Factors associated with recruitment, surveillance participation, and retention in an observational study of pregnant women and influenza.

BACKGROUND: This report describes the results of recruitment efforts and the subsequent participation of pregnant women in study activities in a 2010-2012 observational study focused on influenza illness and vaccination in California and Oregon, USA. METHODS: Socio-demographic and health characteristics extracted from electronic medical records were compared among pregnant women who enrolled in the study, refused to participate, or were never reached for study invitation. These characteristics plus additional self-reported information were compared between women who enrolled in two study tracks: a prospective cohort vs. women enrolled following an acute respiratory illness (ARI) medical encounter. The characteristics of women who participated in weekly ARI surveillance (cohort enrollees, year one) and a 6-month follow-up interview (all enrollees) were also examined. RESULTS: In year one, we reached 51% (6938/13,655) of the potential participants we tried to contact by telephone, and 20% (1374/6938) of the women we invited agreed to join the prospective cohort. Women with chronic medical conditions, pregnancy complications, and medical encounters for ARI (prior to pregnancy or during the study period) were more likely to be reached for recruitment and more likely to enroll in the cohort. Twenty percent of cohort enrollees never started weekly surveillance reports; among those who did, reports were completed for 55% of the surveillance weeks. Receipt of the influenza vaccine was higher among women who joined the cohort (76%) than those who refused (56%) or were never reached (54%). In contrast, vaccine uptake among medical enrollees in year one (54%; 53/98) and two (52%; 79/151) was similar to other pregnant women in those years. Study site, white race, non-Hispanic ethnicity, and not having a child aged < 13 years at home were most consistently associated with joining as a cohort or medical enrollee and completing study activities after joining. CONCLUSIONS: We observed systematic differences in socio-demographic and health characteristics across different levels of participant engagement and between cohort and medical enrollees. More methodological research and innovation in conducting prospective observational studies in this population are needed, especially when extended participant engagement and ongoing surveillance are required.

Influenza and respiratory syncytial virus in infants study (IRIS) of hospitalized and non-ill infants aged <1 year in four countries: study design and methods.

BACKGROUND: This multi-country prospective study of infants aged <1 year aims to assess the frequency of influenza virus and respiratory syncytial virus (RSV) infections associated with hospitalizations, to describe clinical features and antibody response to infection, and to examine predictors of very severe disease requiring intensive care. METHODS/DESIGN: We are enrolling a hospital-based cohort and a sample of non-ill infants in four countries (Albania, Jordan, Nicaragua, and the Philippines) using a common protocol. We are currently starting year 2 of a 2- to 3-year study and will enroll approximately 3,000 infants hospitalized for any acute illness (respiratory or non-respiratory) during periods of local influenza and/or RSV circulation. After informed consent and within 24 h of admission, we collect blood and respiratory specimens and conduct an interview to assess socio-demographic characteristics, medical history, and symptoms of acute illness (onset ≤10 days). Vital signs, interventions, and medications are documented daily through medical record abstraction. A follow-up health assessment and collection of convalescent blood occurs 3-5 weeks after enrollment. Influenza and RSV infection is confirmed by singleplex real time reverse transcriptase polymerase chain reaction (rRT-PCR) assays. Serologic conversion will be assessed comparing acute and convalescent sera using hemagglutination inhibition assay for influenza antibodies and enzyme-linked immunosorbent assay (ELISA) for RSV. Concurrent with hospital-based enrollment, respiratory specimens are also being collected (and tested by rRT-PCR) from approximately 1,400 non-ill infants aged <1 year during routine medical or preventive care. DISCUSSION: The Influenza and RSV in Infants Study (IRIS) promises to expand our knowledge of the frequency, clinical features, and antibody profiles of serious influenza and RSV disease among infants aged <1 year, quantify the proportion of infections that may be missed by traditional surveillance, and inform decisions about the potential value of existing and new vaccines and other prevention and treatment strategies.

Severity of influenza and noninfluenza acute respiratory illness among pregnant women, 2010-2012.

OBJECTIVE: The objective of the study was to identify characteristics of influenza illness contrasted with noninfluenza acute respiratory illness (ARI) in pregnant women. STUDY DESIGN: ARI among pregnant women was identified through daily surveillance during 2 influenza seasons (2010-2012). Within 8 days of illness onset, nasopharyngeal swabs were collected, and an interview was conducted for symptoms and other characteristics. A follow-up telephone interview was conducted 1-2 weeks later, and medical records were extracted. Severity of illness was evaluated by self-assessment of 12 illness symptoms, subjective ratings of overall impairment, highest reported temperature, illness duration, and medical utilization. RESULTS: Of 292 pregnant women with ARI, 100 tested positive for influenza viruses. Women with influenza illnesses reported higher symptom severity than those with noninfluenza ARI (median score, 18 vs 16 of 36; P < .05) and were more likely to report severe subjective feverishness (18% vs 5%; P < .001), myalgia (28% vs 14%; P < .005), cough (46% vs 30%; P < .01), and chills (25% vs 13%; P < .01). More influenza illnesses were associated with fever greater than 38.9°C (20% vs 5%; P < .001) and higher subjective impairment (mean score, 5.9 vs 4.8; P < .001). Differences in overall symptom severity, fever, cough, chills, early health care-seeking behavior, and impairment remained significant in multivariate models after adjusting for study site, season, age, vaccination status, and number of days since illness onset. CONCLUSION: Influenza had a greater negative impact on pregnant women than noninfluenza ARIs, as indicated by symptom severity and greater likelihood of elevated temperature. These results highlight the importance of preventing and treating influenza illnesses in pregnant women.

Effectiveness of seasonal trivalent influenza vaccine for preventing influenza virus illness among pregnant women: a population-based case-control study during the 2010-2011 and 2011-2012 influenza seasons.

BACKGROUND: Although vaccination with trivalent inactivated influenza vaccine (TIV) is recommended for all pregnant women, no vaccine effectiveness (VE) studies of TIV in pregnant women have assessed laboratory-confirmed influenza outcomes. METHODS: We conducted a case-control study over 2 influenza seasons (2010-2011 and 2011-2012) among Kaiser Permanente health plan members in 2 metropolitan areas in California and Oregon. We compared the proportion vaccinated among 100 influenza cases (confirmed by reverse transcription polymerase chain reaction) with the proportions vaccinated among 192 controls with acute respiratory illness (ARI) who tested negative for influenza and 200 controls without ARI (matched by season, site, and trimester). RESULTS: Among influenza cases, 42% were vaccinated during the study season compared to 58% and 63% vaccinated among influenza-negative controls and matched ARI-negative controls, respectively. The adjusted VE of the current season vaccine against influenza A and B was 44% (95% confidence interval [CI], 5%-67%) using the influenza-negative controls and 53% (95% CI, 24%-72%) using the ARI-negative controls. Receipt of the prior season's vaccine, however, had an effect similar to receipt of the current season's vaccine. As such, vaccination in either or both seasons had statistically similar adjusted VE using influenza-negative controls (VE point estimates range = 51%-76%) and ARI-negative controls (48%-76%). CONCLUSIONS: Influenza vaccination reduced the risk of ARI associated with laboratory-confirmed influenza among pregnant women by about one-half, similar to VE observed among all adults during these seasons.

Applying the interactive systems framework to the dissemination and adoption of national and state recommendations for hypertension.

The Centers for Disease Control and Prevention (CDC), Division for Heart Disease and Stroke Prevention (DHDSP), commissioned an Institute of Medicine (IOM) report to identify the highest priority action areas for CDC, state health departments, and other public health partners in their efforts to reduce and control hypertension. To assess the dissemination and adoption of the IOM report recommendations, DHDSP developed an evaluation based on the Interactive Systems Framework for Dissemination and Implementation (ISF). The evaluation incorporates data collection at critical points across 3 years. In this article, we focus on the ISF systems to describe the role of funded state partners and their relationship with CDC in implementing public health recommendations. We describe baseline results for three data collection activities: (1) key informant interviews, (2) a Web-based survey, and (3) content analysis of state workplans to determine the degree of alignment with IOM recommendations. For example, currently 30 % of surveyed programs are implementing most (or all) of the recommendations in the IOM report, however 76 % intend to change hypertension program priorities based on the recommendations of the IOM report. Qualitative data suggest that there are several facilitators and barriers in implementing public health policy recommendations. DHDSP will use these baseline results to provide additional technical assistance and support to state health departments in their efforts to implement the IOM report's recommendations.

Trivalent inactivated influenza vaccine (IIV3) during pregnancy and six-month infant development.

OBJECTIVE: Despite recommendations by professional organizations that all pregnant women receive inactivated influenza vaccine, safety concerns remain a barrier. Our objective was to assess the effect of trivalent influenza vaccines (IIV3) during pregnancy on parent report 6-month infant development. METHODS: We conducted a multi-site prospective birth cohort study during the 2010-2011 influenza season and followed pregnant women and their newborns through 6 months of age. Information on IIV3 during pregnancy was ascertained from the EHR and self-report. The Ages and Stages Questionnaire-3 (ASQ-3) was completed by the mother to assess 6-month infant neurodevelopment in five domains (communication, gross motor, fine motor, problem-solving, and personal adaptive skills). Scores for each domain above the cut-off point indicating typical development were categorized as "on schedule" while scores in the zones indicating the need for either monitoring or further assessment were categorized as "not on schedule". Multivariable logistic regression was conducted. RESULTS: Of the 1225 infant-mother pairs, 65% received IIV3 during pregnancy. In bivariate analysis, infants of women who received IIV3 during pregnancy were moderately-less likely to need monitoring or further assessment in the personal social domain compared with infants of unvaccinated women (10.0% vs. 14.1%, p = 0.033; crude OR (cOR): 0.68(95%CI:0.48,0.97)). However, after controlling for potential confounders, the findings were no longer statistically significant (aOR:0.72,95%CI: 0.49,1.06,p = 0.46). No significant unadjusted or adjusted associations emerged in any other ASQ-3 domain. CONCLUSION: There was no significant association between IIV3 exposure during pregnancy and 6-month infant development. Studies of IIV3 during pregnancy to assess longer-term developmental outcomes are indicated.

Knowledge, attitudes and practices related to the influenza virus and vaccine among older adults in Eastern China.

BACKGROUND: This study aims to assess the association between socio-demographic and health characteristics of older adults in Eastern China and knowledge, attitudes, and practices (KAP) about the influenza virus and vaccine. METHODS: A prospective cohort of 1506 older adults (aged ≥60 years) was enrolled from November to December 2015 in Jiangsu Province. We examined the association between demographics, health and functional status, and cognitive impairment at enrollment with awareness of influenza virus and vaccine and KAP items focused on five Health Belief Model domains. At a 12-month follow-up interview we assessed change in awareness and readiness to be vaccinated. RESULTS: One in five older adults was aware of the influenza virus (21%) or vaccine (20%); even fewer reported having at least "a little" knowledge of the virus and vaccine (7% and 4%, respectively); less than 1% reported ever receiving an influenza vaccine. Retirement, higher education and income, and normal cognitive status were consistently associated with both awareness and knowledge of influenza virus. The odds of having at least "a little" knowledge of the vaccine was 2.9-fold (95% CI = 1.6-5.3) higher among older adults with at least some secondary schooling. Among the 108 with knowledge of the virus, 55% said they "worry about getting the flu this season." Among the 73 with knowledge of the vaccine, 92% believed the vaccine was at least somewhat effective and less than half (43%) thought that influenza vaccination was safe. At a 12-month follow-up interview, 33% (442/1333) increased from no knowledge to at least "a little". CONCLUSIONS: If and when influenza vaccines become widely available to older adults in China, our results indicate that influenza vaccination campaigns with basic information on the virus and vaccine could be beneficial for all older adults, especially those with less education and/or more cognitive impairment.

Predictors of Breastfeeding Initiation and Maintenance in an Integrated Healthcare Setting.

BACKGROUND: The American Academy of Pediatrics recommends exclusive breastfeeding to age 6 months. Although breastfeeding rates in the United States have been increasing over time, further improvements are needed to meet Healthy People 2020 targets. Research aim: This study examined predictors of breastfeeding initiation and maintenance among a population of insured pregnant women. METHODS: Participants were 1,149 pregnant women enrolled in the Pregnancy and Influenza Project in two Kaiser Permanente regions in 2010-2011. Data were collected through interviews at enrollment and 1 month and 6 months postpartum and through participants' electronic medical records. RESULTS: Nearly all (99%) women reported initiating breastfeeding. Rates of exclusive breastfeeding were 70% and 54% at 1 month and 6 months, respectively; an additional 22% and 23% of women reported supplementing breastfeeding with formula. Of the women who supplemented, the mean ( SD) infant age at formula introduction was 53 (62) days. Of those who had stopped breastfeeding, the mean ( SD) infant age at cessation was 85 (59) days. Higher maternal education level, better maternal self-rated health, prenatal folic acid use, absence of chronic medical conditions, and infant full-term birth were significantly associated with breastfeeding maintenance. CONCLUSION: Although rates of breastfeeding in this population were higher than national rates, a significant number of women stopped breastfeeding or introduced formula earlier than recommended. Two to 3 months postpartum may be a critical period warranting additional encouragement or intervention by healthcare providers. Mothers' education attainment, maternal health factors, and gestational age at delivery may predict likelihood of breastfeeding maintenance.

Cohort profile: the China Ageing REespiratory infections Study (CARES), a prospective cohort study in older adults in Eastern China.

PURPOSE: This study was established to provide direct evidence on the incidence of laboratory-confirmed influenza virus and respiratory syncytial virus (RSV) infections in older adults in two cities in Jiangsu Province, China, and the potential impact of acute respiratory infections on frailty. PARTICIPANTS: The cohort was enrolled in Suzhou and Yancheng, two cities in Jiangsu Province in Eastern China. Between November 2015 and March 2016, we enrolled 1532 adults who were 60-89 years of age, and collected blood samples along with baseline data on demographics, general health, chronic diseases, functional status and cognitive function through face-to-face interviews using a standardised questionnaire. Participants are being followed weekly throughout the year to identify acute respiratory illnesses. We schedule home visits to ill participants to collect mid-turbinate nasal and oropharyngeal swabs for laboratory testing and detailed symptom information for the acute illness. Regular follow-up including face-to-face interviews and further blood draws will take place every 6-12 months. FINDINGS TO DATE: As of 3 September 2016, we had identified 339 qualifying acute respiratory illness events and 1463 (95%) participants remained in the study. Laboratory testing is ongoing. FUTURE PLANS: We plan to conduct laboratory testing to estimate the incidence of influenza virus and RSV infections in older adults. We plan to investigate the impact of these infections on frailty and functional status to determine the association of pre-existing immune status with protection against influenza and RSV infection in unvaccinated older adults, and to assess the exposure to avian influenza viruses in this population.

Factors associated with seasonal influenza vaccination in pregnant women.

BACKGROUND: This observational study followed a cohort of pregnant women during the 2010-2011 influenza season to determine factors associated with vaccination. METHODS: Participants were 1105 pregnant women who completed a survey assessing health beliefs related to vaccination upon enrollment and were then followed to determine vaccination status by the end of the 2010-2011 influenza season. We conducted univariate and multivariate analyses to explore factors associated with vaccination status and a factor analysis of survey items to identify health beliefs associated with vaccination. RESULTS: Sixty-three percent (n=701) of the participants were vaccinated. In the univariate analyses, multiple factors were associated with vaccination status, including maternal age, race, marital status, educational level, and gravidity. Factor analysis identified two health belief factors associated with vaccination: participant's positive views (factor 1) and negative views (factor 2) of influenza vaccination. In a multivariate logistic regression model, factor 1 was associated with increased likelihood of vaccination (adjusted odds ratio [aOR]=2.18; 95% confidence interval [CI]=1.72-2.78), whereas factor 2 was associated with decreased likelihood of vaccination (aOR=0.36; 95% CI=0.28-0.46). After controlling for the two health belief factors in multivariate analyses, demographic factors significant in univariate analyses were no longer significant. Women who received a provider recommendation were about three times more likely to be vaccinated (aOR=3.14; 95% CI=1.99-4.96). CONCLUSION: Pregnant women's health beliefs about vaccination appear to be more important than demographic and maternal factors previously associated with vaccination status. Provider recommendation remains one of the most critical factors influencing vaccination during pregnancy.

The association between influenza vaccination and other preventative health behaviors in a cohort of pregnant women.

OBJECTIVES: Although pregnant women are a high-priority group for seasonal influenza vaccination, vaccination rates in this population remain below target levels. Previous studies have identified sociodemographic predictors of vaccine choice, but relationships between preconception heath behaviors and seasonal influenza vaccination are poorly understood. This prospective cohort study followed pregnant women during the 2010-2011 influenza season to determine if certain health behaviors were associated with vaccination status. METHOD: Participants were pregnant women receiving prenatal care from Kaiser Permanente Northwest and Kaiser Permanente Northern California. Women were surveyed about preconception smoking, alcohol consumption, and vitamin/supplement use. Vaccination data were obtained from health plan databases and state immunization records. RESULTS: Data from 1,204 women were included in this analysis. Most participants (1,204; 66.4%) received a seasonal influenza vaccine during the study period. Women vaccinated prior to pregnancy were more likely to use a supplement containing folic acid (80%) or vitamin D (30%) compared with women who were vaccinated during pregnancy (72% and 15%, respectively) or unvaccinated women (62% and 12%, respectively, p < .001). Women vaccinated prior to or during pregnancy were more likely (75%) to have never smoked compared with women who were not vaccinated (70%, p = .005). There were no significant differences in alcohol use or household cigarette smoke exposure by vaccination group. CONCLUSIONS: Women who engaged in specific preconception health behaviors were more likely to receive seasonal influenza vaccination. Failure to participate in these health behaviors could alert health care practitioners to patients' increased risk of remaining unvaccinated during pregnancy.

Results of a pilot study using self-collected mid-turbinate nasal swabs for detection of influenza virus infection among pregnant women.

BACKGROUND: We evaluated the feasibility of asking pregnant women to self-collect and ship respiratory specimens. METHODS: In a preliminary laboratory study, we compared the RT-PCR cycle threshold (CT) values of influenza A and B viruses incubated at 4 storage temperatures (from 4 to 35°C) for 6 time periods (8, 24, 48, 72, and 168 hours and 30 days), resulting in 24 conditions that were compared to an aliquot tested after standard freezing (-20°C) (baseline condition). In a subsequent pilot study, during January-February, 2014, we delivered respiratory specimen collection kits to 53 pregnant women with a medically attended acute respiratory illness using three delivery methods. RESULTS: CT values were stable after storage at temperatures <27°C for up to 72 hours for influenza A viruses and 48 hours for influenza B viruses. Of 53 women who received kits during the pilot, 89% collected and shipped nasal swabs as requested. However, 30% (14/47) of the women took over 2 days to collect and ship their specimen. The human control gene, ribonuclease P (RNase P), was detected in 100% of nasal swab specimens. However, the mean CT values for RNase P (26.5, 95% confidence interval [CI] = 26.0-27.1) and for the 8 influenza A virus positives in our pilot (32.2, 95% CI = 28.9-35.5) were significantly higher than the CTs observed in our 2010-2012 study using staff-collected nasal pharyngeal swabs (P-values < 0.01). DISCUSSION: Self-collection of respiratory specimens is a promising research method, but further research is needed to quantify the sensitivity and specificity of the approach.

Safety of influenza vaccination during pregnancy: a review of subsequent maternal obstetric events and findings from two recent cohort studies.

Pregnant women and their infants are vulnerable to severe disease and secondary complications from influenza infection. For this reason, annual influenza vaccination is recommended for all pregnant women in the United States. Women frequently cite concerns about vaccine safety as a barrier to vaccination. This review describes the safety of inactivated influenza vaccination during pregnancy with a focus on maternal obstetric events, including hypertensive disorders, gestational diabetes, and chorioamnionitis. Included in the review are new findings from two studies which examined the safety of seasonal inactivated influenza vaccination during pregnancy. The first study enrolled 641 pregnant women during the 2010-2011 season and prospectively followed them until delivery or pregnancy termination. The second study enrolled 1616 pregnant women during the 2010-2011 influenza season, and followed the women and their infants for six months after delivery. No associations between inactivated influenza vaccination and gestational diabetes, gestational hypertension, preeclampsia/eclampsia, or chorioamnionitis were observed in either cohort. When considered as a whole, these studies should further reassure women and clinicians that influenza vaccination during pregnancy is safe for mothers.