3.1 Basic characteristics of cases of orthopedic spine surgery
The 248 cases included in the DRG study, 123 cases (49.59%) were aged from 31 to 60 years old, 111 cases (44.75%) were over 60 years old, and 14 cases (5.65%) were under 30 years old, besides 125 cases (50.41%) were male and 123 cases (49.59%) were female. Among the payment methods, there were 146 cases (58.87%) of urban workers, 90 cases (36.29%) of urban residents, and 12 cases (4.84%) of other payment methods. The hospitalization days were mainly from 11 to 20 days, 132 cases (53.23%) in total ; 111 cases (44.76%) were critically ill or seriously ill during the hospitalization; 217 cases (87.50%) were with complications; 240 cases (96.77%) were under general anesthesia.
3.2 grouping effect of DRG in orthopedic spine surgery cases
In spine surgery cases, DRG was classified into IB19, IB21 and IB23, and the enrollment rate of IB19 was up to 56.85%. The cost CV values for the DRG subgroups in spine surgery cases were all less than 0.5, indicating good intra-group consistency (Table 1).
Table 1
Case grouping effects of orthopedic spine surgery in sample hospitals
DRG grouping
|
Number of cases (n)
|
Constituent ratio (%)
|
Hospitalization expenses
|
median
|
average value
|
Standard deviation
|
CV
|
IB19
|
141
|
56.85%
|
55,123.53
|
58,917.09
|
22,057.66
|
0.37
|
IB21
|
36
|
14.52%
|
35,183.50
|
33,764.07
|
15,832.01
|
0.47
|
IB23
|
71
|
28.63%
|
14,924.85
|
17,968.87
|
7,878.67
|
0.44
|
3.3 Distribution and test of grouping costs of DRG in orthopedic spine surgery cases
The median group hospitalization cost of DRG in orthopedic spine surgery cases was 42,934.245 yuan, and the median of the average hospitalization days was 16 days. The hospitalization expenses of each subgroup passed the K-S test and showed skewed distribution. By applying the Krus- kal-WallisH test (χ 2 = 151.007, P < 0.001), the difference in the expenses of DRG subgroups was statistically significant (Table 2).
Table 2
Percentage distribution of grouping cost and test results of DRG in orthopedic spine surgery cases
DRG grouping
|
Hospitalization expenses
|
Cost distribution
|
K-S test
|
P25
|
P75
|
kurtosis
|
skewness
|
D
|
P
|
IB19
|
45744.145
|
64477.05
|
20.268
|
3.599
|
0.159
|
0.000
|
IB21
|
19135.025
|
41052.575
|
3.235
|
1.307
|
0.168
|
0.012
|
IB23
|
13048.14
|
19378.38
|
1.589
|
1.578
|
0.194
|
0.000
|
To further determine the difference in hospital costs among the groups, Nemenyi was used. Through statistical analysis, the differences in hospital costs between IB19—IB23 and IB19—IB21 groups were statistically significant (P < 0.05). By analyzing the difference in the median hospital costs among the groups, it was concluded that DRG grouping could objectively reflect the consumption level of medical resources (Table 3).
Table 3
Subgroup cost of DRG in orthopedic spine surgery cases Nemenyi test results
Comparison group
|
Inter-group median difference (yuan)
|
P
|
IB19-IB21
|
19940.035
|
0.04
|
IB21-IB23
|
20258.645
|
0.36
|
IB19-IB23
|
40198.68
|
0.00
|
3.4 Single factor analysis of hospitalization expenses of orthopedic spine surgery cases
Through consulting the literature and experts, combining with the actual situation of the impending bed, we selected seven cases of spinal surgery cost influencing factors for single factor analysis. It was found that age, comorbidities, hospital stay, critical illness and anesthesia affected hospital expenses, and the differences have statistical significance (P < 0.05). Payment method and gender did not affect the hospitalization expenses, and the differences have not statistical significance (P > 0.05). In terms of age distribution From the view of age distribution, the average hospitalization expenses of cases in the high age group were higher than those in the low age group. From whether it has the complications,the number of cases with complications was higher than that without complications and the cost was relatively high. From the view of hospitalization days, the hospitalization days were mainly from 11 to 20 days, and the shorter the hospitalization time was, the lower the hospitalization cost would be. Judging from the critical illness situation, the hospitalization expenses of critically ill patients were relatively high. From the aspect of anesthesia mode, general anesthesia was adopted for the majority, and the cost was higher than that of local anesthesia (Table 4).
Table 4
univariate analysis of influencing factors of orthopedic spine surgery cases cost
Factor
|
Number of cases
|
Mean Average Hospitalization Expenses
|
Standard deviation of mean hospitalization expenses
|
F
|
P
|
Payment method
|
|
|
|
2.256
|
0.107
|
Basic medical insurance for residents
|
90
|
39976.1810
|
20564.90711
|
|
|
Medical insurance for workers
|
146
|
46356.5725
|
28904.90810
|
|
|
other
|
12
|
36057.4783
|
15610.72487
|
|
|
gender
|
|
|
|
0.864
|
0.354
|
man
|
125
|
42031.9513
|
23892.56231
|
|
|
woman
|
123
|
45078.1439
|
27621.35942
|
|
|
age
|
|
|
|
8.308
|
0.000
|
Under 30 years
|
14
|
46640.2879
|
41809.08613
|
|
|
31–60 years
|
123
|
37054.4722
|
21854.48487
|
|
|
Over 60 years old
|
111
|
50341.8153
|
25761.63933
|
|
|
complication
|
|
|
|
32.775
|
0.000
|
without
|
31
|
20182.8361
|
11681.94106
|
|
|
have
|
217
|
46879.8972
|
25550.68876
|
|
|
LOS
|
|
|
|
31.065
|
0.000
|
Less than 10 days
|
44
|
27106.4852
|
12373.86459
|
|
|
11–20 days
|
132
|
39055.5165
|
19469.43116
|
|
|
21–30 days
|
50
|
55335.4638
|
20620.48462
|
|
|
More than 31 days
|
22
|
76537.2223
|
44676.85037
|
|
|
Critically ill
|
|
|
|
26.451
|
0.000
|
yes
|
111
|
52456.3852
|
22675.41899
|
|
|
no
|
137
|
36320.7799
|
25997.15631
|
|
|
Anesthesia method
|
|
|
|
5.717
|
0.018
|
general anaesthesia
|
240
|
44345.8460
|
25785.52602
|
|
|
local anaesthesia
|
8
|
20951.5157
|
10048.18340
|
|
|
3.5 Analysis of multiple factors affecting hospitalization expenses of orthopedic spine surgery cases
In order to further analyze the influencing factors of hospitalization expenses in orthopedic spine surgery cases, the results of single factor analysis were included in the multiple stepwise regression analysis model to analyze multiple factors affecting the hospitalization expenses. Due to the skewed distribution of hospitalization expenses, logarithm (Y) was adopted to normal distribution approximately, and the factors were coded as follows: payment method (X1), age (X2), gender (X3), comorbidity (X4),Hospital stay (X5), critically ill or seriously ill (X6), and mode of anesthesia (X7). The multicollinearity test of the model shows that the VIF values in the model are all greater than 1 and close to 1, indicating that there is no collinearity problem and there is no correlation among the selected sample data, so the model is good. According to the standardized regression coefficient, it is concluded that the factors influencing the significant difference of hospitalization expenses in orthopedic spine surgery cases are as follows: age (X2), comorbidity (X4), hospitalization time (X5), critical illness or serious illness (X6), and anesthesia method (X7). According to the non-standardized regression coefficient, the multiple stepwise regression equations were established as follows: Y = 20343.025 + 5,201.670X2 + 13, 983.596X4 + 15, 334.923X5-13, 708.299X6-18, 457.492X7, as shown in Table 5.
Table 5
Regression model for influencing factors of case cost of orthopedic spine surgery
Variables and constants
|
Unnormalized coefficient
|
Normalization coefficient
|
Collinearity statistics
|
coefficient of regression
|
Standard error
|
Beta
|
t
|
P
|
VIF
|
payment types/methods
|
753.306
|
2,287.687
|
0.016
|
0.329
|
0.742
|
1.055
|
age
|
5,201.670
|
2,592.558
|
0.101
|
2.006
|
0.046
|
1.086
|
gender
|
3,539.039
|
2,284.518
|
0.082
|
1.549
|
0.123
|
1.184
|
complication
|
13,983.596
|
4,117.487
|
0.178
|
3.396
|
0.001
|
1.169
|
LOS
|
15,334.923
|
1,552.974
|
0.498
|
9.875
|
0.000
|
1.085
|
Critically ill or seriously ill
|
-13,708.299
|
2,568.693
|
-0.265
|
-5.337
|
0.000
|
1.055
|
Anesthesia method
|
-18,457.492
|
7,622.568
|
-0.119
|
-2.421
|
0.016
|
1.034
|
constant term
|
20343.025
|
11575.262
|
|
1.757
|
0.080
|
|