The studied general surgical ward had 29 active beds in average during 2016 to 2017; the bed occupancy rate was 74 percent. Based on the results, mean±SD and median of patients’ length of stay in this department were 3.30±3.71 and 2 days respectively. The shortest and longest lengths of stays were 1 and 30 days respectively. The patients’ mean age was 33.94±21.48 years and respective minimum and maximum ages of 1 and 91 years. In general, 80% of patients underwent surgery that considering the nature of the department, most cases were related to general surgery service. Other patients included three groups 1) according to more clinical examination, they didn't need to surgery, 2) canceled operation for any reason, and 3) re-admission due to surgical complications such as surgical site infection. The results of association between study variables and average length of stay are represented in tables 1-4.
Table 1. Relationship between patient's length of stay and demographic variables
Variables
|
n (%)
|
Length of stay
Mean±SD
|
P-value
(<0.05)
|
Gender
|
Male
|
201(64.8)
|
3.60±4.21
|
0.025*
|
Female
|
109(35.2)
|
2.74±2.50
|
Urban Residence
|
Urban
|
194(62.6)
|
3.39±3.98
|
0.575
|
Rural
|
116(37.4)
|
3.15±3.23
|
Ethnicity
|
Native(residents of Bandar Abbas)
|
165(53.2)
|
3.34±4.01
|
0.842
|
Non-native
|
145(46.8)
|
3.26±3.36
|
Age/Elderly(yrs)
|
<=60
|
266(85.8)
|
3.16±3.75
|
0.098
|
>60
|
44(14.2)
|
4.16±3.39
|
Marital Status
|
Married
|
185(59.7)
|
3.39±3.87
|
0.190
|
Single
|
105(33.9)
|
2.91±3.10
|
Unknown
|
20(6.4)
|
4.50±4.89
|
SD= Standard Deviation, *Independent t-test
As shown in table 1, among demographic variables only average length of stay showed a significant difference between groups of gender since men had a longer LOS.
Table 2. Relationship between patient's length of stay and non-clinical variables
Variables
|
n (%)
|
Length of stay
Mean±SD
|
P-value
(<0.05)
|
|
|
Admitted Time
|
Day Shift
|
110(35.5)
|
2.50±2.70
|
<0.001*
|
|
Evening and night shifts
|
200(64.5)
|
3.74±4.11
|
|
Admitted Day/
Admitted on holiday
|
Holiday
|
42(13.5)
|
3.43±3.57
|
0.810
|
|
Regular days
|
268(86.5)
|
3.28±3.74
|
|
Patient Companion
|
Hasn’t Companion
|
17(5.5)
|
3.65±3.06
|
0.641
|
|
Has Companion
|
293(94.5)
|
3.28±3.75
|
|
Admitted Day/
Week’s days
|
Saturday
|
50(16.1)
|
3.58±3.89
|
0.089
|
|
Sunday
|
74(23.9)
|
2.38±1.87
|
|
Monday
|
40(12.9)
|
3.00±2.72
|
|
Tuesday
|
45(14.5)
|
3.58±4.60
|
|
Wednesday
|
34(11.0)
|
3.00±2.79
|
|
Thursday
|
33(10.6)
|
4.70±6.01
|
|
Friday
|
34(11.0)
|
3.82±3.82
|
|
Admitted months/
Solar Hijri calendar
|
Farvardin
|
26(8.4)
|
2.73±2.55
|
0.191
|
|
Ordibehesht
|
25(8.1)
|
2.56±2.55
|
|
Khordad
|
25(8.1)
|
2.80±1.98
|
|
Tir
|
26(8.4)
|
2.73±2.38
|
|
Mordad
|
26(8.4)
|
2.38±2.55
|
|
Shahrivar
|
26(8.4)
|
2.50±1.98
|
|
Mehr
|
26(8.4)
|
4.81±3.95
|
|
Aban
|
26(8.4)
|
4.42±4.49
|
|
Azar
|
26(8.4)
|
4.35±6.19
|
|
Dey
|
26(8.4)
|
3.00±2.23
|
|
Bahman
|
26(8.4)
|
3.69±6.02
|
|
Esfand
|
26(8.4)
|
3.58±3.81
|
|
Insurance Type
|
Social Security Organization
|
72(23.2)
|
2.42±2.13
|
<0.001**
|
|
Medical Services Insurance
|
155(50.0)
|
2.87±3.29
|
|
Imam Khomeini Relief Foundation
|
8(2.6)
|
5.50±3.63
|
|
Armed Forces Medical Services Insurance
|
13(4.2)
|
2.69±2.50
|
|
Road traffic accidents
|
25(8.1)
|
7.72±7.00
|
|
Iranian Health
|
20(6.5)
|
3.50±2.67
|
|
Other
|
17(5.5)
|
3.65±3.32
|
|
Referral Type
|
From physician’s office
|
29(9.4)
|
3.34±2.53
|
<0.001**
|
|
From hospital clinic
|
67(21.6)
|
2.09±2.02
|
|
From emergency unit
|
149(48.1)
|
4.54±4.67
|
|
Other
|
65(21.0)
|
1.69±1.22
|
|
*Independent t-test, **Analysis of variance test (ANOVA)
The average length of stay shows significant difference in terms of time of admission, type of insurance and different levels of referrals (P<0.001). The patients who visited the hospital in afternoon shift to be admitted in surgery ward had longer average LOS. In regard to the variable “type of insurance”, patients’ average length of stay was longer when they used Traffic Accident insurance rather than other insurances (P<0.001).
In cases of referral from emergency department, average length of stay was longer than cases of referral from hospital clinic and other places (P<0.001).
Table 2. Relationship between patient's length of stay and non-clinical variables(continued)
Variables
|
n (%)
|
Length of stay
Mean±SD
|
P-value
<0.05
|
|
|
Attending Physician Degree
|
Specialist
|
291(93.9)
|
3.29±3.73
|
0.784
|
|
sub-specialist
|
19(6.1)
|
3.53±3.55
|
|
Admitting Physician Specialty
|
Emergency medicine
|
101(32.6)
|
4.37±4.68
|
<0.001**
|
|
General Surgeon
|
132(42.6)
|
3.16±3.51
|
|
Urologist
|
43(13.9)
|
1.86±0.94
|
|
Otorhinolaryngologist (ENT)
|
7(2.2)
|
1.00±.00
|
|
Plastic & Cosmetic Surgeon
|
9(2.9)
|
3.33±2.45
|
|
Other surgeries(Neurosurgeon, Ophthalmologist, Orthopedist)
|
13(4.2)
|
1.62±0.76
|
|
Internist(Internist, Digestive-Liver Disease, infectiousDisease)
|
5(1.6)
|
5.40±3.97
|
|
Attending Physician Specialty
|
Internist(Internist, Digestive-Liver Disease, infectiousDisease)
|
17(5.4)
|
4.76±3.78
|
0.018**
|
|
General Surgeon
|
204(65.8)
|
3.67±4.19
|
|
Urologist
|
56(18.1)
|
2.14±1.41
|
|
Neurosurgeon
|
4(1.3)
|
4.5±5.07
|
|
Otorhinolaryngologist (ENT)
|
7(2.3)
|
1.00±.00
|
|
Ophthalmologist
|
6(1.9)
|
1.33±0.52
|
|
Orthopedist
|
7(2.3)
|
1.43±0.79
|
|
Plastic & Cosmetic Surgeon
|
9(2.9)
|
3.33±2.45
|
|
**Analysis of variance test (ANOVA)
The cases in which admitting physician was emergency medicine specialist were accompanied by longer patient length of stay than cases in which patients were admitted by ENT specialist, general surgeon, urology or other surgeons(P<0.01).
According to post-hoc test, internal medicine specialties as attending physician were followed by patients’ longer length of stay than orthopedics, urology, and ENT specialists as well as eye surgeon(P<0.05).
Table 3. Relationship between patient's length of stay and clinical variables
Variables
|
n (%)
|
Length of stay
Mean±SD
|
P-value
|
|
|
Type of admission
|
Elective
|
161(51.9)
|
2.16±1.94
|
<0.001*
|
|
Emergency
|
149(48.1)
|
4.54±4.67
|
|
Hospitalization History
|
Has
|
223(71.9)
|
3.14±3.28
|
0.236
|
|
Hasn’t
|
87(28.1)
|
3.70±4.65
|
|
Encounter Reason
|
Disease
|
228(73.5)
|
2.82±2.70
|
<0.001**
|
|
Road traffic accidents
|
25(8.1)
|
7.24±6.88
|
|
Other events (Non-disease)
|
57(18.4)
|
3.51±4.29
|
|
Hospitalization Cause/final diagnosis; categories of ICD-10
|
Neoplasms
|
11(3.5)
|
5.64±3.80
|
<0.001**
|
|
Diseases of the digestive system
|
98(31.6)
|
3.14±2.96
|
|
Diseases of the skin and subcutaneous tissue
|
25(8.1)
|
2.08±2.56
|
|
Diseases of the genitourinary system
|
53(17.1)
|
2.09±1.20
|
|
Congenital malformations, deformations and chromosomal abnormalities
|
12(3.9)
|
2.25±1.42
|
|
Injury, poisoning, and certain other consequences of external causes
|
76(24.5)
|
4.84±5.58
|
|
Factors influencing health status and contact with health services
|
10(3.2)
|
1.80±0.92
|
|
Other
|
25(8.1)
|
3.08±3.42
|
|
Patients' status at discharge
|
Recovery & Relative recovery
|
177(57.1)
|
3.01±3.64
|
0.032**
|
|
Discharge without physician order/
Discharge with personal desire
|
25(8.1)
|
4.04±3.27
|
|
Death
|
4(1.3)
|
8.50±5.07
|
|
Need to Follow up
|
95(30.6)
|
3.49±3.78
|
|
Other
|
9(2.9)
|
2.67±3.61
|
|
As a result, emergency admitted cases were accompanied by longer length of stay than non-emergency cases. In regard to the variable of reason of encounter, cases of accident-caused admission were followed by longer length of stay than cases of disease and other events(P<0.001).
The LSD test showed that the difference between the LOS and "cause of hospitalization" related to longer LOS in cases of "neoplasm" and "injury, poisoning and certain other consequences of external causes" compared with those who had other cause (p<0.05).
About patient’s condition at time of discharge, in average, death cases had longer length of stay compared with other condition. (P<0.01).
Table 4. Relationship between patient's length of stay and quantitative variables
Variables
|
Mean±SD
|
Pearson Correlation Coefficient
|
P-value
|
Age
|
33.94±21.48
|
0.146
|
0.01
|
Number of previous hospitalizations
|
0.53±1.16
|
-0.019
|
0.737
|
The number of clinical consultations requested during hospitalization
|
0.53±1.08
|
0.632
|
<0.001
|
Number of visits
|
2.82±3.20
|
0.914
|
<0.001
|
Number of Surgery
|
0.94±0.75
|
0.348
|
<0.001
|
Number of Para-clinical Services
|
8.11±13.15
|
0.660
|
<0.001
|
Correlation is significant at the 0.01 level
As shown in table 4, increase of age, number of consultation, doctor visit, surgery, and para-clinical services (laboratory tests, pathologies, radiography, imaging and other diagnostic services) was followed by longer length of stay and this association was statistically significant.
As correlation coefficients in table 4 suggest, association of visits and number of para-clinical services with length of stay was stronger.
Table 5. Factors associated with patients’ LOS in Multiple Linear Regression analysis
Variables
|
Unstandardized Coefficients
|
Standardized Coefficients
|
Confidence Interval
|
P-value
|
Lower
|
Upper
|
Admitted Months
|
0.052
|
0.048
|
0.006
|
0.098
|
0.028
|
Referral Type
|
-0.201
|
-0.047
|
-0.380
|
-0.022
|
0.028
|
Number of Consultations
|
0.283
|
0.094
|
0.098
|
0.467
|
0.003
|
Number of Visits
|
0.874
|
0.752
|
0.806
|
0.941
|
<0.001
|
Number of Surgery
|
0.482
|
0.097
|
0.265
|
0.698
|
<0.001
|
Number of Para-clinical Services
|
0.038
|
0.135
|
0.023
|
0.053
|
<0.001
|
All qualitative and quantitative factors which satisfied P<0.2 in univariate analysis were added to multiple linear regression model. In this model, the variables with highest p-value were excluded until all of remaining variables of the model satisfied the condition P<0.05. Finally, multivariate regression model of factors with highest association with LOS was reported in table 5.