Department of Quantitative Health Sciences
Biostatistics | Epidemiology | Health Information Technology | Health Services Research
Web-delivered trials are an important component in eHealth services. These trials, mostly behavior-based, generate big heterogeneous data that are longitudinal, high dimensional with missing values. Unsupervised learning methods have been widely applied in this area, however, validating the optimal number of clusters has been challenging. Built upon our multiple imputation (MI) based fuzzy clustering, MIfuzzy, we proposed a new multiple imputation based validation (MIV) framework and corresponding MIV algorithms for clustering big longitudinal eHealth data with missing values, more generally for fuzzy-logic based clustering methods. Specifically, we detect the optimal number of clusters by auto-searching and -synthesizing a suite of MI-based validation methods and indices, including conventional (bootstrap or cross-validation based) and emerging (modularity-based) validation indices for general clustering methods as well as the specific one (Xie and Beni) for fuzzy clustering. The MIV performance was demonstrated on a big longitudinal dataset from a real web-delivered trial and using simulation. The results indicate MI-based Xie and Beni index for fuzzy-clustering are more appropriate for detecting the optimal number of clusters for such complex data. The MIV concept and algorithms could be easily adapted to different types of clustering that could process big incomplete longitudinal trial data in eHealth services.
UMCCTS funding, Big data, Fuzzy clustering, Longitudinal trial, Missing data, Multiple imputation, Validation
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Posted with publisher's permission.
DOI of Published Version
J Med Syst. 2016 Jun;40(6):146. doi: 10.1007/s10916-016-0499-0. First published online 2016 Apr 28. The final publication is available at Springer via http://dx.doi.org/10.1007/s10916-016-0499-0
Journal of medical systems
Zhang, Zhaoyang; Fang, Hua (Julia); and Wang, Honggang, "Multiple Imputation based Clustering Validation (MIV) for Big Longitudinal Trial Data with Missing Values in eHealth" (2016). Quantitative Health Sciences Publications and Presentations. 1159.