title: Discovery of temporal and disease association patterns in condition-specific hospital utilization rates.
abstract: Identifying temporal variation in hospitalization rates may provide insights about disease patterns and thereby inform research, policy, and clinical care. However, the majority of medical conditions have not been studied for their potential seasonal variation. The objective of this study was to apply a data-driven approach to characterize temporal variation in condition-specific hospitalizations. Using a dataset of 34 million inpatient discharges gathered from hospitals in New York State from 2008-2011, we grouped all discharges into 263 clinical conditions based on the principal discharge diagnosis using Clinical Classification Software in order to mitigate the limitation that administrative claims data reflect clinical conditions to varying specificity. After applying Seasonal-Trend Decomposition by LOESS, we estimated the periodicity of the seasonal component using spectral analysis and applied harmonic regression to calculate the amplitude and phase of the condition's seasonal utilization pattern. We also introduced four new indices of temporal variation: mean oscillation width, seasonal coefficient, trend coefficient, and linearity of the trend. Finally, K-means clustering was used to group conditions across these four indices to identify common temporal variation patterns. Of all 263 clinical conditions considered, 164 demonstrated statistically significant seasonality. Notably, we identified conditions for which seasonal variation has not been previously described such as ovarian cancer, tuberculosis, and schizophrenia. Clustering analysis yielded three distinct groups of conditions based on multiple measures of seasonal variation. Our study was limited to New York State and results may not directly apply to other regions with distinct climates and health burden. A substantial proportion of medical conditions, larger than previously described, exhibit seasonal variation in hospital utilization. Moreover, the application of clustering tools yields groups of clinically heterogeneous conditions with similar seasonal phenotypes. Further investigation is necessary to uncover common etiologies underlying these shared seasonal phenotypes.
authors.affiliation: Albert Einstein College of Medicine, Bronx, New York, United States of America.
authors.forename: Julian S
authors.initials: JS
authors.lastname: Haimovich
authors.affiliation: Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, New Haven, Connecticut, United States of America.|Department of Emergency Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America.
authors.forename: Arjun K
authors.initials: AK
authors.lastname: Venkatesh
authors.affiliation: Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, New Haven, Connecticut, United States of America.
authors.forename: Abbas
authors.identifier: http://orcid.org/0000-0003-1803-3284
authors.initials: A
authors.lastname: Shojaee
authors.affiliation: Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, New Haven, Connecticut, United States of America.
authors.forename: Andreas
authors.initials: A
authors.lastname: Coppi
authors.affiliation: Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, New Haven, Connecticut, United States of America.
authors.forename: Frederick
authors.identifier: http://orcid.org/0000-0001-5588-7372
authors.initials: F
authors.lastname: Warner
authors.affiliation: Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, New Haven, Connecticut, United States of America.
authors.forename: Shu-Xia
authors.initials: SX
authors.lastname: Li
authors.affiliation: Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, New Haven, Connecticut, United States of America.|Section of Cardiovascular Medicine, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, United States of America.|The Robert Wood Johnson Foundation Clinical Scholars Program, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, United States of America.|Department of Health Policy and Management, Yale School of Public Health, New Haven, Connecticut, United States of America.
authors.forename: Harlan M
authors.initials: HM
authors.lastname: Krumholz
mesh_terms: D000208:Acute Disease / Q000145:classification / Q000453:epidemiology*; D000067575:Administrative Claims, Healthcare / Q000706:statistics & numerical data*; D016000:Cluster Analysis; D016208:Databases, Factual; D005260:Female; D006760:Hospitalization / Q000639:trends*; D006801:Humans; D015233:Models, Statistical; D009518:New York / Q000453:epidemiology; D010051:Ovarian Neoplasms / Q000453:epidemiology; D010351:Patient Discharge / Q000639:trends*; D012559:Schizophrenia / Q000453:epidemiology; D012621:Seasons; D014397:Tuberculosis, Pulmonary / Q000453:epidemiology