Partial palivizumab prophylaxis and increased risk of hospitalization due to respiratory syncytial virus in a Medicaid population: a retrospective cohort analysis.

BACKGROUND: Infection with respiratory syncytial virus (RSV) is common among young children insured through Medicaid in the United States. Complete and timely dosing with palivizumab is associated with lower risk of RSV-related hospitalizations, but up to 60% of infants who receive palivizumab in Medicaid population do not receive full prophylaxis. The purpose of this study was to evaluate the association of partial palivizumab prophylaxis with the risk of RSV hospitalization among high-risk Medicaid-insured infants. METHODS: Claims data from 12 states during 6 RSV seasons (October 1st to April 30th in the first year of life in 2003-2009) were analyzed. Inclusion criteria were birth hospital discharge before October 1st, continuous insurance eligibility from birth through April 30th, ≥ one palivizumab administration from August 1st to end of season, and high-risk status (≤34 weeks gestational age or chronic lung disease of prematurity [CLDP] or hemodynamically significant congenital heart disease [CHD]). Fully prophylaxed infants received the first palivizumab dose by November 30th with no gaps >35 days up to the first RSV-related hospitalization or end of follow-up. All other infants were categorized as partially prophylaxed. RESULTS: Of the 8,443 high-risk infants evaluated, 67% (5,615) received partial prophylaxis. Partially prophylaxed infants were more likely to have RSV-related hospitalization than fully prophylaxed infants (11.7% versus 7.9%, p< 0.001). RSV-related hospitalization rates ranged from 8.5% to 24.8% in premature, CHD, and CLDP infants with partial prophylaxis. After adjusting for potential confounders, logistic regression showed that partially prophylaxed infants had a 21% greater odds of hospitalization compared with fully prophylaxed infants (odds ratio 1.21, 95% confidence interval 1.09-1.34). CONCLUSIONS: RSV-related hospitalization rates were significantly higher in high-risk Medicaid infants with partial palivizumab prophylaxis compared with fully prophylaxed infants. These findings suggest that reduced and/or delayed dosing is less effective.

Risk factors for respiratory syncytial virus illness among patients with chronic obstructive pulmonary disease.

Respiratory syncytial virus (RSV), although not typically considered an important pathogen in adults, may cause acute exacerbation of chronic obstructive pulmonary disease (COPD). It is unclear which COPD patients are at highest risk for developing serious RSV illness. Our objective was to identify risk factors for RSV illness among adult patients with COPD. We conducted a pooled analysis of data from COPD patients in 2 previously published longitudinal studies that examined RSV infection in high risk adults for ≤ 2 RSV seasons. Risk factors for RSV illness studied included age, sex, race, smoking status, exposure to children, home oxygen use, inhaled or oral steroid use, instrumental activities of daily living scores, and co-morbid conditions. Outcomes studied included symptomatic and medically attended RSV illness. Logistic regression was used to identify significant risk factors for RSV illness among older adults with COPD. Among 379 patients with COPD, the rate of symptomatic RSV illness was 11.1% (42/379); almost half (20/42) of whom required medical attention. In multivariable analyses, congestive heart failure (odds ratio [OR] = 4.18; 95% CI: 1.38, 12.69) and exposure to children (OR = 2.38; 95% CI: 1.03, 5.51) were risk factors for symptomatic RSV illness. Congestive heart failure (OR = 4.16; 95% CI: 1.02, 17.01) was the only significant risk factor for developing medically attended RSV illness. Exposure to children and congestive heart failure are risk factors for RSV illness among adult patients with COPD. Future prospective, well-designed studies are needed to corroborate these findings and examine other risk factors, including history of exacerbations.

Systematic literature review assessing tobacco smoke exposure as a risk factor for serious respiratory syncytial virus disease among infants and young children.

BACKGROUND: The role of environmental tobacco smoke (ETS) exposure as a risk factor for serious respiratory syncytial virus (RSV) disease among infants and young children has not been clearly established. This systematic review was conducted to explore the association between ETS exposure and serious RSV disease in children younger than 5 years, including infants and young children with elevated risk for serious RSV disease. METHODS: A systematic review of English-language studies using the PubMed and EMBASE databases (1990-2009) was performed to retrieve studies that evaluated ETS as a potential risk factor for serious RSV illness. Studies assessing risk factors associated with hospitalization, emergency department visit, or physician visit due to RSV (based on laboratory confirmation of RSV or clinical diagnosis of RSV) in children under the age of 5 years were included. RESULTS: The literature search identified 30 relevant articles, categorized by laboratory confirmation of RSV infection (n = 14), clinical diagnosis of RSV disease (n = 8), and assessment of RSV disease severity (n = 8). Across these three categories of studies, at least 1 type of ETS exposure was associated with statistically significant increases in risk in multivariate or bivariate analysis, as follows: 12 of 14 studies on risk of hospitalization or ED visit for laboratory-confirmed RSV infection; 6 of 8 studies of RSV disease based on clinical diagnosis; and 5 of the 8 studies assessing severity of RSV as shown by hospitalization rates or degree of hypoxia. Also, 7 of the 30 studies focused on populations of premature infants, and the majority (5 studies) found a significant association between ETS exposure and RSV risk in the multivariate or bivariate analyses. CONCLUSION: We found ample evidence that ETS exposure places infants and young children at increased risk of hospitalization for RSV-attributable lower respiratory tract infection and increases the severity of illness among hospitalized children. Additional evidence is needed regarding the association of ETS exposure and outpatient RSV lower respiratory tract illness. Challenges and potential pitfalls of assessing ETS exposure in children are discussed.

Cost utility of palivizumab prophylaxis among pre-term infants in the United States: a national policy perspective.

OBJECTIVE: The cost-effectiveness of palivizumab has previously been reported among certain guideline-eligible, high-risk premature infants in Medicaid. Because guideline authorities base decisions on a national perspective, the economic model of palivizumab was adapted to include all infants, that is, public and privately insured patients (60% of palivizumab use is public, 40% is private). METHODS: This study examined four groups of premature infants without chronic lung disease of prematurity or congenital heart disease: (1) <32 weeks gestational age (wGA) and ≤ 6 months chronologic age (CA); (2) 32-34 wGA, ≤ 3 months CA, with 2009 American Academy of Pediatrics (AAP) risk factors (RFs); (3) 32-35 wGA, ≤ 6 months CA, with 2006 AAP RFs; and (4) 32-35 wGA, ≤ 6 months CA, with ≤ 1 RF. An average estimate was used between public and private payors for (1) background rates of respiratory syncytial virus hospitalization (RSV-H), (2) direct medical costs associated with RSV-H, and (3) cost of palivizumab. Incremental cost-effectiveness ratios (ICERs) are reported in cost per quality-adjusted life-year (QALY) gained. Sensitivity analyses were performed. RESULTS: Palivizumab saved costs and improved QALYs among infants <32 wGA. Palivizumab was cost-effective in infants 32-34 wGA with 2009 AAP RFs ($44,774 per QALY) and in infants 32-35 wGA with 2006 AAP RFs ($79,477 per QALY). The ICER for infants 32-35 wGA with ≤ 1 RF was $464,476 per QALY. Influential variables in the sensitivity analysis included background rate of RSV-H and cost and efficacy of palivizumab. LIMITATIONS: The results are not generalizable to populations outside of the US. The model did not examine all RFs. The wholesale acquisition cost was used as a payment benchmark; actual price paid by end providers varies. CONCLUSIONS: From a national policy perspective, palivizumab remained cost-effective for publically and commercially insured, guideline-eligible, high-risk premature infants. Palivizumab was not cost-effective in infants of 32-35 wGA with ≤ 1 RF.

Agreement between Internet-based self- and proxy-reported health care resource utilization and administrative health care claims.

OBJECTIVES: Although Internet-based surveys are becoming more common, little is known about agreement between administrative claims data and Internet-based survey self- and proxy-reported health care resource utilization (HCRU) data. This analysis evaluated the level of agreement between self- and proxy-reported HCRU data, as recorded through an Internet-based survey, and administrative claims-based HCRU data. METHODS: The Child and Household Influenza-Illness and Employee Function study collected self- and proxy-reported HCRU data monthly between November 2007 and May 2008. Data included the occurrence and number of visits to hospitals, emergency departments, urgent care centers, and outpatient offices for a respondent's and his or her household members' care. Administrative claims data from the MarketScan® Databases were assessed during the same time and evaluated relative to survey-based metrics. Only data for individuals with employer-sponsored health care coverage linkable to claims were included. The Kappa (κ) statistic was used to evaluate visit concordance, and the intraclass correlation coefficient was used to describe frequency consistency. RESULTS: Agreement for presence of a health care visit and the number of visits were similar for self- and proxy-reported HCRU data. There was moderate to substantial agreement related to health care visit occurrence between survey-based and claims-based HCRU data for inpatient, emergency department, and office visits (κ: 0.47-0.77). There was less agreement on health care visit frequencies, with intraclass correlation coefficient values ranging from 0.14 to 0.71. CONCLUSIONS: This study's agreement values suggest that Internet-based surveys are an effective method to collect self- and proxy-reported HCRU data. These results should increase confidence in the use of the Internet for evaluating disease burden.

Residential crowding and severe respiratory syncytial virus disease among infants and young children: a systematic literature review.

BACKGROUND: The objective of this literature review was to determine whether crowding in the home is associated with an increased risk of severe respiratory syncytial virus (RSV) disease in children younger than 5 years. METHODS: A computerized literature search of PubMed and EMBASE was conducted on residential crowding as a risk factor for laboratory-confirmed RSV illness in children younger than 5 years. Study populations were stratified by high-risk populations, defined by prematurity, chronic lung disease of prematurity, hemodynamically significant congenital heart disease, or specific at-risk ethnicity (i.e. Alaska Native, Inuit), and mixed-risk populations, including general populations of mostly healthy children. The search was conducted for articles published from January 1, 1985, to October 8, 2009, and was limited to studies reported in English. To avoid indexing bias in the computerized databases, the search included terms for multivariate analysis and risk factors to identify studies in which residential crowding was evaluated but was not significant. Methodological quality of included studies was assessed using a Cochrane risk of bias tool. RESULTS: The search identified 20 relevant studies that were conducted in geographically diverse locations. Among studies of patients in high-risk populations, 7 of 9 found a statistically significant association with a crowding variable; in studies in mixed-risk populations, 9 of 11 found a significant association with a crowding variable. In studies of high-risk children, residential crowding significantly increased the odds of laboratory-confirmed RSV hospitalization (i.e. odds ratio ranged from 1.45 to 2.85). In studies of mixed-risk populations, the adjusted odds ratios ranged from 1.23 to 9.1. The findings on the effect of residential crowding on outpatient RSV lower respiratory tract infection were inconsistent. CONCLUSIONS: Residential crowding was associated with an increased risk of laboratory-confirmed RSV hospitalization among high-risk infants and young children. This association was consistent despite differences in definitions of residential crowding, populations, or geographic locations.

Cost-effectiveness analysis of palivizumab among pre-term infant populations covered by Medicaid in the United States.

OBJECTIVE: Medicaid infants are at high risk of severe respiratory syncytial virus (RSV) disease. The study objective was to estimate the cost-effectiveness of palivizumab in a Medicaid population. METHODS: A societal cost-utility analysis was conducted of prophylaxis with palivizumab vs no prophylaxis among four groups of premature infants: (1) <32 weeks gestational age (wGA) and ≤ 6 months chronologic age (CA); (2) 32-34 wGA, ≤ 3 months CA with 2009 American Academy of Pediatrics (AAP) risk factors (RF); (3) 32-35 wGA, ≤ 6 months CA with 2006 AAP RF; and (4) 32-35 wGA, ≤ 6 months CA with ≤ 1 RF. Full dosing of palivizumab was assumed throughout the RSV season (consistent with the FDA-approved label). All costs were in 2010 US dollars. The societal public payer spend for palivizumab was estimated using Medicaid reimbursement methodologies for the top 10 palivizumab-using states in 2010 minus mandatory manufacturer rebates. This study reports the incremental cost-effectiveness ratios (ICERs) in cost per quality-adjusted life-year (QALY) gained. Sensitivity and probabilistic analyses were also conducted. RESULTS: Palivizumab saved costs and improved QALYs among infants <32 wGA. Palivizumab was cost-effective in infants 32-34 wGA with 2009 AAP RF ($16,037 per QALY) and in infants 32-35 wGA with 2006 AAP RF ($38,244 per QALY). The ICER for infants 32-35 wGA with ≤ 1 RF was $281,892 per QALY. Influential variables in the sensitivity analysis included the background rate of RSV hospitalization, the cost of palivizumab, and the efficacy of palivizumab. KEY LIMITATIONS: These results are not generalizable to commercially insured infants or infants outside of the US. CONCLUSIONS: This is the first cost-utility analysis of palivizumab in a Medicaid population. Palivizumab, when dosed consistent with the FDA-approved labeling, was either cost-saving or cost-effective among current guideline-eligible infants in the Medicaid population. Palivizumab did not demonstrate cost-effectiveness in 32-35 wGA infants with ≤ 1 RF.

Association of RSV lower respiratory tract infection and subsequent healthcare use and costs: a Medicaid claims analysis in early-preterm, late-preterm, and full-term infants.

OBJECTIVE: Healthcare use and costs within 1 year of a respiratory syncytial virus lower respiratory tract infection (RSV-LRI) among Medicaid early-preterm and late-preterm infants compared with full-term infants were evaluated. METHODS: Infants born during 2003-2005 were identified from the Thomson Reuters MarketScan Multi-State Medicaid Database. Infants <1 year of age were grouped based on RSV-LRI and unspecified bronchiolitis/pneumonia (UBP) diagnosis codes and stratified by inpatient or outpatient setting. Infants without RSV-LRI/UBP were selected for comparison. Economic and clinical outcomes were analyzed descriptively; the relationship between RSV-LRI/UBP and costs incurred within 1 year of infection were analyzed using logged ordinary least squares models. Results were stratified by gestational age. RESULTS: Most infants were diagnosed with RSV-LRI/UBP after 90 days of chronologic age. Early-preterm infants had the greatest mean number of inpatient, outpatient, and emergency department visits after an RSV-LRI/UBP episode. The marginal costs among infants with RSV-LRI compared with controls were $34,132 (p < 0.001) and $3869 (p = 0.115) among inpatients and outpatients, respectively. Among late-preterm infants, the marginal costs were $17,465 (p < 0.001) and $2158 (p < 0.001) among inpatients and outpatients, respectively. Full-term infants had the lowest marginal costs (inpatients, $9151 [p < 0.001]; outpatients, $1428 [p < 0.001]). Overall, inpatient infants with RSV-LRI/UBP had higher costs than outpatients, suggesting that increased downstream costs are associated with severity of RSV-LRI/UBP disease. LIMITATIONS: Infants with unknown etiology for bronchiolitis were assigned to the UBP group, which may underestimate the costs of the comparison group. CONCLUSIONS: The burden of RSV-LRI was substantial among early-preterm Medicaid infants. Costs were also higher among late-preterm relative to full-term infants.

A survey of children's preferences for influenza vaccine attributes.

BACKGROUND: While annual influenza vaccination is recommended by the CDC for children 6 months and older, vaccination rates remain suboptimal. For healthy, US children 2 years of age and older, influenza vaccine is available as an intramuscular injection (TIV) or an intranasal spray (LAIV), respectively. Little is known about children's experiences and preferences for influenza vaccine attributes. OBJECTIVE: To examine preferences for influenza vaccine attributes and their relative importance among children. METHODS: A quantitative web-survey was administered to children aged 8-12 years sampled from a standing online panel representative of the US population. Children were stratified by age, gender and parent's influenza vaccination behavior. The survey included questions to ascertain children's preferences for influenza vaccine attributes, including efficacy, chance of common side effects, and mode of administration. It included conjoint (trade-off) questions in which children traded-off different attributes in their choice between two influenza vaccines with differing features. We also surveyed children's comprehension of and ability to complete the conjoint questions. RESULTS: 544 children completed the survey (response rate 37%). Children most frequently selected efficacy as the most important vaccine attribute followed by mode of administration (45% and 31%, respectively). When asked for their preference to receive influenza vaccine as a "shot" or a "nose spray", the majority (69%) preferred the nose spray. An evaluation of children's ability to complete the conjoint survey demonstrated that 85% of the sample was able to complete the conjoint tasks. Analysis of the conjoint responses demonstrated that mode of administration and efficacy had the greatest impact on preferences, with a relative importance of 40.5% and 30.6%, respectively. In a direct comparison of vaccine profiles representing the efficacy, side effects, and other characteristics of LAIV and TIV, 79% of children preferred the LAIV-like profile. CONCLUSION: Children in the sample had consistent opinions regarding influenza vaccine attributes and consider vaccine efficacy and mode of administration to be important. Children can be informed participants in influenza prevention and can be included in discussions regarding influenza vaccination.

Children's perceptions of influenza illness and preferences for influenza vaccine.

INTRODUCTION: In this qualitative study we explored children's perceptions of influenza, preferences for influenza vaccines, and ability to understand "risk" of vaccine adverse effects and different attributes between injectable and intranasal vaccines. METHOD: In-person, semi-structured interviews were conducted among 28 U.S. children aged 6 through 12 years. RESULTS: Many children understood the concept of influenza illness and believed vaccination was important. Efficacy, adverse effects, and mode of administration affected their preferences for influenza vaccines. Children 8 years of age and older were able to consider multiple attributes when selecting between hypothetical vaccines, and their responses were consistent with their previously stated preferences for individual attributes. Most children would prefer a nasal spray over a shot vaccine when all other vaccine attributes were equal. DISCUSSION: Efficacy, adverse effects, and mode of administration were important factors in children's preferences for influenza vaccine. Children as young as 8 years of age appeared to understand vaccine "risk" and were able to consider multiple attributes simultaneously when choosing between vaccine alternatives.

Mortality and morbidity among infants at high risk for severe respiratory syncytial virus infection receiving prophylaxis with palivizumab: a systematic literature review and meta-analysis.

OBJECTIVES: A systematic literature review and meta-analysis was performed to evaluate the impact of prophylaxis with palivizumab on mortality and morbidity associated with respiratory syncytial virus infection in infants at high risk (≤ 35 wks of gestational age, chronic lung disease, or congenital heart disease). DATA SOURCES: MEDLINE, EMBASE, and Current Contents were used. MEDLINE was searched from January 1, 1990 to May 16, 2007. The bibliographies of accepted studies and recent reviews and proceedings from the past 2 yrs were searched to identify additional relevant studies. STUDY SELECTION: Randomized controlled trials and prospective or retrospective cohort studies evaluating all-cause and respiratory syncytial virus-specific mortality, respiratory syncytial virus hospitalizations, and health care use in infants at high risk for respiratory syncytial virus infection receiving prophylaxis with palivizumab. DATA EXTRACTION: Data elements from each accepted study were extracted by one researcher and confirmed by a second researcher. Differences were resolved before data entry and analysis. DATA SYNTHESIS: A total of 2473 citations were screened and ten comparative studies of palivizumab prophylaxis evaluating >15,000 infants were included. Comparisons of mortality and hospitalization outcomes between infant groups using prophylaxis and not using prophylaxis were made using meta-analyses. CONCLUSIONS: Prophylaxis and nonprophylaxis infant groups appeared to be comparable at baseline. All-cause mortality during the respiratory syncytial virus season was 12 of 6380 (0.19%) for infants with prophylaxis vs. 33 of 8182 (0.53%) for infants without prophylaxis (Peto odds ratio, 0.30; 95% confidence interval, 0.17-0.55). Only five respiratory syncytial virus-specific deaths were reported, and the majority of the studies did not report respiratory syncytial virus-related deaths. The rate of respiratory syncytial virus hospitalization was significantly lower among preterm infants with prophylaxis compared with those without prophylaxis (4.1% vs. 10.4%; odds ratio, 0.35; 95% confidence interval, 0.25-0.47). Prophylaxis with palivizumab was associated with a reduction in all-cause mortality and respiratory syncytial virus hospitalization among preterm infants at high risk. Additional research on cause of death among infants at high risk is needed.

Parent preferences for pediatric influenza vaccine attributes.

Influenza vaccine is available as an intramuscular injection or an intranasal spray for eligible children. This study was conducted to examine parents' preferences for influenza vaccine attributes and the attributes' relative importance regarding the vaccination of their children. A quantitative Web survey was administered to 500 parents of children aged 2 to 12 years. The survey included general preference questions and conjoint (trade-off) questions. Parents most frequently selected efficacy, risk of temporary side effects, and physician recommendation as important vaccine attributes from a provided list (92%, 75%, and 59%, respectively). For attributes selected as important, parents rated the importance of the attribute; the highest mean importance ratings were given to efficacy, presence of mercury-containing preservative, and physician recommendation.The highest relative importance ratings in the conjoint section were given to efficacy and presence of mercury-containing preservative. Parental education on influenza vaccine efficacy and safety may help to improve pediatric vaccination rates.

Respiratory outcomes, utilization and costs 12 months following a respiratory syncytial virus diagnosis among commercially insured late-preterm infants.

OBJECTIVES: To determine, among a commercially-insured population of late-preterm infants, utilization of healthcare resources and costs during the 1 year following a diagnosis of respiratory syncytial virus lower respiratory infection (RSV LRI). METHODS: Administrative claims for non-capitated, commercially-insured infants <1 year old were used to identify infants diagnosed with RSV LRI and unspecified bronchiolitis/pneumonia (UBP). Infants were stratified by the setting of diagnosis. Infants without evidence of RSV LRI or UBP were selected as a comparison group. Economic and clinical outcomes were analyzed descriptively using propensity score weighting and logged ordinary least squares models were used to examine the relationship between RSV and costs (adjusted to 2006 USD) incurred within 1 year of RSV LRI. RESULTS: The majority of infants were 3 months or older at the time of RSV LRI or UBP diagnosis. The rate of wheezing was significantly greater for infants in the RSV LRI and UBP cohorts relative to the comparison group (p < 0.001). Infantile asthma rates were 6-9 times higher among RSV LRI and UBP infants than the comparison group. RSV LRI and UBP infants also had significantly more emergency department visits and outpatient visits than the comparison group. The marginal healthcare costs were significantly higher for RSV LRI inpatients ($24,027) and outpatients ($2703) infants than for the comparison group (all p < 0.001). CONCLUSION: Commercially insured late-preterm infants with RSV infection are at high risk for recurrent wheezing and infantile asthma during the 1-year period after the initial episode and impose a significant economic burden to the healthcare system.

Attending work while sick: implication of flexible sick leave policies.

OBJECTIVE: To examine the impact of various flexible sick leave policies (FSLPs) on workplace attendance of employees with self-reported "severe" influenza-like-illness (ILI) symptoms. METHODS: This is a prospective study of employees from three US employers, which involved collection of information on employees' access to FSLPs and monthly experience with ILI and workplace attendance from November 2007 to April 2008. Multivariate analyses were used to estimate the impact of FSLPs on employees' workplace attendance while they were experiencing severe ILI symptoms. RESULTS: Among 793 employees with ILI, the average duration of severe ILI symptoms was 3.0 days. Most employees (71.9%) attended work with severe ILI symptoms, for an average of 1.3 days. Employees who could telework had a 29.7% lower rate of attending work with severe ILI symptoms (P = 0.026). CONCLUSIONS: Employers that implement teleworking policies may be able to reduce employee-to-employee transmission of respiratory illness, including seasonal and pandemic influenza.

Employees' willingness to pay to prevent influenza.

OBJECTIVES: To quantify employees' preferences, as measured by willingness to pay, to prevent influenza in themselves and in their child and adult household members and to examine factors associated with willingness to pay. STUDY DESIGN: Prospective observational cohort study of a convenience sample of employees from 3 large US employers. Participants had at least 1 child (< or = 17 years) living in their household for at least 4 days per week. METHODS: Each month from November 2007 to April 2008, employees completed Web-based surveys regarding acute respiratory illness in their household. In the final survey, employees were presented with descriptions of influenza and questions regarding their willingness to pay to prevent influenza. Factors associated with willingness to pay were examined using multivariate ordinary least squares regression analysis of the log of willingness to pay. RESULTS: Among 2006 employees, 31.3% were female, the mean age was 41.7 years, 85.3% were of white race/ethnicity, and the mean household size was 4.0. Employees' median (mean) willingness to pay to prevent influenza was $25 ($72) for themselves, $25 ($82) for their adult household members, and $50 ($142) (P <.01) for children. However, influenza vaccination rates were approximately equal for children (27.5%), employees (31.5%), and other adult household members (24.5%). This finding may be explained by barriers such as cost, dislike of vaccinations, and disagreement with national influenza vaccination recommendations, which were significantly associated with lower willingness to pay for prevention of influenza (P <.05). CONCLUSION: Employees expressed a stronger preference to prevent influenza in their children than in themselves or other household members; however, modifiable barriers depress vaccination rates.

Parents' decision-making regarding vaccinating their children against influenza: A web-based survey.

BACKGROUND: Despite the recommendation from the Centers for Disease Control and Prevention that children between the ages of 6 months and 18 years be vaccinated against influenza annually, vaccination rates remain suboptimal. OBJECTIVES: This study was conducted to explore factors that influence parents' decisions regarding influenza vaccination for children aged 2 to 12 years, to quantify the relative importance of these factors, to identify an appropriate theoretical model for illustrating the relationships among these factors, and to characterize parents by their likelihood of vaccinating their children against influenza. METHODS: A quantitative Web-based survey was administered to a sample of parents from an online panel representative of the US population. Parents were stratified based on self-reported rates of their personal influenza vaccination (every year, sometimes, or never) and the age of their child (2-4 years or 5-12 years). The results were examined by parents' likelihood of vaccinating their child in the next year (high, medium, or low). Participants were asked to rank their agreement with statements representing various beliefs and perceptions about influenza and influenza vaccine on a scale from 1 = strongly agree to 5 = strongly disagree. Parents who indicated that they vaccinate their child every year were asked to select the drivers of their decision to vaccinate; parents who indicated that they never vaccinate their child were asked to select the barriers affecting their decision not to vaccinate; and parents who responded that they sometimes vaccinate their child were asked to select both the drivers and barriers affecting their decision. Participants were then asked to rank the importance of each driver or barrier on a scale from 1 = a little important to 5 = extremely important. Mean agreement ratings were calculated for parents' beliefs and perceptions about influenza and influenza vaccine and were compared across likelihood subgroups. Mean importance ratings of the drivers and barriers to vaccination were also calculated and compared across likelihood subgroups. RESULTS: The survey sample consisted of 500 parents; their mean (SD) age was 37.4 (6.82) years, 57.2% were female, and 78.2% were non-Hispanic white. Among those who reported that they vaccinated their child against influenza every year or sometimes, the major drivers of vaccination were prevention of influenza (95.1%), a doctor's recommendation (89.5%), and the desire to reduce influenza symptoms (83.3%). Among those who reported sometimes or never vaccinating their child against influenza, barriers to vaccination were more variable. The most common barriers were low perceived risk of influenza (46.0%), the perception that the vaccine caused influenza (44.0%), and side effects caused by the vaccine (36.6%). Distinct differences were found in beliefs and perceptions of influenza and influenza vaccine according to respondents' likelihood of vaccination. A high likelihood of vaccination was associated with a greater perceived threat of influenza and less concern about the efficacy and safety of the vaccine. Convenience was an important factor among parents with a medium likelihood of vaccination. The Health Belief Model was identified as an appropriate theoretical framework for illustrating the factors influencing parents' decision-making about influenza vaccination. CONCLUSIONS: Prevention of influenza, reduction of influenza symptoms, and doctor recommendation were the main drivers of parents' decision to vaccinate their child against influenza. Barriers to vaccination were more variable and primarily included the risk of adverse effects and the perceived low risk of influenza. Increasing parents' awareness of the threat of influenza and the efficacy and safety of the vaccine, as well as improving the convenience of getting vaccinated, may help improve rates of pediatric influenza vaccination.

Fatality rates in published reports of RSV hospitalizations among high-risk and otherwise healthy children.

OBJECTIVE: To review the fatalities among children hospitalized with respiratory syncytial virus (RSV) infection, and identify factors leading to a fatal outcome. RESEARCH DESIGN AND METHODS: Review of literature identified from a structured search of PubMed (1966-2009) using the following Medical Subject Headings: respiratory syncytial virus infection; hospitalized; infants; and risk factors. Publications were restricted to: English language; full papers; inclusion of > or =10 subjects; children aged < or =18 years, hospitalization for RSV infection; and deaths reported. Case fatality rates were defined as number of deaths divided by number of children hospitalized for RSV and were calculated for each study. RESULTS: Thirty-six studies met the inclusion and exclusion criteria. Case fatality rates among children hospitalized for RSV ranged from 0 to 33%. In general, studies showed that subgroups of high-risk children (chronic lung disease [CLD] 3.5-23%, congenital heart disease [CHD] 2-37%, and prematurity 0-6.1%) had higher fatality rates than older or otherwise healthy children (consistently <1%). Presence of severe underlying comorbidities such as neuromuscular disease, immunosuppression, and malignancies was associated with death among term and/or older (>1 year) children. Higher fatality rates were reported for infants receiving intensive unit care (1.1-8.6%), extracorporeal life support (33%) or for those who acquired nosocomial RSV infection (0-12.2%). The majority of studies did not report cause of death and clinical details of the fatal cases were often not provided. Other limitations of this review include our search limits, the possibility of inherent bias in our methodology that could result in an under or over estimation of case-fatality rates, and potential publication bias. CONCLUSIONS: Children at high risk for RSV (CLD, CHD and prematurity), those with severe underlying comorbidities, or those with nosocomial RSV appear to be at increased risk for death after RSV hospitalization. More data are needed on cause of death and how much is directly attributable to RSV.

Healthcare costs within a year of respiratory syncytial virus among Medicaid infants.

Limited research exists on the economic impact of respiratory syncytial virus lower respiratory infection (RSV LRI) among vulnerable infant populations. This study evaluated healthcare costs of full-term and late-preterm Medicaid infants with RSV LRI within 1 year of infection. Medicaid administrative claims were used to conduct a retrospective study of infants born 2003-2005. Full-term and late-preterm infants <1 year old were assigned to groups based on RSV LRI and unspecified bronchiolitis/pneumonia (UBP) diagnosis codes and stratified by setting of diagnosis. Infants without evidence of RSV LRI/UBP were selected as a comparison group. Economic and clinical outcomes were analyzed descriptively using propensity score weighting, and logged ordinary least squares models were used to examine relationship between RSV and costs incurred within 1 year of infection. RSV LRI and UBP infants, regardless of gestational age or healthcare setting, were more likely to experience respiratory diagnoses of wheezing and infantile asthma versus comparisons. Adjusted and weighted healthcare costs were significantly higher for all groups of RSV LRI and UBP infants relative to comparison infants (P < 0.001). Among late-preterm infants with inpatient and outpatient RSV, marginal costs compared with controls were $17,465 and $2,158, respectively. Costs for RSV LRI and UBP Medicaid infants are substantial. While much of the costs result from initial RSV episodes, higher post-episode costs and rates of respiratory events, procedures, and medications in RSV and UBP infants versus comparisons indicate long-term economic impact from infection and the impact is greater among late-preterm compared to full-term infants.