| 1. |
- Haghighi, Mona, et al.
(författare)
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A Comparison of Rule-based Analysis with Regression Methods in Understanding the Risk Factors for Study Withdrawal in a Pediatric Study
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Regression models are extensively used in many epidemiological studies to understand the linkage between specific outcomes of interest and their risk factors. However, regression models in general examine the average effects of the risk factors and ignore subgroups with different risk profiles. As a result, interventions are often geared towards the average member of the population, without consideration of the special health needs of different subgroups within the population. This paper demonstrates the value of using rule-based analysis methods that can identify subgroups with heterogeneous risk profiles in a population without imposing assumptions on the subgroups or method. The rules define the risk pattern of subsets of individuals by not only considering the interactions between the risk factors but also their ranges. We compared the rule-based analysis results with the results from a logistic regression model in The Environmental Determinants of Diabetes in the Young (TEDDY) study. Both methods detected a similar suite of risk factors, but the rule-based analysis was superior at detecting multiple interactions between the risk factors that characterize the subgroups. A further investigation of the particular characteristics of each subgroup may detect the special health needs of the subgroup and lead to tailored interventions.
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| 2. |
- Lundgren, Markus, et al.
(författare)
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Analgesic antipyretic use among young children in the TEDDY study : No association with islet autoimmunity
- 2017
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Ingår i: BMC Pediatrics. - : Springer Science and Business Media LLC. - 1471-2431. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: The use of analgesic antipyretics (ANAP) in children have long been a matter of controversy. Data on their practical use on an individual level has, however, been scarce. There are indications of possible effects on glucose homeostasis and immune function related to the use of ANAP. The aim of this study was to analyze patterns of analgesic antipyretic use across the clinical centers of The Environmental Determinants of Diabetes in the Young (TEDDY) prospective cohort study and test if ANAP use was a risk factor for islet autoimmunity. Methods: Data were collected for 8542 children in the first 2.5 years of life. Incidence was analyzed using logistic regression with country and first child status as independent variables. Holm's procedure was used to adjust for multiplicity of intercountry comparisons. Time to autoantibody seroconversion was analyzed using a Cox proportional hazards model with cumulative analgesic use as primary time dependent covariate of interest. For each categorization, a generalized estimating equation (GEE) approach was used. Results: Higher prevalence of ANAP use was found in the U.S. (95.7%) and Sweden (94.8%) compared to Finland (78.1%) and Germany (80.2%). First-born children were more commonly given acetaminophen (OR 1.26; 95% CI 1.07, 1.49; p = 0.007) but less commonly Non-Steroidal Anti-inflammatory Drugs (NSAID) (OR 0.86; 95% CI 0.78, 0.95; p = 0.002). Acetaminophen and NSAID use in the absence of fever and infection was more prevalent in the U.S. (40.4%; 26.3% of doses) compared to Sweden, Finland and Germany (p < 0.001). Acetaminophen or NSAID use before age 2.5 years did not predict development of islet autoimmunity by age 6 years (HR 1.02, 95% CI 0.99-1.09; p = 0.27). In a sub-analysis, acetaminophen use in children with fever weakly predicted development of islet autoimmunity by age 3 years (HR 1.05; 95% CI 1.01-1.09; p = 0.024). Conclusions: ANAP use in young children is not a risk factor for seroconversion by age 6 years. Use of ANAP is widespread in young children, and significantly higher in the U.S. compared to other study sites, where use is common also in absence of fever and infection.
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| 3. |
- Oresic, Matej, 1967-, et al.
(författare)
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Dysregulation of lipid and amino acid metabolism precedes islet autoimmunity in children who later progress to type 1 diabetes
- 2008
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Ingår i: Journal of Experimental Medicine. - New York, USA : Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 205:13, s. 2975-2984
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Tidskriftsartikel (refereegranskat)abstract
- The risk determinants of type 1 diabetes, initiators of autoimmune response, mechanisms regulating progress toward beta cell failure, and factors determining time of presentation of clinical diabetes are poorly understood. We investigated changes in the serum metabolome prospectively in children who later progressed to type 1 diabetes. Serum metabolite profiles were compared between sample series drawn from 56 children who progressed to type 1 diabetes and 73 controls who remained nondiabetic and permanently autoantibody negative. Individuals who developed diabetes had reduced serum levels of succinic acid and phosphatidylcholine (PC) at birth, reduced levels of triglycerides and antioxidant ether phospholipids throughout the follow up, and increased levels of proinflammatory lysoPCs several months before seroconversion to autoantibody positivity. The lipid changes were not attributable to HLA-associated genetic risk. The appearance of insulin and glutamic acid decarboxylase autoantibodies was preceded by diminished ketoleucine and elevated glutamic acid. The metabolic profile was partially normalized after the seroconversion. Autoimmunity may thus be a relatively late response to the early metabolic disturbances. Recognition of these preautoimmune alterations may aid in studies of disease pathogenesis and may open a time window for novel type 1 diabetes prevention strategies.
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| 4. |
- Arkkola, Tuula, et al.
(författare)
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Relationship of maternal weight status and weight gain rate during pregnancy to the development of advanced beta cell autoimmunity in the offspring : a prospective birth cohort study
- 2011
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Ingår i: Pediatric Diabetes. - : WILEY. - 1399-543X .- 1399-5448. ; 12:5, s. 478-484
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This study set out to examine how maternal initial body mass index (BMI) and weight gain during pregnancy associate with advanced beta cell autoimmunity in the offspring. Subjects: A population-based birth cohort of 4093 children with increased human leukocyte antigen (HLA)-conferred susceptibility to type 1 diabetes (T1D) and their mothers were recruited between 1997 and 2002 in two university hospital regions in Finland. Methods: The children were monitored for T1D-associated autoantibodies at 3- to 12-month intervals. Advanced beta cell autoimmunity was defined as repeated positivity for islet cell antibodies and at least one of the other three autoantibodies (antibodies to insulin, glutamate decarboxylase and islet antigen 2). Mothers were asked to record the results of the weight measurements during their first and last visits to the antenatal clinic. The initial BMI and weight gain rate were calculated for each woman. Results: Altogether, 175 children developed advanced beta cell autoimmunity or T1D during the follow-up. Maternal BMI before pregnancy or weight gain during pregnancy was not associated with the end-point. Maternal vocational education was associated with child's smaller risk of developing advanced beta cell autoimmunity.
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| 5. |
- Baxter, Judith, et al.
(författare)
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Differences in recruitment and early retention among ethnic minority participants in a large pediatric cohort: The TEDDY Study
- 2012
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Ingår i: Contemporary Clinical Trials. - : Elsevier BV. - 1551-7144. ; 33:4, s. 633-640
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Tidskriftsartikel (refereegranskat)abstract
- 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. (C) 2012 Elsevier Inc. All rights reserved.
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| 6. |
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| 7. |
- Johnson, Suzanne Bennett, et al.
(författare)
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Predicting Later Study Withdrawal in Participants Active in a Longitudinal Birth Cohort Study for 1 Year: The TEDDY Study.
- 2016
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Ingår i: Journal of Pediatric Psychology. - : Oxford University Press (OUP). - 1465-735X .- 0146-8693. ; 41:3, s. 373-383
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 8. |
- Johnson, Suzanne Bennett, et al.
(författare)
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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.
- 2011
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Ingår i: Pediatric Diabetes. - : Hindawi Limited. - 1399-543X. ; 12, s. 165-171
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Tidskriftsartikel (refereegranskat)abstract
- Johnson SB, Lee H-S, Baxter J, Lernmark B, Roth R, Simell T for the TEDDY Study Group. 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.
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| 9. |
- Lernmark, Barbro, et al.
(författare)
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Enrollment experiences in a pediatric longitudinal observational study: The Environmental Determinants of Diabetes in the Young (TEDDY) study.
- 2011
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Ingår i: Contemporary Clinical Trials. - : Elsevier BV. - 1551-7144. ; 32, s. 517-523
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 10. |
- Lernmark, Barbro, et al.
(författare)
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Participant Experiences in the Environmental Determinants of Diabetes in the Young Study: Common Reasons for Withdrawing.
- 2016
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Ingår i: Journal of Diabetes Research. - : Hindawi Limited. - 2314-6753 .- 2314-6745. ; 2016
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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