Yale University EliScholar – A Digital Platform for Scholarly Publishing at Yale Yale Medicine Thesis Digital Library School of Medicine January 2020 Development And Validation Of A Predictive Model For Oncology Hospital-At-Home Keval Niraj Desai Follow this and additional works at: https://elischolar.edu/ymtdl Recommended Citation Desai, Keval Niraj, "Development And Validation Of A Predictive Model For Oncology Hospital-At-Home" (2020). Yale Medicine Thesis Digital Library.edu/ymtdl/3894 This Open Access Thesis is brought to you for free and open access by the School of Medicine at EliScholar – A Digital Platform for Scholarly Publishing at Yale. It has been accepted for inclusion in Yale Medicine Thesis Digital Library by an authorized administrator of EliScholar – A Digital Platform for Scholarly Publishing at Yale. For more information, please contact elischolar@yale.
Development and Validation of a Predictive Model for Oncology Hospital-at-Home A Thesis Submitted to the Yale University School of Medicine in Partial Fulfillment of the Requirements for the Degree of Doctor of Medicine By Keval Niraj Desai 2020 ABSRACT Background: Hospital-at-Home (HaH) is a unique care model that allows for the provision of inpatient level care in the patient’s home. HaH has been used to facilitate early discharge from inpatient care or to substitute entirely for an inpatient admission. Hospital-at-Home has been shown to have similar clinical outcomes to inpatient care, while reducing cost and complications associated with inpatient admission. Application of the HaH model to patients with oncologic disease is a promising avenue to reduce healthcare costs while improving patients’ quality of life by increasing time spent at home.
A major challenge to implementing a Hospital-at-Home program for cancer patients is the lack of validated criteria to inform the selection of admissions most suitable for home-based hospital level care. Methods and Results: Admissions to the Yale New Haven Smilow Cancer Hospital’s medical oncology floor in New Haven from Jan 2015- Jun 2019 were included in the analysis (N=3,322). The analysis focused entirely on patients with solid tumors hospitalized for unplanned admissions. The definition of suitability for HaH was based on a substitutive model and identified admissions that did not receive any services that would be difficult to deliver or were inconsistent with safe care in the home.
Twenty-seven-point-three percent of admissions were identified as suitable for HaH, accounting for 908 admissions during the study period. Admissions that were suitable for HaH were shorter in duration (2.41 days), more likely to result in discharge home rather than to other healthcare facility (87.5%), and less likely to be readmitted in the following 30 days (25. A predictive logistic model constructed using a purposeful selection process identified 13 statistically significant predictors for suitability for HaH: Black/African American race (vs all other), observation status, patient evaluated in the emergency department (ED) or oncology extended care center (vs admitted directly from clinic), primary admission diagnosis of secondary malignancy, primary admission diagnosis of fever, primary admission diagnosis of digestive diseases, oncology diagnosis of secondary or unknown malignancy, initial pre-admission respiratory rate >20 breaths/min, final pre-admission systolic blood pressure <100 mmHg, final pre-admission temperature >100o F, Sodium < 135 mmol/L, hemoglobin <10 g/dL and ED visit in the previous 90 days. The predictive model had moderate discrimination (c-statistic 0.686) and was well calibrated in the validation cohort (Hosmer-Lemeshow P-value >0.
Conclusion: We describe the first predictive model of suitability for Hospital-at-Home in oncology patients. This model serves as a starting point to creating selection criteria and can be further refined and tested in prospective validation and pilot studies. The modest discrimination of the model indicates that much of the variability that allows for accurate prediction is still unaccounted for and would benefit from larger studies and inclusion of clinician judgement. ACKNOWLEDGEMENTS First, I would like to thank God for the many blessings he has bestowed on my life, including the privilege to study medicine at such a wonderful institution.
My parents, who shaped my personality and character in countless ways are largely responsible for the success I have achieved. Thanks to their tireless support, timely guidance, and endless encouragement I have learned to be resilient in adversity and humble in accomplishment. My spiritual teacher and Guru, the late Pandurang Shastri Athavale (Dadaji), has played an almost invisible hand in making me the person I am today, and I was privileged to spend two years at an institution he founded to teach applied philosophy and spirituality to students from around the world. My fiancé Ushma has been a constant source of support and love since the day we met.
I owe my deep gratitude to countless mentors, teachers, friends, and colleagues who have shaped me as a physician and become role models through their actions. Kevin Chen for allowing me to join in his work and mentoring me throughout the project. Sarwat Chaudhry provided critical mentorship and guidance in the writing of this thesis. Soundari Sureshanand from the Yale JDAT team has been immensely helpful with getting the data for this project and answering our many questions.
Without her this project would not have been completed in a timely fashion. Kerin Adelson and Dr. Cary Gross have provided timely comments and input into the project from their personal expertise that has been immensely helpful. Alexandra Hajduk has provided critical statistical insight into the methods in this thesis.
Table of Contents INTRODUCTION. 1 History of Hospital-at-Home. 1 Favorable Outcomes and Reduced Complications in HaH. 5 Oncology Hospital-at-Home.
7 Statement of Purpose and Specific Aims. 12 Defining Suitability for HaH. 14 Separation of Training and Validation Cohorts. 15 Predictive Model Construction.
15 Assessment of the Predictive Models. 17 Creation of Clinical Calculator. 19 Suitability for HaH. 19 Creation of Derivation and Validation Cohorts.
23 Predictive Model Creation. 25 Assessment of the Predictive Model. 29 Creation of Clinical Calculator. 42 1 INTRODUCTION With the rising prevalence of cancer the United States, treatment for cancer and its complications is becoming a larger part of healthcare and a significant contributor to costs [1,2].
A significant portion of that cost comes from inpatient care, with the cost of inpatient treatment for patients with cancer being 350% more expensive than similar patients without a cancer diagnosis [3]. Compared to those without a cancer diagnosis, patients with cancer are more likely to be admitted to the hospital after visiting the emergency department and have longer length of hospital stays [4–8]. Hospital-at-Home (HaH) is a care model designed to replace inpatient hospitalization for acute illnesses by providing the resources to care for patients in their homes [9]. HaH has been proposed as a way to reduce inpatient hospitalization for oncology patients [10].
One barrier to use of HaH in oncology patients is the lack of selection criteria to identify which admissions would potentially be safe for home-based hospital level care [10]. This study aims to inform the creation of such criteria by developing and validating a predictive model based on previous admissions to the medical oncology floor of Yale New Haven Hospital’s Smilow Cancer Hospital. History of Hospital-at-Home Modern medical HaH programs have been around since the late 1980s and are starting to gain momentum in United States. In Australia, they have become an important part of the healthcare delivery apparatus [11].
A review of studies of HaH among medical patients shows that outcomes are comparable to inpatient admission [12]. Reductions in the total cost of care and decreased utilization of healthcare resources such as laboratory studies have been observed in multiple settings [13–15]. The potential to increase satisfaction and quality while reducing costs makes HaH a promising addition to the broader healthcare delivery system [16]. In the context of the larger healthcare system, HaH provides an avenue for better allocation of costly hospital resources 2 toward high risk patients, while allowing relatively stable patients to receive care in the home for their acute illness.
House calls and home care were common in healthcare until the 20th century when the rise of the hospital was fueled by the rapid advances in pharmacology and medical technology, the rise of multiple payors, and increased concerns about liability and accountability [17]. Early HaH models were developed and tested in Israel, England, and the United States [17–26]. Early successes led to expansion of models and continued scholarship, especially within public health systems and markets that had strong alignment between payors and providers. While there has been increasing interest in HaH in the United States, broad expansion has been limited by lack of a favorable funding mechanism [27].
Early studies in the 1990s established the feasibility of hospital at home and motivated interest around the world. The Edward Hines Jr VA in Chicago had developed a hospital-based home care program in 1971 and in 1992 they published a randomized trial comparing hospital and home care admission for terminally ill veterans. While in many aspects this was a study focusing on home- based hospice care, it was one of the first studies to show that home care could be used to replace hospital care for a broad range of diagnoses. This study reported an average reduction in 5.9 hospital days per patient leading to an 18% reduction in cost with no difference in clinical outcomes (survival, activities of daily living, and cognitive function) and significant improvement in patient and caregiver satisfaction [18].
From 1995-98, a series of randomized trials of HaH were published in the British Medical Journal. Taken together they showed that for many conditions, there was no significant difference in clinical outcomes between patients randomized to HaH verses inpatient care, with some improvements in patient satisfaction and significant patient preference for HaH. The studies showed mixed results when it came to cost analysis and length of 3 stay [22,23,28]. The clinical outcomes measured included mortality, readmission, Dartmouth Cooperative Functional Assessment Charts, SF-36 to measure mobility, COPD disease questionnaire, and Barthel Index for activities of daily living.
The HaH programs implemented in these studies varied in their use of physician supervision, and whether the programs diverted patients from an inpatient admission or served as a pathway for early discharge. A common critique of the early hospital-at-home studies is that the heterogeneity of models makes it difficult to compare programs and differentiate them from home-based skilled nursing care or chronic ambulatory care [29,30]. There have been proposals to tighten the definition of HaH to those programs that substitute entirely for inpatient admission and provide around-the clock services similar to what is available in an inpatient setting [30]. Highlighting this distinction, separate Cochrane reviews are devoted to analyzing the evidence base for HaH programs that avoided inpatient admission (i., a “substitutive” model, 16 randomized trials with 1814 patients) verses those who focused on offering an avenue for early discharge (32 randomized trials with 4746 patients) [12,31].
Most early trials of HaH were conducted within single-payer health systems, limiting their applicability to the United States outside the VA. In 2005, a large multi-center quasi-experimental trial concluded that HaH was feasible, safe, and resulted in reduced length of stay and lower total costs [32]. The study focused on substitutive HaH for four medical illnesses (exacerbations of heart failure or COPD, pneumonia, and cellulitis) in elderly patients over 65. This was one of the first studies to show that patients in the HaH cohort had improvements in the functional status compared to traditionally-hospitalized patients, as measured by ability to complete instrumental activities of daily living and activities of daily living [33].
On cost analysis, they found significant cost savings for patients admitted for exacerbations of COPD and congestive heart failure but not 4 pneumonia nor cellulitis. For all diagnoses, the HaH cohort had significantly lower laboratory and procedure costs [14]. These results were validated by numerous models implemented across the country [15,27,34]. Since then, HaH programs have been created and studied at multiple large academic centers, including Johns Hopkins (Baltimore, MD), Mount Saini (New York City, NY), Presbyterian Health Services (New Mexico), and Brigham and Women’s Hospital (Boston, MA) [13,15,35,36].