Consent Rates Reported in Published Pediatric Randomized Controlled Trials.

OBJECTIVE: To determine the average reported consent rate for published pediatric randomized controlled trials (RCTs) and whether this rate varies by trial characteristics. STUDY DESIGN: A review of pediatric RCTs published in Medline in 2009, 2010, or 2015 was performed. Secondary analyses of prior trials, trials including adults, trials not requiring consent, or trials with missing or unclear consent data were excluded. Consent rate was defined as the number of patients enrolled divided by number of eligible patients where families were approached. Random effects meta-regression was conducted to determine the weighted average consent rate. RESULTS: Of 2347 trials identified, 1651 were excluded. An additional 418 of 696 (60%) were excluded because the consent rate was missing or unclear. The average consent rate for 278 included RCTs was 82.6% (95% CI, 80.3%-84.8%) and was higher for vaccination compared with behavioral trials and for industry-funded compared with National Institutes of Health-funded or other government-funded trials. The average consent rate was <70% for 26% of included trials. Of these trials, US trials (28/77 [36.4%]) had a higher probability of a consent rate of <70% than non-US studies (35/64 [21.3%]) and multinational (9/37 [24.3%]) studies. There was slight variation by funding category. CONCLUSIONS: Although the average consent rate for published trials was reasonably high, approximately one-quarter of trials had consent rates of <70%. Consent rates reporting has improved over time, but remains suboptimal. Our findings should assist with the planning of future pediatric RCTs, although consent data from unpublished trials are also needed.

Impact of sociodemographic and clinical factors on offer and parental consent to postmortem following stillbirth or neonatal death: a UK population-based cohort study.

OBJECTIVE: To identify factors associated with the offer of and consent to perinatal post-mortem. DESIGN: National population-based cohort study SETTING: The UK. POPULATION: 26 578 perinatal deaths born between 1 January 2013 and 31 December 2017. MAIN OUTCOME MEASURES: Postmortem offer by clinical staff; parental consent to post-mortem. RESULTS: Postmortem offer rates were high but varied significantly with time of death from 97.8% for antepartum deaths to 88.4% for neonatal deaths following neonatal admission. Offer rates did not significantly vary by gestation, year of birth, mother's socioeconomic deprivation, ethnicity or age. Only 44.5% of parents consented to a postmortem. Mothers from the most deprived areas were less likely to consent than those from the least deprived areas (relative risk (RR)=0.76, 95% CI 0.71 to 0.80). Consent rates were similar for mothers of white, mixed, Asian Indian, black Caribbean and black African ethnicity (43%-47%), but significantly lower for mothers of Asian Pakistani (20%) and Asian Bangladeshi (18%) ethnicity. Consent increased with increasing gestation (p<0.001) and was lower for deaths following neonatal unit admission than for antepartum death (RR 0.71, 95% CI 0.67 to 0.75). CONCLUSIONS: The current profile of cause of perinatal deaths in the UK is likely to be biased with less postmortem information available for babies dying in the neonatal period and those born to mothers from deprived areas and of Asian Pakistani or Asian Bangladeshi ethnicity. Such bias severely limits the design of effective strategies for reducing mortality in these high-risk groups. These findings have implications for high-income countries seeking to explore and improve the understanding of perinatal deaths.

Perceived benefits and risks of participation in a clinical trial for Ugandan children with sickle cell anemia.

INTRODUCTION: Understanding factors that affect the decisions of caregivers of African children to enroll their children in clinical trials would lead to more fully informed consent. METHODS: During the NOHARM study (NCT01976416), a placebo-controlled clinical trial of hydroxyurea for Ugandan children with sickle cell anemia (SCA), 206 caregivers were given a semistructured questionnaire about factors that influenced participation in the study and their perceptions of study benefits and risks. Factors were further assessed with focus group discussions. RESULTS: Caregivers identified education provided during the recruitment process (44%), the child's current poor state of health (35%), and the possibility of improvement in the child's health (16%) as their primary initial reasons for deciding to participate in the NOHARM trial. Concerns regarding the drug or participation in a research study, including the stated concern of death by several caregivers, were outweighed by the possibility of improvement in the child's health. During the study, 72% of caregivers cited improved health as an advantage of study participation, while disadvantages cited included the potential side effects of hydroxyurea, most of which did not occur during the trial. DISCUSSION: Our study findings highlight the generally poor state of health of Ugandan children with SCA, the desperation by caregivers for anything that could improve the child's health, and the inevitable improvements in care that result from strict adherence to a study protocol, even a protocol based on local guidelines. Studies in this vulnerable population must be careful not to portray improved care as a primary incentive for participation.

The factors associated with maternal consent to human papillomavirus vaccination among adolescents in Israel.

Purpose: To evaluate the knowledge and attitudes toward the human papillomavirus (HPV) vaccine among mothers of 8th graders in Israel, and to determine the factors associated with maternal consent to the HPV vaccine.Methods: We conducted a cross-sectional study among mothers of 8th grade students in 27 schools in Haifa and Northern districts of Israel during the 2016-17 school year. Data were collected using a structured telephone questionnaire.Results: 313 mothers answered the questionnaire (response rate = 91.8%). The mean knowledge level score was low (3.96 points [out of 10] ±2.68). Knowledge level was positively associated with Jewish nationality, being secular in religious practice and higher education. The attitude mean score was low-moderate (11.22 points [out of 18] ± 5.01). Attitude score was positively associated with Arab nationality. No significant association was found between knowledge level and attitudes. According to multivariate analysis, mothers' consent to the HPV vaccine was associated with the knowledge level score (OR = 0.82; 95%CI 0.68-0.98), the attitude score (OR = 1.76; 95%CI 1.53-2.02) and nationality (OR = 27.86, 95%CI 3.41-227.56).Conclusions: The knowledge level and attitudes toward the HPV vaccine were found to be unsatisfactory with racial disparities between Arabs and Jews. Jewish mothers compared with Arab mothers, mothers with a higher knowledge level or less positive attitudes were less likely to consent to the vaccine. These findings could contribute toward adapting programs to the different Israeli sectors in order to improve the rates of HPV vaccine receipt among adolescents.

Neonatal end-of-life decision-making almost 20 years after the EURONIC study: A French survey.

Nearly 20 years ago the EURONIC study reported that French neonatologists sometimes deemed it legitimate to terminate the lives of newborn infants when the prognosis appeared extremely poor. Parents were not always informed of these decisions. Major change has occurred since then and is described herein. MATERIAL AND METHODS: A survey was conducted in the Île-de-France region, from 1 January to 31 January 2016. Professionals from 15 neonatal intensive care units (NICUs) were invited to complete a questionnaire. RESULTS: A total of 702 questionnaires were collected and 670 responses were analyzed. Knowledge of the law differed according to professional status, with 71% of MDs (medical staff, MS), compared with 28% of nonmedical staff (NMS) declaring that they had good knowledge of the law. Most MDs and NMS believed that withholding or withdrawing life-sustaining treatments (WWLST) could be decided and implemented after a delay. Half of them thought that WWLST would always result in death. Although required by law, a consulting MD attended the collegial meeting required before deciding on WWLST in only half of the cases. Parents were almost always informed of the decision thereafter by the physician in charge of their infant. The most frequent disagreement with parents was observed when WWLST was the option selected. In this case, most professionals suggested postponing WWLST, continuing intensive care and dialogue with parents, aiming at a final shared decision. Major differences were observed between NICUs with regard to the withdrawal of artificial nutrition and hydration. Finally, 14% of MDs declared that infant active terminations of life still occurred in their NICU. Major differences concern WWLST and active termination of life, whose meaning has been partly modified since 2001. CONCLUSION: Several major changes were observed in this survey: (1) treatment withdrawal decisions are made today in agreement with the law; (2) parents' information and involvement in the decision process have profoundly changed; (3) active termination of life (euthanasia) very rarely occurs; only at the end of a process in accordance with ethical principles and within the law is this decision made.

Enhancing Parent Consent for School-Based Primary and Reproductive Health Care Among Vulnerable Youth.

This quality-improvement initiative evaluated procedures to increase parental consent for students, 13 to 18+ years old, to access a school-based health clinic that provides primary and reproductive health care in a Hispanic immigrant neighborhood in the U.S. Southwest. Six consent-retrieval procedures were sequentially implemented. Procedures included school registration, competition, hand delivery, PTO meetings, self-consent, and mail. Age, grade, and number of completed consents were calculated and compared. The percentage of students with completed consents increased from 35% to 72%. Lessons learned include increasing the number of completed consents is difficult; however, it is important to increase students' access to health-care services.

Trial Characteristics That Affect Parental Consent in Neonatal Drug Trials.

OBJECTIVE: The main purpose of this article is to determine parental consent rates in neonatal drug trials and describe trial characteristics associated with higher rates. STUDY DESIGN: We included neonatal drug trials published between 2009 and 2014 and compared parental consent rates among the following characteristics: phase type, gestational age, randomization type, drug administration route, drug dosing frequency, blood sampling, control type, length of study, funding source, and length of treatment. We compared characteristics using chi-square, Fisher's exact, one-way analysis of variance or Kruskal-Wallis tests. RESULTS: We identified 52 trials: 38 trials (73%) reported data of parental consent. Median percentage (interquartile range) of parental consent was 79% (62, 89). Higher rates were observed in studies that used active comparators (87%) and shorter study lengths (81% for studies <24 hours). CONCLUSION: Parental consent rates for neonatal drug trials varied by study characteristics. Information on proportion of parents consented is valuable to assess generalizability of trial results and for preparing trial protocols.

Drivers for human papillomavirus vaccination in Valencia (Spain) / Factores asociados a la vacunación contra el virus del papiloma humano en Valencia (España)

Objective: To describe the drivers associated with HPV vaccination in adolescent girls and their parent's opinion on the vaccine. Methods: We conducted an observational and cross-sectional study on adolescent girls and their parents in Valencia (Spain), between September 2011 and June 2012. A consultation was made at a random sample of schools of the 14-year-old girls that should have received the vaccine in the free vaccination programme. We ran a personal survey on knowledge and attitudes regarding HPV infection and the vaccine. A binary logistic regression model was performed to determine which factors were most associated with vaccination. Results: The survey was run on a binomial of 1,278 girls/mothers in 31 schools, to which 833 girls and their mothers responded (64.0%). The factors associated with vaccination were: country of origin of the families (adjusted OR [aOR]: 0.49; 95% confidence interval [95%CI]: 0.24-0.98), civil status of the parents (aOR: 0.33; 95%CI: 0.13-0.81), knowledge/beliefs about the vaccine when the source of information was the nurse (aOR: 1.83; 95%CI: 1.01-3.35), information source about the vaccine (aOR: 2.32; 95%CI: 1.37-3.92), preventive health centre visits (aOR: 2.1; 95%CI: 1.10-4.07), and nurse advice (aOR: 6.6; 95%CI: 3.19-13.56). Conclusions: The main factor associated with HPV vaccination was the advice of health professionals. Therefore, the most effective interventions to improve vaccination coverage should focus on health professionals

Objetivo: Describir qué factores se asocian a la vacunación contra el virus del papiloma humano (VPH) en adolescentes y la opinión de sus padres/madres sobre dicha vacuna. Métodos: Se llevó a cabo un estudio observacional y transversal en chicas adolescentes y sus progenitores en Valencia (España), entre septiembre de 2011 y junio de 2012. Se realizaron consultas a las niñas de 14 años que tendrían que haber sido vacunadas dentro del programa de vacunación gratuita, en una muestra aleatoria de colegios. Se preguntó sobre conocimientos y actitud respecto a la infección por el VPH y la vacuna, mediante entrevista personal. Se llevó a cabo un modelo de regresión logística binaria para determinar qué factores estaban más asociados con la vacunación. Resultados: Se entrevistó a 1278 binomios chica/madre, con una tasa de respuesta del 64,0% (833). Los factores asociados a la vacunación fueron el país de origen de las familias (odds ratio ajustada [ORa]: 0,49; intervalo de confianza del 95% [IC95%]: 0,24-0,98), el estado civil de los progenitores (ORa: 0,33; IC95%: 0,13-0,81), los conocimientos/creencias sobre la vacuna cuando la principal fuente de información fue la enfermera (ORa: 1,83; IC95%: 1,01-3,35), la fuente de información sobre la vacuna (ORa: 2,32; IC95%: 1,37-3,92), las visitas preventivas al centro de salud (ORa: 2,12; IC95%: 1,10-4,07) y el consejo de la enfermera (ORa: 6,57; IC95%: 3,19-13,56). Conclusiones: El principal factor asociado a la vacuna del VPH fue el consejo del personal sanitario, por lo que las intervenciones para aumentar la cobertura vacunal deben centrarse en este colectivo

Parents' knowledge, beliefs, and acceptance of the HPV vaccination in relation to their socio-demographics and religious beliefs: A cross-sectional study in Thailand.

Thailand has one of the world's highest prevalence of cervical cancer, mainly caused by the human papillomavirus (HPV). HPV infections can successfully be prevented by vaccination, which is available at a cost but not yet implemented in the national vaccination program. Parents play a critical role in deciding whether to vaccinate their child against HPV. Thus, the aim was to examine the association between parents' knowledge, beliefs, and acceptance of the HPV vaccination for their daughters, considering their socio-demographics and religious beliefs. A cross-sectional design was used among three schools in Thailand: Nakorn Phatom province (suburban) and Bangkok (urban). Parents of 9-12-year-old daughters completed the questionnaires, guided by the Health Belief Model. In total, 359 parents completed the questionnaires; of those, 301 were included in the final analyses. The ordinary least squares (OLS) regression analysis showed that background knowledge of HPV and the HPV vaccine was positively related to knowledge of HPV and cervical cancer. For beliefs, knowledge was positively associated with susceptibility (i.e., parents' perceived risk of an HPV infection/ related disease), severity, and benefit. However, knowledge was not significantly related to barriers. For acceptance, higher susceptibility and benefit were related to higher acceptance, and greater knowledge was associated with higher acceptance. Thus, we found associations between parents' knowledge, beliefs, and acceptance of the HPV vaccination for their daughters, considering their socio-demographics and religious beliefs. Parents, who reported religion as important, as opposed to those who did not, were more favorable toward the HPV vaccination. Four out of ten mothers had never undergone a cervical cancer screening, but most had accepted previous childhood vaccinations for their daughters. The overall acceptance of the vaccine was high, and we believe our results are promising for future implementation of the HPV vaccination in the national childhood vaccination program in Thailand.

Oral health survey of five-year-olds 2014/15: Have strategies for increasing the levels of parental consent in Bradford been effective?

Public Health England facilitates national epidemiological surveys of five-year-olds to monitor oral health, both locally and nationally. Positive consent for participation in surveys such as these was introduced in 2006 following guidance from the Department of Health. Following this change, consent rates have fallen slightly. Bradford, a city in West Yorkshire in the north of England, has actively tried to encourage an increase in consent rates. In the 2014/15 survey several measures were implemented to encourage parents to return their consent forms in order to increase consent levels. Despite these additional measures consent rates have continued to fall. The schools involved in both the current (2014/15) and previous (2011/12) surveys were directly compared and the results showed a 4% decrease in consent returns. Consequently, recommendations have been made to investigate alternative strategies for increasing levels of survey participation. One of the suggested strategies is to gain consent for all health screening including dental examinations at school entry.

To Consent or Decline HPV Vaccination: A Pilot Study at the Start of the National School-Based Vaccination Program in Sweden.

BACKGROUND: Parents' beliefs about human papillomavirus (HPV) vaccination influence whether they allow their daughters to be vaccinated. We examined the association between parents' refusal and sociodemographic background, knowledge and beliefs about HPV, and the HPV vaccination in relation to the Health Belief Model. METHODS: The sample consisted of 200 (55%) parents of children aged 11-12 years in the Swedish national vaccination program. Data were collected using a self-reported questionnaire. Most parents (N = 186) agreed to the vaccination. Pearson's chi-square, Fisher's exact test, and the Mann-Whitney U test were used to analyze data. RESULTS: Declining parents saw more risks and fewer benefits of HPV vaccination but no differences in beliefs regarding the severity or young girls' susceptibility to HPV were found. There was an association between refusing the HPV vaccine and lower acceptance of previous childhood vaccinations, and their main source of information was the Internet. Parents who declined the vaccine believed it could adversely affect condom use, the age of their daughter's sexual debut, and the number of sexual partners. CONCLUSION: Parents should have the possibility to discuss HPV and HPV vaccine with a school nurse or other health care professionals, and should have access to evidence-based information on the Internet.

Eliciting parental support for the use of newborn blood spots for pediatric research.

BACKGROUND: Biomarkers of exposures such as infection or environmental chemicals can be measured in small volumes of blood extracted from newborn dried blood spots (DBS) underscoring their potential utility for population-based research. However, few studies have evaluated the feasibility and utility of this resource; particularly the factors associated with parental consent, and the ability to retrieve banked samples with sufficient remaining volume for epidemiologic research. METHODS: At 8 months postpartum, 5,034 mothers of infants born (2008-2010) in New York (57 counties excluding New York City) were asked to consent for the use of residual DBS for the quantification of cytokines and environmental chemicals. Mothers were part of the Upstate KIDS study, a longitudinal birth cohort designed to evaluate child development through 3 years of age. Information on parental and infant characteristics was obtained from birth certificates and maternal report at 4 months postpartum. Multivariate logistic regression was used to identify factors associated with parental consent and with successful retrieval of DBS. RESULTS: Sixty-two percent (n = 3125) of parents consented. Factors significantly associated with consent included non-Hispanic ethnicity (odds ratio 2.04; 95% CI: 1.43-2.94), parity (1.29; 1.05-1.57), maternal obesity (1.42; 1.11-1.80) and reported alcohol use during pregnancy (1.51; 1.12-2.06). However, these associations corresponded to small absolute differences in proportions (4 to 8%), suggesting that the two groups remained comparable. Infant characteristics such as preterm delivery did not significantly differ by consent status among singletons and only ventilator use (OR 2.39; 95% CI: 1.06-5.41) remained borderline significant among twins in adjusted analyses. Among consented infants, 99% had at least one 3.2 mm punch successfully retrieved for biomarker analyses and 84% had a full DBS circle available. CONCLUSION: Parental characteristics varied slightly by consent, and the availability of samples for research purposes was high, demonstrating the feasibility of this resource for population based research.

Pulse Oximetry Screening for Critical Congenital Heart Disease after Home Birth and Early Discharge.

OBJECTIVES: To assess the feasibility of pulse oximetry (PO) screening in settings with home births and very early discharge. We assessed this with an adapted protocol in The Netherlands. STUDY DESIGN: PO screening was performed in the Leiden region in hospitals and by community midwives. Measurements were taken ≥ 1 hour after birth and on day 2 or 3 during the midwife visit. Primary outcome was the percentage of screened infants with parental consent. The time point of screening, oxygen saturation, false positive (FP) screenings, critical congenital heart defects (CCHDs), and other detected pathology were registered. RESULTS: In a 1-year period, 3625 eligible infants were born. Parents of 491 infants were not approached for consent, and 44 refused the screening. PO screening was performed in 3059/3090 (99%) infants with obtained consent. Median (IQR) time points of the first and second screening were 1.8 (1.3-2.8) and 37 (27-47) hours after birth. In 394 infants with screening within 1 hour after birth, the median pre- and postductal oxygen saturations were 99% (98%-100%) and 99% (97%-100%). No CCHD was detected. The FP prevalence was 1.0% overall (0.6% in the first hours after birth). After referral, important noncritical cardiac and other noncardiac pathology was found in 62% of the FP screenings. CONCLUSIONS: PO screening for CCHD is feasible after home births and very early discharge from hospital. Important neonatal pathology was detected at an early stage, potentially increasing the safety of home births and early discharge policy.

A Systematic Review of Consent Procedures, Participation Rates, and Main Findings of Health-Related Research in Alternative High Schools From 2010 to 2015.

There is a well-established link between educational attainment and health. Alternative high schools (AHSs) serve students who are at risk for school dropout. Health-related research conducted in AHSs has been sparse. Achieving high participation rates is critical to producing generalizable results and can be challenging in research with adolescents for reasons such as using active consent. These challenges become greater when working with vulnerable populations of adolescents. In this systematic review, we examined health-related studies conducted in AHSs between 2010 and 2015. Results indicated that (1) health-related research in AHSs has increased over the past 5 years, (2) AHS students continue to experience significant disparities, (3) active consent is commonly used with AHS students, (4) 42% of studies reported participation rates or provided enough information to calculate participation rates, and (5) school nurses are missing from health-related research conducted in AHSs. Implications for future research and school nursing are discussed.

Ethics of children's participation in a Saudi biobank: an exploratory survey.

PURPOSE: The aim of this study was to investigate the ethical issues involved in children's participation in research biobanks in Saudi Arabia and the Middle East. METHODS: A survey of 160 respondents from four groups (researchers, physicians, medical students, and laypersons) was conducted at King Abdulaziz Medical City in Riyadh, Saudi Arabia. RESULTS: A clear and positive attitude toward pediatric clinical and genetic research inside and outside of Saudi Arabia was found. Parental consent is viewed as essential, with 60% saying parental consent is sufficient for children up to 12, and 40% saying it is sufficient for children 12-18 years old. More than 90% of respondents preferred to gain approval from any child with a decision-making capability; 58.2 and 38.6% of them believed that children between 12 and 18, and >18 years of age, respectively, can understand and thus give their approval for genetic research. Clear majorities in the study agreed with re-consenting children when they become adults, allowing them to withdraw at any time. A clear majority agreed that either parent could sign a consent form for their child to participate in a research biobank. CONCLUSION: All four groups believed, to varying degrees, that elements of ethical consideration were critical when involving children in research.Genet Med 18 8, 806-813.

Implementation and Evaluation of a School-Based Human Papillomavirus Vaccination Program in Rural Kentucky.

INTRODUCTION: Human papillomavirus (HPV) vaccination rates remain marginal across the U.S., including Kentucky, a state recognized for increased HPV-related cancer burden. School-based HPV immunization programs may be a viable approach to improving vaccination initiation and completion rates among youth. Therefore, the purpose of this study was to design, implement, and evaluate a school-based HPV vaccination program conducted in rural south-central Kentucky. METHODS: Guided by evidence-based approaches to increasing immunization rates, the practical expertise of school nursing staff, and a detailed study protocol, academic and health department-based investigators implemented an HPV vaccination project in two high schools during the 2012-2013 academic year; data were analyzed in 2013-2014. Rates of returned parental consent forms, parental consent/declination, and HPV vaccination rates were documented. RESULTS: At the beginning of the school year, all 935 students at the two schools were given HPV vaccination parental consent forms. Five hundred eleven students returned consent forms (55% return rate), and 447 of these students were HPV vaccine naïve (87%). Of these students, 315 (70%) initiated the vaccine series, with 276 (62%) completing the entire three-dose series, so that 88% of students initiating the vaccine series successfully completed the series. In estimating rates for the entire school body, 45% of students had received all three doses by the end of the project. CONCLUSIONS: Despite study design limitations, results of this project provide further evidence about school-based immunization programs as an effective strategy for improving HPV vaccination rates among Kentucky and U.S. adolescents.

Current status of newborn screening worldwide: 2015.

Newborn screening describes various tests that can occur during the first few hours or days of a newborn's life and have the potential for preventing severe health problems, including death. Newborn screening has evolved from a simple blood or urine screening test to a more comprehensive and complex screening system capable of detecting over 50 different conditions. While a number of papers have described various newborn screening activities around the world, including a series of papers in 2007, a comprehensive review of ongoing activities since that time has not been published. In this report, we divide the world into 5 regions (North America, Europe, Middle East and North Africa, Latin America, and Asia Pacific), assessing the current NBS situation in each region and reviewing activities that have taken place in recent years. We have also provided an extensive reference listing and summary of NBS and health data in tabular form.

Does the use of passive or active consent affect consent or completion rates, or dietary data quality? Repeat cross-sectional survey among school children aged 11-12†years.

OBJECTIVES: An expectation of research is that participants should give fully informed consent. However, there is also a need to maximise recruitment to ensure representativeness. We explored the impact of passive or active parental consent on consent, completion rates and on dietary data quality in a survey among children aged 11-12 years. SETTING: Six middle schools in North-East England. PARTICIPANTS: All children aged 11-12 years attending the six middle schools were eligible to participate (n=1141). PRIMARY OUTCOMES: whether or not each eligible child's parent gave consent and provided a complete dietary diary; whether or not a child completed their dietary diary but only among children who agreed to participate, and whether or not children providing diaries were classified as an under-reporter or not. RESULTS: Parents were more likely to consent passively than actively. This difference was greater among the more deprived: OR 16.9 (95% CI 5.7 to 50.2) in the least and 129.6 (95% CI 39.9 to 420.6) in the most deprived quintile (test for interaction: method of consent by level of deprivation, p=0.02). For all children eligible, completion was more likely if passive consent was used (OR 2.8, 95% CI 2.2 to 3.7). When only children who gave consent are considered, completion was less likely when passive rather than active consent was used (OR 0.6, 95% CI 0.4 to 0.9). Completion rate decreased as level of deprivation increased; we found no evidence that the OR for the method of consent varied by level of deprivation. There was no evidence that the quality of dietary data, as measured by an assessment of under-reporting, differed by method of consent (OR 0.8, 95% CI 0.5 to 1.2). CONCLUSIONS: Passive consent led to a higher participation rate and a more representative sample without compromising data quality.