socio-demographics were associated with whether they reported their diagnosis as epilepsy or as seizure disorder. Lifetime and active prevalence rates were 0.54% and 0.21%, respectively for 'epilepsy' and 1.30% and 0.70%, respectively for 'seizure disorder'. Seizure disorder was reported significantly more often than epilepsy among blacks, females, respondents≥50years, those with lower level education, respondents who lived alone and in low income neighborhoods, and those who resided in DC for at least five years. Clinicians should assure that patients and caregivers understand that epilepsy is synonymous with seizure disorder and other culturally appropriate terms, in order to optimize compliance with treatment, disease management instructions, and utilization of other resources targeted at persons with epilepsy. Furthermore, education and awareness campaigns aimed at improving access-to-care, reducing stigma, and increasing awareness of adverse events, such as SUDEP, should include a more diverse definition of epilepsy in their messages.

Racial and socioeconomic disparities in epilepsy in the District of Columbia.

We investigated social and demographic factors as they relate to prevalence and incidence of epilepsy in Washington, DC, a culturally diverse area. Probability-based sampling was used to select 20,000 households to complete a mailed epilepsy screening survey on all household members. Screened individuals with a history of epilepsy were sent a detailed case survey about seizures and treatment. Prevalence and incidence of epilepsy were estimated using weighted data. Lifetime prevalence was 1.53% overall; 0.77% in Whites, 2.13% in Blacks, and 3.4% in those with less than a high school diploma. Prevalence of active epilepsy was 0.79% and followed similar subgroup comparisons as lifetime prevalence. Age-adjusted lifetime and active epilepsy from multivariate analyses demonstrated significantly higher rates for Blacks compared to Whites and for those not completing high school compared to those that attended graduate school. The incidence of epilepsy was 71 per 100,000 persons. Adults with active epilepsy were significantly less likely to live alone than those without epilepsy. Residents of DC for <4 years had the lowest prevalence and incidence of all subgroups indicating a possible healthy mover effect. This is the first study to provide estimates and profiles of the epilepsy population in DC which can help better target resources to improve the health and outcomes of people with epilepsy and their families.

Analysis of Salmonella control performance in U.S. young chicken slaughter and pork slaughter establishments.

In the 1996 U.S. Food Safety and Inspection Service's (FSIS) "Pathogen Reduction; Hazard Analysis and Critical Control Point (PR/HACCP) Systems, Final Rule," Salmonella was selected for microbiological testing and monitoring. Using data from an FSIS-sponsored survey of meat and poultry slaughter establishments, inspection results, and other establishment characteristics, potential variables affecting pathogen control, as measured by Salmonella test results, were investigated. The analysis data sets included 153 federally inspected young chicken slaughter establishments, of which 111 exceeded half the Salmonella performance standard at least once from 2003 through 2005, and 121 federally inspected pork slaughter establishments, of which 28 exceeded half the Salmonella performance standard. Logistic regression results for young chicken slaughter establishments indicate they were more likely to exceed half the standard if they had higher inspection noncompliance rates (P = 0.10) and older production space (P = 0.10), and were less likely to exceed it if they used a higher percentage of raw poultry inputs purchased from outside sources (P = 0.10). Results for pork slaughter establishments indicate they were more likely to exceed half the standard if they had a higher rate of voluntary microbiological testing (P = 0.08), and were less likely to exceed it if they were larger (P = 0.08) and used a higher percentage of raw pork inputs purchased from outside sources (P = 0.02). In general, indicators of plant characteristics, food safety practices, and management philosophy are associated with different levels of pathogen control performance that vary by species slaughtered.

Tracking chronic disease and risk behavior prevalence as survey participation declines: statistics from the behavioral risk factor surveillance system and other national surveys.

INTRODUCTION: Response rates for the Behavioral Risk Factor Surveillance System (BRFSS) have declined in recent years. The response rate in 1993 was approximately 72%; in 2006, the response rate was approximately 51%. To assess the impact of this decline on the quality of BRFSS estimates, we compared selected health and risk factor estimates from BRFSS with similar estimates from the National Health Interview Survey (NHIS) and the National Health and Nutrition Examination Survey (NHANES). METHODS: We reviewed questionnaires from the 3 surveys and identified a set of comparable measures related to smoking prevalence, alcohol consumption, medical conditions, vaccination, health status, insurance coverage, cost barriers to medical care, testing for human immunodeficiency virus, and body measurements (height and weight). We compared weighted estimates for up to 15 outcome measures, including overall measures and measures for 12 population subgroups. We produced design-appropriate point estimates and carried out statistical tests of hypotheses on the equality of such estimates. We then calculated P values for comparisons of NHIS and NHANES estimates with their BRFSS counterparts. RESULTS: Although BRFSS and NHIS estimates were statistically similar for 5 of the 15 measures examined, BRFSS and NHANES estimates were statistically similar for only 1 of 6 measures. The observed differences for some of these comparisons were small, however. CONCLUSION: These surveys produced similar estimates for several outcome measures, although we observed significant differences as well. Many of the observed differences may have limited consequences for implementing related public health programs; other differences may require more detailed examination. In general, the range of BRFSS estimates examined here tends to parallel those from NHIS and NHANES, both of which have higher rates of participation.