17 results on '"Vilchuck, Konstantin"'
Search Results
2. Breastfeeding during infancy and neurocognitive function in adolescence: 16-year follow-up of the PROBIT cluster-randomized trial
- Author
-
Yang, Seungmi, Martin, Richard M., Oken, Emily, Hameza, Mikhail, Doniger, Glen, Amit, Shimon, Patel, Rita, Thompson, Jennifer, Rifas-Shiman, Sheryl L., Vilchuck, Konstantin, Bogdanovich, Natalia, and Kramer, Michael S.
- Subjects
Cognitive development -- Research ,Medical research ,Breast feeding -- Psychological aspects ,Biological sciences - Abstract
Background Evidence on the long-term effect of breastfeeding on neurocognitive development is based almost exclusively on observational studies. In the 16-year follow-up study of a large, cluster-randomized trial of a breastfeeding promotion intervention, we evaluated the long-term persistence of the neurocognitive benefits of the breastfeeding promotion intervention previously observed at early school age. Methods and findings A total of 13,557 participants (79.5% of the 17,046 randomized) of the Promotion of Breastfeeding Intervention Trial (PROBIT) were followed up at age 16 from September 2012 to July 2015. At the follow-up, neurocognitive function was assessed in 7 verbal and nonverbal cognitive domains using a computerized, self-administered test battery among 13,427 participants. Using an intention-to-treat (ITT) analysis as our prespecified primary analysis, we estimated cluster- and baseline characteristic-adjusted mean differences between the intervention (prolonged and exclusive breastfeeding promotion modelled on the Baby-Friendly Hospital Initiative) and control (usual care) groups in 7 cognitive domains and a global cognitive score. In our prespecified secondary analysis, we estimated mean differences by instrumental variable (IV) analysis to account for noncompliance with the randomly assigned intervention and estimate causal effects of breastfeeding. The 16-year follow-up rates were similar in the intervention (79.7%) and control groups (79.3%), and baseline characteristics were comparable between the two. In the cluster-adjusted ITT analyses, children in the intervention group did not show statistically significant differences in the scores from children in the control group. Prespecified additional adjustment for baseline characteristics improved statistical precision and resulted in slightly higher scores among children in the intervention for verbal function (1.4 [95% CI 0.3-2.5]) and memory (1.2 [95% CI 0.01-2.4]). IV analysis showed that children who were exclusively breastfed for [greater than or equal to]3 (versus Conclusions We observed no benefit of a breastfeeding promotion intervention on overall neurocognitive function. The only beneficial effect was on verbal function at age 16. The higher verbal ability is consistent with results observed at early school age; however, the effect size was substantially smaller in adolescence. PROBIT trial registration ClinicalTrials.gov NCT01561612, Author(s): Seungmi Yang 1,*, Richard M. Martin 2,3, Emily Oken 4, Mikhail Hameza 5, Glen Doniger 6, Shimon Amit 6, Rita Patel 2, Jennifer Thompson 4, Sheryl L. Rifas-Shiman 4, [...]
- Published
- 2018
- Full Text
- View/download PDF
3. Effects of promoting longer-term and exclusive breastfeeding on childhood eating attitudes: a cluster-randomized trial
- Author
-
Skugarevsky, Oleg, Wade, Kaitlin H, Richmond, Rebecca C, Martin, Richard M, Tilling, Kate, Patel, Rita, Vilchuck, Konstantin, Bogdanovich, Natalia, Sergeichick, Natalia, Davey Smith, George, Gillman, Matthew W, Oken, Emily, and Kramer, Michael S
- Published
- 2014
- Full Text
- View/download PDF
4. Prospective associations between problematic eating attitudes in midchildhood and the future onset of adolescent obesity and high blood pressure123
- Author
-
Wade, Kaitlin H, Kramer, Michael S, Oken, Emily, Timpson, Nicholas J, Skugarevsky, Oleg, Patel, Rita, Bogdanovich, Natalia, Vilchuck, Konstantin, Davey Smith, George, Thompson, Jennifer, and Martin, Richard M
- Subjects
Male ,Health Knowledge, Attitudes, Practice ,Pediatric Obesity ,problematic eating attitudes ,Adolescent ,Obesity and Eating Disorders ,Blood Pressure ,Body Mass Index ,Risk Factors ,Surveys and Questionnaires ,Cluster Analysis ,Humans ,adolescents ,Prospective Studies ,Child ,Adiposity ,Feeding Behavior ,prospective ,Overweight ,Socioeconomic Factors ,Hypertension ,Multivariate Analysis ,Female ,Follow-Up Studies - Abstract
Background: Clinically diagnosed eating disorders may have adverse cardiometabolic consequences, including overweight or obesity and high blood pressure. However, the link between problematic eating attitudes in early adolescence, which can lead to disordered eating behaviors, and future cardiometabolic health is, to our knowledge, unknown. Objective: We assessed whether variations in midchildhood eating attitudes influence the future development of overweight or obesity and high blood pressure. Design: Of 17,046 children who participated in the Promotion of Breastfeeding Intervention Trial (PROBIT), we included 13,557 participants (79.5% response rate) who completed the Children’s Eating Attitudes Test (ChEAT) at age 11.5 y and in whom we measured adiposity and blood pressure at ages 6.5, 11.5, and 16 y. We assessed whether ChEAT scores ≥85th percentile (indicative of problematic eating attitudes) compared with scores
- Published
- 2016
5. Ongoing monitoring of data clustering in multicenter studies
- Author
-
Guthrie Lauren B, Oken Emily, Sterne Jonathan AC, Gillman Matthew W, Patel Rita, Vilchuck Konstantin, Bogdanovich Natalia, Kramer Michael S, and Martin Richard M
- Subjects
Medicine (General) ,R5-920 - Abstract
Abstract Background Multicenter study designs have several advantages, but the possibility of non-random measurement error resulting from procedural differences between the centers is a special concern. While it is possible to address and correct for some measurement error through statistical analysis, proactive data monitoring is essential to ensure high-quality data collection. Methods In this article, we describe quality assurance efforts aimed at reducing the effect of measurement error in a recent follow-up of a large cluster-randomized controlled trial through periodic evaluation of intraclass correlation coefficients (ICCs) for continuous measurements. An ICC of 0 indicates the variance in the data is not due to variation between the centers, and thus the data are not clustered by center. Results Through our review of early data downloads, we identified several outcomes (including sitting height, waist circumference, and systolic blood pressure) with higher than expected ICC values. Further investigation revealed variations in the procedures used by pediatricians to measure these outcomes. We addressed these procedural inconsistencies through written clarification of the protocol and refresher training workshops with the pediatricians. Further data monitoring at subsequent downloads showed that these efforts had a beneficial effect on data quality (sitting height ICC decreased from 0.92 to 0.03, waist circumference from 0.10 to 0.07, and systolic blood pressure from 0.16 to 0.12). Conclusions We describe a simple but formal mechanism for identifying ongoing problems during data collection. The calculation of the ICC can easily be programmed and the mechanism has wide applicability, not just to cluster randomized controlled trials but to any study with multiple centers or with multiple observers.
- Published
- 2012
- Full Text
- View/download PDF
6. The effect of an intervention to promote breastfeeding on asthma, lung function and atopic eczema at age 16 years
- Author
-
Flohr, Carsten, Henderson, A. John, Kramer, Michael S., Patel, Rita, Thompson, Jennifer, Rifas-Shiman, Sheryl L., Yang, Seungmi, Vilchuck, Konstantin, Bogdanovich, Natalia, Hameza, Mikhail, Martin, Richard M., and Oken, Emily
- Subjects
Adult ,Male ,Adolescent ,Vital Capacity ,Infant, Newborn ,Health Promotion ,Article ,Asthma ,Dermatitis, Atopic ,Young Adult ,Breast Feeding ,Spirometry ,Forced Expiratory Volume ,Humans ,Female ,Follow-Up Studies - Abstract
Atopic diseases, including asthma and atopic eczema, are the most common chronic conditions of childhood.To investigate whether an intervention to promote prolonged and exclusive breastfeeding protects against asthma, atopic eczema, and low lung function in adolescence.Follow-up of the Promotion of Breastfeeding Intervention Trial (PROBIT), a cluster randomized trial in 30 Belarusian maternity hospitals and affiliated polyclinics; recruitment of 17 046 healthy term infants took place from June 15, 1996, to December 31, 1997. Data analysis was conducted from May 9, 2016, to April 21, 2017. The primary analytic approach was by modified intention-to-treat analysis.Randomization to receive a breastfeeding promotion intervention vs usual care.Spirometry and flexural eczema on standardized skin examination by study pediatricians were the primary outcomes; secondary outcomes were self-reported asthma diagnosis ever, and wheezing and flexural eczema symptoms in the previous year.A total of 13 557 (79.5%) participants were followed up from September 15, 2012 to July 15, 2015. The intervention (7064 [79.7%]) and control (6493 [79.4%]) groups were similar at follow-up (3590 [50.8%] and 3391 [52.2%] male; mean [SD] age, 16.2 [0.6] and 16.1 [0.5] years, respectively). In the intervention group, 0.3% (21 of 7064) had flexural eczema on skin examination and mean (SD) forced expiratory volume in the first second of expiration/forced vital capacity (FEV1/FVC) ratio z score was -0.10 (1.82), compared with 0.7% (43 of 6493) and 0.35 (1.34), respectively, in the control group. In modified intention-to-treat analysis, accounting for clustering by polyclinic, a 54% lower risk of flexural eczema on skin examination was observed in the intervention compared with the control group (odds ratio [OR], 0.46; 95% CI, 0.25 to 0.86). Self-reported flexural eczema symptoms in the past year (OR, 0.57; 95% CI, 0.27 to 1.18), asthma (OR, 0.76; 95% CI, 0.47 to 1.23), and wheezing in the past year (OR, 0.66; 95% CI, 0.37 to 1.18) were less frequently reported in the intervention compared with the control group, but 95% CIs were wide and included the null. There was no significant difference in the FEV1/FVC ratio z score (β -0.15; 95% CI, -0.76 to 0.45). All results were similar with additional adjustment for baseline characteristics, on instrumental variable analysis, and with multiple imputation among all 17 046 randomized participants.A breastfeeding promotion intervention reduced flexural dermatitis risk but had no detectable effect on lung function or questionnaire-derived measures of atopic eczema or asthma in adolescence in a setting where atopic eczema and allergies are rare.clinicaltrials.gov Identifier: NCT01561612.
- Published
- 2018
7. Effects of promoting longer-term and exclusive breastfeeding on adolescent adiposity, blood pressure, and longitudinal growth trajectories: evidence from the PROBIT cluster-randomized trial
- Author
-
Martin, Richard M, Kramer, Michael S., Patel, Rita, Rifas-Shiman, Sheryl L., Thompson, Jennifer, Yang, Seungmi, Vilchuck, Konstantin, Bogdanovich, Natalia, Hameza, Mikhail, Tilling, Kate, and Oken, Emily
- Subjects
Male ,Adolescent ,Blood Pressure ,Growth ,Article ,Body Mass Index ,Breast Feeding ,Risk Factors ,Cluster Analysis ,Humans ,Female ,Obesity ,Waist Circumference ,Adiposity ,Follow-Up Studies - Abstract
Evidence that breastfeeding reduces child obesity risk and lowers blood pressure (BP) is based on potentially confounded observational studies.To investigate the effects of a breastfeeding promotion intervention on adiposity and BP at age 16 years and on longitudinal growth trajectories from birth.Cluster-randomized Promotion of Breastfeeding Intervention Trial. Belarusian maternity hospitals and affiliated polyclinics (the clusters) were allocated into intervention (n = 16) or control arms (n = 15) in 1996 and 1997. The trial participants were 17 046 breastfeeding mother-infant pairs; of these, 13 557 children (79.5%) were followed up at 16 years of age between September 2012 and July 2015.Breastfeeding promotion, modeled on the Baby-Friendly Hospital Initiative.Body mass index (BMI, calculated as weight in kilograms divided by height in meters squared); fat and fat-free mass indices and percentage of body fat from bioimpedance; waist circumference; overweight and obesity; height; BP; and longitudinal growth trajectories. The primary analysis was modified intention-to-treat (without imputation for losses to follow-up) accounting for within-clinic clustering.We examined 13 557 children at a median age of 16.2 years (48.5% were girls). The intervention substantially increased breastfeeding duration and exclusivity compared with the control arm (exclusively breastfed: 45% vs 6% at 3 months, respectively). Mean differences at 16 years between intervention and control groups were 0.21 (95% CI, 0.06-0.36) for BMI; 0.21 kg/m2 (95% CI, -0.03 to 0.44) for fat mass index; 0.00 kg/m2 (95% CI, -0.21 to 0.22) for fat-free mass index; 0.71% (95% CI, -0.32 to 1.74) for percentage body fat; -0.73 cm (-2.48 to 1.02) for waist circumference; 0.05 cm (95% CI, -0.85 to 0.94) for height; -0.54 mm Hg (95% CI, -2.40 to 1.31) for systolic BP; and 0.71 mm Hg (95% CI, -0.68 to 2.10) for diastolic BP. The odds ratio for overweight/obesity (BMI ≥85th percentile vs85th percentile) was 1.14 (95% CI, 1.02-1.28) and the odds ratio for obesity (BMI ≥95th percentile vs95th percentile) was 1.09 (95% CI, 0.92-1.29). The intervention resulted in a more rapid rate of gain in postinfancy height (1 to 2.8 years), weight (2.8 to 14.5 years), and BMI (2.8 to 8.5 years) compared with the control arm. The intervention had little effect on BMI z score changes after 8.5 years.A randomized intervention that increased the duration and exclusivity of breastfeeding was not associated with lowered adolescent obesity risk or BP. On the contrary, the prevalence of overweight/obesity was higher in the intervention arm. All mothers initiated breastfeeding, so findings may not apply to comparisons of the effects of breastfeeding vs formula feeding.isrctn.org: ISRCTN37687716; and clinicaltrials.gov: NCT01561612.
- Published
- 2017
8. Prospective associations between problematic eating attitudes in midchildhood and the future onset of adolescent obesity and high blood pressure
- Author
-
Wade, Kaitlin H, primary, Kramer, Michael S, additional, Oken, Emily, additional, Timpson, Nicholas J, additional, Skugarevsky, Oleg, additional, Patel, Rita, additional, Bogdanovich, Natalia, additional, Vilchuck, Konstantin, additional, Davey Smith, George, additional, Thompson, Jennifer, additional, and Martin, Richard M, additional
- Published
- 2017
- Full Text
- View/download PDF
9. The Association of Early Childhood Cognitive Development and Behavioural Difficulties with Pre-Adolescent Problematic Eating Attitudes
- Author
-
Richmond, Rebecca C., primary, Skugarevsky, Oleg, additional, Yang, Seungmi, additional, Kramer, Michael S., additional, Wade, Kaitlin H., additional, Patel, Rita, additional, Bogdanovich, Natalia, additional, Vilchuck, Konstantin, additional, Sergeichick, Natalia, additional, Smith, George Davey, additional, Oken, Emily, additional, and Martin, Richard M., additional
- Published
- 2014
- Full Text
- View/download PDF
10. Effects of Promoting Longer-Term and Exclusive Breastfeeding on Cardiometabolic Risk Factors at Age 11.5 Years
- Author
-
Martin, Richard M., primary, Patel, Rita, additional, Kramer, Michael S., additional, Vilchuck, Konstantin, additional, Bogdanovich, Natalia, additional, Sergeichick, Natalia, additional, Gusina, Nina, additional, Foo, Ying, additional, Palmer, Tom, additional, Thompson, Jennifer, additional, Gillman, Matthew W., additional, Smith, George Davey, additional, and Oken, Emily, additional
- Published
- 2014
- Full Text
- View/download PDF
11. Effects of promoting increased duration and exclusivity of breastfeeding on adiposity and insulin-like growth factor-I at age 11.5 years:a randomized trial
- Author
-
Martin, Richard M., Patel, Rita, Kramer, Michael S., Guthrie, Lauren, Vilchuck, Konstantin, Bogdanovich, Natalia, Sergeichick, Natalia, Gusina, Nina, Foo, Ying, Palmer, Tom, Rifas-Shiman, Sheryl L., Gillman, Matthew W., Davey Smith, George, Oken, Emily, Martin, Richard M., Patel, Rita, Kramer, Michael S., Guthrie, Lauren, Vilchuck, Konstantin, Bogdanovich, Natalia, Sergeichick, Natalia, Gusina, Nina, Foo, Ying, Palmer, Tom, Rifas-Shiman, Sheryl L., Gillman, Matthew W., Davey Smith, George, and Oken, Emily
- Abstract
IMPORTANCE: Evidence that increased duration and exclusivity of breastfeeding reduces child obesity risk is based on observational studies that are prone to confounding. OBJECTIVE: To investigate effects of an intervention to promote increased duration and exclusivity of breastfeeding on child adiposity and circulating insulin-like growth factor (IGF)-I (which regulates growth). DESIGN: Cluster-randomized controlled trial. SETTING: 31 Belarusian maternity hospitals and their affiliated polyclinics, randomized to usual practices (n=15) or a breastfeeding promotion intervention (n=16). PARTICIPANTS: 17,046 breastfeeding mother-infant pairs enrolled in 1996/7, of whom 13,879 (81.4%) were followed-up between January 2008 and December 2010 at a median age of 11.5 years. INTERVENTION: Breastfeeding promotion intervention modeled on the WHO/UNICEF Baby Friendly Hospital Initiative. MAIN OUTCOME MEASURES: Body mass index (BMI), fat and fat-free mass indices (FMI and FFMI), percent body fat, waist circumference, triceps and subscapular skinfold thicknesses, overweight and obesity, and whole-blood IGF-I. Primary analysis was based on modified intention-to-treat (without imputation), accounting for clustering within hospitals/clinics. RESULTS: The experimental intervention substantially increased breastfeeding duration and exclusivity (43% vs. 6% and 7.9% vs. 0.6% exclusively breastfed at 3 and 6 months, respectively) versus the control intervention. Cluster-adjusted mean differences in outcomes at 11.5 years between experimental vs. control groups were: 0.19 kg/m(2) (95% 4 CI: −0.09, 0.46) for BMI; 0.12 kg/m(2) (−0.03, 0.28) for FMI; 0.04 kg/m(2) (−0.11, 0.18) for FFMI; 0.47% (−0.11, 1.05) for % body fat; 0.30 cm (−1.41, 2.01) for waist circumference; −0.07 mm (−1.71, 1.57) for triceps and −0.02 mm (−0.79, 0.75) for subscapular skinfold thicknesses; and −0.02 standard deviations (−0.12, 0.08) for IGF-I. The cluster-adjusted odds ratio for overweight / obesity (BMI ≥85(th) per
- Published
- 2013
12. Effects of an intervention to promote breastfeeding on maternal adiposity and blood pressure at 11.5 y postpartum:results from the Promotion of Breastfeeding Intervention Trial, a cluster-randomized controlled trial
- Author
-
Oken, Emily, Patel, Rita, Guthrie, Lauren B., Vilchuck, Konstantin, Bogdanovich, Natalia, Sergeichick, Natalia, Palmer, Tom M., Kramer, Michael S., Martin, Richard M., Oken, Emily, Patel, Rita, Guthrie, Lauren B., Vilchuck, Konstantin, Bogdanovich, Natalia, Sergeichick, Natalia, Palmer, Tom M., Kramer, Michael S., and Martin, Richard M.
- Abstract
BACKGROUND: Differences between mothers who do and do not succeed in breastfeeding are likely to confound associations of lactation with later maternal adiposity. OBJECTIVE: We compared adiposity and blood pressure (BP) in women randomly assigned to an intervention to promote prolonged and exclusive breastfeeding or usual care. DESIGN: We performed a cluster-randomized trial at 31 hospitals in Belarus in 1996-1997. RESULTS: Of 17,046 women enrolled at delivery, we assessed 11,867 women (69.6%) at 11.5 y postpartum. The prevalence of exclusive breastfeeding ≥3 mo was 44.5% in 6321 women in the intervention group and 7.1% in 5546 women in the control group. At 11.5 y postpartum, mean (±SD) body mass index (BMI; in kg/m(2)) was 26.5 ± 5.5, the percentage of body fat was 33.6% ± 8.3%, and systolic BP was 124.6 ± 14.6 mm Hg. On intention-to-treat analysis (without imputation) with adjustment for clustering by hospital, mean outcomes were lower in intervention compared with control mothers for BMI (mean difference: -0.27; 95% CI: -0.91, 0.37), body fat (-0.49%; 95% CI: -1.25%, 0.27%), and systolic BP (-0.81 mm Hg; 95% CI: -3.33, 1.71 mm Hg), but effect sizes were small, CIs were wide, and results were attenuated further toward the null after adjustment for baseline characteristics. Results were similar in sensitivity analyses [ie, by using conventional observational analyses disregarding treatment assignment, instrumental variable analyses to estimate the causal effect of breastfeeding, and multiple imputation to account for missing outcome measures (n = 17,046)]. CONCLUSION: In women who initiated breastfeeding, an intervention to promote longer breastfeeding duration did not result in an important lowering of adiposity or BP. This trial was registered at clinicaltrials.gov as NCT01561612 and at Current Controlled Trials as ISRCTN37687716.
- Published
- 2013
13. Filter Paper Blood Spot Enzyme Linked Immunoassay for Adiponectin and Application in the Evaluation of Determinants of Child Insulin Sensitivity
- Author
-
Martin, Richard M., primary, Patel, Rita, additional, Oken, Emily, additional, Thompson, Jennifer, additional, Zinovik, Alexander, additional, Kramer, Michael S., additional, Vilchuck, Konstantin, additional, Bogdanovich, Natalia, additional, Sergeichick, Natalia, additional, Foo, Ying, additional, and Gusina, Nina, additional
- Published
- 2013
- Full Text
- View/download PDF
14. Cohort Profile: The Promotion of Breastfeeding Intervention Trial (PROBIT)
- Author
-
Patel, Rita, primary, Oken, Emily, additional, Bogdanovich, Natalia, additional, Matush, Lidia, additional, Sevkovskaya, Zinaida, additional, Chalmers, Beverley, additional, Hodnett, Ellen D, additional, Vilchuck, Konstantin, additional, Kramer, Michael S, additional, and Martin, Richard M, additional
- Published
- 2013
- Full Text
- View/download PDF
15. Filter Paper Blood Spot Enzyme Linked Immunoassay for Insulin and Application in the Evaluation of Determinants of Child Insulin Resistance
- Author
-
Martin, Richard M., primary, Patel, Rita, additional, Zinovik, Alexander, additional, Kramer, Michael S., additional, Oken, Emily, additional, Vilchuck, Konstantin, additional, Bogdanovich, Natalia, additional, Sergeichick, Natalia, additional, Gunnarsson, Robert, additional, Grufman, Lisa, additional, Foo, Ying, additional, and Gusina, Nina, additional
- Published
- 2012
- Full Text
- View/download PDF
16. Cohort Profile: The Promotion of Breastfeeding Intervention Trial (PROBIT).
- Author
-
Patel, Rita, Oken, Emily, Bogdanovich, Natalia, Matush, Lidia, Sevkovskaya, Zinaida, Chalmers, Beverley, Hodnett, Ellen D, Vilchuck, Konstantin, Kramer, Michael S, and Martin, Richard M
- Subjects
BREASTFEEDING ,RANDOMIZED controlled trials ,GASTROINTESTINAL diseases ,FOLLOW-up studies (Medicine) ,RESPIRATORY infections ,BLOOD pressure ,APOLIPOPROTEINS - Abstract
SummaryThe PROmotion of Breastfeeding Intervention Trial (PROBIT) is a multicentre, cluster-randomized controlled trial conducted in the Republic of Belarus, in which the experimental intervention was the promotion of increased breastfeeding duration and exclusivity, modelled on the Baby-friendly hospital initiative. Between June 1996 and December 1997, 17 046 mother–infant pairs were recruited during their postpartum hospital stay from 31 maternity hospitals, of which 16 hospitals and their affiliated polyclinics had been randomly assigned to the arm of PROBIT investigating the promotion of breastfeeding and 15 had been assigned to the control arm, in which breastfeeding practices and policies in effect at the time of randomization was continued. Of the mother–infant pairs originally recruited for the study, 16 492 (96.7%) were followed at regular intervals until the infants were 12 months of age (PROBIT I) for the outcomes of breastfeeding duration and exclusivity; gastrointestinal and respiratory infections; and atopic eczema. Subsequently, 13 889 (81.5%) of the children from these mother–infant pairs were followed-up at age 6.5 years (PROBIT II) for anthropometry, blood pressure (BP), behaviour, dental health, cognitive function, asthma and atopy outcomes, and 13 879 (81.4%) children were followed to the age of 11.5 years (PROBIT III) for anthropometry, body composition, BP, and the measurement of fasted glucose, insulin, adiponectin, insulin-like growth factor-I, and apolipoproteins. The trial registration number for Current Controlled Trials is ISRCTN37687716 and that for ClinicalTrials.gov is NCT01561612. Proposals for collaboration are welcome, and enquires about PROBIT should be made to an executive group of the study steering committee (M.S.K., R.M.M., and E.O.). More information, including information about how to access the trial data, data collection documents, and bibliography, is available at the trial website (http://www.bristol.ac.uk/social-community-medicine/projects/probit/). [ABSTRACT FROM PUBLISHER]
- Published
- 2014
- Full Text
- View/download PDF
17. Ongoing Monitoring Of Data Clustering In Multicenter Studies
- Author
-
Patel, Rita, Vilchuck, Konstantin, Bogdanovich, Natalia, Oken, Emily, Gillman, Matthew William, Guthrie, Lauren B., Sterne, Jonathan A.C., Kramer, Michael S., and Martin, Richard M.
- Abstract
Background: Multicenter study designs have several advantages, but the possibility of non-random measurement error resulting from procedural differences between the centers is a special concern. While it is possible to address and correct for some measurement error through statistical analysis, proactive data monitoring is essential to ensure high-quality data collection. Methods: In this article, we describe quality assurance efforts aimed at reducing the effect of measurement error in a recent follow-up of a large cluster-randomized controlled trial through periodic evaluation of intraclass correlation coefficients (ICCs) for continuous measurements. An ICC of 0 indicates the variance in the data is not due to variation between the centers, and thus the data are not clustered by center. Results: Through our review of early data downloads, we identified several outcomes (including sitting height, waist circumference, and systolic blood pressure) with higher than expected ICC values. Further investigation revealed variations in the procedures used by pediatricians to measure these outcomes. We addressed these procedural inconsistencies through written clarification of the protocol and refresher training workshops with the pediatricians. Further data monitoring at subsequent downloads showed that these efforts had a beneficial effect on data quality (sitting height ICC decreased from 0.92 to 0.03, waist circumference from 0.10 to 0.07, and systolic blood pressure from 0.16 to 0.12). Conclusions: We describe a simple but formal mechanism for identifying ongoing problems during data collection. The calculation of the ICC can easily be programmed and the mechanism has wide applicability, not just to cluster randomized controlled trials but to any study with multiple centers or with multiple observers.
- Published
- 2012
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.