Retention strategies and predictors of attrition in an urban pediatric asthma study

T cell hybrid immunity against SARS-CoV-2 in children: a longitudinal study

BACKGROUND

Hybrid immunity to SARS-CoV-2, resulting from both vaccination and natural infection, remains insufficiently understood in paediatric populations, despite increasing rates of breakthrough infections among vaccinated children.

METHODS

We conducted a prospective longitudinal study to investigate the magnitude, specificity, and cytokine profile of antigen-specific T cell responses elicited by breakthrough SARS-CoV-2 infection in a cohort of mRNA-vaccinated children (n = 29) aged 5-11. This longitudinal analysis involved six distinct time points spanning a 16-month period post-vaccination, during which we analysed a total of 159 blood samples. All children who were followed for at least 12 months (n = 26) experienced a breakthrough infection. We conducted cytokine release assays using minimal blood samples, and we verified the cellular origin of these responses through intracellular cytokine staining.

FINDINGS

After breakthrough infection, children who had received mRNA vaccines showed enhanced Th1 responses specific to Spike peptides. Additionally, their Spike-specific T cells exhibited a distinctive enrichment of CD4+ IFN-γ+IL10+ cells, a characteristic akin to adults with hybrid immunity. Importantly, vaccination did not impede the development of multi-specific T cell responses targeting Membrane, Nucleoprotein, and ORF3a/7/8 antigens.

INTERPRETATION

Children, previously primed with a Spike-based mRNA vaccine and experiencing either symptomatic or asymptomatic breakthrough infection, retained the ability to enhance and diversify Th1/IL-10 antigen-specific T cell responses against multiple SARS-CoV-2 proteins. These findings mirror characteristics associated with hybrid cellular immunity in adults, known to confer resistance against severe COVID-19.

FUNDING

This study was funded by the National Medical Research Council (NMRC) Singapore (COVID19RF-0019, MOH-000019, MOH-000535, OFLCG19May-0034 and MOH-OFYIRG19nov-0002).

Structures and Strategies for Retaining an International Pediatric Cohort from Birth: Lessons from The Environmental Determinants of Diabetes in the Young (TEDDY) Study

Background

Retention of study participants in observational studies is essential to maintaining the representativeness of the population, minimizing selection bias, and assuring sufficient statistical power. The aim of this report is to describe the structures and strategies used to retain participants in The Environmental Determinants of Diabetes in the Young (TEDDY) Study, an observational study of children at increased genetic risk for type 1 diabetes followed in an intense protocol with frequent clinic visits from birth until age 15.

Methods

A systematic review of methodologies used to retain research subjects identified four domains: barrier reduction strategies; community building strategies; follow-up/reminder strategies; and tracing strategies. Independent reviewers categorized the retention strategies implemented by the TEDDY Study into each of these domains. Strategies not fitting into any of these categories were placed into a fifth category unique to TEDDY.

Results

TEDDY identified over one hundred retention strategies used during the 15 years of follow-up; most could be categorized in these domains. Those unique to TEDDY included (1) study organization and structures to support retention; (2) efforts to meet the changing developmental needs of the TEDDY population, (3) implementation of efforts to address protocol challenges in real-time; and (4) employment of a re-engagement protocol for those who had dropped out of the study.

Conclusion

Pediatric cohort studies should include strategies, structures, and resources addressing retention at the study's initiation. It is recommended that child and parent engagement in addition to the developmental needs of the child be an integrated focus of all strategies. Putting mechanisms in place to address protocol and retention challenges in real time would facilitate effectively addressing challenges as they arise.

Trial registration

ClinicalTrials.gov Identifier: NCT00279318.

Pre-notifications increase retention in a 17-year follow-up of adolescents born very preterm

OBJECTIVE

Retention is essential in follow-up studies to reduce missing data, which can cause bias and limit the generalizability of the results. We investigated whether pre-notification letters would increase the response rates of approval forms and questionnaires and reduce the need for post-notifications in a prospective follow-up study of 17-year-old adolescents.

STUDY DESIGN

and settings This long-term follow-up study included 269 adolescents were randomized (1:1) into a pre-notification group (n = 132) and a no pre-notification group (n = 137). The pre-notification letter was sent prior to the approval form and questionnaires. The outcome measures were the response rates to the approval forms and questionnaires and the rate of post-notifications required.

RESULTS

The adolescents who received the pre-notifications were more likely to return approval forms (n = 88/132, 67%) than the adolescents who did not receive the pre-notifications (n = 79/137, 58%) (OR 1.5, 95% CI 0.9-2.4). The rates of returned questionnaires were higher in the pre-notification group (n = 82/88, 93%) than in the no pre-notification group (n = 68/79, 86%) (OR 2.2, 95% CI 0.8-6.3). The adolescents who did not receive the pre-notifications were more likely to need the post-notifications than the adolescents who received the pre-notifications (OR 3.0, 95% CI 1.4 to 6.5).

CONCLUSIONS

Pre-notifications decreased the need for post-notifications and may increase retention in 17-year-old adolescents. Based on our findings, pre-notification letters are recommended in future follow-up studies in adolescents.

TRIAL REGISTRATION

The Ethics Review Committee of the Hospital District of South-West Finland approved the 17-year PIPARI Study protocol in January 2018 (23.1.2018; 2/180/2012). The study has been registered to the SWAT repository as SWAT 179. Filetoupload,1457904,en.pdf (qub.ac.uk).

Relationship Between Social Vulnerability Indicators and Trial Participant Attrition: Findings From the HYVALUE Trial

BACKGROUND

Social vulnerability indicators are associated with health care inequities and may similarly impede ongoing participation in research studies. We evaluated the association of social vulnerability indicators and research participant attrition in a trial focused on reducing health disparities.

METHODS

Self-identified White or Black adults enrolled in the HYVALUE trial (Hypertension and VALUEs), a randomized trial testing a values-affirmation intervention on medication adherence, from February 2017 to September 2019 were included. The self-reported measures of social vulnerability indicators included: (1) Black race; (2) female gender; (3) no health insurance; (4) unemployment; (5) a high school diploma or less; and (6) financial-resource strain. Full attrition was defined as not completing at least one 3- or 6-month follow-up study visit. Log-binomial regression models adjusted for age, gender, race, medical comorbidities, and the other social vulnerability indicators to estimate the relative risk of each social vulnerability indicator with study attrition.

RESULTS

Among 825 participants, the mean age was 63.3 years (±11.7 years), 60% were women, 54% were Black, and 97% reported at least one social vulnerability. Overall, 21% participants had full attrition after study enrollment. After adjustment for all other social vulnerabilities, only financial-resource strain remained consistently associated with full attrition (relative risk, 1.71 [95% CI, 1.28-2.29]). In a secondary analysis of partial attrition (completed only one follow-up visit), financial-resource strain (relative risk, 1.40 [95% CI, 1.09-1.81]) and being uninsured (relative risk, 1.54 [95% CI, 1.01-2.34]) were associated with partial attrition.

CONCLUSIONS

In a trial aimed at reducing disparities in medication adherence, participants who reported financial-resource strain had a higher risk of participant attrition independent of race or gender. Our findings suggest that efforts to retain diverse populations in clinical trials should extend beyond race and gender to consider other social vulnerability indicators.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT03028597.

Pediatric Participant Retention Rates in a Longitudinal Malaria Immunology Study

The resurgence of drug-resistant Plasmodium falciparum parasites continues to motivate the development of a safe and efficacious malaria vaccine. Immuno-epidemiologic studies of naturally acquired immunity (NAI) have been a useful strategy to identify new malaria vaccine targets. However, retention of pediatric participants throughout longitudinal studies is essential for gathering comprehensive exposure and outcome data. Within the context of a 3-year cohort (N = 400) study involving monthly finger prick and bi-annual venous blood sample collections, we conducted qualitative surveys to assess factors impacting participant retention. Phase 1 was conducted 3 months after enrollment in July 2018 and phase 2, 12 months later. In phase 1, 236 parents/guardians participated in focus groups and three withdrawn participants and 10 community health volunteers (CHVs) in key informant interviews. Qualitative analysis indicated overall satisfaction with the study, with 61.8% (136/220 respondents) reporting no concerns. Focus group discussants associated attendance with benefits such as improved access to comprehensive healthcare services. Community health volunteers reported concerns over village rumors of inappropriate use of blood samples and dangers associated with venous blood draws. Phase 2 involved 205 parents/guardians and revealed continued satisfaction, with 46.3% (95/205) identifying no concerns, but expressed increasing worries regarding the amount of venous blood sample. This concern was reflected in an uptick of missed visits when venous blood samples were scheduled. Future studies will address parental concerns to determine whether community engagement and education measures increase study retention until completion.

Preventing asthma in high risk kids (PARK) with omalizumab: Design, rationale, methods, lessons learned and adaptation

Asthma remains one of the most important challenges to pediatric public health in the US. A large majority of children with persistent and chronic asthma demonstrate aeroallergen sensitization, which remains a pivotal risk factor associated with the development of persistent, progressive asthma throughout life. In individuals with a tendency toward Type 2 inflammation, sensitization and exposure to high concentrations of offending allergens is associated with increased risk for development of, and impairment from, asthma. The cascade of biological responses to allergens is primarily mediated through IgE antibodies and their production is further stimulated by IgE responses to antigen exposure. In addition, circulating IgE impairs innate anti-viral immune responses. The latter effect could magnify the effects of another early life exposure associated with increased risk of the development of asthma - viral infections. Omalizumab binds to circulating IgE and thus ablates antigen signaling through IgE-related mechanisms. Further, it has been shown restore IFN-α response to rhinovirus and to reduce asthma exacerbations during the viral season. We therefore hypothesized that early blockade of IgE and IgE mediated responses with omalizumab would prevent the development and reduce the severity of asthma in those at high risk for developing asthma. Herein, we describe a double-blind, placebo-controlled trial of omalizumab in 2-3 year old children at high risk for development of asthma to prevent the development and reduce the severity of asthma. We describe the rationale, methods, and lessons learned in implementing this potentially transformative trial aimed at prevention of asthma.

A community-based asthma program: Study design and methods of RVA Breathes

Disparities in pediatric asthma morbidity and healthcare utilization exist on the basis of race, ethnicity, environment, and income; interventions are needed to address these inequities. The following protocol describes an evidence-based intervention, RVA Breathes, designed to coordinate pediatric asthma care across family, home, community, and medical sectors. Community stakeholder feedback was utilized to refine the intervention specifically for the Richmond, Virginia community. The aims of this study are to assess the effect of RVA Breathes on asthma-related healthcare utilization, as well as secondary outcomes of asthma control, asthma symptoms, and quality of life. We will enroll 300 elementary school children from the Richmond City Public School system. Participants will be between the ages of 5-11, have a diagnosis of asthma, and have had an asthma exacerbation (as indicated by an asthma-related ED visit, hospitalization, unscheduled PCP visit, or use of systemic steroids) in the last two years. Participants will be randomized to one of three groups: asthma education + home environment remediation + school intervention, asthma education + home environment remediation, or a comparator condition. Data will be collected across one baseline research visit, four intervention sessions, and four follow-up research visits over the course of 18 months. A General Linear Mixed Model (GLMM) will be used to test primary aims. We expect the findings will provide support for coordination of asthma care across sectors. Further, we hope RVA Breathes will serve as a model of community-based pediatric asthma care.

Prädiktoren der Teilnahmebereitschaft von Jugendlichen in Langzeitstudien: Ergebnisse der Ohrkan Kohortenstudie zur Freizeitlärmexposition

Hintergrund und Ziel In Kohortenstudien kann der Verlust von Teilnehmern während der Nachbeobachtungsphasen zu Verzerrungen führen, wenn sich Teilnehmer und Nichtteilnehmer unterscheiden. Viele Studien haben den Einfluss soziodemografischer und gesundheitlicher Faktoren auf die Teilnahmebereitschaft untersucht, es liegen jedoch nur relativ wenige Studien für schulbasierte Kohorten vor. Ziel dieser Arbeit ist die Bestimmung von Prädiktoren der Teilnahmebereitschaft im Rahmen der Ohrkan Kohortenstudie, die die Exposition von Jugendlichen gegenüber Freizeitlärm und mögliche Effekte auf das Hörvermögen im Zeitverlauf untersucht.

Methoden Die Daten dieser Studie basieren auf den Angaben der Ohrkankohorte (n=2148), die 2009–2011 (O-I) unter den Neuntklässlern weiterführender Schulen in Regensburg rekrutiert und 2012–14 (O-II) und 2015–16 (O-III) nachbefragt wurde.

Ergebnisse Die Teilnahmewahrscheinlichkeit in O-II und O-III war höher für Personen ohne Migrationshintergrund, die zu Studienbeginn das Gymnasium besuchten und deren Eltern ein höheres Bildungsniveau hatten oder zusammenlebten. Auch nahmen Personen, die in den letzten 2,5 Jahren ihren Wohnort nicht gewechselt hatten, 3-mal so häufig teil wie Befragte mit Wohnortwechsel.

Schlussfolgerung Die Kenntnis von Merkmalen der Studienteilnehmer, die die Teilnahmebereitschaft vorhersagen, ermöglicht durch gezielte Ansprache den Verlust von Studienteilnehmern zu reduzieren bzw. die statistische Korrektur von fehlenden Daten.

Participant retention in follow-up studies of prematurely born children

Background

Follow-up studies of infants born prematurely are essential to understand the long-term consequences of preterm birth and the efficacy of interventions delivered in the neonatal period. Retention of participants for follow-up studies, however, is challenging, with attrition rates of up to 70%. Our aim was to examine retention rates in two follow-up studies of prematurely born children and identify participant or study characteristics that were associated with higher attrition, and to discuss retention strategies with regard to the literature.

Methods

Data from children recruited at birth to one of two studies of prematurely born infants were assessed. The two studies were the United Kingdom Oscillation Study (UKOS, a randomised study comparing two modes of neonatal ventilation in infants born less than 29 weeks of gestational age (GA)), and an observational study examining the impact of viral lower respiratory tract infections in infancy in those born less than 36 weeks of GA (virus study). The UKOS participants, but not those in the virus study, had regularly been contacted throughout the follow-up period. UKOS subjects were followed up at 11 to 14 years of age and subjects in the virus study at 5–7 years of age. At follow up in both studies, pulmonary function and respiratory morbidity were assessed. Retention rates to follow-up in the two studies and baseline characteristics of those who were and were not retained were assessed.

Results

Retention was significantly higher in UKOS than the virus study (61% versus 35%, p < 0.0001). Subjects lost to UKOS follow up had greater deprivation scores (p < 0.001), a greater likelihood of intrauterine tobacco exposure (p = 0.001) and were more likely to be of non-white ethnicity (p < 0.001). In the virus study, those lost to follow-up had higher birth weights (p = 0.036) and were less likely to be oxygen dependent at hospital discharge (p = 0.003) or be part of a multiple birth (p = 0.048).

Conclusions

Higher retention was demonstrated when there was regular contact in the follow-up period. Both social factors and initial illness severity affected the retention into follow-up studies of prematurely born infants, though these factors were not consistent across the two studies.

Recruitment and retention of the Hardest-to-Reach families in community-based asthma interventions

BACKGROUND/AIMS

Engaging underserved populations in research requires substantial effort for recruitment and retention. The objective of this study is to describe the effort needed to recruit and retain urban participants in pediatric asthma studies and to characterize the Hardest-to-Reach group by demographics and asthma severity.

METHODS

We included 311 children (3-10 years) with persistent asthma enrolled in two school-based asthma interventions in Rochester, NY. Contact logs were collected at four time points (baseline, 2 month, 4 month, 6 month). We defined "Hardest-to-Reach" (vs "Easier-to-Reach") as being unable to reach a family by telephone at any given contact attempt due to disconnected or wrong numbers. Chi-square and Mann-Whitney tests were used to compare groups.

RESULTS

Overall, we enrolled 311 children (60% Black, 29% Hispanic, 70% Medicaid, response rate 70%). On average, 3.1 contact attempts were required for recruitment (range 1-15), and 35% required rescheduling at least once for the enrollment visit. All but 12 participants completed each follow-up (retention rate = 96%). Completion of follow-ups required an average of 7.6 attempts; we considered 38% of caregivers "Hardest-to-Reach." Caregivers in the Hardest-to-Reach group were slightly younger (33 vs 36 years, p = 0.007) with more depressive symptoms (41% vs 29%, p = 0.035) and smokers in the home (59% vs 48%, p = 0.048). Furthermore, more of the Hardest-to-Reach children had moderate-severe versus mild persistent asthma (64% vs 52%, p = 0.045). Importantly, even the Easier-to-Reach families required many contact attempts, with 52% having >5 attempts for at least one follow-up.

CONCLUSION

In conclusion, we found that among an already vulnerable population, the Hardest-to-Reach families demonstrated higher risk and had children with significantly worse asthma. This study highlights the importance of persistence in reaching those in greatest need.

Age, HIV status, and research context determined attrition in a longitudinal cohort in Nigeria

OBJECTIVES

We explored determinants of attrition in a longitudinal cohort study in Nigeria.

STUDY DESIGN AND SETTING

We enrolled 1,020 women into a prospective study. Of these, 973 were eligible to return for follow-up. We investigated the determinants of attrition among eligible women using a sequential mixed methods design. We used logistic regression models to compare the baseline characteristics of responders and nonresponders. At the end of the parent study, we conducted four focus group discussions and eight key informant interviews with nonresponders.

RESULTS

Of the 973 women included in the quantitative analysis, 26% were nonresponders. From quantitative analysis, older women were less likely to drop out than younger women (reference: women ≤30 years; OR 0.46; 95% confidence interval [CI] 0.30-0.70, P < 0.001 women 31-44 years; and OR 0.31; 95% CI 0.17-0.56, P < 0.001 women ≥45 years). HIV-positive women were also less likely to drop out of the study (OR 0.45; 95% CI 0.33-0.63, P < 0.001). From qualitative analysis, contextual factors that influenced attrition were high cost of participation, therapeutic misconceptions, inaccurate expectations, spousal disapproval, unpleasant side effects, challenges in maintaining contact with participants, and participant difficulties in locating the study clinic.

CONCLUSION

Several participant-, research-, and environment-related factors influence attrition. Retention strategies that address these barriers are important to minimize attrition.

Demographic and Operational Factors Predicting Study Completion in a Multisite Case-Control Study of Preschool Children

Participant attrition can limit inferences drawn from study results and inflate research costs. We examined factors associated with completion of the Study to Explore Early Development (2007-2011), a multiple-component, case-control study of risk factors for autism spectrum disorder in preschoolers, conducted in California, Colorado, Georgia, Maryland, North Carolina, and Pennsylvania. Participants (n = 3,769) were asked to complete phone interviews, questionnaires, an in-person evaluation, and biologic sampling. We examined whether participant demographic and administrative factors predicted completion using mixed-effects logistic regression models. Completion of individual key study components was generally 70% or higher. However, 58% of families completed all per-protocol data elements (defined a priori as key study components). Per-protocol completion differed according to mother's age, race, educational level, driving distance to clinic, number of contact attempts to enroll, and number of telephone numbers provided (all P < 0.05). Case status was not associated with completion, despite additional data collection for case-confirmation. Analysis of a subset that completed an early interview revealed no differences in completion by household factors of income, primary language spoken, number of adults, or number of children with chronic conditions. Differences in completion by race and education were notable and need to be carefully considered in developing future recruitment and completion strategies.

Respiratory viral infections in infancy and school age respiratory outcomes and healthcare costs

OBJECTIVES

To determine the impact of viral lower respiratory tract infections (LRTIs) in infancy including rhinovirus (RV) and infancy respiratory syncytial virus (RSV), on school age pulmonary function and healthcare utilization in prematurely born children.

WORKING HYPOTHESIS

School age respiratory outcomes would be worse and healthcare utilization greater in children who had viral LRTIs in infancy.

STUDY DESIGN

Prospective study.

SUBJECT SELECTION

A cohort of prematurely born children who had symptomatic LRTIs during infancy documented, was recalled.

METHODS

Pulmonary function was assessed at 5 to 7 years of age and health related costs of care from aged one to follow-up determined.

RESULTS

Fifty-one children, median gestational age 33⁺⁶ weeks, were assessed at a median (IQR) age 7.03 (6.37-7.26) years. Twenty-one children had no LRTI, 14 RV LRTI, 10 RSV LRTI, and 6 another viral LRTI (other LRTI). Compared to the no LRTI group, the RV group had a lower FEV₁ (P = 0.033) and the other LRTI group a lower FVC (P = 0.006). Non-respiratory medication costs were higher in the RV (P = 0.018) and RSV (P = 0.013) groups. Overall respiratory healthcare costs in the RV (£153/year) and RSV (£27/year) groups did not differ significantly from the no LRTI group (£56/year); the other LRTI group (£431/year) had higher respiratory healthcare costs (P = 0.042).

CONCLUSIONS

In moderately prematurely born children, RV and RSV LRTIs in infancy were not associated with higher respiratory healthcare costs after infancy. Children who experienced LRTIs caused by other respiratory viruses (including RV) had higher respiratory healthcare costs and greater pulmonary function impairment.

Effect of Physical Activity on Cognitive Development: Protocol for a 15-Year Longitudinal Follow-Up Study

The aim of the study is to investigate the relationship between physical activity as assessed by accelerometers and cognitive development across the human age ranges (from children and adolescents to adults). Additionally, this study seeks to explore whether physical activity contributes to cognitive development via modification of plasma insulin-like growth factor 1 (IGF-1) and brain-derived neurotrophic factor (BDNF). In the study, 500 preschool children (3.5–5.5 years old) are taking part in 6 triennial assessment waves over the span of 15 years. At each wave, participant measures included (a) 7-day physical activity monitoring using ActiGraph's GT3X accelerometers, (b) the evaluation of cognitive development, (c) anthropometric and physical fitness assessments, (d) plasma IGF-1 and BDNF concentrations, and (e) retrospective questionnaires. Linear regression models are used to examine the effect of physical activity on cognitive development; plasma IGF-1 and BDNF concentrations are considered as mediators into data analyses. The results of the study may help to inform future health interventions that utilize physical activity as a means to improve cognitive development in children, adolescents, and adults. Additionally, the study may assist in determining whether the putative effects occur via modification of plasma IGF-1 or BDNF concentrations.

Contactable Non-responders Show Different Characteristics Compared to Lost to Follow-Up Participants: Insights from an Australian Longitudinal Birth Cohort Study

Objective This research aims to identify predictors of attrition in a longitudinal birth cohort study in Australia and assess differences in baseline characteristics and responses in subsequent follow-up phases between contactable non-responders and uncontactable non-responders deemed "lost to follow-up (LTF)". Methods 3368 women recruited from three public hospitals in Southeast Queensland and Northern New South Wales during antenatal visits in 2006-2011 completed a baseline questionnaire to elicit information on multiple domains of exposures. A follow-up questionnaire was posted to each participant at 1 year after birth to obtain mother's and child's health and development information. Multivariate logistic regression was used to model the association between exposures and respondents' status at 1 year. The effect of an inverse-probability-weighting method to adjust for non-response was studied. Results Overall attrition at 1-year was 35.4 %; major types of attrition were "contactable non-response" (27.6 %) and "LTF" (6.7 %). These two attrition types showed different responses at the 3-year follow-up and involved different predictors. Besides shared predictors (first language not English, higher risk of psychological distress, had smoked during pregnancy, higher levels of family conflict), distinguishable predictors of contactable non-responders were younger age, having moved home in the past year and having children under 16 in the household. Attrition rates increased substantially from 20 % in 2006 to 54 % in 2011. Conclusions This observed trend of increased attrition rates raises concern about the use of traditional techniques, such as "paper-based" questionnaires, in longitudinal cohort studies. The supplementary use of electronic communications, such as online survey tools and smart-device applications, could provide a better alternative.

Lessons learned on recruitment and retention in hard-to-reach families in a phase III randomised controlled trial of preparatory information for children undergoing general anaesthesia

BACKGROUND

Recruitment and retention are documented as two of the most difficult elements of conducting clinical trials. These issues are even more challenging in paediatric trials, particularly when the families being recruited and retained are deemed 'hard to reach'.

METHODS

Through the authors' own reflection on the conduct of the trial this paper examines recruitment and retention with hard to reach families from the perspective of a recently completed clinical trial on preparatory information for children undergoing general anaesthesia for tooth extractions in which approximately 83% of those approached and eligible agreed to participate.

RESULTS

The lessons learned for recruitment include: the importance of children's assent; maximising limited resources when screening and approaching potential participants; valuing families' time; and developing effective professional relationships. The retention rate was 83-85.5% at follow up time points up to 3.5 weeks following recruitment, insights into how this was accomplished include: ensuring continuity of care; determination to connect via telephone; valuing families' time; and close monitoring of appointment date changes.

CONCLUSIONS

Implications for future paediatric trials with hard to reach families are discussed.

TRIAL REGISTRATION

ISRCTN18265148 ; NIHR Portfolio 10,006. Date of Registration: 29 November 2013. The trial was registered after commencement but before completion of data collection.

Predictors of successful telephone follow-up in a multicenter study of infants with severe bronchiolitis

PURPOSE

To identify the characteristics that predict successful telephone follow-up with parents of infants with severe bronchiolitis.

METHODS

We analyzed data from a 17-center, prospective cohort study of infants (age <1 year) hospitalized with bronchiolitis during three consecutive fall/winter seasons. Participant contact information and clinical data were collected during the index hospitalization. Parents were called at 6-month intervals (based on the child's age) after discharge to assess respiratory problems. The primary outcome was age 12-month telephone interview status. Participants were classified as unreachable after 28 days of unsuccessful attempts.

RESULTS

798 of 916 children (87%) completed the age 12-month telephone interview. In unadjusted analyses, factors associated with successful follow-up included: private health insurance, annual household income $60,000 or more, and residing in the Northeast, Midwest, or West. Follow-up was less common among non-Hispanic blacks, Hispanics, and households with 3 or more children. In multivariable analyses, follow-up was more likely among parents of females, and, compared with the South, in the Northeast and Midwest (all P < .05). Compared with non-Hispanic whites, non-Hispanic blacks and Hispanics remained less likely to complete the interview as did households with 3 or more children (all P < .05).

CONCLUSION

Sociodemographic and geographic factors predict successful telephone follow-up, even among parents of infants with severe illness.

The School Inner-City Asthma Intervention Study: Design, rationale, methods, and lessons learned

Asthma is the most common chronic disease of childhood in the United States, causes significant morbidity, particularly in the inner-city, and accounts for billions of dollars in health care utilization. Home environments are established sources of exposure that exacerbate symptoms and home-based interventions are effective. However, elementary school children spend 7 to 12h a day in school, primarily in one classroom. From the observational School Inner-City Asthma Study we learned that student classroom-specific exposures are associated with worsening asthma symptoms and decline in lung function. We now embark on a randomized, blinded, sham-controlled school environmental intervention trial, built on our extensively established school/community partnerships, to determine the efficacy of a school-based intervention to improve asthma control. This factorial school/classroom based environmental intervention will plan to enroll 300 students with asthma from multiple classrooms in 40 northeastern inner-city elementary schools. Schools will be randomized to receive either integrated pest management versus control and classrooms within these schools to receive either air purifiers or sham control. The primary outcome is asthma symptoms during the school year. This study is an unprecedented opportunity to test whether a community of children can benefit from school or classroom environmental interventions. If effective, this will have great impact as an efficient, cost-effective intervention for inner city children with asthma and may have broad public policy implications.

A successful approach to minimizing attrition in racial/ethnic minority, low-income populations

BACKGROUND

Recruiting and retaining minority participants in clinical trials continue to be major challenges. Although multiple studies document lower minority trial enrollment, much less is known about effective minority retention strategies. Our objectives were to evaluate an innovative approach to high RCT retention of minority children, and identify child/caregiver characteristics predicting attrition.

METHODS

The Kids' HELP trial examined the effects of Parent Mentors on insuring uninsured minority children. We tested a retention strategic framework consisting of: 1) optimizing cultural/linguistic competency; 2) staff training on participant relationships and trust; 3) comprehensive participant contact information; 4) an electronic tracking database; 5) reminders for upcoming outcomes-assessment appointments; 6) frequent, sustained contact attempts for non-respondents; 7) financial incentives; 8) individualized rapid-cycle quality-improvement approaches to non-respondents; 9) reinforcing study importance; and 10) home assessment visits. We compared attrition in Kids' HELP vs. two previous RCTs in similar populations, and conducted bivariate and multivariable analyses of factors associated with Kids' HELP attrition.

RESULTS

Attrition in Kids' HELP was lower than in two similar RCTs, at 10.9% vs. 37% and 40% (P <0.001). After multivariable adjustment, missing the first outcomes follow-up assessment was the only factor significantly associated with attrition (relative risk=1.5; 95% confidence interval, 1.1-2.0).

CONCLUSIONS

A retention strategic framework was successful in minimizing attrition in minority, low-income children. Participants missing first assessment appointments were at highest risk of subsequent attrition. These findings suggest that deploying this framework may help RCT retention of low-income minority children, particularly those at the highest risk of subsequent attrition.

Evaluation of a Home-Based Environmental and Educational Intervention to Improve Health in Vulnerable Households: Southeastern Pennsylvania Lead and Healthy Homes Program

This evaluation examined whether participation in a home-based environmental educational intervention would reduce exposure to health and safety hazards and asthma-related medical visits. The home intervention program focused on vulnerable, low-income households, where children had asthma, were at risk for lead poisoning, or faced multiple unsafe housing conditions. Home visitors conducted two home visits, two months apart, consisting of an environmental home assessment, Healthy Homes education, and distribution of Healthy Homes supplies. Measured outcomes included changes in participant knowledge and awareness of environmental home-based hazards, rate of children’s asthma-related medical use, and the presence of asthma triggers and safety hazards. Analysis of 2013–2014 baseline and post-intervention program data for a cohort of 150 families revealed a significantly lower three-month rate (p < 0.05) of children’s asthma-related doctor visits and hospital admissions at program completion. In addition, there were significantly reduced reports of the presence of home-based hazards, including basement or roof leaks (p = 0.011), plumbing leaks (p = 0.019), and use of an oven to heat the home (p < 0.001). Participants’ pre- and post- test scores showed significant improvement (p < 0.05) in knowledge and awareness of home hazards. Comprehensive home interventions may effectively reduce environmental home hazards and improve the health of asthmatic children in the short term.

Participants' Accounts on Their Decision to Join a Cohort Study With an Attached Biobank: A Qualitative Content Analysis Study Within Two German Studies

Reliable participation and sustained retention rates are crucial in longitudinal studies involving human subjects and biomaterials. Understanding the decision to enroll is an essential step to develop adequate strategies promoting long-term participation. Semi-structured interviews were implemented with newly recruited and long-term participants randomly drawn from two ongoing longitudinal studies with a biobank component in Germany. Iterative qualitative content analysis was applied to the transcribed interviews. Participants (n = 31) expressed their decision to enroll or remain in the study as the result of the complex interplay of individual factors, institutional cues, study-related features, and societal dynamics. Different forms of trust were identified as central within the elements used to explain participation and could be compared to Dibben, Morris, and Lean's dynamic model of interpersonal trust. Given these high levels of trust, an investigation of the morality of the trustful relationship at stake between participants and research(ers) is warranted.

Factors influencing attrition in a multisite, randomized, clinical trial following traumatic brain injury in adolescence

BACKGROUND

Attrition in longitudinal research negatively affects statistical power, disrupts statistical stability, and can produce unwanted bias.

OBJECTIVE

To investigate factors associated with shorter length of study participation and lower rates of study completion (ie, attrition) in a large, multisite, longitudinal, randomized, clinical trial examining the efficacy of a Web-based family problem-solving treatment following traumatic brain injury (TBI) in adolescence.

SETTING

Five major trauma centers in the central and western regions of the United States.

PARTICIPANTS

Children (N = 132) aged 12 to 17 years hospitalized for complicated mild to severe TBI within the previous 6 months.

RESULTS

Completers had a higher primary caregiver education and higher family income than noncompleters, whereas ethnicity, latency to baseline assessment, and intervention group were not significantly associated with study completion.

CONCLUSION

This is the first study that has specifically examined factors of attrition in a pediatric TBI population. The results suggest that research on pediatric TBI populations may be biased toward higher-income families and highlights the importance of designing studies with increased awareness of the impact of participant demographic factors.

Use of mobile devices and the internet for multimedia informed consent delivery and data entry in a pediatric asthma trial: Study design and rationale

INTRODUCTION

Phase III/IV clinical trials are expensive and time consuming and often suffer from poor enrollment and retention rates. Pediatric trials are particularly difficult because scheduling around the parent, participant and potentially other sibling schedules can be burdensome. We are evaluating using the internet and mobile devices to conduct the consent process and study visits in a streamlined pediatric asthma trial. Our hypothesis is that these study processes will be non-inferior and will be less expensive compared to a traditional pediatric asthma trial.

MATERIALS/METHODS

Parents and participants, aged 12 through 17 years, complete the informed consent process by viewing a multi-media website containing a consent video and study material in the streamlined trial. Participants are provided an iPad with WiFi and EasyOne spirometer for use during FaceTime visits and online twice daily symptom reporting during an 8-week run-in followed by a 12-week study period. Outcomes are compared with participants completing a similarly designed traditional trial comparing the same treatments within the same pediatric health-system. After 8 weeks of open-label Advair 250/50 twice daily, participants in both trial types are randomized to Advair 250/50, Flovent 250, or Advair 100/50 given 1 inhalation twice daily. Study staff track time spent to determine study costs.

RESULTS

Participants have been enrolled in the streamlined and traditional trials and recruitment is ongoing.

CONCLUSIONS

This project will provide important information on both clinical and economic outcomes for a novel method of conducting clinical trials. The results will be broadly applicable to trials of other diseases.

Introducing an environmental assessment and intervention program in inner-city schools

Home-based environmental interventions have demonstrated clinical benefit for children with asthma. Although much is known about school-based exposures, few studies have comprehensively examined the role the school environment plays in asthma and how effectively changing the environment might reduce morbidity when adjusting for exposures in the home. This review summarizes the importance and common challenges of school-based environmental assessment and intervention studies linked to health effects. We focus on the key components of study development and the challenges and benefits to implementation.

Factors associated with recruitment and retention of diverse children with asthma

This study examines factors associated with recruitment and retention of Latino, Dominican (DR) and mainland Puerto Rican (PR), and non-Latino white (NLW) families into a pediatric asthma study. Over eleven hundred (n=1185) families were screened, and 489 (n= 174 NLW, n= 160 DR, n= 155 PR) were enrolled. Rates of recruitment by source of recruitment and rates of retention differed by ethnic group. Families whose caregiver had never married had lower odds of completing the study. The findings highlight the need for further study to examine the effectiveness of specific recruitment and retention strategies with Latino and non-Latino white families.

An Intervention to Decrease Stigma in Young Adults With Sickle Cell Disease

Young adults with sickle cell disease (SCD) are often stigmatized when they seek care for pain. The purpose of this pilot study was to test an intervention to decrease health-related stigma during care-seeking. Young adults with SCD ages 18 to 35 years ( n = 90) were randomized to either the care-seeking intervention (CSI) or an attention control group that participated in life review interviews. The two groups were compared by t tests and longitudinal data analyses on the change from baseline to the last time point in total health-related stigma and health-related stigma by doctors. Findings suggest that the CSI was associated with significant increased awareness of perceived total stigma and stigma by doctors compared with the attention control group. These findings are promising in terms of lessons learned from a pilot intervention that focused on the role communication skills play in decreasing health-related stigma in young adults with SCD.

Reconnecting with urban youth enrolled in a randomized controlled trial and overdue for a 12-month follow-up survey

BACKGROUND

Retention of study participants in randomized controlled trials (RCTs) is crucial to study validity.

PURPOSE

We analyzed the results of four retention strategies used to reconnect with urban teens enrolled in a school-based RCT and overdue for a 12-month follow-up survey.

METHODS

Traditional retention strategies used to reconnect with teens categorized as 'unable to contact' were weekly redials of nonworking telephone numbers and mailings to the student's home. Nontraditional retention strategies were obtaining assistance from school administration and performing outreach on Facebook.

RESULTS

Of the 422 students enrolled, 125 (29.5%) were overdue for a 12-month follow-up survey, but had no working telephone number (unable to contact). We made 196 attempts to contact these 125 students, of which 82 attempts (41.8%) were successful in 'reconnecting' with the student. Using 'mailed reminder letters' as the referent category, odds ratios (95% confidence intervals) for the association between the strategy used and reconnecting were 4.60 (1.8-11.8), 1.94 (1.01-3.73), and 2.91 (0.58-14.50), respectively, for telephone number redials, Facebook outreach, and school administration assistance. Of the 422 students, 380 (90%) ultimately completed the 12-month follow-up survey.

LIMITATIONS

Retention strategies were not applied hierarchically or systematically. We were unable to determine student preference for a particular strategy. Findings are likely only applicable to similar study populations.

CONCLUSION

A mix of traditional retention strategies and more contemporary methods was effective in reconnecting with urban teenagers enrolled in a school-based RCT and in controlling attrition during the 12-month follow-up survey period.

Study protocol: longitudinal study of the transition of young people with complex health needs from child to adult health services

BACKGROUND

Young people with complex health needs have impairments that can limit their ability to carry out day-to-day activities. As well as coping with other developmental transitions, these young people must negotiate the transfer of their clinical care from child to adult services. The process of transition may not be smooth and both health and social outcomes may suffer.Increasingly, policy-makers have recognised the need to ensure a smoother transition between children's and adult services, with processes that are holistic, individualised, and person-centred; however, there is little outcome data to support proposed models of care. This study aims to identify the features of transitional care that are potentially effective and efficient for young people with complex health needs making their transition.

METHODS/DESIGN

Longitudinal cohort study. 450 young people aged 14 years to 18 years 11 months (with autism spectrum disorder and an additional mental health problem, cerebral palsy or diabetes) will be followed through their transition from child to adult services and will contribute data at baseline, 12, 24 and 36 months. We will collect data on: health and wellbeing outcomes (participation, quality of life, satisfaction with services, generic health status (EQ-5D-Y) and condition specific measure of disease control or management); exposure to proposed beneficial features of services (such as having a key worker, appropriate involvement of parents); socio-economic characteristics of the sample; use of condition-related health and personal social services; preferences for the characteristics of transitional care.We will us regression techniques to explore how outcomes vary by exposure to service features and by characteristics of the young people. These data will populate a decision-analytic model comparing the costs and benefits of potential alternative ways of organising transition services.In order to better understand mechanisms and aid interpretation, we will undertake qualitative work with 15 young people, including interviews, non-participant observation and diary collection.

DISCUSSION

This study will evaluate the effect of service components of transitional care, rather than evaluation of specific models that may be unsustainable or not generalisable. It has been developed in response to numerous national and international calls for such evaluation.

Maximizing retention with high risk participants in a clinical trial

PURPOSE

To describe effective retention strategies in a clinical trial with a high risk, low-income, and vulnerable patient population with serious mental illness.

DESIGN

Follow-up assessments were conducted for a randomized clinical tobacco treatment trial at 3, 6, and 12 months postbaseline. Initial follow-up rates of <40% at 3 months led to implementation of proactive retention strategies including obtaining extensive contact information; building relationships with case managers and social workers; contacting jails and prisons; text messaging, e-mailing, and messaging via social networking sites; identifying appointments via electronic medical record; and field outreach to treatment facilities, residences, and parks.

SETTING

Large urban public hospital.

SUBJECTS

Participants were current smokers recruited from 100% smoke-free locked psychiatry units.

MEASURES

Assessments covered demographics, substance use, and mental health functioning.

ANALYSIS

Retention rates were plotted over time in relation to key retention strategies. Chi-square and t-tests were used to examine participant predictors of retention at each follow-up. At the 12-month follow-up, the retention strategies that most frequently led to assessment completion were identified.

RESULTS

The sample (N = 100) was 65% male; age x = 39.5 years (SD = 11.3); 44% non-Hispanic white; 46% on Medicaid and 34% uninsured; 79% unemployed; and 48% unstably housed. Proactive retention strategies dramatically increased follow-up rates, concluding at 3 months = 82.65%, 6 months = 89.69%, and 12 months = 92.78%. Married and divorced/separated/widowed participants, those with higher income, and participants with alcohol or illicit drug problems had increased retention from 3- to 12-month follow-up.

CONCLUSION

Follow-up rates improved as proactive methods to contact participants were implemented. Dedicated research staff, multiple methods, community networking, and outreach within drug treatment settings improved retention.

Sociodemographic, clinical, and psychological factors associated with attrition in a prospective study of cardiovascular prevention: the Heart Strategies Concentrating on Risk Evaluation study

PURPOSE

To identify factors associated with attrition in a longitudinal study of cardiovascular prevention.

METHODS

Demographic, clinical, and psychosocial variables potentially associated with attrition were investigated in 1841 subjects enrolled in the southwestern Pennsylvania Heart Strategies Concentrating on Risk Evaluation study. Attrition was defined as study withdrawal, loss to follow-up, or missing 50% or more of study visits.

RESULTS

Over 4 years of follow-up, 291 subjects (15.8%) met criteria for attrition. In multivariable regression models, factors that were independently associated with attrition were black race (odds ratio [OR], 2.21; 95% confidence interval [CI], 1.55-3.16; P < .001), younger age (OR per 5-year increment, 0.88; 95% CI, 0.79-0.99; P < .05), male gender (OR, 1.79; 95% CI, 1.27-2.54; P < .05), no health insurance (OR, 2.04; 95% CI, 1.20-3.47; P < .05), obesity (OR, 1.80; 95% CI, 1.07-3.02; P < .05), CES-D depression score 16 or higher (OR, 2.02; 95% CI, 1.29-3.19; P < .05), and higher ongoing life events questionnaire score (OR, 1.09; 95% CI, 1.04-1.13; P < .001). Having a spouse/partner participating in the study was associated with lower odds of attrition (OR, 0.60; 95% CI, 0.37-0.97; P < .05). A synergistic interaction was identified between black race and depression.

CONCLUSIONS

Attrition over 4 years was influenced by sociodemographic, clinical, and psychological factors that can be readily identified at study entry. Recruitment and retention strategies targeting these factors may improve participant follow-up in longitudinal cardiovascular prevention studies.

Determinants of Attrition to Follow-Up in a Multicentre Cohort Study in Children-Results from the IDEFICS Study

Cohort participant retention is a crucial element and may depend on several factors. Based on data from a multicentre cohort of European children, the effect of baseline participation on attrition and the association with and the impact of single determinants in relation to the extent of attrition were investigated. Data was available for 16,225 children from the IDEFICS baseline survey (2007/2008). Attrition was defined as nonparticipation in the first follow-up examination (2009/2010). Determinants of attrition were analysed by logistic regression. The statistical significance level was set at α=0.01 to account for the large sample size. The strongest associations were seen for baseline item non-response, especially when information on migration background (odds ratio (OR) = 1.55; 99% confidence interval (CI): 1.04, 2.31), single parenthood (OR = 1.37; 99% CI: 1.12, 1.67), or well-being (OR = 1.46; 99% CI: 1.19, 1.79) was lacking. Drop-out proportion rose with the number of missing items. Overweight, low education, single parenthood and low well-being scores were independent determinants of attrition. Baseline participation, and the individual determinant effects seemed unrelated to the variation of the extent of attrition between study centres. A high level of item nonresponse as well as overweight and disadvantageous sociodemographic conditions were identified as main attrition determinants, suggesting the consideration of these aspects in conduct and analysis of cohort studies in childhood obesity research.

Recruitment and retention strategies in a clinical trial for children with chronic hepatitis C infection

Successful strategies for recruitment and retention (R & R) in pediatric trials are needed. The purpose of our study was to analyze the effectiveness of R&R in a trial for children with hepatitis C. Recruitment strategies were (1) Initial (months 0-12) and (2) extra effort (months 13-18). Initial strategies enrolled 70/114 (61%) of patients. Extra effort strategies included: (1) radio broadcasts, (2) contact with adult hepatologists, (3) dissemination of study material and (4) modification of the exclusion criteria. The overall retention rate was 84% at 2 years. Lessons learned will be valuable in designing future pediatric trials.

Socioeconomic determinants associated with willingness to participate in medical research among a diverse population

INTRODUCTION

Although it is federally-mandated that racial/ethnic minorities be included in research studies, recruiting diverse populations remains a challenge. This is particularly difficult when research involves children. The purpose of this study was to assess attitudes and beliefs toward medical research among a racially and socioeconomically diverse population of parents of school children.

METHODS

A cross-sectional parent-report survey was conducted in New York City public elementary schools using stratified random selection to obtain a diverse population. Fear of medical research and likelihood to participate in medical research were assessed using a validated questionnaire. Differences in fear/likelihood to participate in research across race/ethnicity and socioeconomic characteristics were evaluated.

RESULTS

In general, parents were afraid of their child "being treated as a guinea pig", but were willing to allow their child to participate in research if asked by their own doctor. Factors associated with a lower score on fear toward research were; primary language other than English (OR=0.59), access to an interpreter (OR=0.73) and access to medical service within a day (OR=0.51). Latinos had the highest fear score (OR=1.87) compared to Whites. Asians were the ethnic group most likely to participate in research (OR=1.71). Low education level (OR=2.18) and public health insurance (OR=1.37) were associated with a higher score for likelihood of allowing one's child to participate in medical research.

CONCLUSION

Minority parents reported more fear of allowing their children to participate in medical research, but were as likely to consent their children's participation, especially if asked by their own physician.

Maintaining participation and momentum in longitudinal research involving high-risk families

PURPOSE

The purpose of the current study was to identify and describe strategies available to optimize retention of a high-risk research cohort and assist in the recovery of study participants following participant dropout.

DESIGN AND METHODS

The Maternal Lifestyle Study (MLS), which investigated the effects of prenatal substance exposure (cocaine or opiates) on child outcome, is a prospective longitudinal follow-up study that extended from birth through 15 years of age. Retention strategies to maximize participation and factors that might negatively impact compliance were examined over the course of five follow-up phases.

FINDINGS

At the conclusion of the 15-year visits, MLS had successfully maintained compliance at 76%. Retention rates did not differ by exposure group.

CONCLUSIONS

Maintaining ongoing participation of enrolled study subjects is a critical element of any successful longitudinal study. Strategies that can be used to reengage and maintain participants in longitudinal research include persistence, flexibility with scheduling, home visits, long-distance trips, increased incentives, and development of a computerized tracking system. Establishing rapport with families and ensuring confidentiality contributed to overall participant retention. The use of multiple tracking techniques is essential.

CLINICAL RELEVANCE

Researchers are challenged to maintain participants in longitudinal studies to ensure the integrity of their research.

The school inner-city asthma study: design, methods, and lessons learned

BACKGROUND

Children spend a significant amount of time in school. Little is known about the role of allergen exposure in school environments and asthma morbidity.

OBJECTIVES

The School Inner-City Asthma Study (SICAS) is a National Institutes of Health (NIH)-funded prospective study evaluating the school/classroom-specific risk factors and asthma morbidity among urban children.

METHODS/RESULTS

This article describes the design, methods, and important lessons learned from this extensive investigation. A single center is recruiting 500 elementary school-aged children, all of whom attend inner-city metropolitan schools. The primary hypothesis is that exposure to common indoor allergens in the classroom will increase the risk of asthma morbidity in children with asthma, even after controlling for home allergen exposures. The protocol includes screening surveys of entire schools and baseline eligibility assessments obtained in the spring prior to the academic year. Extensive baseline clinical visits are being conducted among eligible children with asthma during the summer prior to the academic school year. Environmental classroom/school assessments including settled dust and air sampling for allergen, mold, air pollution, and inspection data are collected twice during the academic school year and one home dust sample linked to the enrolled student. Clinical outcomes are measured every 3 months during the academic school year.

CONCLUSION

The overall goal of SICAS is to complete the first study of its kind to better understand school-specific urban environmental factors on childhood asthma morbidity. We also discuss the unique challenges related to school-based urban research and lessons being learned from recruiting such a cohort.