Single subject design: Use of time series analyses in a small cohort to understand adherence with a prescribed fluid restriction

• Type of Material: Article
• Authors: Carolyn Miller Reilly, Emory University; Melinda K Higgins, Emory University; Andrew L Smith, Emory University; Steven D Culler, Emory University; Sandra B Dunbar, Emory University
• Language: English
• Date: 2015-11-01
• Publisher: WB Saunders
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2015 Elsevier Inc.
• Final Published Version (URL): http://dx.doi.org/10.1016/j.apnr.2015.01.005
• Title of Journal or Parent Work: Applied Nursing Research
• ISSN: 0897-1897
• Volume: 28
• Issue: 4
• Start Page: 356
• End Page: 365
• Grant/Funding Information: Study Supported by the NIH/ NINR NRSA 5F32 NR010451-02(C.M. Reilly, PI), Interdisciplinary Pilot Research Grant NIH/NINR P20 NR007798, the National Center for Advancing Translational Sciences of the National Institutes of Health under Award Number UL1TR00045; and Biosite, Inc. Grant In Aid of equipment and supplies.; The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
• Keywords: Fluid therapy; RESOURCE UTILIZATION; INTERVENTION; QUALITY-OF-LIFE; Self-care; Science & Technology; Life Sciences & Biomedicine; Research design; LIPID PROFILES; Nursing; INTRATHORACIC IMPEDANCE; ELDERLY-PATIENTS; Electric impedance; RANDOMIZED-TRIAL; BREAST-CANCER SURVIVORS; THERAPY; Heart failure; CONGESTIVE-HEART-FAILURE
• Research Categories: Health Sciences, Medicine and Surgery; Health Sciences, Public Health

Abstract

Purpose: This paper presents a secondary in-depth analysis of five persons with heart failure randomized to receive an education and behavioral intervention on fluid restriction as part of a larger study. Methods: Using a single subject analysis design, time series analyses models were constructed for each of the five patients for a period of 180. days to determine correlations between daily measures of patient reported fluid intake, thoracic impedance, and weights, and relationships between patient reported outcomes of symptom burden and health related quality of life over time. Results: Negative relationships were observed between fluid intake and thoracic impedance, and between impedance and weight, while positive correlations were observed between daily fluid intake and weight. Conclusions: By constructing time series analyses of daily measures of fluid congestion, trends and patterns of fluid congestion emerged which could be used to guide individualized patient care or future research endeavors. Employment of such a specialized analysis technique allows for the elucidation of clinically relevant findings potentially disguised when only evaluating aggregate outcomes of larger studies.