Mary Nowalk
University of Pittsburgh, Family Medicine, Faculty Member
Research Interests: Medicine, Population, Humans, Cost Effectiveness Analysis, United States, and 13 moreCost effectiveness, Vaccination, Middle Aged, Quality adjusted life years, Adult, Economic Models, Cost Benefit Analysis, Tetanus, Diphtheria, Vaccination coverage, Immunization Programs, Decision Support Techniques, and Influenza vaccines
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Background:Pneumococcal vaccination policy for US adults is evolving, but previous research has shown that programs to increase vaccine uptake are economically favorable, despite parameter uncertainty. Using value of information (VOI)... more
Background:Pneumococcal vaccination policy for US adults is evolving, but previous research has shown that programs to increase vaccine uptake are economically favorable, despite parameter uncertainty. Using value of information (VOI) analysis and prior analyses, we examine the value of further research on vaccine uptake program parameters.Methods:In US 50–64-year-olds, current vaccine recommendations with and without an uptake program were analyzed. In older adults, current recommendations and an alternative strategy (polysaccharide vaccine for all, adding conjugate vaccine only for the immunocompromised) with and without uptake programs were examined. Uptake program parameters were derived from a clinical trial (absolute uptake increase 12.3% [range 0%-25%], per-person cost $1.78 [range $0.70-$2.26]), with other parameters obtained from US databases. VOI analyses incorporated probabilistic sensitivity analysis outputs into R-based regression techniques.Results:In 50–64-year-olds, an uptake program cost $54,900/QALY gained compared to no uptake program. For ages ≥65, the program cost $287,000/QALY gained with the alternative strategy and $765,000/QALY with current recommendations. In younger adults, population-level expected value of perfect information (EVPI) was $59.7 million at $50,000/QALY gained and $2.8 million at $100,000/QALY gained. In older adults, EVPI values ranged from ∼$1 million to $34.5 million at $100,000 and $200,000/QALY thresholds. The population expected value of partial perfect information (EVPPI) for combined uptake program cost and uptake improvement parameters in the younger population was $368,700 at $50,000/QALY and $43,900 at $100,000/QALY gained thresholds. In older adults, population EVPPI for vaccine uptake program parameters was $0 at both thresholds, reaching a maximum value of $445,000 at a $225,000/QALY threshold. Other model parameters comprised larger components of the global EVPI.Conclusion:VOI results do not support further research on pneumococcal vaccine uptake programs in adults at commonly cited US cost-effectiveness benchmarks. Further research to reduce uncertainty in other aspects of adult pneumococcal vaccination is justifiable.
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INTRODUCTION Use of the 13-valent pneumococcal conjugate vaccine in nonimmunocompromised adults aged ≥65 years is controversial. Higher-valency conjugate vaccines (15-valent and 20-valent ) are under development; their potential cost... more
INTRODUCTION Use of the 13-valent pneumococcal conjugate vaccine in nonimmunocompromised adults aged ≥65 years is controversial. Higher-valency conjugate vaccines (15-valent and 20-valent ) are under development; their potential cost effectiveness in older adults is unknown, particularly when potential indirect (herd immunity) effects from childhood vaccination are considered. METHODS A Markov model estimated the cost effectiveness of current U.S. recommendations and alternative strategies using currently available and in-development pneumococcal conjugate vaccines in seniors. Separately, strategies using a hypothetical 20-valent vaccine adding the 7 most common disease-causing non-13-valent vaccine serotypes were considered. Sensitivity analyses were performed and alternative scenarios were examined. Data were gathered and the analyses were performed in 2020. RESULTS In analyses considering only existing and in-development vaccines, sole 20-valent vaccine use cost $172,491/quality-adjusted life year gained compared with current U.S. recommendations under baseline assumptions (equal serotype effectiveness and no childhood vaccination indirect effects). Strategies using 15-valent vaccine were more costly and less effective. When 13-valent/20-valent vaccines were assumed ineffective against pneumococcal serotype 3 and 15-valent vaccine was fully effective, 15-valent vaccine cost $237,431/quality-adjusted life year gained. With indirect effects considered, 15-valent or 20-valent vaccine cost >$449,000/quality-adjusted life year gained. When adding hypothetical 20-valent vaccine under baseline assumptions, hypothetical 20-valent vaccine cost $139,348/quality-adjusted life year gained. CONCLUSIONS In-development pneumococcal conjugate vaccines may be economically unreasonable in older adults, regardless of serotype effectiveness assumptions, particularly when considering potential indirect effects from use of those vaccines in children. Adult vaccines containing high-risk serotypes not contained in childhood vaccines may be more promising.
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Objective:To increase the proportion of inpatients vaccinated against pneumococcal infection.Design:Pre- and post-intervention study.Setting:University medical center–affiliated, suburban community teaching hospital.Patients:Unvaccinated... more
Objective:To increase the proportion of inpatients vaccinated against pneumococcal infection.Design:Pre- and post-intervention study.Setting:University medical center–affiliated, suburban community teaching hospital.Patients:Unvaccinated inpatients 65 years and older and those 2 to 64 years old who had chronic medical conditions predisposing them to invasive pneumococcal infection.Intervention:The nursing staff screened newly admitted patients for eligibility based on age, diagnosis, or medications from a computer-generated admissions list and placed a pre-printed order form for the pneumococcal polysaccharide vaccine (PPV) on the charts of eligible patients. Following the physician's order, the nursing staff administered the PPV and recorded it. Ongoing quality improvements including admission vaccination screening and computer-based record keeping were initiated to identify unvaccinated eligible patients and track vaccination status.Results:Efforts resulted in rates of in-hospital vaccination ranging from 3.1% to 7.9% (mean, 5.2% ± 1.7% [standard deviation]) and significant improvements in the assessment of previous vaccination status, reaching 54% of eligible patients after 1 year. Ascertainment of a previous vaccination increased significantly following the initiation of the use of admission forms that specifically assessed vaccination status and a system to permanently record vaccination status in an electronic medical record (P < .05).Conclusion:Concerted efforts using electronic medical records significantly improved the assessment and documentation of inpatient vaccination status. Greater improvement of the rates of in-hospital vaccination will require healthcare system–wide efforts such as a standing order policy for vaccinating all eligible patients. Standing orders for inpatient immunization supported by effective assessment and tracking systems have the potential to raise vaccination rates to the goals of Healthy People 2010 (Infect Control Hosp Epidemiol 2003;24:526-531)
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Research Interests: Adolescent, Medicine, Human, Biological Sciences, Humans, and 15 moreFemale, Male, Influenza, Aged, Middle Aged, Adult, Odds ratio, Public Health Surveillance, Age Factors, influenza A virus, Influenza Vaccine, Confidence Interval, Medical and Health Sciences, Influenza vaccines, and Outcome Assessment Health Care
The treatment regimen for patients with diabetes involves a complex series of self-care behaviors. This article conceptualizes the regimen in terms of a behavioral self-regulation model for the control of blood sugar. The model, based on... more
The treatment regimen for patients with diabetes involves a complex series of self-care behaviors. This article conceptualizes the regimen in terms of a behavioral self-regulation model for the control of blood sugar. The model, based on a negative feedback control system, includes four components: (a) behaviors related to the detection of discrepancies between actual and normal blood sugar, by urine
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Background Few studies have focused on the immune response to more recent influenza vaccine formulations such as cell-cultured inactivated influenza vaccine (ccIIV4) or live-attenuated influenza vaccine (LAIV4) in older children and young... more
Background Few studies have focused on the immune response to more recent influenza vaccine formulations such as cell-cultured inactivated influenza vaccine (ccIIV4) or live-attenuated influenza vaccine (LAIV4) in older children and young adults, or differences in immunoglobulin response using newer antibody landscape technology. Methods Participants ages 4–21 were randomized to receive ccIIV4 (n = 112) or LAIV4 (n = 118). A novel high-throughput multiplex influenza antibody detection assay was used to provide detailed IgG, IgA, and IgM antibody isotypes, along with hemagglutination inhibition levels (HAI), measured pre- and 28 days post-vaccination. Results The HAI and immunoglobulin isotype response to ccIIV4 was greater than LAIV4, with significant increases in IgG but not IgA or IgM. The youngest participants had the highest LAIV4 response. Prior LAIV4 vaccination was associated with a higher response to current season ccIIV4. Cross-reactive A/Delaware/55/2019(H1N1)pdm09 antibodies were present pre-vaccination and increased in response to ccIIV4, but not LAIV4. Immunoglobulin assays strongly correlated with and confirmed the findings of HAI titers to measure immune response. Conclusions Age and prior season vaccination may play a role in the immune response in children and young adults to ccIIV4 and LAIV4. While immunoglobulin isotypes provide high-level antigen-specific information, HAI titers alone can provide a meaningful representation of day 28 post-vaccination response. Clinical Trials No NCT03982069
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We determined the barriers to and facilitators of colorectal cancer (CRC) screening among two faith-based, inner city neighborhood health centers in Southwestern Pennsylvania. Data from a random sample of patients 50 years and older (n =... more
We determined the barriers to and facilitators of colorectal cancer (CRC) screening among two faith-based, inner city neighborhood health centers in Southwestern Pennsylvania. Data from a random sample of patients 50 years and older (n = 375) were used to estimate logistic regression equations to compare and contrast the predictors of four different CRC screening protocols: (1) fecal occult blood test (FOBT) < or = 2 years ago, (2) colonoscopy < or = 10 years ago, (3) lower endoscopy (colonoscopy or sigmoidoscopy) < or = 10 years ago, and (4) any of these screening measures. Racial differences (between African Americans or Caucasians) in type of colon cancer screening were not found. Controlling for covariates, logistic regression equations showed that a physician's support of colon cancer screening was positively associated with the receipt of colonoscopy (OR: 19.47, 95% CI: 5.45-69.54), lower endoscopy (OR: 10.96, 95% CI: 3.77-31.88) and any colon cancer screening (OR: 10.12, 95% CI: 3.36-30.46). Patients who see their physicians more frequently were also more likely to be screened for CRC. Unlike other studies, the faith-based environment in which these patients are treated may explain the lack of racial disparity specific to our measures of CRC screening.
Research Interests: Community Health, Medicine, Logistic Regression, Colorectal cancer, Humans, and 15 moreInternal Medicine, African American, Female, Male, Ethnic Groups, Colonoscopy, Aged, Middle Aged, Public health systems and services research, Colon cancer, Colorectal Cancer Screening, Community Health Centers, Racial differences, mass Screening, and Colonic Neoplasms
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Background During 2017–2018, influenza vaccine effectiveness (VE) against A(H3N2) illness was highest among children <5 years compared with all other ages. A child’s first influenza infection can shape later immune... more
Background During 2017–2018, influenza vaccine effectiveness (VE) against A(H3N2) illness was highest among children <5 years compared with all other ages. A child’s first influenza infection can shape later immune responses. The emergence of antigenically distinct influenza A(H3N2) viruses in 2014–2015 provided an opportunity to explore potential effects of first virus infection on vaccine effects. We compared VE against influenza A(H3N2) during 2016–2017 and 2017–2018 among children born after and before 2014. Methods Outpatient children aged 6 months–17 years with acute respiratory illness with cough were enrolled in the United States Influenza VE Network and tested for influenza infection by RT–PCR. Vaccination status was derived through medical records and immunization registries. Children with partial or unknown vaccination status were excluded. We used a test-negative design to estimate VE and 95% confidence intervals (CI) from logistic regression, adjusting for potential confounders. Cohorts were defined by birth after or before June 2014; we assumed exposure to the new A(H3N2) virus among children born after June 2014. Results During 2016–2017, among 2,545 children, 445 (18%) tested positive for A(H3N2) and 1,809 (71%) tested negative. VE against A(H3N2) did not differ among children born after June 2014 and among those born before June 2014 [49% (95% CI: −12%, 77%) vs. 43% (27%, 55%); interaction P < 0.75]. During 2017–2018, among 2,936 patients, 631 (22%) tested positive for A(H3N2), and 1,852 (63%) tested negative. VE against A(H3N2) was 59% (36%, 74%) among children born after June 2014 vs. 20% (−1%, 37%) among those born before June 2014 (interaction P < 0.01). Conclusion We did not consistently see differences in VE against A(H3N2) between children potentially exposed to different A(H3N2) viruses. However, error in exposure assignment to A(H3N2) viruses and few seasons since the emergence of the new A(H3N2) viruses limit our interpretation. Future study will include additional A(H3N2) seasons as initial exposures to current circulating viruses increase among young children. Alternative explanations for age-related differences will also be explored, such as prior seasonal vaccination. Disclosures All authors: No reported disclosures.
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Research Interests: Family Medicine, Medicine, Multivariate Analysis, Humans, Philosophy and Religious Studies, and 15 moreFemale, Male, Immunization, Pennsylvania, Aged, Middle Aged, Adult, Cross Sectional Studies, Logistic Models, Receipt, Health services for the aged, Guideline Adherence, Health Services Accessibility, Medical and Health Sciences, and Referral
Research Interests: Nursing, Occupational Health, Adolescent, Medicine, Workplace, and 14 moreHumans, Young Adult, Vaccination, Incentive, Aged, Middle Aged, Adult, Public health systems and services research, Cost Savings, Influenza Vaccine, Monte Carlo Method, Occupational and environmental medicine, Immunization Programs, and Influenza vaccines
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Research Interests: Primary Health Care, Family Medicine, Health Care, Health Equity, Medicine, and 15 moreUrban, Population, Humans, Demographics, Minority Groups, Pennsylvania, Aged, Ethnic Group, European Continental Ancestry Group, Private Practice, Cross Sectional Studies, Medical Audit, healthcare disparities, Immunization Schedule, and Mass vaccination
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Introduction:Recommending both the conjugate and polysaccharide pneumococcal vaccines to all U.S. seniors may have little public health impact and be economically unreasonable. Public health impact and cost effectiveness of using both... more
Introduction:Recommending both the conjugate and polysaccharide pneumococcal vaccines to all U.S. seniors may have little public health impact and be economically unreasonable. Public health impact and cost effectiveness of using both vaccines in all adults aged ≥65 years were estimated compared with an alternative strategy (omitting pneumococcal conjugate vaccine in the non-immunocompromised) and with the newly revised recommendation (giving or omitting conjugate vaccine based on patient-physician shared decision making).Methods:Strategies were examined in hypothetical U.S. 65-year-old population cohorts and segmented into health states based on age- and population-specific data in a Markov state-transition model with a lifetime time horizon from a healthcare perspective. Black population cohorts were examined separately given greater illness risk and lower vaccine uptake. Model parameters came from the Centers for Disease Control Active Core Bacterial Surveillance network, National Health Interview Survey, and Nationwide Inpatient Sample data. Outcomes included incremental costs per quality-adjusted life year (QALY) gained and pneumococcal disease outcomes for each strategy. Data were gathered and analysis performed in 2018.Results:Giving both vaccines, either routinely or with shared decision making, was most effective, reducing pneumococcal disease incidence compared with no vaccination, but costing $765,000–$2.18 million/QALY gained. Depending on examined population and scenario, the alternative strategy cost $65,700–$226,700/QALY gained (less in black populations) and reduced cases and deaths by 0.3%–0.9%.Conclusions:A vaccination strategy that omits pneumococcal conjugate vaccine in immunocompetent U.S. seniors may be economically reasonable, particularly for black seniors. Use of both pneumococcal vaccines was more effective, but substantially more expensive.
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Background The COVID-19 pandemic is causing declines in childhood immunization rates. We examined potential COVID-19-related changes in pediatric 13-valent pneumococcal conjugate vaccine (PCV13) use, subsequent impact on childhood and... more
Background The COVID-19 pandemic is causing declines in childhood immunization rates. We examined potential COVID-19-related changes in pediatric 13-valent pneumococcal conjugate vaccine (PCV13) use, subsequent impact on childhood and adult pneumococcal disease rates, and how those changes might affect the favorability of PCV13 use in non-immunocompromised adults aged ≥65 years. Methods A Markov model estimated pediatric disease resulting from decreased PCV13 use in children aged <5 years; absolute decreases from 10 to 50% for 1–2 years duration were examined, assuming no catch-up vaccination and that decreased vaccination led to proportionate increases in PCV13 serotype pneumococcal disease in children and seniors. Integrating pediatric model output into a second Markov model examining 65-year-olds, we estimated the cost effectiveness of older adult pneumococcal vaccination strategies while accounting for potential epidemiologic changes from decreased pediatric vaccination. Results One year of 10–50% absolute decreases in PCV13 use in <5-year-olds increased pneumococcal disease by an estimated 4–19% in seniors; 2 years of decreased use increased senior rates by 8–38%. In seniors, a >53% increase in pneumococcal disease was required to favor PCV13 use in non-immunocompromised seniors at a $200,000 per quality-adjusted life-year gained threshold, which corresponded to absolute decreases in pediatric PCV13 vaccination of >50% over a 2-year period. In sensitivity analyses, senior PCV13 vaccination was unfavorable if absolute decreases in pediatric PCV13 receipt were within plausible ranges, despite model assumptions favoring PCV13 use in seniors. Conclusion COVID-19-related decreases in pediatric PCV13 use would need to be both substantial and prolonged to make heightened PCV13 use in non-immunocompromised seniors economically favorable.
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INTRODUCTION Mid-season influenza vaccine effectiveness (VE) estimates are a useful tool to help guide annual influenza vaccine strain selection, vaccine policy, and public health messaging. We propose using a sample size-driven approach... more
INTRODUCTION Mid-season influenza vaccine effectiveness (VE) estimates are a useful tool to help guide annual influenza vaccine strain selection, vaccine policy, and public health messaging. We propose using a sample size-driven approach with data-driven inputs for publication of mid-season influenza VE. METHODS We used pooled inputs for VE by (sub)type and average vaccine coverage by age groups using data from eight seasons of the US Influenza VE Network to calculate sample sizes needed to estimate mid-season VE. RESULTS We estimate that 135 influenza-positive cases would be needed to detect an overall VE of 40% with 55% vaccine coverage among test-negative controls. Larger sample sizes would be required to produce reliable estimates specifically against influenza A/H3N2 and for older age groups. CONCLUSION Using an existing network, most of the recent influenza seasons in the US would facilitate valid mid-season VE estimates using the proposed sample sizes for broad age groupings.
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BackgroundWe estimated SARS‐CoV‐2 Delta‐ and Omicron‐specific effectiveness of two and three mRNA COVID‐19 vaccine doses in adults against symptomatic illness in US outpatient settings.MethodsBetween October 1, 2021, and February 12,... more
BackgroundWe estimated SARS‐CoV‐2 Delta‐ and Omicron‐specific effectiveness of two and three mRNA COVID‐19 vaccine doses in adults against symptomatic illness in US outpatient settings.MethodsBetween October 1, 2021, and February 12, 2022, research staff consented and enrolled eligible participants who had fever, cough, or loss of taste or smell and sought outpatient medical care or clinical SARS‐CoV‐2 testing within 10 days of illness onset. Using the test‐negative design, we compared the odds of receiving two or three mRNA COVID‐19 vaccine doses among SARS‐CoV‐2 cases versus controls using logistic regression. Regression models were adjusted for study site, age, onset week, and prior SARS‐CoV‐2 infection. Vaccine effectiveness (VE) was calculated as (1 − adjusted odds ratio) × 100%.ResultsAmong 3847 participants included for analysis, 574 (32%) of 1775 tested positive for SARS‐CoV‐2 during the Delta predominant period and 1006 (56%) of 1794 participants tested positive during the ...
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BACKGROUND In the United States (U.S.), annual influenza vaccination has been recommended for all persons aged ≥6 months with the Healthy People 2020 coverage target of 70%. However, vaccination coverage has remained around 42-49% during... more
BACKGROUND In the United States (U.S.), annual influenza vaccination has been recommended for all persons aged ≥6 months with the Healthy People 2020 coverage target of 70%. However, vaccination coverage has remained around 42-49% during the past eight influenza seasons. We sought to quantify influenza vaccination coverage and factors associated with vaccination in persons seeking outpatient medical care for an acute respiratory illness (ARI). METHODS We enrolled outpatients aged ≥6 months with ARI from >50 U.S. clinics from 2011 to 2012 through 2018-2019 influenza seasons and tested for influenza with molecular assays. Vaccination status was based on documented receipt of the current season's influenza vaccine. We estimated vaccination coverage among influenza-negative study participants by study site, age, and season, and compared to state-level influenza coverage estimates in the general population based on annual immunization surveys. We used multivariable logistic regression to examine factors independently associated with receipt of influenza vaccines. RESULTS We enrolled 45,424 study participants with ARI who tested negative for influenza during the study period. Annual vaccination coverage among influenza-negative ARI patients and the general population in the participating states averaged 55% (range: 47-62%), and 52% (range: 46-54%), respectively. Among enrollees, coverage was highest among adults aged ≥65 years (82%; range, 80-85%) and lowest among adolescents aged 13-17 years (38%; range, 35-41%). Factors significantly associated with non-vaccination included non-White race, no college degree, exposure to cigarette smoke, absence of high-risk conditions, and not receiving prior season influenza vaccine. CONCLUSIONS Influenza vaccination coverage over eight seasons among outpatients with non-influenza respiratory illness was slightly higher than coverage in the general population but 15% lower than national targets. Increased efforts to promote vaccination especially in groups with lower coverage are warranted to attain optimal health benefits of influenza vaccine.
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Background: Unintended pregnancies continue to account for half of all pregnancies in the United States, primarily due to incorrect or inconsistent use of contraception methods. Long-acting reversible contraception (LARC) methods are safe... more
Background: Unintended pregnancies continue to account for half of all pregnancies in the United States, primarily due to incorrect or inconsistent use of contraception methods. Long-acting reversible contraception (LARC) methods are safe and highly effective, yet underutilized. Low uptake of LARC may be due to inadequate education, misconceptions, and cultural factors such as race, ethnicity, or religion. This study examined racial differences in contraceptive awareness and use among women seeking care at family health centers. Materials and Methods: Focus groups were used to identify recurrent themes in contraceptive choice of participants and develop a survey, completed by nonpregnant female patients 18-45 years of age from seven family health centers. Results: Among a total of 465 participants, 210 (46.2%) of whom were non-white, awareness of most types of birth control was generally high. Awareness of all types of contraceptives was significantly higher among white than non-white women (p < 0.001). Across most types of contraceptives, use was significantly higher among white women than non-white women with the exception of injectable hormones which were used significantly more often by non-white women (46.0% vs. 28.5%; p < 0.001). Reasons for using LARC did not vary by type nor by race but reasons for not using LARC varied by race and by specific method. Conclusions: Differing patterns of awareness, use, and perceptions of contraceptive methods between white and non-white women were revealed. By understanding factors that influence contraceptive awareness, use, and perceptions, clinicians can better address the contraceptive needs and concerns of their female patients. Clinical Trial # NCT03486743.