{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T16:18:05Z","timestamp":1777393085496,"version":"3.51.4"},"reference-count":48,"publisher":"SAGE Publications","issue":"4","license":[{"start":{"date-parts":[[2024,10,8]],"date-time":"2024-10-08T00:00:00Z","timestamp":1728345600000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JAD"],"published-print":{"date-parts":[[2024,10,8]]},"abstract":"<jats:p>Background: Multimorbidity is common in older adults and complicates diagnosing and care for this population. Objective: We investigated co-occurrence patterns (clustering) of medical conditions in persons with Alzheimer\u2019s disease (AD) and their matched controls. Methods: The register-based Medication use and Alzheimer\u2019s disease study (MEDALZ) includes 70,718 community-dwelling persons with incident AD diagnosed during 2005-2011 in Finland and a matched comparison cohort. Latent Dirichlet Allocation was used to cluster the comorbidities (ICD-10 diagnosis codes). Modeling was performed separately for AD and control cohorts. We experimented with different numbers of clusters (also known as topics in the field of Natural Language Processing) ranging from five to 20. Results: In both cohorts, 17 of the 20 most frequent diagnoses were the same. Based on a qualitative assessment by medical experts, the cluster patterns were not affected by the number of clusters, but the best interpretability was observed in the 10-cluster model. Quantitative assessment of the optimal number of clusters by log-likelihood estimate did not imply a specific optimal number of clusters. Multidimensional scaling visualized the variability in cluster size and (dis)similarity between the clusters with more overlapping of clusters and variation in group size seen in the AD cohort. Conclusions: Early signs and symptoms of AD were more commonly clustered together in the AD cohort than in the comparison cohort. This study experimented with using natural language processing techniques for clustering patterns from an epidemiological study. From the computed clusters, it was possible to qualitatively identify multimorbidity that differentiates AD cases and controls.<\/jats:p>","DOI":"10.3233\/jad-240490","type":"journal-article","created":{"date-parts":[[2024,9,20]],"date-time":"2024-09-20T10:35:33Z","timestamp":1726828533000},"page":"1393-1403","source":"Crossref","is-referenced-by-count":0,"title":["Identifying Comorbidity Patterns in People with and without Alzheimer\u2019s Disease Using Latent Dirichlet Allocation"],"prefix":"10.1177","volume":"101","author":[{"given":"Blair","family":"Rajamaki","sequence":"first","affiliation":[{"name":"School of Pharmacy, University of Eastern Finland, Kuopio, Finland"},{"name":"Kuopio Research Centre of Geriatric Care, University of Eastern Finland, Kuopio, Finland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Billy","family":"Braithwaite","sequence":"additional","affiliation":[{"name":"School of Pharmacy, University of Eastern Finland, Kuopio, Finland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sirpa","family":"Hartikainen","sequence":"additional","affiliation":[{"name":"School of Pharmacy, University of Eastern Finland, Kuopio, Finland"},{"name":"Kuopio Research Centre of Geriatric Care, University of Eastern Finland, Kuopio, Finland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anna-Maija","family":"Tolppanen","sequence":"additional","affiliation":[{"name":"School of Pharmacy, University of Eastern Finland, Kuopio, Finland"},{"name":"Kuopio Research Centre of Geriatric Care, University of Eastern Finland, Kuopio, Finland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"179","reference":[{"key":"10.3233\/JAD-240490_ref1","doi-asserted-by":"crossref","first-page":"430","DOI":"10.1016\/j.arr.2011.03.003","article-title":"Aging with multimorbidity: A systematic review of the literature","volume":"10","author":"Marengoni","year":"2011","journal-title":"Ageing Res Rev"},{"key":"10.3233\/JAD-240490_ref2","unstructured":"World Health Organization (WHO). 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Foundations of Statistical Natural Language Processing. Cambridge, MA USA: MIT Press, https:\/\/mitpress.mit.edu\/9780262133609\/foundations-of-statistical-natural-language-processing\/ (1999, accessed 15 November 2022)."},{"key":"10.3233\/JAD-240490_ref8","first-page":"993","article-title":"Latent Dirichlet allocation","volume":"3","author":"Blei","year":"2003","journal-title":"J Mach Learn Res"},{"key":"10.3233\/JAD-240490_ref9","doi-asserted-by":"crossref","first-page":"101855","DOI":"10.1016\/j.artmed.2020.101855","article-title":"Mining post-surgical care processes in breast cancer patients","volume":"105","author":"Chiudinelli","year":"2020","journal-title":"Artif Intell Med"},{"key":"10.3233\/JAD-240490_ref10","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1016\/j.jbi.2016.04.005","article-title":"Using phrases and document metadata to improve topic modeling of clinical reports","volume":"61","author":"Speier","year":"2016","journal-title":"J Biomed Inform"},{"key":"10.3233\/JAD-240490_ref11","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1016\/j.jbi.2015.12.012","article-title":"Incorporating comorbidities into latent treatment pattern mining for clinical pathways","volume":"59","author":"Huang","year":"2016","journal-title":"J Biomed Inform"},{"key":"10.3233\/JAD-240490_ref12","doi-asserted-by":"crossref","first-page":"104434","DOI":"10.1016\/j.ijmedinf.2021.104434","article-title":"Mining topic and sentiment dynamics in physician rating websites during the early wave of the COVID-19 pandemic: Machine learning approach","volume":"149","author":"Shah","year":"2021","journal-title":"Int J Med Inform"},{"key":"10.3233\/JAD-240490_ref13","first-page":"43","article-title":"Discovering associations among diagnosis groups using topic modeling","volume":"2014","author":"Li","year":"2014","journal-title":"AMIA Jt Summits Transl Sci Proc"},{"key":"10.3233\/JAD-240490_ref14","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1016\/j.jbi.2018.04.008","article-title":"Co-occurrence of medical conditions: Exposing patterns through probabilistic topic modeling of snomed codes","volume":"82","author":"Bhattacharya","year":"2018","journal-title":"J Biomed Inform"},{"key":"10.3233\/JAD-240490_ref15","doi-asserted-by":"crossref","unstructured":"Le Lannou E , Post B , Haar S , et al. 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ICD-10 version, https:\/\/apps.who.int\/classifications\/apps\/icd\/ClassificationDownload\/DLArea\/Download.aspx (2015, accessed 25 March 2021)."},{"key":"10.3233\/JAD-240490_ref18","doi-asserted-by":"crossref","first-page":"339","DOI":"10.1186\/s12913-023-09345-3","article-title":"Diagnostic groups of hospital stays and outpatient visits during 10 years before Alzheimer\u2019s disease","volume":"23","author":"M\u00e4klin","year":"2023","journal-title":"BMC Health Serv Res"},{"key":"10.3233\/JAD-240490_ref19","unstructured":"Hoffman M , Bach F , Blei D . Online learning for latent Dirichlet allocation. In: Advances in Neural Information Processing Systems. Curran Associates, Inc., https:\/\/papers.nips.cc\/paper_files\/paper\/2010\/hash\/71f6278d140af599e06ad9bf1ba03cb0-Abstract.html (2010, accessed 8 September 2023)."},{"key":"10.3233\/JAD-240490_ref20","first-page":"1303","article-title":"Stochastic variational inference","volume":"14","author":"Hoffman","year":"2013","journal-title":"J Mach Learn Res"},{"key":"10.3233\/JAD-240490_ref21","unstructured":"Pedregosa F , Varoquaux G , Gramfort A , et al. Scikit-learn: machine learning in Python."},{"key":"10.3233\/JAD-240490_ref22","doi-asserted-by":"crossref","unstructured":"Kruskal JB and Wish M. Multidimensional Scaling. 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