Medicare claims versus beneficiary self-report for influenza vaccination surveillance

Vaccine patterns among older adults with Guillain-Barré syndrome and matched comparators, 2006-2019

BACKGROUND

Some vaccines have a small risk of triggering Guillain-Barré syndrome (GBS), an autoimmune disorder where nerve damage leads to paralysis. There is a CDC precaution for patients whose GBS was associated with an influenza or tetanus toxoid-containing vaccine (GBS occurring within 42 days following vaccination).

METHODS

We described vaccine patterns before and after a GBS diagnosis with a matched cohort design in a 20% random sample of fee-for-service Medicare enrollees. We defined the index date as an ICD-9-CM or ICD-10-CM GBS diagnosis code in the primary position of an inpatient claim. We matched each GBS patient to five non-GBS comparators on sex, exact age, racial and ethnic category, state of residence and the month of preventive health visits during baseline; used weighting to balance covariates; and measured frequency of vaccines received per 100 people during year before and after the index date using the weighted mean cumulative count (wMCC).

RESULTS

We identified 1567 patients with a GBS diagnosis with at least 1 year of prior continuous enrollment in Medicare A and B that matched to five comparators each. The wMCCs in the 1 year before the index date were similar for both groups, with a wMCC of 74 vaccines/100 people in the GBS group (95% CI 71, 77). Within 1 year after the index date, patients with GBS had received 26 vaccines/100 people (95% CI 23, 28), which was 41 fewer vaccines than matched non-GBS comparators (95% CI -44, -38). Among GBS patients, 11% were diagnosed with GBS within 42 days after a vaccine.

CONCLUSIONS

GBS diagnosis has a strong impact on reducing subsequent vaccination even though there is no warning or precaution about future vaccines for most patients diagnosed with GBS. These data suggest discordance between clinical practice and current vaccine recommendations.

Geographic Variation in Racial Disparities in Receipt of High-Dose Influenza Vaccine Among US Older Adults

BACKGROUND

Racial disparities in receipt of high-dose influenza vaccine (HDV) have been documented nationally, but whether small-area geographic variation in such disparities exists remains unknown. We assessed the distribution of disparities in HDV receipt between Black and White traditional Medicare beneficiaries vaccinated against influenza within states and hospital referral regions (HRRs).

METHODS

We conducted a nationally representative retrospective cohort study of 11,768,724 community-dwelling traditional Medicare beneficiaries vaccinated against influenza during the 2015-2016 influenza season (94.3% White and 5.7% Black). Our comparison was marginalized versus privileged racial group measured as Black versus White race. Vaccination and type of vaccine were obtained from Medicare Carrier and Outpatient files. Differences in the proportions of individuals who received HDV between Black and White beneficiaries within states and HRRs were used to measure age- and sex-standardized disparities in HDV receipt. We restricted to states and HRRs with ≥ 100 beneficiaries per age-sex strata per racial group.

RESULTS

We detected a national disparity in HDV receipt of 12.8 percentage points (pps). At the state level, the median standardized HDV receipt disparity was 10.7 pps (minimum, maximum: 2.9, 25.6; n = 30 states). The median standardized HDV receipt disparity among HRRs was 11.6 pps (minimum, maximum: 0.4, 24.7; n = 54 HRRs).

CONCLUSION

Black beneficiaries were less likely to receive HDV compared to White beneficiaries in almost every state and HRR in our analysis. The magnitudes of disparities varied substantially across states and HRRs. Local interventions and policies are needed to target geographic areas with the largest disparities to address these inequities.

Influenza vaccination uptake among at-risk patients in Switzerland-The potential of national claims data for surveillance

Background

Swiss national surveillance of influenza vaccination uptake rates (VURs) relies on self-reported vaccination status. The aim of this study was to determine VURs among at-risk patients, namely, patients ≥65 of age and adult patients with chronic diseases, using claims data, instead of self-reported measures, to investigate factors of vaccine uptake, and to assess different methodological approaches to conduct vaccination surveillance.

Methods

In this retrospective cross-sectional analysis, we determined VURs in three influenza seasons (2015/2016-2017/2018). Medication, diagnosis, or medical services claims were used as triggers to identify patients. For the calculation of VURs in patients with chronic diseases, we identified those by triggers in the given season only (Model 1) and in the given and previous seasons (Model 2). Regression analysis was used to identify factors associated with vaccination status.

Results

Data from 214,668 individual patients were analyzed. VURs over all seasons ranged from 18.4% to 19.8%. Most patients with chronic diseases were identified with the medication trigger, and we found no clinical significant differences in VURs comparing both models. Having a chronic disease, age, male gender, and regular health care provider visits were associated with increased odds of being vaccinated.

Conclusions

VURs were below the recommended thresholds, and our analysis highlighted the need for efforts to increase VURs. We assessed the identification of chronic diseases by medication claims and the calculation of VURs based on data of the given season only as an effective approach to conduct vaccination surveillance. Claims data-based surveillance may complete the national surveillance.

Vaccine patterns among patients diagnosed with Guillain-Barré Syndrome and matched counterparts in a Medicare supplemental population, 2000-2020

Some vaccines have a small risk of Guillain-Barré Syndrome (GBS), a rare autoimmune disorder characterized by paralysis if untreated. The CDC's Advisory Committee on Immunization Practices (ACIP) guidelines do not consider GBS a precaution for future vaccines unless GBS developed within six weeks after a tetanus-toxoid-containing vaccine or influenza vaccine. Our goal was to describe vaccine patterns before and after GBS diagnosis. We matched each of 709 patients diagnosed with GBS from 2002 to 2020 with Medicare supplemental insurance to 10 counterparts without GBS (1:10) on age and sex. Propensity score-based weighting balanced covariates between groups, and we estimated weighted mean cumulative counts (wMCC) of vaccines/person before and after GBS diagnosis. Among patients with GBS, 7% were diagnosed within 42 days after a vaccine. Prior to GBS diagnosis, the wMCC of vaccines per person was similar between GBS cases and matched counterparts, but after two years of follow-up, GBS patients received 21 fewer vaccines/100 people than counterparts (wMCC difference -0.21 vaccines/person, 95% CI -0.24 to -0.18); GBS patients received 16 vaccines/100 people while matched counterparts received 36/100. Vaccine use was reduced following GBS diagnosis despite no ACIP precaution for most (93%) patients in this study. The observed drop in vaccines after GBS diagnosis indicates a disconnect between clinical practice and current recommendations.

Influenza Vaccination Coverage Among Medicare Fee-for-Service Beneficiaries

INTRODUCTION

Influenza vaccination is the best prevention strategy to protect against influenza infection. Determining accurate influenza vaccination coverage is critical. This study assesses the concordance between self-reported and claimed-based influenza vaccination coverage and examines vaccination disparities in the U.S.

METHODS

Data from the 2016-2019 Medicare Current Beneficiary Survey linked to survey participants' influenza vaccination claims were analyzed in 2022. The study population included survey participants aged ≥65 years and enrolled in a Medicare fee-for-service plan. Sensitivity, specificity, kappa statistics, and net bias (the difference between the estimated vaccination coverage based on survey and claims data) were reported. Associations between receipt of influenza vaccine and beneficiaries' characteristics and sex, racial and ethnic, and urban‒rural disparities in influenza vaccination were examined using logistic regressions.

RESULTS

The analysis included 20,854 beneficiaries. Claimed-based vaccination coverage was 60.0%, and survey-based coverage was 76.3%. The net bias was 16.3 percentage points, and kappa statistic indicated moderate data agreement. The sensitivity of self-reported influenza vaccination was 98.7%, and the specificity was 57.4%. Net bias was high among male, non-Hispanic Black and Hispanic beneficiaries, and rural residents. Sex, racial and ethnic, and urban‒rural disparities in influenza vaccination were noticeably smaller according to the survey than claims data.

CONCLUSIONS

The level of data agreement differed by beneficiaries' characteristics and was low among males, racial and ethnic minority groups, and rural residents.

Vaccination Coverage of Privately Insured Children: Comparing U.S. Survey and Administrative Data

INTRODUCTION

National Immunization Survey-Child data are used widely to assess childhood vaccination coverage in the U.S. This study compares National Immunization Survey-Child coverage estimates with estimates using other supplementary data sources.

METHODS

Retrospective analyses in 2021 assessed vaccination coverage of privately insured children for vaccines recommended by the Advisory Committee on Immunization Practices by age 2 years, using the 2015-2018 MarketScan Commercial Claims and Encounters databases and the 2018-2019 Healthcare Effectiveness Data and Information Set. The coverage estimates were compared statistically with those using the 2016-2018 National Immunization Survey-Child.

RESULTS

Estimated coverage ranged from 69.9% (≥2 doses of influenza vaccine) to 95.0% (≥3 doses of diphtheria, tetanus toxoids, and acellular pertussis vaccine) using the MarketScan Commercial Claims and Encounters data and from 68.0% (≥2 doses of influenza vaccine) to 92.2% (≥1 dose of measles, mumps, and rubella vaccine) using the Healthcare Effectiveness Data and Information Set. The difference between the MarketScan Commercial Claims and Encounters and National Immunization Survey-Child estimates ranged from 0.1 to 4.3 percentage points and was statistically significant for 6 of the 13 assessed vaccines/doses and percentage of children receiving no vaccinations. The difference between the Healthcare Effectiveness Data and Information Set and National Immunization Survey-Child estimates ranged from 0.4 to 7.2 percentage points and was statistically significant for 6 of the 10 assessed vaccines/doses.

CONCLUSIONS

For certain vaccines and populations of interest, the National Immunization Survey-Child, MarketScan Commercial Claims and Encounters, and Healthcare Effectiveness Data and Information Set data might give comparable coverage of privately insured children.

Impact of influenza infection on the short- and long-term health of patients with chronic obstructive pulmonary disease

BACKGROUND

Influenza is a common cause of acute respiratory infection that leads to exacerbation of underlying chronic obstructive pulmonary disease (COPD). To elucidate the short- and long-term effects of influenza in patients with COPD, we examined health care resource utilization (HRU) and costs up to 13 months following influenza infection.

METHODS

We conducted a retrospective cohort study using U.S. insurance claims data from MarketScan. Patients with an influenza diagnosis during the 2012-2014 influenza seasons and continuous enrollment in a health plan from 12 months before to 13 months after the index influenza diagnosis were identified and propensity score-matched 1:5 to controls without evidence of influenza. COPD- and pneumonia-related outcomes were assessed over 13 months following influenza diagnosis.

RESULTS

COPD-associated outcomes after diagnosis were significantly worse in patients with influenza (n = 7,087) vs. controls (n = 35,435) during the first month (exacerbation: 16.1 vs. 3.4%; outpatient visits: 57.1 vs. 35.2%; emergency department (ED) visits: 10.5 vs. 1.8%; and inpatient visits: 5.6 vs. 0.7%) and months 2-13 (exacerbation: 25.1 vs. 21.1%; outpatient visits: 86.1 vs. 85.8%; ED visits: 20.0 vs. 15.7%; and inpatient visits: 6.5 vs. 5.3%). COPD- and pneumonia-associated costs for months 1 and 2-13 were higher in patients with influenza.

LIMITATIONS

The study was subject to a residual imbalance between cohorts despite propensity score matching. The use of diagnostic codes to select patients and identify complications could introduce inaccuracies in estimating events.

CONCLUSIONS

HRU and costs were higher in COPD patients with influenza during the first month and over the entire year following infection. This suggests influenza has an impact on respiratory health in patients with COPD that lasts beyond the acute infection.

Influenza Vaccine Uptake and Missed Opportunities Among the Medicare-Covered Population With High-Risk Conditions During the 2018 to 2019 Influenza Season : A Retrospective Cohort Study

BACKGROUND

Seasonal influenza causes substantial morbidity and mortality among older U.S. adults and those with comorbid health conditions.

OBJECTIVE

To describe seasonal influenza vaccine uptake and identify factors associated with missed opportunities for influenza vaccination.

DESIGN

Retrospective cohort study.

SETTING

Medicare fee-for-service claims.

PARTICIPANTS

31.6 million U.S. adults continuously enrolled under Medicare Parts A and B during the 2018 to 2019 influenza season.

MEASUREMENTS

Influenza vaccine uptake and missed opportunities by patient demographic characteristics, high-risk status (that is, ≥1 condition increasing influenza complication risk), Medicare-Medicaid dual-eligibility status, and health care provider visits (that is, vaccination opportunities).

RESULTS

Overall, 50.5% of beneficiaries aged 19 years or older had Medicare claims for influenza vaccination: 31.6% among people aged 19 to 64 years and 54% among people aged 65 years or older. More White beneficiaries were vaccinated (52.9%) than Black (34.9%) or Hispanic (30.4%) beneficiaries. Uptake was higher (56.1%) for beneficiaries with high-risk conditions than for those without (27.6%). Among unvaccinated beneficiaries overall, 77.4% visited a provider during influenza season; among unvaccinated beneficiaries with and without high-risk conditions, 91% and 43%, respectively, had seen a provider at least once. The proportion of beneficiaries with missed opportunities for influenza vaccination was 44.2% and was higher for beneficiaries in the non-high-risk group (59.1%) than those in the high-risk group (42.2%). Uptake was lower and proportions of missed opportunities were higher among beneficiaries in younger age groups, of Black and Hispanic race/ethnicity, without high-risk conditions, or with Medicare-Medicaid dual eligibility.

LIMITATIONS

Influenza vaccinations without claims could not be captured. Data on reasons for nonvaccination were unavailable.

CONCLUSION

Influenza vaccination coverage for Medicare beneficiaries continues to be suboptimal, with missed opportunities despite availability of influenza vaccination with no copayment. Disparities persist in vaccination uptake by race/ethnicity.

PRIMARY FUNDING SOURCE

None.

Digital intervention increases influenza vaccination rates for people with diabetes in a decentralized randomized trial

People with diabetes (PWD) have an increased risk of developing influenza-related complications, including pneumonia, abnormal glycemic events, and hospitalization. Annual influenza vaccination is recommended for PWD, but vaccination rates are suboptimal. The study aimed to increase influenza vaccination rate in people with self-reported diabetes. This study was a prospective, 1:1 randomized controlled trial of a 6-month Digital Diabetes Intervention in U.S. adults with diabetes. The intervention group received monthly messages through an online health platform. The control group received no intervention. Difference in self-reported vaccination rates was tested using multivariable logistic regression controlling for demographics and comorbidities. The study was registered at clinicaltrials.gov: NCT03870997. A total of 10,429 participants reported influenza vaccination status (5158 intervention, mean age (±SD) = 46.8 (11.1), 78.5% female; 5271 control, Mean age (±SD) = 46.7 (11.2), 79.4% female). After a 6-month intervention, 64.2% of the intervention arm reported influenza vaccination, vers us 61.1% in the control arm (diff = 3.1, RR = 1.05, 95% CI [1.02, 1.08], p = 0.0013, number needed to treat = 33 to obtain 1 additional vaccination). Completion of one or more intervention messages was associated with up to an 8% increase in vaccination rate (OR 1.27, 95% CI [1.17, 1.38], p < 0.0001). The intervention improved influenza vaccination rates in PWD, suggesting that leveraging new technology to deliver knowledge and information can improve influenza vaccination rates in high-risk populations to reduce public health burden of influenza. Rapid cycle innovation could maximize the effects of these digital interventions in the future with other populations and vaccines.

Agreement between state registry, health record, and self-report of influenza vaccination

BACKGROUND

Documentation of influenza vaccination, including the specific product received, is critical to estimate annual vaccine effectiveness (VE).

METHODS

We assessed performance of the Michigan Care Improvement Registry (MCIR) in defining influenza vaccination status relative to documentation by provider records or self-report among subjects enrolled in a study of influenza VE from 2011 through 2019.

RESULTS

The specificity and positive predictive value of MCIR were high; however, >10% of vaccinations were identified only by other sources each season. The proportion of records captured by MCIR increased from a low of 67% in 2013-2014 to a high of 89% in 2018-2019, largely driven by increased capture of vaccination among adults.

CONCLUSIONS

State vaccine registries, such as MCIR, are important tools for documenting influenza vaccination, including the specific product received. However, incomplete capture suggests that documentation from other sources and self-report should be used in combination with registries to reduce misclassification.

Healthcare Resource Use and Burden Associated with Influenza Transmission Among Household Members with a Primary Infection: Commercial Claims Data Analysis

PURPOSE

To assess the burden of influenza transmission and care-seeking patterns over 3 influenza seasons among commercially insured households with a primary influenza infection.

PATIENTS AND METHODS

This retrospective cohort study used commercial claims data from the US MarketScan® Commercial and Medicare Supplemental databases for the 2014, 2015, and 2016 influenza seasons. Patients with a billed diagnosis of influenza and with coverage for at least 1 household member under the same health plan policy were included. A secondary diagnosed case was defined as a diagnosis of influenza in a second household member occurring within 14 days of the index case in a household.

RESULTS

Among 1,224,808 households with ≥2 members and a primary case of influenza, a secondary case of influenza was reported in 119,883 households (9.8%). A secondary diagnosed case of influenza occurred within 4 days of the primary diagnosis in 93,883 (78.3%) of those households. Both primary and secondary diagnosed influenza cases occurred most often among children (~60%). Household size was positively correlated to both the risk of a second case (6.4% of households with 2 or 3 members versus 12.6% of households with ≥4 members, P < 0.001) and the time to diagnosis of a second case (Spearman rank correlation coefficient = 0.09; P < 0.001).

CONCLUSION

Claims data for 3 influenza seasons (2014, 2015, 2016) showed that intrahousehold transmission of influenza occurs in approximately 10% of households with a primary case and poses a higher burden on larger households. Intrahousehold transmission of influenza represents a large healthcare resource use burden, with an unmet need for interventions that limit transmission.

Guillain-Barré Syndrome After High-Dose Influenza Vaccine Administration in the United States, 2018-2019 Season

BACKGROUND

The Vaccine Safety Datalink (VSD) identified a statistical signal for an increased risk of Guillain-Barré syndrome (GBS) in days 1-42 after 2018-2019 high-dose influenza vaccine (IIV3-HD) administration. We evaluated the signal using Medicare.

METHODS

We conducted early- and end-of-season claims-based self-controlled risk interval analyses among Medicare beneficiaries ages ≥65 years, using days 8-21 and 1-42 postvaccination as risk windows and days 43-84 as control window. The VSD conducted chart-confirmed analyses.

RESULTS

Among 7 453 690 IIV3-HD vaccinations, we did not detect a statistically significant increased GBS risk for either the 8- to 21-day (odds ratio [OR], 1.85; 95% confidence interval [CI], 0.99-3.44) or 1- to 42-day (OR, 1.31; 95% CI, 0.78-2.18) risk windows. The findings from the end-of-season analyses were fully consistent with the early-season analyses for both the 8- to 21-day (OR, 1.64; 95% CI, 0.92-2.91) and 1- to 42-day (OR, 1.12; 95% CI, 0.70-1.79) risk windows. The VSD's chart-confirmed analysis, involving 646 996 IIV3-HD vaccinations, with 1 case each in the risk and control windows, yielded a relative risk of 1.00 (95% CI, 0.06-15.99).

CONCLUSIONS

The Medicare analyses did not exclude an association between IIV3-HD and GBS, but it determined that, if such a risk existed, it was similar in magnitude to prior seasons. Chart-confirmed VSD results did not confirm an increased risk of GBS.

Surveillance for Guillain-Barré syndrome after influenza vaccination among U.S. Medicare beneficiaries during the 2017-2018 season

BACKGROUND

The U.S. Food and Drug Administration and the Centers for Medicare & Medicaid Services have been actively monitoring the risk of Guillain-Barré syndrome (GBS) following influenza vaccination among Fee-for-Service (FFS) Medicare beneficiaries every season since 2008. We present our evaluation of the GBS risk following influenza vaccinations during the 2017-2018 season.

METHODS

We implemented a multilayered approach to active safety surveillance that included near real-time surveillance early in the season, comparing GBS rates post-vaccination during the 2017-2018 season with rates from five prior seasons using the Updating Sequential Probability Ratio Test (USPRT), and end-of-season self-controlled risk interval (SCRI) analyses.

RESULTS

We identified approximately 16 million influenza vaccinations. The near real-time surveillance did not signal for a potential 2.5-fold increased GBS risk either in days 8-21 or 1-42 post-influenza vaccination. In the SCRI analyses, we did not detect statistically significant increased GBS risks among influenza-vaccinated Medicare beneficiaries ≥65 years for either the 8-21 or 1-42-day risk windows for all seasonal vaccines combined, high-dose vaccine, or standard-dose vaccines; we did detect an increased GBS risk in days 8-21 post-vaccination for individuals vaccinated with the adjuvanted vaccine (OR: 3.75; 95% CI: 1.01, 13.96), although this finding was not statistically significant after multiplicity adjustment (p = 0.146).

CONCLUSIONS

Our multilayered surveillance approach-which allows for early detection of elevated GBS risk and provides reliable end-of-season SCRI estimates of effect size-did not identify an increased GBS risk following 2017-2018 influenza vaccinations. The slightly increased GBS risk with the adjuvanted vaccine, which was not statistically significant following multiplicity adjustment, is consistent with the package inserts of all U.S.-licensed influenza vaccines, which warn of a potential low increased GBS risk. The benefits of influenza vaccines in preventing morbidity and mortality heavily outweigh this potential risk.

Letters designed with behavioural science increase influenza vaccination in Medicare beneficiaries

The influenza ('flu') vaccination is low cost¹ and effective, typically reducing the likelihood of infection by 50-60%². It is recommended for nearly everyone older than 6 months of age³; yet, only 40% of Americans are immunized each year. Vaccination rates are higher among at-risk groups, such as those ≥65 years of age, but still only 6 in 10 receive it⁴. There have been numerous attempts to improve vaccination rates using strategies such as school-based programmes, financial incentives and reminders, but these have generally had limited success^5-7. Of the attempts that are successful, most are expensive-limiting scalability-and have not been evaluated in the elderly⁸. Conversely, lower-cost interventions, such as mailed information, hold promise for a scalable solution, but their limited effectiveness may result from how they have been designed. We randomly assigned 228,000 individuals ≥66 years of age to one of five versions of letters intended to motivate vaccination, including versions with an implementation intention prompt and an enhanced active choice implementation prompt. We found that a single mailed letter significantly increased influenza vaccination rates compared with no letter. However, there was no difference in vaccination rates across the four different letters tailored with behavioural science techniques.

Identifying Gender Minority Patients' Health And Health Care Needs In Administrative Claims Data

Health care utilization patterns for gender minority Medicare beneficiaries (those who are transgender or gender nonbinary people) are largely unknown. We identified gender minority beneficiaries using a diagnosis-code algorithm and compared them to a 5 percent random sample of non-gender minority beneficiaries from the period 2009-14 in terms of mental health and chronic diseases, use of preventive and mental health care, hospitalizations, and emergency department (ED) visits. Gender minority beneficiaries experienced more disability and mental illness. When we adjusted for age and mental health, we found that they used more mental health care. And when we adjusted for age and chronic conditions, we found that they were more likely to be hospitalized and to visit the ED. There were several small but significant differences in preventive care use. Findings were similar for disabled and older cohorts. These findings underscore the need to capture gender identity in health data to better address this population's health needs.

Variations in Influenza and Pneumonia Immunizations for Medicare Beneficiaries Served by Rural Health Clinics

The availability of a rural health clinic (RHC) database over the period of 6 years (2008-2013) offers a unique opportunity to examine the trends and patterns of disparities in immunization for influenza and pneumonia among Medicare beneficiaries in the southeastern states. The purpose of this exploratory study was twofold. First, it examined the rural trends and patterns of immunization rates before (2008-2009) and after (2010-2013) the Affordable Care Act (ACA) enactment by state and year. Second, it investigated how contextual, organizational, and aggregate patient characteristics may influence the variations in immunization for influenza and pneumonia of Medicare beneficiaries served by RHCs. Four data sources from federal agencies were merged to perform a longitudinal analysis of the influences of contextual, organizational, and aggregate patient characteristics on the disparities in immunization rates of rural Medicare beneficiaries for influenza and pneumonia. We included both time-varying and time-constant predictors in a multivariate analysis using Generalized Estimating Equation. This study revealed the increased immunization rates for both influenza and pneumonia over a period of 6 years. The ACA had a positive effect on increased immunization rates for pneumonia, but not for influenza, in rural Medicare beneficiaries in the eight states. The RHCs that served more dually-eligible patients had higher immunization rates. For influenza immunization, provider-based RHCs had a higher rate than the independent RHCs. For pneumonia immunization, no organizational variables were relevant in the explanation of the variability. The results also showed that no single dominant factor influenced health care disparities. This investigation suggested further improvements in preventive care are needed to target poor and isolated rural beneficiaries. Furthermore, the integration of immunization data from multiple sources is critically needed for understanding health disparities.