Delaware Chapter, ASA

Dinner Meeting: Setember 2012

NOTE: Times are shifted slightly earlier than usual, starting at 5:45 PM.

Meeting location: Townsend Hall on the University of Delaware campus -- Commons Area. Townsend Hall    

Biostatistician at Nemours Biomedical Research
Title:   Evaluating the performance of clustering using different inputs and algorithms to group children based on early childhood growth patterns

Speaker slides and Meeting photos.


Early childhood growth patterns are potential determinants of body composition and body weight at later ages. Weight-for-length (for age < 2 years) and body mass index (BMI) (for age = 2 years) are commonly used measures of body composition and weight. Standardized scores of these two measures are weight-for-length z-score and BMI z-score. For simplicity, we termed both as bmiz score. We planned to group 3365 children based on patterns of temporal changes in the trajectories of bmiz score of their first five years of life. We calculated or interpolated (when height-weight data for a time point was not available) bmiz score at every six-month interval of age (a total of 11 time points) for each child. We performed exploratory cluster analysis of many algorithms and used several cluster inputs such as bmiz score of different time points (treating bmiz at each time point as a separate variable), random coefficients (that specify the individual growth model) of mixed effects model, principal component (PC) scores, factor scores, and coefficients of auto regressive model for each patient. It was fitted the bmiz of children nested within a cluster as a polynomial function of time to evaluate the cluster performance.


Jobayer Hossain has been working at Nemours, nations one of the largest pediatric health care provider and a leading pediatric health research organization, as a research faculty (biostatistics) for about five years. His primary duties at Nemours include providing statistical assistance to clinicians/researchers with designing clinical trials, pre-clinical, epidemiological and survey studies, power and sample size calculation, randomization, data management, data analysis, writing statistical section of research protocols and manuscripts, and authoring statistical analysis results in clinical study reports/ manuscripts, teaching statistics courses for researchers/medical fellows throughout the Nemours and graduate statistics courses at the University of Delaware. The topic is based on a paper he gave at the JSM Meeting 2012 in San Diego, August 1: Md Jobayer Hossain, Timothy T. Wysocki, Samuel S. Gidding, Mingxing Gong, H. Timothy Bunnell, Optimum Grouping of Children Based on Early Childhood Growth Patterns.

Date: Thursday, September 20, 2012

Social time -- 5:45 pm
Buffet -- 6:00 pm
Speaker -- 6:30 pm

Townsend Hall
South College Ave.
University of Delaware
Newark, DE   Directions/Map
Menu: (Catered by Aramark, University of Delaware Food Services)
Simply Italian
  • Caesar Salad
  • Broccoli with lemon zest
  • Garlic bread
  • Chicken Parmesan
  • Rotini Marinara and Tiramisu

Cost: $20 for members/others, students $5, FREC students free
Reservations to: 

Irina Baldycheva by Monday, September 17, 2012.
Phone: 302-885-9136
Email: Irina Baldycheva.


Note: Please be sure to RSVP by this date. Aramark requires an accurate count of the number of plates three days prior to an event, and we pay by the plate.

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