Efficacy-cost analysis of endoscopic mucosal resection and cold snare polypectomy: A propensity score matching analysis

Abstract

BACKGROUND

Although substantial evidence supports the advantages of cold snare polypectomy (CSP) in terms of polypectomy efficacy and reduced postoperative adverse events, few studies have examined the cost differences between CSP and traditional endoscopic mucosal resection (EMR) for the treatment of intestinal polyps.

AIM

To compare the efficacy-cost of EMR and CSP in the treatment of intestinal polyps.

METHODS

A total of 100 patients with intestinal polyps were included in the retrospective data of our hospital from April 2022 to May 2023. According to the treatment methods, they were divided into EMR (n = 46) group and CSP (n = 54) group. The baseline data of the two groups were balanced by 1:1 propensity score matching (PSM), and the cost-effectiveness analysis was performed on the two groups after matching. The recurrence rate of the two groups of patients was followed up for 1 year, and they were divided into recurrence group and non-recurrence group according to whether they recurred. Multivariate logistic regression analysis was used to screen out the influencing factors affecting the recurrence of intestinal polyps after endoscopic resection.

RESULTS

Significant disparities were observed in the number of polyps and smoking background between the two groups before PSM (P < 0.05). Following PSM, the number of polyps and smoking history were well balanced between the EMR and CSP groups. The direct cost incurred by the CSP group was markedly higher than that incurred by the EMR group. Concurrently, the cost-effectiveness ratio in the CSP group was substantially reduced when juxtaposed with that in the EMR group (P < 0.05). Upon completion of the 1-year follow-up, the rate of recurrence after endoscopic intestinal polypectomy was 38.00%. Multivariate methods revealed that age ≥ 60 years, male sex, number of polyps ≥ 3, and pathological type of adenoma were risk factors for recurrence after endoscopic intestinal polypectomy (all P < 0.05).

CONCLUSION

CSP was more cost-effective for the treatment of intestinal polyps. An age ≥ 60 years, male sex, having a number of polyps ≥ 3, and pathological type of adenoma are independent influencing factors for recurrence.

Key Words: Propensity score matching method; Endoscopic mucosal resection; Cold snare polypectomy; Intestinal polyps; Curative effect; Cost analysis

Core Tip: This study utilizes propensity score matching to evaluate the efficacy and cost-effectiveness of cold snare polypectomy (CSP) vs endoscopic mucosal resection in colorectal polyp treatment. CSP shows a higher rate of complete resection and a more favorable cost-to-effectiveness ratio. The research also identifies an age over 60 years, male sex, presence of three or more polyps, and adenomatous histology as key predictors of polyp recurrence, advocating for CSP's adoption and personalized patient follow-up strategies.

INTRODUCTION

Intestinal polyps, a common digestive tract disease, refer to vegetation on the surface of the colon and rectal mucosa protruding into the intestinal cavity[1]. Clinically, to distinguish the possibility of cancer, intestinal polyps are divided into adenomatous polyps and non-adenomatous polyps, in which adenomatous polyps are closely related to intestinal cancer[2]. Therefore, it is recommended that colorectal polyps be clinically removed. In recent years, endoscopic mucosal resection (EMR) has frequently been used to resect colon polyps in clinical practice. In addition, argon knife resection, high-frequency electrocoagulation electro-resection, hot snare polypectomy, endoscopic mucosal dissection, and other techniques have been used for the EMR of colon polyps. EMR is characterized by low cost and fast recovery; therefore, it is preferred by clinicians and patients[3,4]. However, there are complications related to EMR, such as bleeding, perforation, and electrocoagulation syndrome after polypectomy, of which bleeding is the most common[5]. The occurrence of postoperative adverse events increases the cost of hospitalization and aggravates the burden on patients.

Cold snare polypectomy (CSP) is a suitable endoscopic resection technique for small polyps and is recommended by several national endoscopic society guidelines[6]. Moreover, CSP does not result in bleeding due to electrocoagulation, which can reduce damage to the surrounding blood vessels and intestinal walls; therefore, CSP is associated with low risk of bleeding[7,8].

EMR and CSP have their own advantages and disadvantages, which have been disputed by many scholars. Although there is much evidence indicating the advantages of CSP in terms of the efficacy of polypectomy and postoperative adverse events, few studies have explored the difference in treatment costs between CSP and traditional EMR. Therefore, this study aimed to analyze the cost-effectiveness of the two surgical methods for the treatment of intestinal polyps based on the propensity score matching (PSM) method through an in-depth study of CSP and EMR. Furthermore, we evaluated the health economics to provide patients with the best treatment options.

The cancer rate of intestinal polyps is high, and adenomatous polyps are considered precancerous lesions in colorectal cancer. Previous studies have shown that 60%-80% of colon cancers progress from intestinal polyps[9]. Therefore, emphasis should be placed on early diagnosis of the disease, and targeted treatment should be provided based on a clear diagnosis to alleviate symptoms and delay disease progression. Endoscopic procedures represent the primary therapeutic approach for the management of intestinal polyps and effectively lower the incidence and mortality rates of colorectal cancer[10]. However, the postoperative recurrence rate is high, and invasive colorectal cancer can develop in severe cases. Therefore, this study aimed to explore the factors associated with the postoperative recurrence of intestinal polyps, providing a reference for the formulation and implementation of prevention and treatment measures.

MATERIALS AND METHODS

General information

One hundred patients with intestinal polyps who were treated at the Ezhou Central Hospital between April 2022 and May 2023 were selected as research participants. The inclusion criteria were as follows: (1) Colonoscopy and histopathological examination in line with the clinical diagnostic criteria for intestinal polyps[11]; (2) No previous history of colon surgery; (3) Complete clinical data; and (4) Not taking antiplatelet or anticoagulant drugs. The exclusion criteria were as follows: (1) Patients with mental disorders, cognitive dysfunction, or autoimmune diseases; (2) Patients with abnormal coagulation function, intestinal malignant disease, or intestinal tuberculosis; (3) Patients with surgical contraindications, severe disturbance of consciousness, or pregnancy or lactation; and (4) Patients with serious diseases of the heart, liver, kidney, or other organs. Furthermore, the exclusion shedding criteria were as follows: (1) After inclusion, cases that did not meet the inclusion criteria, did not use drugs according to the test plan, or cases with incomplete data were excluded; (2) Patients who withdrew or did not complete the whole course of treatment and affected the efficacy or safety judgment were excluded; and (3) Patients who required specialist treatment or transfer because of other diseases were removed from the study. The study was reviewed and approved by the Institutional Review Board of Ezhou Central Hospital.

Surgical methods

The EMR group underwent the following surgical protocol: (1) First, patients underwent bowel preparation, including emptying the bowel and fasting, to ensure that the operation was performed smoothly; (2) The endoscope was inserted through the anus and entered into the colon. The clinician observed the polyps in the intestine through an endoscope and used special instruments to clamp and fix the polyps; (3) Next, the doctor passed the resection device through the endoscopic catheter, clipped the polyp tissue, and removed it. Clinicians carefully observed the endoscopic operation to ensure that the resection range was correct and that the blood vessels were not damaged; (4) After the operation was complete, it was necessary to perform hemostatic treatment at the resection site, check whether the resection range was sufficient, and assess whether there were any other abnormalities. The entire operational process requires extensive operational skill and rich experience. Clinicians strictly followed the operational processes and norms to ensure the safety and effectiveness of the operation; and (5) After surgery, patients underwent a recovery period and avoided overconsumption or eating irritating food. Simultaneously, the wound was closely monitored to determine whether bleeding or infection occurred; if so, timely medical treatment was sought.

The CSP group underwent the following surgical protocol: (1) A routine colonoscopy was performed, and the appropriate snare was maneuvered to the lesion through the colonoscopy biopsy channel; (2) The snare was opened within a clear field of vision, and the polyps were surrounded. Normal colonic polyp tissues measuring 1-2 mm around the polyps were collected together in the snare. The snare was slowly closed for 10 seconds, until the polyps were completely cut off; and (3) The wound was washed with normal saline. The wounds were routinely clipped using metal clips.

PSM

R language software (R 4.1.2, Lucent Technologies, Molly Mountain, NJ, United States) was used for PSM. When the caliper value was set to 0.2, the EMR and CSP groups were matched at a ratio of 1:1 for variables with differences in the baseline data analysis before matching, such as smoking and number of polyps. The standardized mean difference (SMD) was used to test the balance between the groups after PSM, and a SMD < 0.1 was considered to be a good matching effect[12].

Observation indicators and judgment criteria

Efficacy-cost analysis was performed according to the following guidelines: (1) Cost estimation refers to the determination of the resource value consumed by a specific treatment plan or drug treatment that is concerned or needed, including hidden, direct, and indirect costs. Various types of direct costs are involved. The income cost of all patients in this study was calculated according to the charging standards set by the local price bureau. The direct costs for the CSP and EMR groups were anesthesia fee + examination and laboratory fee + operation fee + registration fee + drug fee + bed care fee; (2) The effect index (efficacy) of this study was replaced with the histological complete resection rate. If the resected polyp specimens and the bottom margin biopsy specimens were all negative, it was a histologically complete resection; and if there was ≥ 1 lesion tissue, it was incomplete resection; and (3) Efficacy-cost = cost (C)/efficacy (E).

Patients were followed-up with for 1 year. Subsequently, the patients were classified into recurrence and non-recurrence groups based on the presence or absence of recurrence. Recurrence rates were assessed and documented for both groups, with subsequent examination and comparison of the clinical profiles between patients with recurrent episodes and those who remained free from recurrence. To analyze the factors influencing recurrence, various items were substituted into the logistic regression equation.

Statistical analysis

Statistical software SPSS (SPSS 20.0, IBM, United States) was used to analyze the data. The measurement data that were normally distributed were reported as the mean ± SD, and the t test was used for comparison between groups. The measurement data with a skewed distribution were reported as the median and quartiles [M (P25, P75)], and the Mann-Whitney U test was used for comparisons. The tabulated count data were articulated as fractions, n (%), and a comparative analysis between groups was executed using the χ² test for R × C contingency tables. Subsequently, logistic regression analysis was conducted to discern the determinants affecting the recurrence of intestinal polyps post-surgery. Statistical significance was set at a P value < 0.05.

RESULTS

Baseline data before PSM

Of the 100 patients enrolled in the study, 46 underwent EMR and 54 underwent CSP. As detailed in Table 1, notable disparities were observed in smoking habits and the number of polyps between the two groups (P < 0.05).

Table 1 Baseline data of patients in the two groups before propensity score matching, n (%).

Items	EMR group (n = 46)	CSP group (n = 54)	χ2/t	P value
Age			1.771	0.183
≥ 60 years	22 (47.83)	33 (61.11)
< 60 years	24 (52.17)	21 (38.89)
Sex			0.100	0.752
Male	27 (58.70)	30 (55.56)
Female	19 (41.30)	24 (44.44)
BMI (kg/m2)	22.48 ± 1.43	22.19 ± 2.68	0.678	0.499
Smoking			3.904	0.048
Yes	27 (58.70)	21 (38.89)
No	19 (41.30)	33 (61.11)
Diabetes mellitus			0.549	0.459
Yes	23 (50.00)	23 (42.59)
No	23 (50.00)	31 (57.41)
Combined hypertension			0.343	0.558
Yes	24 (52.17)	25 (46.30)
No	22 (47.83)	29 (53.70)
Polyp diameter			0.244	0.621
≥ 10 mm	21 (45.65)	22 (40.74)
< 10 mm	25 (54.35)	32 (59.26)
Number of polyps			3.904	0.048
≥ 3	27 (58.70)	21 (38.89)
< 3	19 (41.30)	33 (61.11)
Polyp location			0.362	0.547
Colon	28 (60.87)	36 (66.67)
Rectum	18 (39.13)	18 (33.33)
Pathological type			2.347	0.126
Inflammatory hyperplasia	30 (65.22)	27 (50.00)
Adenomatous	16 (34.78)	27 (50.00)

EMR: Endoscopic mucosal resection; CSP: Cold snare polypectomy; BMI: Body mass index.

Baseline data after PSM

Following 1:1 PSM, a cohort of 80 patients across both groups was successfully paired. After matching, the baseline data, such as smoking history and polyp number, of the two groups were balanced (Table 2).

Table 2 Baseline data of two groups of patients after propensity score matching, n (%).

Items	EMR group (n = 40)	CSP group (n = 40)	χ2/t	P value
Age,			1.818	0.178
≥ 60 years	25 (62.50)	19 (47.50)
< 60 years	15 (37.50)	21 (52.50)
Sex,			0.051	0.822
Male	22 (55.00)	23 (57.50)
Female	18 (45.00)	17 (42.50)
BMI (kg/m2)	22.55 ± 1.45	21.97 ± 2.68	1.209	0.230
Smoking			0.000	1.000
Yes	21 (52.50)	21 (52.50)
No	19 (47.50)	19 (47.50)
Diabetes mellitus			0.202	0.653
Yes	19 (47.50)	17 (42.50)
No	21 (52.50)	23 (57.50)
Combined hypertension			0.000	1.000
Yes	19 (47.50)	19 (47.50)
No	21 (52.50)	21 (52.50)
Polyp diameter			0.052	0.820
≥ 10 mm	16 (40.00)	17 (42.50)
< 10 mm	24 (60.00)	23 (57.50)
Number of polyps			0.000	1.000
≥ 3	21 (52.50)	21 (52.50)
< 3	19 (47.50)	19 (47.50)
Polyp location			0.220	0.639
Colon	25 (62.50)	13 (32.50)
Rectum	15 (37.50)	27 (67.50)
Pathological type			2.489	0.115
Inflammatory hyperplasia	26 (65.00)	19 (47.50)
Adenomatous	14 (35.00)	21 (52.50)

EMR: Endoscopic mucosal resection; CSP: Cold snare polypectomy; BMI: Body mass index.

Comparison of the direct treatment cost and cost-efficacy after PSM

The direct cost (C) of the CSP group was 4528.23 ± 457.19 yuan, which was higher than that of the EMR group (3961.56 ± 328.47 yuan; t = 6.366, P < 0.001). The histological complete resection rate in the CSP group was 92.50% (37/40), which was higher than the 75.00% (32/48) in the EMR group (χ² = 4.501, P = 0.034). The cost-efficacy (C/E) value of the CSP group (48.95 ± 4.94) was significantly lower than that of the EMR group (52.82 ± 4.38) (t = 3.707, P < 0.001), as shown in Figure 1.

Figure 1 Comparison of the direct treatment cost and cost-efficiency between the two groups following propensity score matching. A: Direct cost fee; B: Cost-efficiency. ^aP < 0.05. EMR: Endoscopic mucosal resection; CSP: Cold snare polypectomy.

Univariate analysis of recurrence after endoscopic intestinal polypectomy

After 1 year of follow-up, among the 100 patients with intestinal polyps included, 38 instances (38.00%) of recurrence were observed following endoscopic intestinal polypectomy, categorizing these patients into the recurrence group. Conversely, 62 cases remained recurrence-free and were allocated to the non-recurrence group. Divergent trends were noted when comparing the two groups in terms of age, sex, the diameter of the polyps, polyp count, and histological classification (P < 0.05), with specifics provided in Table 3.

Table 3 Single factor analysis of recurrence after endoscopic intestinal polypectomy, n (%).

Items	Recurrence group (n = 38)	Non-recurrence group (n = 62)	χ2/t	P value
Age			4.461	0.035
≥ 60 years	26 (68.42)	29 (46.77)
< 60 years	12 (31.58)	33 (53.23)
Sex			4.938	0.026
Male	27 (71.05)	30 (48.39)
Female	11 (28.95)	32 (51.61)
BMI (kg/m2)	21.96 ± 2.03	22.57 ± 2.26	-1.360	0.177
Smoking			0.261	0.609
Yes	17 (44.74)	31 (50.00)
No	21 (55.26)	31 (50.00)
Diabetes mellitus			0.395	0.530
Yes	19 (50.00)	27 (43.55)
No	19 (50.00)	35 (56.45)
Combined hypertension			2.226	0.136
Yes	15 (39.47)	34 (54.84)
No	23 (60.53)	28 (45.16)
Polyp diameter			5.548	0.019
≥ 10 mm	22 (57.89)	21 (33.87)
< 10 mm	16 (42.11)	41 (66.13)
Number of polyps			10.240	0.001
≥ 3	26 (68.42)	22 (35.48)
< 3	12 (31.58)	40 (64.52)
Polyp location			3.438	0.064
Colon	20 (52.63)	44 (70.97)
Rectum	18 (47.37)	18 (29.03)
Pathological type
Inflammatory hyperplasia	13 (34.21)	44 (70.97)	12.987	< 0.001
Adenomatous	25 (65.79)	18 (29.03)
Surgical approach			3.491	0.062
EMR	22 (57.89)	24 (38.71)
CSP	16 (42.11)	38 (61.29)

EMR: Endoscopic mucosal resection; CSP: Cold snare polypectomy; BMI: Body mass index.

Multivariate analysis of recurrence after endoscopic intestinal polypectomy

Recurrence after surgery was the dependent variable (recurrence = 1, no recurrence = 0). The statistically significant variables included as independent variables in the multivariate analysis, and the assignment of each variable, are shown in Table 4. The multivariate analysis showed that age ≥ 60 years, male sex, number of polyps ≥ 3, and pathological type of adenoma were risk factors for recurrence after endoscopic intestinal polypectomy (P < 0.05), as shown in Figure 2.

Figure 2  Forest plot of the multivariate analysis of recurrence after endoscopic polypectomy.

Table 4 Assignment table for multivariate analysis.

Variable	Assignment
Age (≥ 60 years)	Yes = 1, No = 0
Sex (male)	Yes = 1, No = 0
Number of polyps (≥ 3)	Yes = 1, No = 0
Polyp diameter (≥ 10 mm)	Yes = 1, No = 0
Pathological type (adenoma)	Yes = 1, No = 0

DISCUSSION

Intestinal polyps refer to the abnormal growth of tissues protruding from the surface of the intestinal mucosa. Colonic and rectal polyps are the most common, whereas small intestinal polyps are less common. Clinical manifestations include diarrhea, lower gastrointestinal bleeding, and other symptoms, and there is a risk of cancerization[13]. Approximately two-thirds of all colonic polyps are adenomas[14], and 60%-70% of colon cancers develop from adenomas[15]. With continuous improvements in living standards, changes in eating habits have led to various intestinal problems. The incidence and mortality of colorectal cancer have maintained a significant upward trend[16]. Approximately 800000 people worldwide die of colorectal cancer each year, accounting for the top five causes of cancer-related deaths worldwide[17]. It seriously affects the lives and health of patients; therefore, early intervention, regular tracking, and polyp removal are required to reduce the risk of colon cancer[18].

Endoscopic EMR and CSP are common minimally invasive treatment methods for colonic polyps. The complete histopathological resection rate is an important index for evaluating the effect of polypectomy procedures. In this study, the complete resection rate was higher in the CSP group than in the EMR group, indicating a greater effect of CSP surgery. Bleeding during CSP is rare; therefore, the endoscopist does not need to flush out the bleeding, the field of vision is clear, and the tissue can be quickly found for resection to ensure a high complete histological resection rate. Incomplete resection of polyps will increase the risk of polyp recurrence. Repeated invasive procedures not only increase the economic pressure of patients, but also increase the psychological burden of patients.

With an increase in the number of patients with intestinal polyps and the diversification of methods for treating the disease, researchers have paid increasing attention to the economics of colonic polyps. The DISCARD3 study[19] showed that the overall medical cost of patients with colorectal polyps was about USD 88000. A cost-benefit analysis of CSP[20] pointed out that the medical cost of treating giant sessile colorectal polyps was about USD 5213, and the number of days of lost productivity due to hospitalization was about 6.2 days. From the perspective of treatment, an analysis was carried out by comparing different treatment methods, and the optimal scheme was selected[21]. Based on PSM, this study conducted a cost-effectiveness analysis of the two methods in patients with intestinal polyps. The findings indicated that the C/E ratio for the CSP group was inferior to that of the EMR group, indicating that CSP surgery reduced the medical and economic costs for patients. CSP has certain economic advantages and helps reduce the medical costs of patients with colorectal polyps. Postoperative adverse events and lesion recurrence may lead to prolonged hospital stay and increased costs. Compared with EMR, CSP may cause fewer complications, reducing the possibility of additional treatment or hospitalization due to complications. Although the direct cost of CSP is higher, the C/E value is lower, indicating that CSP is more cost-effective in obtaining the same effect. Regardless of whether the cost or treatment results are ignored, both are indispensable. Therefore, balancing the best treatment effects with the lowest cost has become a hot topic in medical economics.

Previous studies[22,23] have shown that the recurrence rate of intestinal polyps is 25.8%-48.3%. In most cases, the recurrence of colorectal polyps is related to continuous mechanical and inflammatory stimulation. Therefore, colonoscopy findings should be regularly reviewed after polypectomy. In this study, the recurrence rate of intestinal polyps was 38.00%, which is similar to the results reported in the literature. This finding suggests that more attention should be paid to the clinical and active measures to reduce the risk of recurrence. In addition, after endoscopic treatment, it is particularly important to understand the risk factors for the recurrence of colonic polyps, select a reasonable follow-up time, and prevent the recurrence of colonic polyps. Logistic regression analysis showed that male sex, age ≥ 60 years, number of intestinal polyps ≥ 3, Polyp diameter ≥ 10 mm, and histopathological type of adenoma were risk factors for postoperative recurrence of intestinal polyps, which was similar to the results of previous studies[23]. A possible reason for the sex difference is that the estrogen/progesterone levels in female patients are higher than those in male patients, which can reduce the recurrence rate of colon polyps[24]. In addition, there were significant differences in smoking and drinking habits between men and women, which may also be one of the reasons for the high recurrence rate in men. Previous studies on the risk factors for recurrence of colon polyps in the general population have also confirmed the role of age ≥ 60 years in the prevalence and recurrence of colon polyps. With the increasing age of the patients, the physiological function of the patients may decrease, the incidence of diarrhea, constipation and intestinal dysfunction may increase, and the intestinal stimulation may increase. At the same time, the immune function of elderly patients is reduced, which in turn increases the risk of postoperative recurrence[25,26].

The concept of a greater risk of recurrence after multiple polyps has been recognized by many researchers. The increase in the number of intestinal polyps provides conditions for further polyp growth. Studies have shown that the risk of cancer in patients with intestinal polyps increases with the number of polyps[27]. This study also confirmed that an independent risk factor for postoperative recurrence was having three or more intestinal polyps, consistent with the results in the literature[28]. The size of intestinal polyps remains a controversial risk factor for recurrence of intestinal polyps. Other studies used the size, number, and tissue type of colonic polyps as determinants of the monitoring interval for colonic polyps[11]. However, this study did not find that the size of the intestinal polyps was related to their recurrence after surgery. This discrepancy may be due to differences in race, diet, or other factors, as different countries and regions use different monitoring guidelines.

This study found a correlation between the recurrence of intestinal polyps and the pathological types, especially adenomatous intestinal polyps, which have a high recurrence rate and a high possibility of cancer. This may be because adenomatous intestinal polyps have a faster division growth rate than normal tissues, which is more likely to induce the recurrence and carcinogenesis of intestinal polyps.

This study has some limitations, such as a small sample size, limited analysis of direct costs, and lack of assessment of the influence of other factors, such as differences in diet, exercise, living habits, use of non-steroidal anti-inflammatory drugs, and inconsistent review time of intestinal polyps, which will be analyzed in a follow-up study.

CONCLUSION

In summary, this study suggests that CSP is more economical than EMR for patients with intestinal polyps. There are many schemes for the endoscopic resection of intestinal polyps. In future studies, further health economic evaluations of more endoscopic schemes can provide a basis for clinical decision-making and the rational allocation of medical resources, which has both clinical and public health significance. In addition, understanding the factors influencing the recurrence of colonic polyps, formulating individualized follow-up plans, and rationally using medical resources can help prevent their recurrence.