Introduction
Gastric cancer is the 3rd leading cancer-related cause of death with more than 720,000 deaths per year worldwide. The global incidence of gastric cancer is the highest in East Asian countries such as South Korea and Japan [
1]. As socioeconomic levels and hygiene status are improved with universalized eradication therapy of
Helicobacter pylori, the strongest etiologic factor of stomach cancer, the global incidence of gastric cancer is steadily declining [
2]. With dramatic improvement of endoscopic techniques for visualization and resection of early gastric cancer (EGC), early detection and curative endoscopic resection of EGC have made a significant contribution to the decline of cancer-related mortality [
3]. However, if gastric cancer is diagnosed at a later stage with distant metastasis, chance for cure declines dramatically and overall prognosis remains poor. A previous study has shown that if gastric cancer is diagnosed at stage III or IV, overall 5-year survival rate is only 35% regardless of surgical resection of tumor [
4].
Gastric cancer is not considered as a major cancer in terms of incidence and mortality in the United States. However, recent data have shown that the incidence of gastric cancer in the US is 6.6 per 100,000 population with a morality rate of 3.3 per 100,000 during 2012–2016, imposing a burden to the healthcare system [
5]. Unfortunately, very limited studies have evaluated demographic descriptive data and changing trends of inpatient hospitalization of gastric cancer patients [
6]. Furthermore, little is known about the current status and changing trend of palliative care for gastric cancer patients, particularly patients who are near end of life (EOL). Palliative care is a comprehensive approach to manage serious illness such as terminal malignancy and other chronic ill diseases. It is known to be effective for improving the quality of life and avoiding unnecessary invasive procedures [
7]. With this background, the objective of this study was to investigate changing trends of hospitalization, palliative care consultation, and palliative procedures for gastric cancer patients in the US from 2009 to 2018 using a nationwide database. We will also examine factors associated with utilization of palliative care consultation and palliative procedures and factors influencing hospital charges of gastric cancer patients during hospitalization.
Discussion
Our study presents changing trends of hospitalization status and utilization of palliative care consultation and palliative procedures during the recent 10-year in the US. In addition, it analyzed factors affecting hospital costs from a socioeconomic perspective using a nationwide database. Our study showed that the annual number of hospitalizations showed a slow decrease during 2009–2018, with CAGR of 0.8%. This result was consistent with a previous study showing decreased mortality and hospitalizations of gastric cancer patients in the US [
6]. In that study, the authors showed that 23,921 admissions as a primary discharge diagnosis of gastric cancer were detected in 2003 compared with 21,540 in 2014 (
P < 0.001). In addition, LOS was decreased significantly (10.9 vs. 8.9 days,
P < 0.001), while mean hospital charges per patient significantly increased from $75,341 in 2003 to $91,385 in 2014 (
P < 0.0001) [
6]. However, the present study did not show such changing trends of palliative care consultation or palliative procedures in patients with gastric cancer. Our study showed that both palliative care consultation and palliative procedures had gradually increased during 2009–2018, although the number of hospitalizations was decreased. To the best of our knowledge, this is the first study to use nationwide data for investigating temporal trends of palliative care consultation and palliative procedures as well as the annual number of hospitalizations among gastric cancer patients in the US. It is expected that patients near end of life (EOL) due to advanced illness usually receive more palliative care consultation with less interventional or life-sustaining procedures such as ventilation, cardiopulmonary resuscitation, blood transfusion, and dialysis [
18]. In our study, we limited included procedures to those used only for palliative purpose, such as non-surgical bypass, gastrostomy, enterostomy, dilation, drainage, nutrition, and irrigation, while aggressive life-sustaining procedures were not included. This might have led to parallel increasing trends of utilization of palliative procedures with palliative care consultation. Interestingly, the utilization of palliative care consultation increased more rapidly than that of palliative procedures (CAGR 9.3% vs. CAGR 1.6%), the details of which will need to be explored in the future.
Factors associated with the utilization of palliative care consultation were also analyzed in this study. It was found that older age group, female, Hispanic and Asian-Pacific Islander, and Medicaid users received more palliative care consultation, while patients in small to medium sized hospitals and rural or urban-nonteaching hospitals received significantly less palliative care consultation. These findings are broadly consistent with a previous study investigating determinants of palliative care utilization among patients hospitalized with metastatic gastrointestinal malignancies. In that study, the authors analyzed the NIS database and found that female, Hispanic or African-American, Medicaid (compared with Medicare) user, and large sized and urban-teaching hospitals were associated with inpatient palliative care utilization [
19]. It is unclear why gender, racial, and insurance differences were observed in the utilization of palliative care consultation. It could be partially explained by the following findings: 1) males with malignant diseases near EOL might have more risk of emergency department attendance than females [
20]; and 2) Medicaid is a commercial insurance with higher self-pay status compared to Medicare users [
21]. We also found that the severity of illness and the number of diagnoses were positive factors for palliative care utilization, as expected. Interestingly, in-hospital death was also highly associated with palliative care utilization. Previous studies have shown that introduction of early palliative care has advantages to effectively improve health care utilization by reducing hospital charges and in-hospital mortality in patients with advanced chronic illness and malignant diseases [
22‐
25]. The present study showed similar results to previous studies in terms of hospital costs. However, our result on the association between palliative care and in-hospital mortality was inconsistent with previous studies. Due to the lack of previous data about palliative care consultation in patients with gastric cancer in the US, the cause of discrepancy in such results of in-hospital mortality between ours and previous studies could not be determined. Patients with gastric cancer might be referred to hospitals at a later stage, which might have led to a late introduction of palliative care consultation and an increase of in-hospital mortality because gastric cancer is not a major malignancy in the US and its associated symptoms are vague until it is developed at an advanced stage [
26].
Factors associated with the utilization of palliative procedures were also analyzed in this study. It was found that females and black or Hispanic patients were less likely to receive palliative procedures. However, median income by zip code was a positive factor for utilization of palliative procedures. It is generally known that minority patients with EOL are less likely to receive advanced care directives [
27], while patients with higher socioeconomic status are more likely to receive it [
20], However, our study did not demonstrate significant differences in the utilization of palliative procedures according to the insurance type. Our data of palliative procedures considering hospital characteristics such as hospital bed size and hospital location with teaching status showed very similar pattern to those of palliative care consultation. This suggests that both palliative care consultation and palliative procedures for gastric cancer patients in the US are usually performed in large, urban-teaching hospitals. It is noteworthy that utilization of palliative procedures was negatively associated with in-hospital mortality, in contrast with palliative care consultation. This finding suggests that palliative procedures in gastric cancer patients near EOL may facilitate a transition to improved EOL care outside the hospital setting. This finding deserves further investigation of the actual factors involved.
Our analysis for factors associated with total hospital charges showed that multiple independent variables contributed to the increase or decrease of hospital charges in gastric cancer patients. It was noticeable that hospital charges were significantly decreased over the period of 2009–2018 and that utilization of palliative care was a strong factor for reduced hospital charges. These results suggest that increased utilization of palliative care consultation may reduce unnecessary health care costs. However, we found that utilization of palliative procedure was positively associated with hospital cost, consistent with our previous study showing that systemic or local procedure was associated with higher hospital charges in terminally ill patients [
9]. There were gender and racial differences in that females paid less hospital charges while Hispanic and Asian-Pacific Islanders paid significantly more in the present study, consistent with a previous study [
19]. Hospital factors were also significantly associated with hospital charges, with large and urban-teaching hospitals showing increased hospital charges, which was expected.
Study limitations
This study has several limitations. First, we included palliative care consultation only based on palliative care (ICD-9 code: V66.7, ICD-10 code: Z51.5) and advance care planning (ICD-9 code: V69.89, ICD-10 code: Z71.89) codes, which might have led to a low sensitivity due to missing data. For example, a recent validation study of the V66.7 code for palliative care consultation has shown a low sensitivity (66.3%) among metastatic cancer patients, although it showed an optimal specificity (99.1%) [
10]. Second, palliative care can be supplied in outpatient or home-based settings as well as inpatient settings. However, out study cohort did not include home-based palliative care population. Thus, results of this study cannot be applied to outpatient or home-based palliative care settings [
12]. Third, we captured gastric cancer cases only based on the ICD-9 and ICD-10 codes. Thus, we could not differentiate stages of gastric cancer patients. In addition, since NIS does not have a variable to distinguish a recent diagnosis from all other diagnoses of gastric caner, we might have included early staged gastric cancer cases not relevant to our study. Finally, as we relied on ICD codes for detecting palliative procedures, selected procedures might be actually performed for life-sustaining purpose rather than palliative purpose.
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