Background
Recent publications have shown that patients with cancer incur high costs of care, particularly after diagnosis and in the last year of life.1–3 Given the increasing number of patients with cancer4 and increasing treatment costs,5 policymakers are continually seeking ways to bend the cost curve without sacrificing the quality of care. Focusing on high-cost (HC) patients is likely to have a large impact on health system costs, because these patients account for most healthcare spending. Many jurisdictions have implemented high-risk care management strategies to reduce costs and improve quality. However, it is not clear which costs can be reduced, especially among patients who require costly care, such as those with cancer. One potential solution to decrease costs without sacrificing care is to target preventable or avoidable acute care—that is, acute care for which good outpatient care could likely prevent the need for emergency department (ED) visits and/or hospitalization. Previous research has shown that ED visits and hospitalizations make up more than half of all costs among HC patients.6 Furthermore, some studies have shown that a substantial proportion of ED visits7,8 and hospitalizations9–12 may be prevented.
Little is known about HC patients with cancer and their healthcare utilization and spending patterns. Previous work has shown that individuals with cancer make up 20% of all HC patients.13 This is not surprising given that the population is aging, the number of patients diagnosed with cancer is increasing,4 and the introduction of newer and more expensive treatments has contributed to an increase in treatment costs.5 Wodchis et al14 examined the cost trajectories of patients with cancer over time and identified patient and system characteristics associated with high system costs after cancer treatment. The most common trajectory consisted of patients who were low-cost in the year before cancer treatment and remained low-cost after completing cancer treatment. In addition, the investigators found that increases in age and multimorbidity and low continuity of care were the strongest predictors of high costs after cancer treatment. Lam et al15 examined Medicare data for HC and non–high-cost (NHC) patients with and without cancer in 2014, and found that despite 15% of Medicare patients having a cancer diagnosis, the prevalence of cancer was higher among HC patients (33% vs 13%). Furthermore, the investigators found that HC patients had 3 times greater odds of having cancer and higher total annual spending ($66,685 vs $59,427).
However, it is not clear which costs, if any, can be reduced for this patient population. Joynt et al16 examined preventable and nonpreventable acute care spending among HC Medicare patients using validated algorithms and found that only a small percentage of costs resulted from preventable acute care. Graven et al17 replicated that analysis, using Oregon’s All Payer All Claims database and Medicaid data from the Oregon Health Authority, and found that preventable acute care spending for HC patients accounted for <6% of their total spending. Using data from Canada, Ronksley et al18 examined preventable acute care spending among hospitalized HC patients (at the Ottawa Hospital) using an ambulatory care–sensitive conditions algorithm. They found that among the HC inpatient population, most costs were due to a single nonpreventable acute care episode. Despite this work, none of these studies specifically examined HC subgroups, such as patients with cancer.
The objectives of this analysis were to provide an in-depth characterization of HC patients diagnosed with cancer, while comparing them to NHC patients with cancer, and to quantify the costs of potentially preventable/avoidable acute care (ie, ED visits and inpatient hospitalizations).
Methods
Data
We used administrative healthcare data available through ICES (Institute for Clinical Evaluative Sciences) in Toronto, Ontario, which includes individual-level linkable data on most publicly funded healthcare services for all legal residents of Ontario, Canada’s most populous province.19 Data on inpatient care are captured in the Discharge Abstract Database, the Ontario Mental Health Reporting System, the Continuing Care Reporting System, and the National Rehabilitation Reporting System, whereas data on ambulatory care are recorded in the National Ambulatory Care Reporting System. The Ontario Health Insurance Plan claims database captures data on physician visits, including fee-for-service visits and shadow-billed services, and laboratory claims. The Ontario Drug Benefit program database includes information on all outpatient prescription drugs dispensed to individuals eligible for public drug coverage (ie, individuals on social assistance and those aged ≥65 years). The Home Care Database records all unique visits by home care providers. The Ontario Cancer Registry provides data on all patients diagnosed with a malignant neoplasm in Ontario. The ICES data repository also includes other databases, which provide useful sociodemographic data on patients. The Registered Persons Database, a population-based registry, provides basic demographic data (such as age and sex) on all legal residents of Ontario. The Immigration, Refugees, and Citizenship Canada database provides information on all legal immigrants and refugees in Canada. Census data, obtained through Statistics Canada, contain information on neighborhood-level data, such as income and rurality. All databases were linked using unique encoded identifiers and analyzed at ICES, in compliance with Ontario’s privacy legislation. A full description of the databases can be found in supplemental eTable 1, available with this article at JNCCN.org.
Patient Cohorts
We selected all adult patients (aged ≥18 years) eligible for public healthcare insurance and residing in Ontario in 2013. All individuals who did not contact the Ontario healthcare system in 2013 and those who died during 2013 (but not those in their last year of life) were excluded, in line with previous research,16 because assessing the preventability of end-of-life care costs was beyond the scope of this analysis.
HC patients were defined as those above the 90th percentile of the cost distribution (ie, the top decile) in 2013, in line with previous work.20 All other patients were defined as NHC patients. This threshold provided a larger cohort of patients compared with other thresholds. Within each group, we identified those ever diagnosed with cancer (before or during 2013) through use of the Ontario Cancer Registry. To estimate healthcare costs and thus determine patients with costs above the 90th percentile, we used a cost estimation algorithm, available at ICES.19 Healthcare costs included all costs borne by the public third-party payer (ie, the Ontario Ministry of Health and Long-Term Care)19: inpatient hospitalizations (both psychiatric and acute), other institution-based care (inpatient rehabilitation, complex continuing care, long-term care), ED visits and other ambulatory care, outpatient clinic visits, physician visits and outpatient care, outpatient prescription drugs (for individuals covered under the public provincial drug plan), and home care. Costs captured by the algorithm accounted for >90% of all government-paid healthcare costs.21
Identifying Preventable Acute Care
To identify preventable ED visits, we used an updated version of a validated algorithm created at NYU Wagner22 by John Billings and colleagues and used in prior research examining HC Medicare patients.16 The NYU algorithm uses specified diagnosis codes to determine the following type of ED visits: nonemergent, emergent but primary care treatable, emergent ED care needed but preventable, and emergent ED care needed and not preventable. The updated version of the algorithm includes additional categories for injury, mental health, alcohol use, and drug use.23 Based on these classifications, Billings et al24 compiled a set of probabilistic weights that were applied to ED discharge data using the primary discharge ICD-10 diagnosis codes to determine the percentage of ED use attributable to each category. ED visits with diagnosis codes not mapped to any of the 8 categories were assigned to the “unclassified” category. Preventable ED visits were defined as nonemergent, emergent/primary care treatable, and emergent/ED care needed but preventable, in line with prior work.16
To identify potentially preventable hospitalizations, we used a validated algorithm, Quality Prevention Quality Indicators, developed by the Agency for Healthcare Research and Quality25 and used elsewhere.26–28 This algorithm defines potentially preventable hospitalizations as those related to conditions, such as heart failure, diabetes, hypertension, and asthma, for which good outpatient care can likely prevent the need for hospitalization. In addition, we used the respective prevention quality indicators for common nonpreventable clinical diagnosis groups to identify nonpreventable hospitalizations (see supplemental eAppendix 1 for codes).
Analysis
Patient Descriptives
HC and NHC patients with cancer were characterized and compared in terms of sociodemographic (sex, age, migrant status, neighborhood-level income quintile, urban/rural residence) and clinical characteristics (chronic conditions, frailty, residence in a long-term care home). We used the existing ICES-derived cohorts/registries to ascertain chronic conditions among patients29–40 and the Johns Hopkins Adjusted Clinical Groups Case-Mix System41 to obtain data on patient frailty. Residence in a long-term care facility was determined through the Continuing Care Reporting System. Using information included in the Ontario Cancer Registry, we also characterized patient groups by cancer type (solid vs hematologic) and site, cancer stage at diagnosis (where available), treatment phase (initial, continuing, terminal),1,2 and days since first diagnosis (patients with multiple cancers were assigned to the first cancer diagnosed; see supplemental eTable 2 for ICD-O codes). Patient characteristics between HC and NHC individuals with cancer were compared using a chi-square test for differences.
Costs of Preventable Acute Care Among HC Patients
We estimated the total costs of preventable and nonpreventable acute care by category of visit (for ED visits) and condition (for inpatient hospitalizations) for HC and NHC patients with cancer. All costs were reported in 2016 constant Canadian dollars using the Statistics Canada Consumer Price Index for healthcare.42
All analyses were performed using SAS Enterprise Guide 7.1 (SAS Institute Inc). The study was approved by the research ethics board of Sunnybrook Health Sciences Centre.
Results
Patient Characteristics
In 2013, 10,031,865 individuals contacted the Ontario healthcare system; 1,003,187 were defined as HC patients, and the remainder were defined as NHC (n=9,028,678). After excluding all patients who died during 2013 (n=90,555), we were left with 929,726 HC and 9,011,584 NHC patients. Across both groups, 557,192 patients had cancer; 187,770 were HC and 369,422 were NHC.
HC patients with cancer were older (mean age, 69.9 vs 64.5 years) and slightly more represented in the lower neighborhood income quintile (19.0% vs 15.6%) compared with NHC patients, but the 2 groups were roughly the same for all other sociodemographic characteristics (Table 1). HC patients with cancer had a higher proportion of all chronic conditions examined, particularly HIV, chronic heart failure, and dementia. HC patients with cancer also had a higher degree of frailty and were more likely to be living in long-term care facilities (Table 2). Among all patients, most were diagnosed with breast, prostate, and colorectal cancers (Table 3). However, multiple myeloma and pancreatic and liver cancers were overrepresented among HC patients, whereas testicular, thyroid, and cervical cancers and melanoma were overrepresented among NHC patients. Moreover, although most patients had missing data on cancer stage, a higher proportion of patients with stages III and IV was seen in the HC group. There was also a higher proportion of patients in the initial and terminal phases of treatment among the HC group (note that the terminal phase did not include patients who died but rather those in the last year of life, for whom death likely occurred in 2014). HC patients with cancer also had a shorter length of time since first diagnosis (2,917.9 vs 3,844.6 days).
Sociodemographic Characteristics of Patient Cohorts
Clinical Characteristics of Patient Cohorts
Cancer-Specific Characteristics of Study Cohorts
Costs of Preventable and Nonpreventable Acute Care
ED Visits
Within the HC cohort, 30.8% of the ED costs were classified as preventable (Table 4). Patterns were somewhat similar for the NHC cohort, with 35.3% of costs deemed preventable. Emergent, primary care treatable ED visits made up the highest proportion of preventable care costs for both HC and NHC patients (13.2% and 15.5%, respectively). However, HC patients had a higher proportion of nonpreventable ED visit costs than NHC patients (20.1% vs 13.8%). In addition, costs of ED visits with injuries represented a relatively high proportion among NHC patients (16.4%).
Costs of Preventable and Nonpreventable ED Visits
Inpatient Care
HC patients with cancer had a higher proportion of preventable inpatient costs than NHC patients (7.3% vs 6.6%) (Table 5). The most common reasons for preventable hospitalizations among HC patients with cancer included chronic obstructive pulmonary disease (COPD), bacterial pneumonia, and urinary tract infections; this was also the case for NHC patients (but with different rankings). In contrast, the most common reasons for nonpreventable hospitalizations were cancer and chemotherapy (28.1%), orthopedic conditions (5.0%), and ischemic heart disease (4.0%) for HC patients, and cancer and chemotherapy (13.8%), gastrointestinal infections and disorders (10.7%), and syncope and dizziness (3.3%) among NHC patients (data not shown).
Costs of Preventable and Nonpreventable Hospitalizations
Combining both acute settings, 9.0% of HC patients’ costs were considered potentially preventable compared with 29.9% for HNC patients.
Discussion
We examined a population-based sample of HC patients with cancer and estimated potentially preventable acute care spending while comparing them with NHC patients with cancer. HC patients were older, slightly more represented in the lowest neighborhood income quintile, sicker, and more likely to live in long-term care homes compared with NHC patients. HC patients were also more likely to be diagnosed with high-mortality cancers, such as multiple myeloma and pancreatic and liver cancers, and to have an advanced stage at diagnosis. Moreover, HC patients were more likely to be in the initial and terminal phases of treatment and to have a shorter length of time since first diagnosis. Roughly 30.9% of ED visit costs and 7.3% of hospitalization costs among HC patients could potentially be avoided, in contrast to roughly 35.4% and 6.6%, respectively, for NHC patients. The top categories for preventable care were primary care–treatable ED visits and hospitalizations for COPD, pneumonia, and urinary tract infections. Combining both acute settings, 9.0% of HC patients’ costs were considered potentially preventable, whereas the corresponding value for NHC patients was more than 3 times higher (29.9%).
Previous research has found that patients with high-mortality cancers have higher treatment costs.43 This is also the case for patients with advanced cancer1 and those in the initial and terminal phases of treatment.1,2,44,45 Moreover, another study on HC patients showed that long-term care residence has a large impact on costs.46 Therefore, it is not surprising that patients with these characteristics were more often in the HC category.
Some research has examined the relationship between being an HC patient and having cancer. For example, Wodchis et al14 examined the cost trajectories of patients with cancer over time to understand the predictors of being an HC patient after a cancer diagnosis. The most common trajectory was low-cost in the years before and after cancer treatment (31.4%). The next most common trajectory, which accounted for nearly 15% of cases examined, included patients who were low-cost before diagnosis but HC in the year after cancer treatment ended, suggesting that cancer plays a role in becoming a HC patient. Lam et al15 examined Medicare data for HC and NHC patients with and without cancer in 2014 and found that the prevalence of cancer was higher among HC patients (33% vs 13%) and that these patients had 3 times greater odds of having cancer and higher total annual spending. No existing studies have specifically examined preventable acute care among specific HC subgroups, such as HC patients with cancer; most of the literature on this topic has examined all HC patients and found that only a small percentage of costs were due to preventable acute care.13,16,17 We also found this to be the case for HC patients with cancer. In particular, we found that only 9% of acute care costs were considered preventable, which is close to what other researchers have found in the United States, albeit for the entire HC population.
These results suggest that overall, among HC patients with cancer, there is limited scope to prevent acute care costs. However, a greater opportunity may exist to prevent these costs among some types of cancer and/or cancer sites. For example, despite small differences, HC patients with hematologic cancers had a slightly higher proportion of preventable acute care costs than those with solid cancers (data not reported). Future work should seek to undertake this analysis by cancer type/site. Despite the fact that more than one-third of acute care costs were for healthcare encounters that could not be classified, a large proportion of costs were for nonpreventable acute care. In particular, the largest proportion of nonpreventable hospitalization costs was for episodes of care involving chemotherapy, which is standard treatment for many patients with cancer. Chemotherapy costs tend to represent a large proportion of treatment costs, and these costs have been increasing over time.5 Thus, the ability to lower acute care costs through better outpatient care may be limited. Nonetheless, there may be instances when chemotherapy may be avoided47 or deemed unnecessary,48 despite these hospitalizations being defined as nonpreventable by the algorithm. Moreover, costs could potentially be reduced by making hospital care more efficient so that each inpatient care episode is less costly,16 and through less costly encounters involving chemotherapy.
Strengths of our study include its use of a population-based sample of all adult HC patients with cancer in Ontario, which is Canada’s most populous province, whereas many existing studies tend to be limited to older populations.15,16 Additionally, we accounted for all costs associated with ED visits and hospitalization, given the presence of a (sole) third-party public payer for acute care in Ontario. We provided an in-depth characterization of the HC patient population with cancer and quantified the costs of potentially preventable acute care.
Nonetheless, this study is not without limitations. We did not examine patients aged <18 years, because these patients typically have different cancers compared with adults and their cancer-related care is organized differently compared with adults. We also did not examine the preventability of end-of-life care, because this was outside the scope of the analysis. Additionally, data on cancer stage were missing for most patients during the analysis period. Lastly, we used algorithms developed in the United States to identify preventable acute care; however, these algorithms could not classify all visits, and considered all ED visits for mental health and alcohol and drug use as nonpreventable, although it is likely that some of these visits could potentially be preventable. Furthermore, these algorithms are not disease-specific and thus did not examine preventable cancer-specific acute care; future work should explore this area and what constitutes potentially preventable cancer-specific acute care.
Conclusions
HC patients with cancer are a unique subpopulation within the HC patient population, with specific needs and healthcare utilization patterns. Given the care they receive, there seems to be limited scope to prevent acute care spending. To reduce costs, other strategies should be explored, such as making hospital care more efficient and ensuring encounters involving chemotherapy are less costly.
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