Abstract
Abstract
Background:
Cost savings associated with palliative care (PC) consultation have been demonstrated for total hospital costs and daily costs after PC involvement. This analysis adds another approach by examining costs stratified by hospital length of stay (LOS).
Objective:
To examine cost savings for patients who receive PC consultations during short, medium, and long hospitalizations.
Methods:
Data were analyzed for 1815 PC patients and 1790 comparison patients from two academic medical centers between 2005 and 2008, matched on discharge disposition, LOS category, and propensity for a PC consultation. We used generalized linear models and regression analysis to compare cost differences for LOS of 1 to 7 days (38% of consults), 8 to 30 days (48%), and >30 days (14%). Comparisons were done for all patients in both hospitals (n=3605) and by discharge disposition: survivors (n=2226) and decedents (n=1379); analyses were repeated for each hospital.
Results:
Significant savings per admission were associated with shorter LOS: For stays of 1 to 7 days, costs were lower for all PC patients by 13% ($2141), and for survivors by 19.1% ($2946). For stays of 8 to 30 days, costs were lower for all PC patients by 4.9% ($2870), and for survivors by 6% ($2487). Extrapolating the per admission cost across the PC patient groups with lower costs, these programs saved about $1.46 million for LOS under a week and about $2.5 million for LOS of 8 to 30 days. Patients with stays >30 days showed no differences in costs, perhaps due to preferences for more aggressive care for those who stay in the hospital more than a month.
Conclusion:
Cost savings due to PC are realized for short and medium LOS but not stays >30 days. These findings suggest savings can be achieved by earlier involvement of palliative care, and support screening efforts to identify patients who can benefit from PC services early in an admission.
Introduction
There are many different ways of studying hospital costs including examining total costs per admission, costs by service unit (e.g., room, nursing, pharmacy, lab, etc.), and daily costs before and after PC is introduced.2,5,10,11 Our analysis adds another approach by examining costs by length of stay (LOS), which as Smith and Cassel note, 5 has been used as both a predictor (or trigger) for PC consultation as well as an outcome. Because of this dual role in care, LOS may be a significant confounder in determining cost savings for PC programs. We were interested in exploring this potential confounding and examining costs by LOS for several reasons. In monitoring our inpatient PC programs as they matured over a 4-year period, we observed a trend toward earlier referrals as hospital clinicians gained exposure to the services and benefits of involving PC in managing complex and seriously ill patients. About one-third of the consultations occurred during hospital stays of 1 to 7 days (Fig. 1). In addition, we also observed that 14% of the consultations occurred during admissions lasting over a month. Both of these time periods were described as outliers in the cost analyses done by Morrison and colleagures, 4 in part because of a paucity of cases with LOS of longer or shorter duration than the targeted 8 to 30 days in that study's hospitals (personal communication, R. S. Morrison, October 2011). In our hospitals, only about half of the consultations occurred during the 8- to 30-day period used in the Morrison et al. study. Therefore, we were interested in determining whether cost savings associated with PC consultations also occurred when consults happened during short (within one week) and long (over a month) stays in the hospital.

Palliative care consultations by length of stay and discharge disposition.
Methods
Setting and study population
Using a payer perspective and a retrospective, observational study design, we examined cost differences between patients who received at least one PC consultation and a matched usual care group in two academic medical centers for hospitalizations occurring between 2005 and 2008. Both hospitals serve a five-state region, providing tertiary and specialty care. Hospital 1 is a quaternary care institution that includes a cancer center that performs solid organ and bone marrow transplants. The PC service began operating in 2005 providing consultations 20 hours/week, Monday through Friday, with phone coverage only nights and weekends. The service was staffed with 0.5 full-time equivalent (FTE) divided across four physicians and a 0.8 FTE (donated) chaplain resident. The service added a 1.00 FTE nurse practitioner in 2008. Consultants usually met patients and families with the primary attending team and made recommendations that were implemented by the team. Consultants followed patients to discharge or death, or until it was deemed by all parties (primary team, patient and family, PC consultants) that they were no longer needed.
Hospital 2 is a county-owned safety net hospital and level I trauma and burn center. The consultation service started in 2003 with a 1.0 FTE nurse practitioner (who directed the service) and 0.25 FTE of physician time; by 2008 the FTE for physicians had grown to 2.0. Consults were available 24 hours per day, 7 days per week. Consultants made recommendations to primary attending teams and also assumed a primary attending role for terminally ill patients who did not have a community primary care provider. This enabled the PC team to follow patients into the community (including long-term care facilities) and serve as the provider of record for hospice referrals.
For PC patients who received consultations on multiple hospitalizations, we used the data only from the initial consultation and hospitalization to assess the impact of consultation services on PC-naïve patients. The sample included 1815 unique PC patients and a comparison sample of 1790 unique patients matched on (1) discharge disposition (survival to discharge or died in hospital); (2) LOS, matched on the exact number of days for all but 61 cases, which were matched on average within 1.7 days (range 1–6); and (3) propensity scores for referral to PC. Propensity scores are a method frequently used in observational studies to control for selection bias and confounding, and to improve estimates of the effect of a treatment or intervention (in this case, PC consultations) on outcomes (cost). 12 We chose these three domains for matching based on evidence of confounding in the literature. We matched first on discharge disposition because of demonstrated differences in costs and patterns of care for survivors and those who die in the hospital, 13 second on LOS to control for the effects of PC on LOS,13,14 and third on propensity scores to assure similar distributions of the measured predictors of referral for PC consultation.
Propensity scores
In this study, propensity scores represent the probability that a patient could be referred to PC for a consultation. Our estimates were computed using a two-part model that included physician and patient factors. First, we estimated the physician factors that we hypothesized would be associated with making a referral to PC based on physician demographics, training, and practice. Attending physicians play a gatekeeper role in the referral process, as their approval is a requirement for initiating a consultation. We wanted to capture their contribution as well as patient factors in computing the propensity score. Physician variables were obtained from secure medical personnel files and included the age, gender, years of employment, and primary affiliation (hospital department). We stratified these scores into terciles (representing low, medium, and high propensity to refer). The propensity score for the attending physician of record for the patient's hospitalization was assigned to each patient's data. The overall propensity score model included this variable along with the following patient characteristics predictive of PC referral: age, gender, race, number of comorbidities (computed using the Healthcare Cost and Utilization Project's [HCUP] comorbidity software, version 3.2 15 ), number of prior hospitalizations, an injury severity score (computed using the International Classification of Diseases, 9th Revision [ICD-9]-CM-Trauma program in Stata/MP version 10.1 to account for the patient population at the trauma and burn hospital), diagnosis-related group (DRG), and diagnosis of any of the following (computed from ICD-9 codes as part of the HCUP comorbidity software): cancer or metastatic cancer, acute myocardial infarction, chronic obstructive pulmonary disease, cerebral vascular disease, or renal disease.
We computed propensity scores for all patients in both hospitals (n=128,952 hospitalizations). We identified the 1815 unique patients who received a PC consultation during the 4-year study period (2005–2008) and performed one-to-one nearest neighbor matching to identify unique comparison patients who had propensity scores within 0.1 of PC patients. 16 We were able to identify 1790 matches for comparison. The 25 cases without matches were from Hospital 1 and are included in the analysis.
Statistical analyses
Cost, provider, and patient data were obtained from the administrative databases at each hospital. These hospitals use the same cost-accounting system that assigns actual costs to services and standardizes costs across units within the hospital and across the two hospitals. We used total costs for each hospitalization that included indirect costs and direct costs for room and board, radiology and laboratory tests, pharmacy, and nursing care. We compared groups using adjusted models to estimate the cost differences attributable to PC. We used multivariable regression and generalized linear models (GLM) with gamma distributions and log link functions to estimate average dollar and percentile cost differences by LOS category: 1 to 7 days (38% of consultations), 8 to 30 days (48% of consultations), and >30 days (14% of consultations). Comparisons were done for all patients (n=3605) and separately for survivors (n=2226) and decedents (n=1379). Both models were adjusted for age, gender, race, number of comorbidities, number of prior hospitalizations, diagnosis of any cancer, acute myocardial infarction, or cerebral vascular disease, injury severity score, DRG, and number of intensive care unit (ICU) days. We ran all models for the two hospitals combined (controlling for site), and separately for each hospital. All analyses were conducted using Stata/MP version 10.1 (StataCorp., College Station, TX).
The study protocol and access to hospital administrative datasets was reviewed and approved by the University of Washington's Institutional Review Board.
Results
Characteristics of the PC (n=1815) and matched usual care (n=1790) patients are described in Table 1 by hospital. The two groups have similar distributions of propensity scores (Table 1, line 1) meaning that overall, the physician and patient characteristics predicting a referral to PC were evenly distributed between the two groups. However, despite propensity score matching, there remained some significant differences between the groups and between the hospitals: In both hospitals, PC patients had higher rates of metastatic cancer, additional prior hospitalizations, and different discharge locations for survivors, with more PC patients discharged to hospice (either at home or in a facility) and skilled nursing facilities and fewer to self care at home. In Hospital 1, PC patients were about 2 years younger and had lower rates of cancer and acute myocardial infarction. In Hospital 2, PC patients had higher rates of cancer, lower rates of cerebrovasular disease, and lower injury severity scores. We also examined the number of days spent in the ICU and found slightly longer ICU LOS for Hospital 1 and no difference for Hospital 2.
AIDS, acquired immune deficiency syndrome; ICU, intensive care unit; SD, standard deviation.
Figure 1 shows the distribution of consultations for decedents and survivors by hospital and LOS category. Table 2 reports the average LOS and number of days between admission and when the PC consultation was initiated for each hospital by LOS category. For all three LOS categories, initial consultations were made about half-way through the hospitalization.
Palliative care patients only.
LOS, length of stay; SD, standard deviation.
The cost results are reported for both hospitals combined and separately, as well as for all patients, and by survivors and decedents. Table 3 reports the average adjusted savings per admission in dollars and Table 4 reports the same data in terms of percent savings. These analyses used different methods (regression and GLM, respectively), which computed different significance values for some of the comparisons (e.g., comparisons of all patients and survivors with LOS of 8 to 30 days is significant in Table 3 but not in Table 4).
Models adjusted for age, race, gender, number of comorbid conditions, number of prior hospitalizations, diagnosis of any cancer or metastatic cancer, acute myocardial infarction, cerebral vascular disease, injury severity score, DRG, number of ICU days, and hospital. Negative numbers indicate palliative care costs were higher than the usual care group.
DRG, diagnosis-related group; ICU, intensive care unit; LOS, length of stay.
Models adjusted for age, race, gender, number of comorbid conditions, number of prior hospitalizations, diagnosis of any cancer or metastatic cancer, acute myocardial infarction, cerebral vascular disease, injury severity score, DRG, number of ICU days, and hospital. Negative numbers indicate palliative care costs were higher than the usual care group.
DRG, diagnosis-related group; ICU, intensive care unit; LOS, length of stay.
Results from both hospitals combined show cost savings for all patients and for survivors with LOS of 1 to 7 days and 8 to 30 days. There were no cost savings for decendents, regardless of LOS, or for any patients with LOS >30 days. For LOS of 1 to 7 days, costs were lower for all PC patients by 13% ($2141) and for survivors by 19.1% ($2946). For stays of 8 to 30 days, costs were lower for all PC patients by 4.9% ($2870) and for survivors by 6% ($2487). We extrapolated the average savings per hospitalization across the patients who received consultations (n=1815) and estimated total cost savings of $3,984,304 over the 4 years, with $2,522,415 in savings for survivors. About one-third of the savings occurred for PC patients with LOS of 1 to 7 days ($1,464,444) and the remaining $2,519,860 in savings was for LOS of 8 to 30 days.
The analysis by hospital shows very different savings patterns. Most of the savings were realized by Hospital 1 (the cancer and transplant center) and happened for all patients with LOS up to 30 days. Hospital 2 (the trauma and burn center) only realized savings for patients who survived with LOS of 1 to 7 days; costs were significantly higher for patients who received PC and died during an admission lasting more than 30 days.
Discussion
This study examined cost savings by short, medium, and long lengths of stay to further understand patterns of savings associated with inpatient PC consultation. As PC programs grow, patterns are shifting toward earlier referrals. Our findings extend the range of cost analyses by including results for LOS of 1 to 7 days and greater than 30 days, and suggest that for these two hospitals, the PC programs saved about $1.46 million for LOS under a week and about $2.5 million for LOS of 8 to 30 days. Patients with stays over a month showed no differences in costs, perhaps because of differences in patient preferences, with those who stay in the hospital for more than a month preferring more aggressive care.
This analysis was motivated by the fact that 30% to 43% of referrals in these two hospitals occurred during hospitalizations of 7 days or less and provides data regarding cost savings for these admissions. The trend in these hospitals is toward earlier referrals, a trend that could be expected in other hospitals with consultation services, especially as they gain more experience and familiarity within their institutions. We describe methods that other hospitals may use to analyze costs based on their own distribution of referrals. We organized the analysis around LOS because it is related to both predictors of referrals to PC programs, 13 as well as being an outcome (reduced LOS) of PC involvement. Because we controlled for the effect of LOS on costs through matching, our estimates of savings are likely to be conservative. Previous studies have attributed savings to shifts in care based on alignment of therapies to palliative goals. For example, studies of PC consultation in ICUs found no change in mortality but shorter LOS for patients who died.14,17
Although all observational studies are limited by selection biases, our analysis is strengthened by the use of propensity scores to select matches for comparison, which helps to reduce error due to confounding but can only do so with the variables available for inclusion in analysis. 12 The differences between the patient characteristics for those in the palliative and usual care groups suggests there are other unmeasured variables that contribute to the propensity to get a PC referral. However, where there were group differences in patient characteristics, the PC patients were the ones with more comorbidities and prior hospitalizations, and higher rates of serious illness, factors that are more likely to be associated with higher rather than lower costs.
We ran several models with different variables to improve the fit for both hospitals, for example, adding injury severity scores to account for the trauma and burn population of Hospital 2. Other hospitals can apply these methods to tailor analyses to the specific characteristics of their own patient and provider populations. The different pattern of savings for the two hospitals may be explained by the differences in patient populations or patient preferences and the opportunities for savings to occur. For example, there may be more ways to tailor therapy for cancer and transplant patients than there are for trauma patients.
Conclusion
These findings suggest that savings can be achieved by earlier involvement of PC and support screening efforts at or near admission to identify patients who can benefit from PC services early in an admission.
Footnotes
Acknowledgments
This work was supported by a career development award from the National Palliative Care Research Center for Dr. Starks, and a midcareer investigator award from the National Heart Lung and Blood Institute (K24-HL-048593) for Dr. Curtis.
Author Disclosure Statement
No competing financial interests exist.
