114 research outputs found

    Subtyping of common complex diseases and disorders by integrating heterogeneous data. Identifying clusters among women with lower urinary tract symptoms in the LURN study.

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    We present a methodology for subtyping of persons with a common clinical symptom complex by integrating heterogeneous continuous and categorical data. We illustrate it by clustering women with lower urinary tract symptoms (LUTS), who represent a heterogeneous cohort with overlapping symptoms and multifactorial etiology. Data collected in the Symptoms of Lower Urinary Tract Dysfunction Research Network (LURN), a multi-center observational study, included self-reported urinary and non-urinary symptoms, bladder diaries, and physical examination data for 545 women. Heterogeneity in these multidimensional data required thorough and non-trivial preprocessing, including scaling by controls and weighting to mitigate data redundancy, while the various data types (continuous and categorical) required novel methodology using a weighted Tanimoto indices approach. Data domains only available on a subset of the cohort were integrated using a semi-supervised clustering approach. Novel contrast criterion for determination of the optimal number of clusters in consensus clustering was introduced and compared with existing criteria. Distinctiveness of the clusters was confirmed by using multiple criteria for cluster quality, and by testing for significantly different variables in pairwise comparisons of the clusters. Cluster dynamics were explored by analyzing longitudinal data at 3- and 12-month follow-up. Five clusters of women with LUTS were identified using the developed methodology. None of the clusters could be characterized by a single symptom, but rather by a distinct combination of symptoms with various levels of severity. Targeted proteomics of serum samples demonstrated that differentially abundant proteins and affected pathways are different across the clusters. The clinical relevance of the identified clusters is discussed and compared with the current conventional approaches to the evaluation of LUTS patients. The rationale and thought process are described for the selection of procedures for data preprocessing, clustering, and cluster evaluation. Suggestions are provided for minimum reporting requirements in publications utilizing clustering methodology with multiple heterogeneous data domains

    Best practices to optimize utilization of the National Living Donor Assistance Center for the financial assistance of living organ donors.

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    Living organ donors face direct costs when donating an organ, including transportation, lodging, meals, and lost wages. For those most in need, the National Living Donor Assistance Center (NLDAC) provides reimbursement to defray travel and subsistence costs associated with living donor evaluation, surgery, and follow-up. While this program currently supports 9% of all US living donors, there is tremendous variability in its utilization across US transplant centers, which may limit patient access to living donor transplantation. Based on feedback from the transplant community, NLDAC convened a Best Practices Workshop on August 2, 2018, in Arlington, VA, to identify strategies to optimize transplant program utilization of this valuable resource. Attendees included team members from transplant centers that are high NLDAC users; the NLDAC program team; and Advisory Group members. After a robust review of NLDAC data and engagement in group discussions, the workgroup identified concrete best practices for administrative and transplant center leadership involvement; for individuals filing NLDAC applications at transplant centers; and to improve patient education about potential financial barriers to living organ donation. Multiple opportunities were identified for intervention to increase transplant programs\u27 NLDAC utilization and reduce financial burdens inhibiting expansion of living donor transplantation in the United States

    Life and expectations post-kidney transplant: a qualitative analysis of patient responses

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    Abstract Background The effect of a kidney transplant on a recipient extends beyond the restoration of kidney function. However, there is limited qualitative analysis of recipient perspectives on life following transplantation, particularly in the United States. To understand the full patient experience, it is necessary to understand recipient views on life adjustments after kidney transplantation, medical management, and quality of life. This could lead to improvements in recipient care and sense of well-being. Methods We conducted a paper-based survey from March 23 to October 1, 2015 of 476 kidney transplant recipients at the University of Michigan Health System in Ann Arbor, Michigan. We analyzed their open-ended responses using qualitative research methods. This is a companion analysis to a previous quantitative report on the closed-ended responses to that survey. Results Common themes relating to changes following transplantation included: improvements in quality of life, a return to normalcy, better health and more energy. Concerns included: duration of graft survival, fears about one day returning to dialysis or needing to undergo another kidney transplant, comorbidities, future quality of life, and the cost and quality of their healthcare. Many recipients were grateful for their transplant, but some were anxious about the burdens transplantation placed on their loved ones. Conclusions While most recipients reported meaningful improvements in health and lifestyle after kidney transplantation, a minority of participants experienced declines in energy or health status. Worries about how long the transplant will function, future health, and cost and quality of healthcare are prevalent. Future research could study the effects of providing additional information, programs, and interventions following transplantation that target these concerns. This may better prepare and support kidney recipients and lead to improvements in the patient experience.https://deepblue.lib.umich.edu/bitstream/2027.42/149149/1/12882_2019_Article_1368.pd

    Clustering of the structures by using "snakes-&-dragons" approach, or correlation matrix as a signal.

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    Biological, ecological, social, and technological systems are complex structures with multiple interacting parts, often represented by networks. Correlation matrices describing interdependency of the variables in such structures provide key information for comparison and classification of such systems. Classification based on correlation matrices could supplement or improve classification based on variable values, since the former reveals similarities in system structures, while the latter relies on the similarities in system states. Importantly, this approach of clustering correlation matrices is different from clustering elements of the correlation matrices, because our goal is to compare and cluster multiple networks-not the nodes within the networks. A novel approach for clustering correlation matrices, named "snakes-&-dragons," is introduced and illustrated by examples from neuroscience, human microbiome, and macroeconomics

    Are three‚Äźday voiding diaries feasible and reliable? Results from the Symptoms of Lower Urinary Tract Dysfunction Research Network (LURN) cohort

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    AimsThe aims of this study were to assess the completeness of voiding diaries in a research context and to correlate diary data with patient‚Äźreported questionnaires.MethodsMen and women enrolled in the Symptoms of Lower Urinary Tract Dysfunction Research Network (LURN) were given a 3‚Äźday voiding and fluid‚Äźintake diary to fill‚Äźout. Diaries were assessed for completeness and intake‚Äźoutput imbalances. They were assigned to one of four categories based on a percentage of missing data and fluid imbalance: no diary submitted, unusable (>40% missing void or intake volumes, or unphysiological fluid imbalance), usable but not complete, and complete.ResultsA total of 1064 participants were enrolled and 85% (n‚ÄČ=‚ÄČ902) returned the bladder diary. Of the diaries returned, 94% (n‚ÄČ=‚ÄČ845) had data on three separate days, 87% (n‚ÄČ=‚ÄČ786) had no missing intake volumes, 61% (n‚ÄČ=‚ÄČ547) had no missing voided volumes, and 70% (n‚ÄČ=‚ÄČ635) had a fluid imbalance within 3‚ÄČL across the 3‚Äźday time period, resulting in 50% (n‚ÄČ=‚ÄČ448) of participants with 100% complete diaries. Younger age was associated with a higher likelihood of not submitting a diary, or submitting an unusable diary. Women had a higher likelihood of submitting an unusable diary or a usable but incomplete diary.ConclusionOverall, 50% of LURN participants returned voiding diaries with perfectly complete data. Incomplete data for voided volumes was the most common deficiency. There was only a moderate correlation between diary data and questionnaire responses, indicating that diaries are a source of unique information.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152022/1/nau24113.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152022/2/nau24113_am.pd

    Kidney transplant graft outcomes in 379 257 recipients on 3 continents

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145422/1/ajt14694_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145422/2/ajt14694.pd

    Estimating the effect of a rare time‚Äźdependent treatment on the recurrent event rate

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143592/1/sim7626_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143592/2/sim7626.pd
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