Predicting Later Study Withdrawal in Participants Active in a Longitudinal Birth Cohort Study for 1 Year: The TEDDY Study.

OBJECTIVE: To identify predictors of later study withdrawal among participants active in The Environmental Determinants of Diabetes in the Young (TEDDY) for 1 year. METHODS: Multiple logistic regression was used to discriminate 3,042 children active in TEDDY for the first 3 years from 432 children who withdrew in Years 2 or 3. Predictor variables were tested in blocks-demographic, maternal lifestyle behaviors, stress and child illness, maternal reactions to child's increased diabetes risk, in-study behaviors-and a final best model developed. RESULTS: Few demographic factors predicted study withdrawal. Maternal lifestyle behaviors, accuracy of the mother's risk perception, and in-study behaviors were more important. Frequent child illnesses were associated with greater study retention. CONCLUSIONS: Demographic measures are insufficient predictors of later study withdrawal among those active in a study for at least 1 year; behavioral/psychological factors offer improved prediction and guidance for the development of retention strategies.

Participant Experiences in the Environmental Determinants of Diabetes in the Young Study: Common Reasons for Withdrawing.

BACKGROUND: To characterize participant reasons for withdrawing from a diabetes focused longitudinal clinical observational trial (TEDDY) during the first three study years. METHODS: 8677 children were recruited into the TEDDY study. At participant withdrawal staff recorded any reason parents provided for withdrawal. Reasons were categorized into (1) family characteristics and (2) protocol reasons. Families who informed staff of their withdrawal were classified as active withdrawals (AW); families without a final contact were considered passive withdrawals (PW). RESULTS: Withdrawal was highest during the first study year (n = 1220). Most families were AW (n = 1549; 73.4%). PW was more common in the United States (n = 1001; 37.8%) and among young mothers (p = 0.001). The most frequent protocol characteristic was blood draw (55%) and the most common family reason was not having enough time (66%). The blood draw was more common among female participants; being too busy was more common among males. Both reasons were associated with study satisfaction. CONCLUSIONS: Results suggest that, for families of children genetically at risk for diabetes, procedures that can be painful/frightening should be used with caution. Study procedures must also be considered for the demands placed on participants. Study satisfaction should be regularly assessed as an indicator of risk for withdrawal.

Maternal anxiety about a child's diabetes risk in the TEDDY study: the potential role of life stress, postpartum depression, and risk perception.

OBJECTIVE: To understand the association between life stress, postpartum depression (PD), maternal perception of her child's risk for type 1 diabetes (T1D) and a mother's anxiety about her child's T1D risk in mothers of genetically at risk children in The Environmental Determinants of Diabetes in the Young (TEDDY) study. METHODS: A short form of the state component (SAI) of the State-Trait Anxiety Inventory, negative life events (LE), the Edinburgh Postnatal Depression Scale (EPDS), and one question about the child's risk of developing T1D risk perceptions (RP) were given to mothers at the 6-month TEDDY clinic visit. The relationship between the four measures was modeled using multiple regressions. RESULTS: Controlling for sociodemographic factors, significant country differences in SAI, LE, EPDS, and RP emerged. LE - particularly interpersonal LE - had a strong association to maternal anxiety about the baby's risk of diabetes. Both evidence of PD and accurate risk perceptions (RPs) about the child's T1D risk were associated with increased maternal anxiety about the child's T1D risk. CONCLUSION: Heightened maternal anxiety in response to the news that a child is at increased risk for T1D is common. Mothers who have experienced recent negative LE, who experience PD and who accurately understand their child's risk may be particularly vulnerable to high levels of anxiety. The findings reported here need to be confirmed in future prospective studies.

Factors associated with maternal-reported actions to prevent type 1 diabetes in the first year of the TEDDY study.

OBJECTIVE: Mothers of children at risk for type 1 diabetes report engaging in preventive behaviors. The purpose of this study is to further document these actions in an international, longitudinal sample and examine variables that predict whether mothers engage in these behaviors. RESEARCH DESIGN AND METHODS: This study examined an international sample (from Finland, Germany, Sweden, and the U.S.) from the naturalistic, longitudinal The Environmental Determinants of Diabetes in the Young (TEDDY) study, which tracked children genetically at risk for type 1 diabetes from birth to age 15 years. Mothers of 7,613 infants aged 6 months and 6,503 infants aged 15 months completed questionnaires assessing psychosocial factors and actions intended to prevent diabetes. RESULTS: Many mothers (29.9% at 6 months and 42.8% at 15 months) reported engaging in a behavior intended to prevent type 1 diabetes, with the largest percentages (20.9-29.2%) reporting making changes to their child's diet (e.g., reducing the consumption of sweets and carbohydrates). Factors related to engaging in preventive behaviors include older maternal age; higher maternal education; minority status; having only one child; having a first-degree relative with type 1 diabetes; being from a country other than Sweden; having an accurate perception of the child's increased risk for developing diabetes; having postpartum depression, maternal anxiety, and worry about the risk of diabetes; and believing that diabetes can be prevented. CONCLUSIONS: The findings of this study suggest that many mothers engage in actions to prevent diabetes and highlight the importance of tracking these behaviors to ensure the validity of naturalistic observational studies.

Differences in recruitment and early retention among ethnic minority participants in a large pediatric cohort: the TEDDY Study.

OBJECTIVE: The TEDDY Study is an international, multi-center prospective study designed to identify the environmental triggers of type 1 diabetes (T1D) in genetically at-risk children. This report investigates ethnic minority (EM) differences in patterns of enrollment and retention in the US centers. METHODS: As of June 2009, 267,739 newborns had been screened at birth for high risk T1D genotypes. Data collected at the time of screening, enrollment and at the baseline visit were used. Descriptive and multiple-logistic regression analyses assessed differences between EM groups regarding exclusion, enrollment and early withdrawal. RESULTS: Of the 10,975 eligible subjects, 6,912 (67%) were invited to participate. EM subjects were more likely to be excluded because of an inability to contact. Of those invited 3,265 (47%) enrolled by the age of 4.5 months. Adjusted analyses showed that except for those classified as other EM, the odds of enrolling were similar across groups. EM subjects had elevated early withdrawal rates. Adjusted models demonstrated that this was significantly more likely among Hispanic subjects. CONCLUSION: Understanding patterns associated with EM participation in research extends our ability to make more accurate inferences and permits assessment of strategies that promote inclusion of EM to better address health disparities.

Reasons for Staying as a Participant in the Environmental Determinants of Diabetes in the Young (TEDDY) Longitudinal Study.

OBJECTIVE: To assess parents' opinions about their participation in the longitudinal, multicenter study - The Environmental Determinants of Diabetes in the Young (TEDDY) consortium. METHODS: A survey was given to parents who had been in the study for ≥ 1 year. Parents rated the importance of different reasons for staying in TEDDY and how well different study components were working. Parents were also asked if they had suggestions for making TEDDY better and if they ever had thought of leaving TEDDY and if so, why. RESULTS: Out of the 3336 eligible families, 2000 completed the survey (59.1%); most (77.6%) were mothers. Survey completion was more common in European than US TEDDY sites and was associated with greater maternal education, more accurate perceptions about their child's risk of type 1 diabetes, longer participation in TEDDY and excellent attendance at TEDDY visits. "Having someone watching the child for development of T1DM" was most important reason given for staying in the study; other important reasons included "Helping science discover causes of diabetes" and "Getting child's antibody results". Most parents were very satisfied with the different components of TEDDY and had not thought of leaving the study. A minority (24%) of parents acknowledged some thoughts of leaving TEDDY and cited the blood draws, being too busy/not having enough time, the demanding protocol, and food diaries as their reasons for considering leaving. CONCLUSIONS: The study highlights factors important for successful implementation of demanding, longitudinal protocols. Friendly, devoted, skilled and knowledgeable staff with continuity makes the family comfortable. Keeping parents involved and informed on study progress is essential as is making procedures as smooth and painless as possible. Although the study is international the survey results were convergent across countries suggesting that the results have relevance to other similar studies to retain study participants.

Enrollment experiences in a pediatric longitudinal observational study: The Environmental Determinants of Diabetes in the Young (TEDDY) study.

OBJECTIVE: Our objective was to identify characteristics of infants and their families who were enrolled, refused to enroll, or were excluded from The Environmental Determinants of Diabetes in the Young (TEDDY) study. METHOD: 16,435 infants screened at birth and identified as at increased genetic risk for type 1 diabetes (T1DM) were placed into one of three categories: enrolled, excluded, or refused to enroll. Enrollment, exclusion and refusal rates were compared across countries and between infants from the general population (GP) and infants with a first degree T1DM relative (FDR). A multivariate logistic model was used to identify factors associated with TEDDY enrollment. RESULTS: TEDDY enrollment, exclusion, and refusal rates differed by country and by GP/FDR status but reasons for refusal to enroll were similar across countries and GP/FDR populations. Sweden had the highest enrollment rate, US had the highest exclusion rate, and Finland had the highest refusal rate. FDR infants were more likely to enroll than GP infants. Inability to re-contact the family was the most common reason for exclusion. Primary reasons for refusal to enroll included protocol factors (e.g. blood draws) or family factors (e.g., too busy). Study enrollment was associated with FDR status, European country of origin, older maternal age, a singleton birth, and having another child in TEDDY. CONCLUSIONS: Findings highlight the importance of country specific estimates for enrollment targets in longitudinal pediatric studies and suggest that enrollment estimates should be lowered when the study involves the general population, painful procedures, or makes multiple demands on families.

The Environmental Determinants of Diabetes in the Young (TEDDY) study: predictors of early study withdrawal among participants with no family history of type 1 diabetes.

OBJECTIVE: The Environmental Determinants of Diabetes in the Young (TEDDY) study seeks to identify environmental triggers of autoimmunity and type 1 diabetes mellitus (T1DM) in children at increased human-leukocyte-antigen conferred genetic risk for this disease. The objective of this study was to identify predictors of early withdrawal from TEDDY among families with no immediate family history of T1DM. METHOD: Logistic multiple regression was used to discriminate 2994 (83%) families currently active in the TEDDY study for ≥1 yr from 763 (17%) families who withdrew in the first year. Data collected on the screening form at the time of the child's birth and from interview and questionnaire data obtained at the baby's first study visit (at ≤4.5 months of age) were used. RESULTS: Significant and independent predictors of early withdrawal included country of residence, young maternal age, no father participation, and female gender of the study participant. Mothers of children who withdrew were more likely to report smoking during pregnancy, abstaining from alcohol, and reducing their work hours or not working at all during pregnancy. Mothers who withdrew were also more likely to underestimate their child's risk for T1DM and fail to respond to multiple items on the enrollment questionnaires or interview. Among mothers with accurate risk perceptions, those experiencing high anxiety about their child's risk were more likely to be early withdrawals. CONCLUSIONS: Identifying families at high risk for study withdrawal at the time of enrollment allows for targeting these families with individually tailored plans to help maintain their participation in the study.

Multiple factors affect the loss of measurable C-peptide over 6 years in newly diagnosed 15- to 35-year-old diabetic subjects.

OBJECTIVE: The aim of this study is to identify risk factors for the loss of measurable plasma C-peptide in newly diagnosed 15- to 35-year-old diabetic subjects. METHODS: This Swedish study included 778 subjects. C-peptide levels were obtained each year for 6 years after diagnosis. Loss of measurable C-peptide was defined as a level at or below the lower detection limit of the local assay (0.13 nmol/l). In addition to C-peptide, other baseline covariates included gender, age, body mass index, HLA genotype, and autoantibody levels. RESULTS: Compared with autoantibody-negative subjects, autoantibody-positive subjects had lower median baseline C-peptide (0.27 vs. 0.50, P<.001), their levels declined over the study period, and the risk of losing measurable C-peptide was significantly higher when more than one autoantibody was present [odds ratio (OR), 4.0; 95% confidence interval (CI), 2.13-7.54]. Among autoantibody-positive individuals, the presence of GAD65Ab (OR, 1.8; 95% CI, 1.24-2.51) and islet cell antibodies (OR, 1.6; 95% CI, 1.19-2.18) conferred a higher risk for loss of measurable C-peptide as did female gender (OR, 1.6; 95% CI, 1.17-2.11) and time after diagnosis (OR, 1.5 for each additional year postdiagnosis; 95% CI, 1.41-1.57). Higher baseline C-peptide levels were protective (OR, 0.5 for each additional log(e) nanomoles per liter; 95% CI, 0.36-0.58). CONCLUSIONS: This study identified autoantibody status, gender, and baseline C-peptide levels as factors that will be useful for predicting the disease course of 15- to 35-year-old diabetic individuals.

Cord blood islet autoantibodies are related to stress in the mother during pregnancy.

A 2-month psychological questionnaire concerning pregnancy was answered by 20,920 nondiabetic mothers of singletons. Retrospective analysis showed increased levels of islet autoantibodies (IA) in 290 (1.4%) newborns. High IA levels in the child's cord blood correlated strongly with IA levels in the mother (GADA r = 0.91, P < 0.0001; IA-2A r = 0.75, P = 0.0001). High IA levels were found in newborns whose mothers during pregnancy had been more worried than usual (P = 0.04), had worried that the child would be sick (P = 0.01) or not survive (P = 0.002), or had experienced serious life events, like "serious accident in the family" (P < 0.0001) or "experienced violence" (P = 0.02). Associations with increased worries by the mother remained in newborns with high type 1 diabetes mellitus (T1DM)-human leukocyte antigen (HLA) risk, but not in non-HLA risk children. The prospective follow-up of these children will determine the importance of this early IA for postnatal islet autoimmunity, type 1 diabetes, or both.

Parent responses to participation in genetic screening for diabetes risk.

Screening for type 1 diabetes (T1DM) risk in newborns has little negative emotional impact on mothers. In this study, the impact on the mother and the father was evaluated both in the general population and in families with diabetes. All parents with a newborn in Skane, Sweden, were invited to a screening for T1DM risk in their children (the Diabetes Prediction in Skane (DiPiS)). Blood was obtained at delivery from the mother and the child. When the child was 2 months old, parents gave written consent and filled out questionnaires, but were not informed about the genetic risk. Of the 10 538 invited families, 6831 (64.8%) consented and 806 (7.7%) declined participation. Five questions addressing both parents were filled out by 6676 (63.4%) mothers and 6099 (57.8%) fathers. In 146/6676 (2.2%) families, one family member had diabetes (D-families). Participation in DiPiS did not affect most parents and the majority was satisfied with the information. The majority of parents (28.9%) were reassured and only 1.1% (140/12,670) reported increased worries because of participation, compared to 2.8% of the mothers in D-families. Parents in D-families more often ascribed diabetes risk to their child as well as the risk being higher. Mothers and fathers differed in their answers on four of the five study questions, with mothers being more satisfied with the information, reporting more knowledge of diabetes, estimating lower risk of their child to get diabetes, but reporting more worries of possible future chronic disease in the child. Parents with lower education, being born abroad, or being younger who reported worries of chronic disease in the child were also reassured by participation in the study. These results confirm that screening for T1DM risk in newborns does not create worries in most parents, but stress that fathers differ from mothers in opinions and reactions, that parents' reactions are affected by diabetes in the family, and that demographic factors might be important for the parents' reports.

Genetic and perinatal factors as risk for childhood type 1 diabetes.

The mechanisms by which gestational infections, blood incompatibility, birth weight, mother's age and other prenatal or neonatal events increase the risk for type 1 diabetes are not understood. Studies so far have been retrospective, and there is a lack of population-based prospective studies. The possibility of identifying children at type 1 diabetes risk among first-degree relatives has resulted in prospective studies aimed at identifying postnatal events associated with the appearance of autoantibody markers for type 1 diabetes and a possible later onset of diabetes. However, the majority (85%) of new onset type 1 diabetes children do not have a first-degree relative with the disease. Population-based studies are therefore designed to prospectively analyse pregnant mothers and their offspring. One such study is DiPiS (Diabetes Prediction in Skåne), which is examining a total of about 10,000 pregnancies expected every year in the Skåne (Scania) region of Sweden that has 1.1 million inhabitants. Blood samples from all mothers in this region are obtained during pregnancy and at the time of delivery. Cord blood is analysed for HLA high-risk alleles and for autoantibodies against the 65 kD isoform of glutamic acid decarboxylase (GADA), the protein tyrosine phosphatase-related IA-2 antigen (IA-2A) and insulin (IAA) as a measure of prenatal autoimmune exposure. Identifying high-risk children by genetic, autoimmune and gestational risk factors followed by prospective analyses will make it possible to test the hypothesis that gestational events may trigger beta cell autoimmunity as a prerequisite for childhood type 1 diabetes.