7/17/2019 out_44.pdf

1/12

Laparoscopic appendectomy for acute appendicitis is morefavorable for patients with comorbidities, the elderly, and those

with complicated appendicitis: a nationwide population-basedstudy

Chun-Chieh Yeh Shih-Chi Wu Chien-Chang Liao

Li-Ting Su Chi-Hsun Hsieh Tsai-Chung Li

Received: 28 October 2010 / Accepted: 21 February 2011 / Published online: 18 March 2011 Springer Science+Business Media, LLC 2011

Abstract

Background Laparoscopic appendectomy (LA) is notroutinely performed for appendicitis because the costs

associated with that procedure are higher than those for open

appendectomy (OA). However, few studies have investi-

gated the economic influence of LA and OA on specific

subpopulations including the elderly, patients with comor-

bidities, and patients with complicated appendicitis. This

population-based study was designed to investigate deter-

minants of costs and hospital length of stay (LOS)

for patients undergoing appendectomy. Furthermore, the

differences in costs and LOS were compared between LA

and OA for various subpopulations.Methods Inpatients who underwent LA or OA for

appendicitis during the period 20012008 were identified

from claims data obtained from Taiwans National Health

Insurance program. Costs and LOS were evaluated by

multiple linear regression models for various subpopula-

tions stratified according to age, number of comorbidities,

and severity of appendicitis.

Results Between 2001 and 2008, 22,252 patients (13.3%)

underwent LA and 14,4438 (86.7%) had OA. Age,

C.-C. YehTrauma and Emergency Center, China Medical UniversityHospital, Taichung 404, Taiwane-mail: b8202034@gmail.com

C.-C. YehGraduate Institute of Clinical Medical Science,China Medical University, Taichung 404, Taiwan

S.-C. Wu C.-H. HsiehTrauma and Emergency Center, China Medical UniversityHospital, China Medical University, Taichung 404, Taiwane-mail: rw114@mail.cmuh.org.tw

C.-H. Hsiehe-mail: chihsun@mail.cmuh.org.tw

C.-C. Liao L.-T. SuManagement Office for Health Data, China Medical UniversityHospital, Taichung 404, Taiwan

L.-T. Sue-mail: sweety@mail.cmu.edu.tw

C.-C. LiaoDepartment of Anesthesiology, Taipei Medical UniversityHospital, Taipei 110, Taiwane-mail: jacky48863027@yahoo.com.tw

C.-C. Liao

L.-T. SuInstitute of Environmental Health, College of Public Health,China Medical University, Taichung 404, Taiwan

T.-C. Li (&)Graduate Institute of Biostatistics, College of Public Health,China Medical University, 91 Hsueh-Shih Road 15F,Taichung 404, Taiwane-mail: tcli@mail.cmu.edu.tw

T.-C. LiGraduate Institute of Chinese Medicine Science,College of Chinese Medicine, China Medical University,Taichung 404, Taiwan

T.-C. LiBiostatistics Center, China Medical University,Taichung 404, Taiwan

T.-C. LiDepartment of Medical Research, China Medical UniversityHospital, Taichung 404, Taiwan

T.-C. LiInstitute of Health Care Administration, College of HealthScience, Asia University, Taichung 404, Taiwan

1 3

Surg Endosc (2011) 25:29322942

DOI 10.1007/s00464-011-1645-x

7/17/2019 out_44.pdf

2/12

comorbidity, and severity of appendicitis were determi-

nants of costs and LOS for both LA and OA. Although the

costs and LOS for appendectomy increased with age and

number of comorbidities, a sharper increase was noted for

OA patients. Laparoscopic appendectomy mildly decreased

LOS at the expense of significantly higher costs for young

patients, those without comorbidities, and patients with

uncomplicated appendicitis. In contrast, compared withOA, LA was associated with comparable costs and reduced

LOS for the elderly, patients with comorbidities, and those

with complicated appendicitis. In addition, hospital mor-

tality and readmission rates for postoperative complica-

tions did not differ significantly between LA and OA.

Conclusion Considering costs and LOS, patients older

than 65 years, patients with comorbidities, and patients

with complicated appendicitis benefit more from the lap-

aroscopic approach for the treatment of appendicitis.

Keywords Comorbidity Complicated appendicitis

Cost

Elderly

Laparoscopic appendectomy

Length of stay

Acute appendicitis is the most common disease requiring

abdominal surgery, with an incidence of approximately 10

per 10,000 person years [1]. Based on this estimation,

approximately 25,000 appendectomies are performed every

year in Taiwan.

For more than a century, open appendectomy (OA) via the

McBurney incision has been the standard operation for acute

appendicitis. However, studies have shown laparoscopic

appendectomy (LA) for the treatment of acute appendicitis tobe a safe and useful alternative for certain populations such

as morbidly obese patients and women of reproductive age

[24]. Although LA is associated with a shorter hospital

length of stay (LOS) and lower complication rates, its high

cost precludes it from replacing OA as the mainstream treat-

ment for acute appendicitis in the general population [510].

As the population in our society ages, coexisting illnesses

in the elderly are undoubtedly important factors in deter-

mining the postoperative outcomes of patients with acute

appendicitis. However, detailed studies comparing the costs

and LOS associated with LA and those associated with OA

for appendicitis accompanied by underlying comorbidities

have yet to be conducted. In addition, because the number of

relevant cases is limited, only a fewstudies have investigated

the difference in costs and LOS between LA and OA for

specific subpopulations such as in the elderly and patients

with varied severities of appendicitis. Furthermore, the

results from these studies often have been controversial

[1014]. The discrepancies in findings among the studies

could be due to their small sample sizes and lack of adequate

stratification or covariate adjustment by regression models.

Therefore, we performed a comprehensive study to

investigate determinants of adjusted hospital costs and

LOS associated with LA and OA for acute appendicitis by

analyzing a nationwide population-based inpatient data-

base. Furthermore, we compared the differences in adjus-

ted costs and LOS between LA and OA for acute

appendicitis in different subpopulations.

Materials and methods

Study design

This study was a nationwide, retrospective, population-based

analysis of insurance claims data from 23 million insured

people obtained from Taiwans National Health Insurance

program via the National Health Research Institutes data-

base. The National Health Insurance program in Taiwan is a

universal insurance system established by the Bureau of

National Health Insurance at the Department of Health.The insurance program was implemented in March 1995,

and by 1996, it covered more than 96% of the population

[15]. The patient information recorded included all medical

services received in 19962008, personal characteristics of

patients, and characteristics of the physicians and hospitals.

The patient identification numbers necessary to link files

with identities were scrambled to ensure patient confiden-

tiality. Thus, ethical approval was not needed for this study.

The study used information including each patients date of

birth, sex, coexisting illness, main diagnosis and procedure

at admission, hospital charge, LOS, accreditation level of

the admission hospital, urbanization of the hospitals sur-rounding area, and discharge status.

Participants

All diagnosis and procedure codes were classified accord-

ing to the International Classification of Diseases, Ninth

Edition, Clinical Modification (ICD-9-CM). Patients with a

clinical diagnosis of appendicitis who received an appen-

dectomy during the period 20012008 were identified from

claims data in the National Health Insurance Research

Database using ICD-9-CM codes (Appendix A). Compli-

cated appendicitis was defined as appendicitis with perfo-

ration, abscess formation, or peritonitis (ICD-9-CM 540.0

and 540.1). Uncomplicated appendicitis was identified by

ICD-9-CM diagnosis codes 540.9, 541, and 542 (Appendix

A). Patients who received OA were identified by ICD-9-

CM procedure codes 47.0 and 47.09, and those who

underwent LA were identified by ICD-9-CM code 47.01

(AppendixA).

Patients for whom LA was converted to OA were incor-

porated into the LA group based on the intention-to-treat

Surg Endosc (2011) 25:29322942 2933

1 3

http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-

7/17/2019 out_44.pdf

3/12

principle. Patients with incidental appendectomy and those

with interval appendectomy were excluded from our

analysis (AppendixA). Readmission for complication was

defined as readmission with the diagnosis of a commonly

encountered postoperative complication within 1 month

after appendectomy (AppendixB).

Outcome of measurement

Length of hospital stay

The period between admission and discharge was defined

as the LOS (measured in days). The LOS was recorded as

1 day for patients discharged on the same day they were

admitted to the hospital.

Hospital costs

The hospital costs were calculated by summing all the

items enumerated in the hospital discharge summaryincluding the operation-associated costs and ward costs.

The operation-associated costs included anesthesia and

surgery fees as well as costs of medical supplies used

during the operation. The surplus costs were classified as

ward costs. The costs expressed in this study are in U.S.

dollars (USD). In 2007, one U.S. dollar was equivalent to

approximately 32.64 Taiwan dollars.

Covariates

The covariates included age, gender, severity of appendi-

citis (complicated vs uncomplicated appendicitis), numberof comorbidities, hospital level (medical center, regional

hospital, or district hospital), and urbanization level of the

hospitals location (low, moderate, high). Hospital levels

are defined by the Bureau of National Health Insurance as

follows. A medical centeris a large-volume hospital with

at least 500 beds for emergency inpatient care that also is

qualified as an academic teaching hospital. A regional

hospital is a medium-sized teaching hospital with at least

250 beds for care of emergency inpatients. A district hos-

pital is a small-volume teaching hospital with at least 20

beds for emergency care.

The comorbidities evaluated in this study included

myocardial infarction, congestive heart failure, peripheral

vascular disease, cerebrovascular disease, chronic pulmon-

ary disease, rheumatologic disease, diabetes mellitus, and all

malignancies (Appendix C). We chose to evaluate those

comorbidities extracted from the Deyo-modified Charlson

scale because they are the most commonly encountered

coexisting illnesses in surgical patients [16,17].

Taiwan has 319 townships and city districts. We calcu-

lated the population density (persons/km2) by dividing the

population by the area (km2) for each of these administra-

tive units. The first and fourth quartiles of population den-

sity were classified as areas of low and high urbanization,

respectively. The second and third quartiles of population

density were considered areas of moderate urbanization.

Primary data analysis

First, Students t-test was used to compare differences in

patient characteristics, sociodemographic status, comor-

bidities, severity of appendicitis, hospital costs, and LOS

between patients who received LA and those who under-

went OA. Second, to explore the effects of age and number

of comorbidities on hospital costs and LOS after LA and

OA, we demonstrated the unadjusted hospital costs and

LOS according to the type of appendectomy and tested for

linear trends according to age and number of comorbidities.

Third, we used multiple linear regression models to identify

the linear effects of age and number of comorbidities on

adjusted hospital costs and LOS separately for laparoscopicand open procedures. Finally, we compared the differences

in costs and LOS between LA and OA among subgroups

stratified by age (\65 vs.365 years), presence of coexis-

ting illness (comorbidity vs no comorbidity), and severity of

appendicitis (complicated appendicitis vs uncomplicated

appendicitis). A P value less than 0.05 was considered to

indicate statistical significance. All tests were two tailed.

All analyses were performed with the statistical package

SAS version 9.1 (SAS Institute Inc. Cary, NC, USA).

Results

Table1 presents the basal demographic results. The

unadjusted outcomes including the hospital costs and LOS

in the LA and OA groups are shown in Fig. 1a and b and

Fig.2a and b. The determinants of adjusted hospital costs

and LOS for LA and OA used to treat appendicitis are

presented in Table2. Table3 details the differences in

adjusted costs and LOS between LA and OA stratified by

age, comorbidity, and severity of appendicitis.

According to the initial hospitalization records for

20012008, 144,438 patients underwent OA and 22,252

patients underwent LA. As shown in Table 1, 55.4% of the

166,690 patients with appendicitis who underwent appen-

dectomy were male. Table 1 also shows that LA patients

were more likely to be hospitalized in a medical center than

OA patients (49.4 vs. 27.8%; P\0.001). Compared with

OA patients, a higher proportion of LA patients lived in

highly urbanized areas (84.1 vs. 74.7%; P\ 0.001). The

average LOS washigher for OA patients than for LA patients

(5.0 0.02 vs. 4.0 0.02 days;P\ 0.001). However, the

average hospital costs were higher for LA patients than for

2934 Surg Endosc (2011) 25:29322942

1 3

http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-

7/17/2019 out_44.pdf

4/12

OA patients (1,178 3 vs. 1,042 1 USD; P\ 0.001). No

statistically significant difference was found in the read-

mission rates (1.3 vs. 1.4%; P[ 0.05) or the hospital mor-

tality rates (0.01 vs. 0.04%;P[ 0.05) between LA and OA.

The unadjusted ward costs for OA and LA patients

increased as age increased (bothpvalues for the linear trend

were\0.001) (Fig.1a). The ward costs associated with OA

were lower than those associated with LA for populations

younger than 65 years. In contrast, the ward costs for OA

were significantly higher than those for LA in patients

65 years of age or older. Furthermore, the discrepancy in

unadjusted ward costs between OA and LA patients

increased as age increased for patients 65 years of age or

older (P\ 0.001 for the interaction). The unadjusted LOS

Table 1 Demographics for open appendectomy (OA) and laparoscopic appendectomy (LA) in appendicitis patients in Taiwan between 2001and 2008

Variable LA (n = 22,252) OA (n = 14,4438)

n % n % P value

Age (years)

\15 3,116 14.0 21,233 14.7

1564 17,737 79.7 111,437 77.1

6574 890 4.0 7,162 5.0

C75 509 2.3 4,606 3.2

Gender

Female 10,832 48.7 63,534 44.0

Male 11,420 51.3 80,904 56.0

Hospital level

Medical center 10,990 49.4 40,135 27.8

Regional hospital 9,393 42.2 67,728 46.9

District hospital 1,869 8.4 36,575 25.3

Urbanizationa

Low 1,239 5.6 7,678 5.3

Moderate 2,299 10.3 28,874 20.0

High 18,714 84.1 107,886 74.7

Comorbiditiesb

0 20,805 93.5 133,538 92.4

1 1,251 5.6 8,889 6.2

2 166 0.8 1,679 1.2

C3 30 0.1 332 0.2

Complicated appendicitisc

No 18,276 82.1 10,9543 75.8

Yes 3,976 17.9 34,895 24.2

Hospital mortality 0.057

No 22,249 99.99 144,381 99.96Yes 3 0.01 57 0.04

Readmission for complicationd 0.169

No 21,970 98.7 142,439 98.6

Yes 282 1.3 1,999 1.4

Mean hospital stay SE (days) 4.0 0.02 5.0 0.02 \0.001

Mean hospital costs SE (US$) 1178 3 1042 1 \0.001

SE, standard error of the meana Urbanization: low= 1st and 2nd quartile of population density, moderate= 3rd quartile of population density, high= 4th quartile ofpopulation densityb Comorbidities were identified by the ICD-9-CM codes described in AppendixCc Complicated appendicitis were defined as appendicitis with perforation, abscess formation, or peritonitisd Readmission for complication was defined as readmission with the diagnosis of a commonly encountered postoperative complication within1 month after appendectomy (AppendixB)

Surg Endosc (2011) 25:29322942 2935

1 3

http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-

7/17/2019 out_44.pdf

5/12

Fig. 1 A Unadjusted operationand ward costs versus differentage groups. The ward costs forboth laparoscopicappendectomy (LA) and openappendectomy (OA) increasedas patients age increased (bothP values for the linear trendwere\0.001). The discrepancyin ward costs between OA andLA increased with increasingage of patients, particularlythose older than 65 years(P\ 0.001 for the interaction).B Unadjusted mean hospitallength of stay (LOS) afterappendectomy for different agegroups of patients withappendicitis. The LOS for bothLA and OA increased aspatients age increased (bothP values for the linear trendwere\0.001). The discrepancyof LOS between OA and LAincreased with increasing age(P\ 0.001 for the interaction)

Fig. 2 AUnadjusted averageoperation and ward costs versusthe number of comorbidities.The ward costs for bothlaparoscopic appendectomy

(LA) and open appendectomyOA increased as patientscomorbidity increased (bothP values for the linear trendwere\0.001). The ward costs ofOA were less than that of LAfor patients withoutcomorbidities but higher thanLA for those with comorbidities(P\ 0.001 for the interaction).B Unadjusted length of stay(LOS) for OA and LA versusthe number of comorbidities inpatients with appendicitis. TheLOS increased with theincreasing number ofcomorbidities in both the OAand LA groups (both P valuesfor the linear trend were\0.001). The difference in LOSbetween OA and LA varied inthe groups with differentnumbers of comorbidities andwas largest in those with twocomorbidities (P\ 0.001 forthe interaction)

2936 Surg Endosc (2011) 25:29322942

1 3

7/17/2019 out_44.pdf

6/12

associated with both OA and LA increased with age

(P\ 0.001 for the linear trend). However, the LOS for

patients who underwent OA was always longer than for

patients who underwent LA (Fig. 1b). The discrepancy in

LOS between OA and LA increased significantly with age

(P\ 0.001 for the interaction).

The unadjusted ward costs for OA and LA increased with

the number of comorbidities (both P values for the linear

trend were\0.001) (Fig.2a). The ward costs of OA were

lower than those of LA for patients without comorbidities

but were higher than those of LA for patients with comor-

bidities (P\0.001 for the interaction). Furthermore, the

discrepancy in ward costs between OA and LA was greatest

for patients with two comorbidities. Similarly, the unad-

justed LOS of OA and LA increased with the number of

comorbidities (P\ 0.001 for the linear trend) (Fig.2b). The

discrepancy in unadjusted LOS between OA and LA varied

among patients with different numbers of comorbidities and

Table 2 Multiple linear regression analysis of determinants of hospital costs (US $) and length of stay stratified by operation methods

Variables Hospital costs (US$) Length of stay (days)

LA OA LA OA

Coefficient SE P value Coefficienta SE P value Coefficient SE P Value Coefficient SE P value

Age (years) (vs.\15)

1564 3 7 0.640 -33 3 \

0.001 0.3 0.1 \

0.001 0.1 0.1 0.0836575 100 15 \0.001 145 6 \0.001 0.2 0.1 0.040 1.2 0.1 \0.001

C75 207 18 \0.001 315 8 \0.001 0.8 0.1 \0.001 2.1 0.1 \0.001

P value for linear trend \0.001 \0.001 0.002 \0.001

Comorbiditiesb (vs 0)

1 198 11 \0.001 265 5 \0.001 1.1 0.1 \0.001 1.5 0.1 \0.001

2 317 30 \0.001 406 11 \0.001 1.6 0.2 \0.001 2.2 0.2 \0.001

C3 473 69 \0.001 541 25 \0.001 2.3 0.4 \0.001 2.6 0.5 \0.001

P value for linear trend \0.001 \0.001 \0.001 \0.001

Complicated appendicitis (vs none) 298 7 \0.001 397 3 \0.001 2.2 0.1 \0.001 3.3 0.1 \0.001

Multiple linear regression was conducted after adjustment for age, gender, hospital level, comorbidities, and complicated appendicitis but not thetarget variable

LA laparoscopic appendectomy; OA open appendectomy; SE standard errora The coefficient is the number in front of each variable on the right side hand of the equation in the multiple linear regression modelsb Comorbidities were identified by the ICD-9-CM codes described in AppendixC

Table 3 Subgroup analysis with multiple linear regression analysis to compare differences of hospital costs (US $) and lengths of stay (days)between patients with open appendectomy (OA) and with laparoscopic appendectomy (LA)

Hospital costs (US$) Length of stay (days)

Operational methods (LA vs. OA) Operational methods (LA vs. OA)

Stratified variables Coefficient. SE P Coefficient (SE) P

Age (years)

\65 146 3 \0.001 -0.7 0.1 \0.001

C65 7 21 0.758 -1.8 0.2 \0.001

Comorbidities

No 145 3 \0.001 -0.7 0.1 \0.001

Yes 21 23 0.363 -1.5 0.2 \0.001

Complicated appendicitis

No 165 3 \0.001 -0.5 0.1 \0.001

Yes 21 11 0.055 -1.8 0.1 \0.001

Multiple linear regression was conducted after adjustment for age, gender, hospital level, comorbidities, and complicated appendicitis but not thetarget variable

LA laparoscopic appendectomy; OA open appendectomy; SEstandard error of mean

Surg Endosc (2011) 25:29322942 2937

1 3

http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-

7/17/2019 out_44.pdf

7/12

was greatest among patients with two comorbidities

(P\ 0.001 for the interaction).

The coefficients in the multiple linear regression models

could be explained as differences in specific outcomes

between the target group and the reference group. For

example, the adjusted costs of LA for patients 75 years of age

or older were US $207 more than those of LA for patients

younger than 15 years (Table2). In addition, the results ofmultiple linear regression models (Table2) showed that age,

comorbidities, and severity of appendicitis were determinants

of adjusted costs and LOS for both the LA and OA groups.

We observed that the magnitude of the differences in the

coefficients of age for costs and LOS in both the LA and OA

groups increased as the age increased (all P values for the

linear trend were\0.01). Furthermore, the magnitude of the

differences in coefficients of age for costs and LOS in

the LA group was smaller than in the OA group. Similarly,

the magnitude of differences in coefficients of comorbid-

ities for costs and LOS in the LA and OA groups increased

as the number of comorbidities increased (all P values forthe linear trend were \0.001). The magnitude of the dif-

ferences in the coefficients of the comorbidities for costs

and LOS in the LA group was smaller than in the OA group.

These findings indicated that age and the number of

comorbidities had a greater impact on costs and LOS for OA

patients than for LA patients. In addition, the costs and LOS

associated with LA and OA for complicated appendicitis

were higher than those for uncomplicated appendicitis. Fur-

thermore, complicated appendicitis had a greater influence on

increased costs and LOS for OA patients than for LA patients.

Table3presents differences in adjusted costs and LOS

between OA patients and LA patients stratified by variousdeterminants. After multivariate adjustment, the adjusted

costs for LA patients were significantly higher than for OA

patients younger than 65 years (US $146; P\ 0.001), for

patients without comorbidities (US $145; P\0.001), and

for those with uncomplicated appendicitis (US $165;

P\ 0.001). Alternatively, the adjusted costs for LA patients

were comparable with those for OA patients 65 years old or

older, for those with one or more comorbidities, and for

patients with complicated appendicitis. As for LOS, the

adjusted LOS for LA patients was significantly shorter than

for OA patients in all subpopulations. The effect of LA on

shortening LOS was more significant for patients 65 years

old or older (1.8 fewer days; P\ 0.001), those with

comorbidities (1.5 fewer days; P\ 0.001), and patients with

complicated appendicitis (1.8 fewer days;P\ 0.001).

Discussion

We found that costs associated with LA and OA were

comparable but that LA for patients older than 65 years,

patients with comorbidities, and patients with complicated

appendicitis was associated with a markedly shorter LOS.

Thus, these patient populations in particular benefit from

the laparoscopic approach for the treatment of appendicitis.

In contrast, for patients younger than 65 years, patients

without comorbidities, and patients with uncomplicated

appendicitis, LA could be less beneficial due to a clinically

insignificant reduction in LOS at the expense of substan-tially increased costs.

The proportion of patients undergoing LA (13.3%) was

lower than that of patients receiving OA for acute appen-

dicitis. However, the frequency of LA increased over time,

from less than 1% in 2001 to 37.2% in 2008 (data not

shown). The application of LA for the treatment of acute

appendicitis has therefore gradually become more com-

monplace in Taiwan.

Advances in medical care increase life expectancy. As a

result, appendicitis in the elderly is commonly encountered

in daily practice [18]. Studies have shown that LA for

appendicitis in the elderly is a safe and efficient procedurebecause of its reduced overall postoperative complication

rates and shorter LOS compared with those for OA [1921].

However, few of those studies were adjusted by adequate

stratification or used regression models to rule out con-

founding influences from gender, comorbidity, hospital

level, and the severity of appendicitis [19,20,22]. In addi-

tion, few studies have evaluated the differences in costs and

LOS between LA and OA among different subpopulations.

Our results demonstrate that elderly patients (C65 years)

undergoing LA have hospital charges comparable with

those for OA, mainly due to reduced ward costs and shorter

adjusted LOS. Thus, elderly patients with appendicitiscould benefit more from the laparoscopic approach than

younger patients. Moreover, the advantages of LA over OA

can be expected to conserve more medical costs in devel-

oped countries wherein charges for ward services are high.

One possible explanation for the superiority of LA is

that laparoscopy provides a more accurate diagnosis and

thorough clearance of intraabdominal soiling for compli-

cated appendicitis, a condition commonly encountered in

elderly patients. Subsequently, it avoids unnecessary ward

costs and LOS due to infectious complications resulting

from residual intraabdominal abscess and wound infection

[13,20,23].

Elderly patients tend to have not only poor physiologic

reserve but also comorbidities, which may cause higher

rates of morbidity and mortality after the treatment of

appendicitis [23,24]. However, most previous studies did

not use age and comorbidity as independent covariates for

separate evaluation of their influences on costs and LOS

associated with surgical treatment for acute appendicitis

[13,19,20]. In addition, chronic diseases such as diabetes

mellitus and ischemic heart disease are gradually becoming

2938 Surg Endosc (2011) 25:29322942

1 3

http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-

7/17/2019 out_44.pdf

8/12

more common in young populations, mainly as a result of

increased fat and salt intake as well as a lack of adequate

exercise [25,26].

Our results show that comorbidity was an independent

determinant of costs and LOS for patients undergoing

appendectomy for acute appendicitis. Patients with

comorbidities benefited more from LA for the treatment of

appendicitis because that procedure is associated with ashorter LOS. In contrast, LA was less favorable for patients

without comorbidities because the reduced LOS did not

outweigh the substantially increased costs associated with

the procedure. Our findings provide a novel opinion on the

choice of operative methods for treating acute appendicitis

in young patients with comorbidities.

It is well known that it costs more to treat complicated

appendicitis than to treat simple appendicitis. However, the

superiority of LA over OA in reducing hospital costs and

LOS for patients with complicated appendicitis still is

inconclusive based on the results of many small population-

based studies because these studies often lacked adequatesubpopulation stratification or covariate adjustment [3,11

14, 2729]. Nonetheless, Sporn et al. [10] found that LAwas

associated with a shorter adjusted LOS but that the higher

costs compared with those for OA. Of particular interest,

they found that such increases in adjusted costs for LA were

less significant for patients with complicated appendicitis

than for those with uncomplicated appendicitis (adjusted

cost for LA was 22% higher than that for OA in uncom-

plicated appendicitis but only 9% higher for complicated

appendicitis) [10]. Consistent with their results, our study

also showed that the adjusted costs for LA were higher than

for OA in uncomplicated appendicitis (USD 165;P\ 0.001). In contrast, LA was associated with statistically

significant but clinically insignificant higher costs for

patients with complicated appendicitis. Furthermore, our

study also showed that LA was more effective than OA in

reducing the LOS for patients with complicated appendicitis

(1.8 days shorter; P \ 0.001). Thus, patients with compli-

cated appendicitis could benefit more from LA than from

OA. In general, those well-documented advantages of LA in

the treatment of complicated appendicitis, namely reduced

wound complications and less pain, may have played a role

in both our study and that of Sporn et al. [ 11,27,28,30].

Our study had several limitations. First, the Bureau of

National Health Insurance collects only in-hospital cases

based on ICD-9-CM codes for disease and procedures.

Error in coding is possible with such a large population-

based database. Second, detailed information on operation

time, patients physical status at admission (i.e., body

weight and hemodynamic status), and laboratory data was

not available in the database.

Because of these limitations, we could investigate only

the influence of operative methods on costs and LOS for

patients with acute appendicitis, although we were able to

use regression models to adjust for confounding influences

including age, gender, admitting hospital level, comorbid-

ity, and severity of appendicitis to determine the advantages

of LA over OA. We were unable to evaluate other clinically

important outcomes such as operation time, postoperative

complications, postoperative pain level, cosmesis, postop-

erative recovery time, and time until return to work. Fur-thermore, from our database, we were unable to identify

those patients who managed their complications on an

ambulatory basis. Nonetheless, those complications that

could be treated at home should be minor ones and would

not significantly affect our conclusion.

Finally, treatment for delayed complications after

appendectomy for acute appendicitis could increase total

costs and LOS. However, the incidence of readmission

after appendectomy was comparable between the LA and

OA patients (LA vs. OA = 1.3% vs. 1.4%). Therefore, the

influence of readmission due to delayed complications after

appendectomy could be ignored.To summarize, in terms of hospital costs and LOS,

elderly patients, patients with comorbidities, and patients

with complicated appendicitis could benefit more from LA

for the treatment of appendicitis. Nevertheless, more pro-

spective investigations should be designed to address the

true economic advantages of LA, such as the time until

return to work and normal daily activity.

Conclusion

Using data from a nationwide health insurance database,we compared the costs and LOS associated with LA and

those associated with OA for the treatment of acute

appendicitis. Our results suggest that the costs for LA are

comparable with those of OA but that the LOS is shorter,

especially for patients older than 65 years, patients with

comorbidities, and patients with complicated appendicitis.

Acknowledgments This study was supported by the National Sci-ences Council, Executive Yuan (grant numbers NSC 99-2621-M-039-001), China Medical University Hospital (grant number 1MS1),Taiwan Department of Health Clinical Trial and Research Center forExcellence (grant number DOH100-TD-B-111-004) and Taiwan

Department of Health Cancer Research Center of Excellence(DOH100-TD-C-111-005).

Disclosures Chun-Chieh Yeh, Shih-Chi Wu, Chien-Chang Liao,Li-Ting Su, Chi-Hsun Hsieh, and Tsai-Chung Li have no conflictsof interest or financial ties to disclose.

Appendix A

(See Table4)

Surg Endosc (2011) 25:29322942 2939

1 3

http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-

7/17/2019 out_44.pdf

9/12

Table 4 Inclusion criteria

2940 Surg Endosc (2011) 25:29322942

1 3

7/17/2019 out_44.pdf

10/12

Appendix B

(See Table5)

Appendix C

(See Table6)

Table 5 ICD-9-CM codes forreadmission due topostoperative complication

ICD-9-CMcodes

Diagnosis

Infectious complication

998.5 Postoperative infection

998.59 Other postoperative infection

998.51 Postoperative infected seroma

Noninfectious complication

998.83 Nonhealing surgical wound

998.12 Hematoma complicating a procedure

998.13 Seroma complicating a procedure

998.3 Disruption of operation wound

998.6 Persistent postoperative fistula

997.5 Urinary tract complication including urine retention and urinary tract infection

997.3 Pulmonary complication including atelectasis and postoperative pneumonia

518.5 Pulmonary insufficiency after trauma and surgery512.1 Iatrogenic pneumothorax

518.4 Postoperative acute pulmonary edema

997.4 Digestive system complications including ileus, pancreatitis, complication ofanastomosis of gastrointestinal tract

997.79 Postoperative deep vein thrombosis

415.11 Postoperative pulmonary emboli

997.02 Iatrogenic cerebrovascular infarction or hemorrhage

997.2 Peripheral vascular complications

997.1 Cardiac complications including cardiac arrest or heart failure

998.2 Accidental puncture or laceration during a procedure

998.4 Foreign body accidentally left during a procedure

998.11 Hemorrhage complicating a procedure

Table 6 ICD-9-CM codes forcomorbidity listed in the study

Myocardial infarction [ICD-9-CM:410.X]: acute myocardial infarction

[ICD-9-CM:412*]: old myocardial infarction

Congestive heart failure [ICD-9-CM:428.X]: heart failure

Cerebrovascular disease [ICD-9-CM:430-438.9]: cerebrovascular disease

Peripheral vasculardisease

[ICD-9-CM:433.9*]: peripheral vascular disease with intermittent claudication

[ICD-9-CM:785.4*]: gangrene[ICD-9-CM:441 or 441.9*]: aortic aneurysm

[ICD-9-CM:V43.4*]: blood vessel replaced by prosthesis

[ICD-9-CM: procedure 38.48]: resection and replacement of lower limbarteries

Chronic pulmonarydisease

[ICD-9-CM:490-496*]: chronic obstructive pulmonary disease

[ICD-9-CM:500-505*]: pneumoconioses

[ICD-9-CM: 506.4*]: chronic respiratory conditions due to fumes and vapors

Diabetes mellitus [ICD-9-CM:250-250.3* or 250.7*]: diabetes mellitus

[ICD-9-CM: 250.4-250.6*]: diabetes mellitus with chronic complication

Surg Endosc (2011) 25:29322942 2941

1 3

http://-/?-http://-/?-http://-/?-http://-/?-

7/17/2019 out_44.pdf

11/12

References

1. Ohmann C, Franke C, Kraemer M, Yang Q (2002) Status reporton epidemiology of acute appendicitis. Chirurg 73:769776

2. Semm K (1983) Endoscopic appendectomy. Endoscopy 15:59643. Varela JE, Hinojosa MW, Nguyen NT (2008) Laparoscopy

should be the approach of choice for acute appendicitis in themorbidly obese. Am J Surg 196:218222

4. Garbarino S, Shimi SM (2009) Routine diagnostic laparoscopy

reduces the rate of unnecessary appendicectomies in youngwomen. Surg Endosc 23:5275335. Schroder DM, Lathrop JC, Lloyd LR, Boccaccio JE, Hawasli A

(1993) Laparoscopic appendectomy for acute appendicitis: isthere really any benefit? Am Surg 59:541547 discussion 78

6. Vallina VL, Velasco JM, McCulloch CS (1993) Laparoscopicversus conventional appendectomy. Ann Surg 218:685692

7. Kurtz RJ, Heimann TM (2001) Comparison of open and lapa-roscopic treatment of acute appendicitis. Am J Surg 182:211214

8. Marzouk M, Khater M, Elsadek M, Abdelmoghny A (2003)Laparoscopic versus open appendectomy: a prospective com-parative study of 227 patients. Surg Endosc 17:721724

9. Wei HB, Huang JL, Zheng ZH, Wei B, Zheng F, Qiu WS, GuoWP, Chen TF, Wang TB (2010) Laparoscopic versus openappendectomy: a prospective randomized comparison. Surg

Endosc 24:26626910. Sporn E, Petroski GF, Mancini GJ, Astudillo JA, Miedema BW,Thaler K (2009) Laparoscopic appendectomy: is it worth thecost? Trend analysis in the U.S. from 2000 to 2005. J Am CollSurg 208:179e2185e2

11. Long KH, Bannon MP, Zietlow SP, Helgeson ER, Harmsen WS,Smith CD, Ilstrup DM, Baerga-Varela Y, Sarr MG (2001) Aprospective randomized comparison of laparoscopic appendec-tomy with open appendectomy: clinical and economic analyses.Surgery 129:390400

12. Johnson AB, Peetz ME (1998) Laparoscopic appendectomy is anacceptable alternative for the treatment of perforated appendici-tis. Surg Endosc 12:940943

13. Harrell AG, Lincourt AE, Novitsky YW, Rosen MJ, Kuwada TS,Kercher KW, Sing RF, Heniford BT (2006) Advantages of lap-

aroscopic appendectomy in the elderly. Am Surg 72:47448014. Cothren CC, Moore EE, Johnson JL, Moore JB, Ciesla DJ, BurchJM (2005) Can we afford to do laparoscopic appendectomy in anacademic hospital? Am J Surg 190:950954

15. Chiang TL (1997) Taiwans 1995 health care reform. HealthPolicy 39:225239

16. Deyo RA, Cherkin DC, Ciol MA (1992) Adapting a clinicalcomorbidity index for use with ICD-9-CM administrative dat-abases. J Clin Epidemiol 45:613619

17. Charlson ME, Pompei P, Ales KL, MacKenzie CR (1987) A newmethod of classifying prognostic comorbidity in longitudinalstudies: development and validation. J Chronic Dis 40:373383

18. Addiss DG, Shaffer N, Fowler BS, Tauxe RV (1990) The epi-demiology of appendicitis and appendectomy in the UnitedStates. Am J Epidemiol 132:910925

19. Paranjape C, Dalia S, Pan J, Horattas M (2007) Appendicitis in

the elderly: a change in the laparoscopic era. Surg Endosc21:777781

20. Kirshtein B, Perry ZH, Mizrahi S, Lantsberg L (2009) Value oflaparoscopic appendectomy in the elderly patient. World J Surg33:918922

21. Guller U, Jain N, Peterson ED, Muhlbaier LH, Eubanks S,Pietrobon R (2004) Laparoscopic appendectomy in the elderly.Surgery 135:479488

22. Marudanayagam R, Williams GT, Rees BI (2006) Review ofthe pathological results of 2, 660 appendicectomy specimens.J Gastroenterol 41:745749

23. Lau WY, Fan ST, Yiu TF, Chu KW, Lee JM (1985) Acuteappendicitis in the elderly. Surg Gynecol Obstet 161:157160

24. Podnos YD, Jimenez JC, Wilson SE (2002) Intraabdominal sepsisin elderly persons. Clin Infect Dis 35:6268

25. Reddy K, Yusuf S (1998) Emerging epidemic of cardiovasculardisease in developing countries. Circulation 97:596

26. Zimmet P (2000) Globalization, coca-colonization, and thechronic disease epidemic: can the Doomsday scenario be aver-ted? J Intern Med 247:301310

27. Yau KK, Siu WT, Tang CN, Yang GP, Li MK (2007) Laparo-scopic versus open appendectomy for complicated appendicitis.J Am Coll Surg 205:6065

28. Pedersen AG, Petersen OB, Wara P, Ronning H, Qvist N,Laurberg S (2001) Randomized clinical trial of laparoscopicversus open appendicectomy. Br J Surg 88:200205

29. Martin LC, Puente I, Sosa JL, Bassin A, Breslaw R, McKenneyMG, Ginzburg E, Sleeman D (1995) Open versus laparoscopicappendectomy: a prospective randomized comparison. Ann Surg222:256261 discussion 6162

30. Buckley RC, Hall TJ, Muakkassa FF, Anglin B, Rhodes RS,Scott-Conner CE (1994) Laparoscopic appendectomy: is it worthit? Am Surg 60:3034

Table 6 continued

Asterisked codes were includedif listed during index or prioradmission; other codes wereincluded only if listed during theindex admission

X means number ranging from 0to 9

Rheumatologic disease [ICD-9-CM:710.0*]: systemic lupus erythematosus

[ICD-9-CM:710.1*]: systemic sclerosis

[ICD-9-CM:710.4*]: polymyositis

[ICD-9-CM: 714.0-714.2*]: adult rheumatoid arthritis

[ICD-9-CM: 714.81*]: Rheumatoid lung

[ICD-9-CM:725*]: Polymyalgia rheumatica

Any malignancy [ICD-9-CM:140-172.9]: solid malignant neoplasm

[ICD-9-CM:174-195.8]: solid malignant neoplasm

[ICD-9-CM:200-208.9]: Leukemia and lymphoma

2942 Surg Endosc (2011) 25:29322942

1 3

7/17/2019 out_44.pdf

12/12

Reproducedwithpermissionof thecopyrightowner. Further reproductionprohibitedwithoutpermission.