Length of Stay, Discharge Disposition, and Hospital Charge Predictors

Length of Stay, Discharge Disposition, and Hospital Charge Predictors Cynthia D. Epps, RN

W

hen chronic osteoarthritis (OA) results in increasing pain and disability, surgical procedures, such as joint arthroplasty, may be considered. The most recent survey of hospital discharges from the National Center for Health Statistics estimates that approximately 486,000 total hip arthroplasties (THAs) and total knee arthroplasties (TKAs) are performed yearly.' Given the pressure to decrease costs by discharging patients more quickly after surgery, it is important to identify factors that lead to a shorter acute care length of stay (LOS), discharge to home instead of discharge to a subacute or rehabilitation unit, and decreased hospital charges. These factors, which are physiological and psychosocial variables that affect desired outcomes, can be classified as patient factors, clinical factors, and treatment factors. Patient factors include age, gender, race, and living arrangement. These factors are either nonmalleable traits or pre-existing states that each patient possesses before joint replacement surgery. Clinical factors include comorbidities and preoperative physical status indicators (eg, total lymphocyte count [TLC], hematocrit). Body mass index (BMI), an indicator of total body fat, also is a relevant clinical indicator because joint stress can be caused by an increased BMI. Treatment factors include surgical factors, such as length of time in surgery and type of anesthesia, and postoperative factors, such as type and amount of postoperative analgesia and postoperative complications.

PURPOSE AND SIGNIFICANCE

The purpose of this study was to explore the effect of patient, clinical, and treatment factors on LOS, discharge disposition, and total acute care hospital charges for older adults undergoing elective THA or TKA. Older adults were defined as people 60 years of age or older. HUMANcom. One group of researchers reported that the success rate of joint replacement surgery for reducing pain and increasing function is greater than 90%: As OA continues to cause disability and pain in an increasing population of older adults, more arthroplasties will be performed. At the same time, reimbursement pressures will continue to press acute care facilities to decrease LOS and costs and to discharge patients quickly.

ABSTRACT 0 THIS STUDY EXPLORED the effect of patient, clinical, and treatment factom on length of stay (LOS), discharge disposition, and total acute care hospital charges for older adults undergoing elective total hip arthroplasty or total knee arthroplasty. 0 A CAUSATIVE RETROSPECTIVE DESIGN was used, and data analysis included descriptive statistics, multiple regression, and logistic regression. 0 SIGNIFICANTDIFFERENCES in predictor variables (ie, age, gender, living arrangement, comorbidities,postoperativecomplications) were found between patients who were discharged to home and those who were discharged to another facility. Only postoperativecomplications contributed significantly to LOS. Total surgical time and postoperative complications contributed significantly to hospital charges. AORNJ 79 (May

2004) 975-997. AORN JOURNAL

975

FINANCIALcom. Despite efforts to curtail reimbursements,the cost of health care in the United States continues to rise. In 1995, $988 billion (ie, 13.6%of the gross domestic product) was spent for health care? Two researchers note that hospital costs account for the largest portion (ie, 35.4%) of health c m expendiWs,3 and THAs and TKAsare noted to be high volume procedures with a high cost per case! Additionally nurse shortages in intensive care units,ORs, and postanesHealth care thesia care units are expected to increase, which providers must also will contribute to the rising cost for these proceidentify d u r e ~ .Meanwhile, ~ deLOS is increasing the variables that creasing patient acuity and, therefore, nursing reinfluence sponsibility, compounding the effects of the nursing outcomes in shortage.

RESEARCH QUO ESN TIS The following research questions were addressed in this studv. What are the difference; in patient, clinical, and treatment factors in older patients who undergo THA and TKA and are discharged to subacute units compared to those discharged to home? Do patient, clinical, and treatment factors contribute to LOS, discharge disposition, and hospital charges in older adults undergoing elective THA or TKA?

LITERATURE RMEW

A number of studies have examined patient, clinical, and treatment factors related to THAs and TKAs. All of the studies reviewed a variety of patient, clinical, and treatment factors as possible correlates or predictors of the outcome variables. LENGTHOF STAY-PATIENT FACTORS. Patient SG I NFICIANCE FOR NURSING. factors that have been studied include knee and hip Health care providers, in- age, gender, race, and living arrangement. Results are contradictory, so no arthroplasties cluding nurses and phys- clear conclusions about the impact of icians, need to identify when they are the variables that influ- patient factors on LOS can be drawn. ence outcomes in knee One group of researchers found no sigand hip arthroplasties to nificant differences in LOS between focusing on link quality of care with younger and older matched groups of relating quality cost of care. Improve- patients who underwent THA or TKA.8 ments in patient educa- Another group of researchers also tion, discharge planning, found no correlation between LOS and of care to and posthospital adjust- age in a group of patients 80 years old ment can be identified or older who underwent THA.9 In concost of care. after predictor variables trast, another study of matched groups are known and an analy- of older and younger patients undergosis of patient outcomes is ing THA found that patients in the performed.6 One major result of out- older group had an average LOS that come research is the implementation of was two days longer than patients in care delivery models grounded in the younger group.'O One study sigrufiresearch and based on data that are cantly correlated age with LOS in patient-centered, measurable, and patients who underwent THA and associated with standards of care. Such TKA, with older patients having delivery models lead to increased satis- increased LOS.2Finally a large Finnish faction for nurses, physicians, and study of 15,461 patients who underwent THA and TKA also found patients.6~~

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increased age predicted increased LOS." Only one study examined gender and LOS. The study found that being a woman sigruficantly predicted increased LOS. The researchers attributed this finding to the increased likelihood for older women to be widows and to live alone, increasing their chances of being kept in the hospital versus being discharged to home." Living arrangements were not found to predict or correlate with LOS in any of the studies examining this ~ariable.~,",'~ LENGTHOF STAY-CLINICAL FACTORS. CliXliCd factors studied include preoperative physical status indicators, such as the preoperative TLC, hematocrit, comorbid conditions, and BMI. Only two studies attempted to relate preoperative laboratory values to LOS for patients who underwent arthroplasty. One group of researchers found that patients who underwent THA and who had an albumin level of less than 3.9 g/dL were twice as likely to require a prolonged Another group of researchers also linked some preoperative laboratory values to LOS. They found that a decreased serum albumin and decreased TLC (ie, below normal values) correlated with an increased LOS in patients who underwent THA and TKA.I4 The impact of clinical factors on LOS, like that of patient factors, is inconclusive. Prediction or correlation of LOS and comorbidities has been studied frequently but with mixed results. Researchers found that the comorbidities of athrosclerotic heart disease, lupus erythematosus, or renal disease were predictive of longer LOS in patients who underwent T H A . I 3 Another study found that diabetes mellitus correlated sigruficantlywith increased LOS in patients who underwent THA and TKA.* One group of researchers found that an increased number of comorbidities was associated with an increased LOS in patients who under-

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went however, five studies found that comorbidities either did not correlate with or did not predict LOS?*10,1216,17 LENGTHOF STAY-TREATMENT FACTORS. Treatment factors are perioperative or postoperative effects of the treatment and postoperative complications that occur as a direct result of the surgical intervention. Research on the effect of perioperative treatment factors for LOS in patients who undergo THA or TKA appears minimal, and the type of anesthesia did not affect LOS in the Prediction or studies reviewed. Two correlatjon of treatment factors-intraoperative blood loss and length surgeon-also were found to have no sigruficant effect on LOS. stay and Another treatment factor-pros thesis typecornorbiditjes was found to affect LOS in only one study." has been studied Studies on postoperative treatment factors of frequently but pain and the mode of postoperative analgesia has yielded administrationhave yieldmixed reSUkS. ed mixed results. One study found that postoperative pain, epidural versus IV postoperative analgesia, and analgesia side effects were not This is consigruficantly related to tradicted somewhat by another study that found LOS decreased sisnrficantly with the use of a pain management program that controlled postoperative pain more efficiently.I8 In contrast, a third study found that patients who received epidural analgesia postoperatively had decreased LOS when compared with patients who received two other types of postoperative analge~ia.'~ The factor of postoperative complications was studied in conjunction with LOS in six of 12 studies that examined postoperative complica-

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tions. The findings of these studies, able and its relationship to discharge like studies of other factors, yield no disposition remains unclear. DISCHARGE DISPOSITION-CLINICAL FACTORS. definitive conclusions. Patients with more complications," a transfusion Only the preoperative physical status complication,2°or a wound infection indicator of comorbidities has been complicationz1"all were found to have studied in relationship to discharge dissignificantly longer LOS. This con- position. This clinical factor was exam2~~ ~ of ~these trasts with findings from two studies ined in five ~ t u d i e s . All that revealed no relationship between studies except one found that patients postoperative complications and discharged to rehabilitation or subacute units were sigruficantly more likely to increased LOS.12*13 have more comorbidities;25however, an DISCHARGEDISPOSITION-PATIENT FACTORS. Increased age was found to be associat- earlier study found the specific comored withn or predicP6dis- bidity of diabetes mellitus alone to be charge to subacute or sigruficantly associated with discharge rehabilitation units. An- to a rehabilitation unit versus to home.* Treatment DISCHARGE DISPOSITION-TREATMENTFACTORS. other study found that discharge disposition was Only the treatment factors of surgeon factors have influenced most by in- and postoperative pain have been studage; however, the ied in relation to the outcome of disbeen examined creased association did not reach charge disposition, and these have been In contrast, examined only minimally. Two studies only minimally ~igruficance.2~ two studies found that examined the surgeon as a variable in age did not predict dis- regard to discharge disposition. Both in relation to charge disposition.28Re- studies found that the surgeon did not search about age as a affect discharge disposition?3 the outcome One study found that postoperative patient factor influencing pain had no sigruficant effect on disdischarge disposition, discharge charge disposition.Z3The other study thus, is not conclusive. The effect of gender on examining this variable found that disposition. discharge disposition was patients discharged to rehabilitation found to be sigruficantin units had sigruficantlyhigher postoperonlv one st~dv.2~ In that ative pain scores than those discharged study, gender pdsitively prehicted dis- to home.26It is apparent that the impact charge disposition, but researchers did of treatment factors on discharge disponot report which gender was predictive. sition has been examined insufficiently. HOSPITALCHARGES-PATIENT FACTORS. No Only three studies examined the variable of living arrangement status in clear conclusions about the impact of relation to discharge disposition.n33 Of patient factors on hospital charges can these, two found that living alone sig- be made. Only three studies examined nificantly influenced discharge disposi- age in relation to hospital charges. All tion for patients who underwent THA three found that age did not sigruficantand TKA.B26Patients who lived alone ly influence hospital Only one group of researchers studand had no one to care for them at home were discharged more often to subacute ied gender in relation to hospital or rehabilitation units. One study, how- charges.28They found that total costs for ever, found that living arrangements THA and TKA were independent of did not sigruficantly affect discharge gender. Finally, one study examined disposition.25Research about this vari- increased hospital costs in association

of

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TABLE1

Descriptive Data for Patient Factors (n = 166) Patient factors Aqe 60 to 65 66 to 70 71 to 75 76 to 80 81 to 85 86 to 90

with living alone. They found no correlation between these variables.= HOSPITALCHARGES-CLINICAL FACTORS. one study examined the relationship of preoperative laboratory values (ie, serum albumin, TLC)to hospital charges. These researchers found that lower serum albumin and TLC were sigruficantly correlated with increased hospital charges.” Three studies examined comorbidities and their relationship to hospital costs.1on3 Two of these studies found that patients with higher comorbidity scores or an inmased number of comorbidities had higher overall hospital ~harges.2’~’ The third study found no relationship between comorbidities and hospital charges.’O

Unknown

Percentage”

37 24 40 32 21 10 2

22 14 24 19 13 6 1

128 38

77 23

132 33 1

80 20 0

Gender Women Men

Race Caucasian African-American Unknown

Uvinq ananqement Living alone

83 50 wlmen (78) Men (5) with spouse 73 44 Women (41) Men (32) In child’s home 9 5 Women (8) Men (1) With paid caregiver 1 1 Women (1) Men (0) * Percentages are rounded to the nearest whole number.

HOSPITALCHARGES-TREATMENTFACTORS.

Only one study found that hospital charges were sigruficantly related to treatment factors. These factors were surgical time; type of procedure; and postoperative complications, especially blood transfusion.” OTHER STUDIES. Several studies examined the relationship of hospital charges to LOS. Three studies found that LOS was the most sigruficant predictor of hospital charges.2830 The relationship of discharge disposition and hospital charges was examined in another study, but no relationship between these two variables was found.=

Number

ous hip or knee arthroplasty, or had received a hip or knee arthroplasty as a result of trauma or fracture of the involved joint. DESIGN AND PROCEDURES A total of 166 records met the criteria A causative retrospective design was and were included in the sample. This used for this study. The sample consist- research activity was exempt from full ed of medical records from a rural med- institutional review board evaluation ical center in middle Georgia. All med- because it used existing data and posed ical records of patients 60 years of age or no risk to patients. Appropriate consent older who underwent unilateral hip or was obtained from the facility.Data analyknee arthroplasty between Nov 1,1999, sis included descriptive statistics, multiand July 15,2001, were selected. Patient ple regression, and logistic regression. records were excluded if the patient 0 was younger than 60 years of age, SAMPLECHARACTERISTICS 0 had experienced bilateral hip or knee Sample characteristics are provided arthroplasty, in Tables 1 through 3. Most of the 0 had undergone a revision of a previpatients were female (ie, 77%) and 0

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Caucasian (ie, SOYO). Half (ie, 50%) lived alone, and 44% resided with their spouse. The TLC in these patients ranged from 460 to 3,564 cells per m3, with a mean of 1,708. The hematocrit ranged from 26 to 52 cells per mm3,with a mean of 39. The number of comorbidities ranged from zero to eight, with a mean of three comorbidities per patient. Finally, BMI ranged from 19 to 53 with a mean of 29. Of the three types of anesthesia (ie, general, spinal/epidural, mixed general and spinal/epidural), the majority (ie, 83%) of patients had spinal/epidural anesthesia, and 14% had general anesthesia. Surgical time ranged from 29 minutes to 240 minutes. The mean surgical time was 84 minutes. Of the seven different types of postoperative analgesia used in the sample, the largest group (ie, 39%)had epidural analgesia via a patient-controlled analgesia (PCA) pump, followed by 17%who had TV PCA. Others received a combination of oral and PCA approaches, and only 5% received intramuscular/oral analgesia. Participants averaged 28 doses of analgesia, with a range of zero to 117 doses, in the first 48 hours after surgery. The number of postoperative complica-

tions ranged from zero to four with a mean of one. Postoperative complications included mild complications, such as nausea and urinary retention, as well as more severe complications, such as bleeding or myocardial infarction.

OUTCOMEVARIABLES The LOS for this sample ranged from three to 18 days, with a mean LOS of 4.2 days. The majority of the patients (ie, SOY0) were discharged to another facility. The range of hospital charges was from $10,149 to $45,792 and was normally distributed. The mean of the charges was $23,332 (Table 4).

DIFFERENCES IN DISCHARGE DS I POST IO IN

Differences in patient, clinical, and treatment factors for patients discharged to home, with and without help, compared to patients discharged to other facilities (ie, subacute or rehabilitation facilities) were examined using the chisquare statistic for categorical variables and one-way analysis of variance (ANOVA) for interval level variables. PATIENTFACIORS. Sigruficant differences were found between discharge groups for the patient factors of age, gender, and living arrangement. No sigruficant differences by discharge group were found for race. Patients who were discharged to anothTABLE2 er facility rather than to home were significantly Descriptive Data for Clinical Factors" older (P c .001). Groups were sigruficantly differNormal Subject Standard ent for gender in patients range range Mean deviation discharged to home commnical factors pared to patients disTotal lymphocyte 1,708 629 460-3,564 charged to another facility 1,800-3,000 count 39 4.8 26-52 37-52 Hematocrit (P < .001). only 11.7"/0of 1.7 3 0-8 1-4' Comorbidities the women were dis29 6 19-53 None Body mass index charged to home; the majority (ie, 88.3%) were *Numbers are rounded to the nearest whole number. discharged to another facility. Men were disknee arthroplasty," JAMA 279 (March 18, 1998)847-852. charged to home or

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TABLE3

Descriptive Data for Treatment Factors* (n = 166) Standard Treatment factors

Number

Anesthesia type General Spinal/ epidural Both (ie, mixed) Unknown

Percentage

23 138

Range

Mean

deviation

29-240

84

25

0-117

28

23

0-4

1

1

14

83 2

4 1

0

Surqical time in minutes Postoperative analgesia Intramuscular (IM) injections Epidural via patient-controlled analgesia (PCA) IV PCA IV PCA/oral IM/oral Epidural via PCA/oral Epidural via PCA/IV

2

1

64

39

29 19 9 25 18

17

11 5 15 11

Number of analqesia doses in 48 hours Number of postoperative complications *Numbers are rounded to the nearest whole number.

TABLE4

Descriptive Data for Outcome Variables* (n = 166) Outcomes

Number

Percentage

Range

Mean

Standard deviation

3-18

4

2

$10,149-$45,792

$23,332

$5,479

Lenqth of stay i n days Discharge disposition Home/no help Women Men Home/ temporary help Women Men Another facility Women Men

6

4

(11 (5) 28 (14)

17

(14)

132 (113)

80

(19)

Hospital charges *Numbers are roiotded to the nearest whole number.

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TABLE5

Differences in Discharge Disposition: Patient Factors (n = 166) _____

Discharged to home

Discharged to facility

Patient factors Age

Mean

Mean

65.8

SD* 4.9

n5

K

75

n

SD

Oh

7.5

Gender Male Female

19 15

50 11.7

19 113

50 88.3

Race (n = 165,l unknown) Caucasian African American

31 3

23.5 9.1

101 30

76.5 90.9

10 23 8 15

12 31.5 5 9

73 50 33 17

88 68.5 20 10

1

11.1

8

88.9

Living arrangement Living alone With spouse Women Men With child/in child's home With paid caregiver

0

1

0

'a' 1

F 46.3lP

1

26.36q

1

3.34

3

9.82 I

1

6.24-

loo

* SD = staridard deviatiori I t = nunrbrr PP < .ooz P < .05 - P < .Ol

'

another facility in equal numbers. Although most individuals were discharged to another facility, those with a spouse were significantly more likely to be discharged to home (P < .05). In a separate analysis of discharge disposition for those living with a spouse, significantly more married women than married men were discharged to another facility ( P c .01) (Table 5). CLINICALFACTORS. Only one clinical factor (ie, the number of comorbid conditions) was found to be sigruficantlydifferent between discharge groups ( P < .001). Group differences in TLC,hematocrit, and BMI were not sigruficant (Table 6). One other variable (ie, LOS) approached sigruficance for discharge disposition ( P < .09).Patients discharged to home had a mean of 2.2 comorbid conditions; patients discharged to another facility had a mean of 3.3 comorbid conditions. Patients discharged to home had a mean LOS of 4.7 days, and those discharged to another facility had a mean LOS of 4.1 days.

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TREATMENT FACTORS. The mean number of postoperative complications for patients discharged to home was 0.6; the mean number of complications for patients discharged to another facility was 1.2. Of the treatment factors (ie, type of anesthesia, time in surgery, type of postoperative analgesia, number of doses of analgesia in the first 48 hours, postoperative complications),only postoperative complications were sigruficantly different between groups (P < .01) (Table 7).

CONTRBIUTO IN OF PATIENT,CLINICAL, TREATMENT FACTORS TO OUTCOMES

AND

Regression analysis was used to determine if any patient, clinical, or treatment factors were sigruficant predictors of the chosen outcomes. Multiple regression was used to determine predictors for LOS and hospital charges, and logistic regression was used to determine predictors of discharge disposition. LENGTHOF STAY. In stepwise multiple regression analysis of the predictor variables and the dependent variable of LOS, only the number of postoperative

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TABLE6

Differences in Discharge Disposition: Clinical Factors Discharged to home Discharged to facility Y

Clinical factors Total lymphocyte count Hematocrit Comorbidities Body mass index Length of stay

Y

Mean

Standard deviation

1592.5 39.3 2.2 28.2

544.7 4.5 1.1 4.4

4.7

.95

,

Mean

1

1

Standard deviation

F

I

d

f

1732.3 38.4 3.3 29.8

644.5 4.9 1.7 6.1

1.09 1.06 12.97' 2.05

152 162 165 165

4.1

1.9

2.82

165

TABLE7

Differences in Discharge Disposition: Treatment Factors (n = 166) Discharged to home Treatment factors Mean Type of anesthesia (n = 165,l unknown) General Epidural Both (ie, mixed) Time in surgery in minutes

78.6

SD*

2 32 0

Postoperative complications

OO /

Discharged to facility Mean

SD

8.7 23.2 0

15.4

Postoperative analgesia Intramuscular (IM) injections Epidural via patientcontrolled analgesia (PCA) 1V PCA IV PCA/oral IM/oral Epidural PCA/oral Epidural PCA/IV Number of analgesia doses in 48 hours

n5

n

21 106 4

85.5

OO /

df 2

F 3.59

165

2.24

91.3 76.8 100

25.5

6 2 13 6 4

0 8 4 32.3 .59

18.5 .99

100 20.3 20.7 21.1 0 32 22.2 26.5 1.17

23.4 1.07

f

0

0

51 23 15 9 17 14

79.7 79.3 78.9

5.5

loo 68 77.8 165

1.79

165

8.4?

'SD = stniidnrd devifltioir 11

= miniher

P < .01

complications was found to be sigruficant ( P < .001).The total number of postoperative complications accounted for 22.3%of the variance in LOS (Table 8). HOSPITALCHARGES. Stepwise multiple regression analysis was used to analyze the contribution of all independent predictor variables to hospital charges. Only

two independent variables were found to contribute sigruficantly to hospital charges. The total surgical time ( P < .001) and the number of postoperative complications ( P < .001) both were found to contribute significantly to hospital charges. These two variables accounted for 33.3% of the variance in hospital AORN JOURNAL

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TABLE8

Multiple Regression Results for Length of Stay Standardized $

Variables

Age Gender Race Living arrangement Total lymphocyte count Hematocrit Comorbidities Body mass index Type of anesthesia Surgical time in minutes Type of postoperative analgesia Amount of analgesia in 48 hours Number of postoperative complications

t

-.13 -.11 .03

-.59 -.02 -1.75 .42 -33 1.46 -1.61 -1.52 .43

-.13

-1.79

-.04

-.56

-.09

-1.17

.77

.47'

-.04

-.oo

-.13 .03 -.02 .ll

Adjusted R2

.22 * P <.001

TABLE9

Multiple Regression Results for Hospital Charges Variables

Standardized f3

Age Gender Race Living arrangement Total lymphocyte count Hematocrit Comorbidities Body mass index Type of anesthesia Surgical time in minutes Type of postoperative analgesia Amount of analgesia in 48 hours Number of postoperative complications

-.05 -.05 -.04 .04 -.02 -2.32 -.02 -.05

t

Adjusted R2

-.75 -.68 -.53 .63 -3

-.oo

.08

.23 .74 1.19

.41

6.05'

.03

.39

.ll

1.68

.38

5.66'

.33

* P <.m1

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charges (Table 9). DISCHARGE DISPOSITION. Discharge disposition is a categorical variable, so logistic regression was conducted to examine whether the independent variables contributed to this outcome. Based on the regression, only age and gender were predictive. The odds of being discharged to a subacute facility were about 6.6 times greater for women than they were for men (P < .05). The odds of discharge to a subacute or rehabilitation facility were about 1.44 times greater for each year in age (P < .001) (Table 10). In summary, sigruhcant differences between the two discharge groups were found for the patient factors of age, gender, and living arrangement. Of the clinical factors only the number of comorbidities was sigruficantly different between the discharge groups. The only treatment factor found to be significant between discharge groups was the number of postoperative complications. Analysis revealed that only postoperative complications contributed sisruficantly to LOS. For the outcome of hospital charges, analysis revealed that total surgical time and number of postoperative complications were significant contributors. Using logistic regression,

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both age and gender increased the odds normal parameters for TLC?* Experts of discharge to a subacute or rehabilita- in the field of geriatric medicine agree tion unit. that anemia (ie, low- or below-normal hematocrit) is not a normal part of aging and should not be accepted withDISCUSSIONAND CONCLUSIONS The demographics of partiapants in out investigation.” Total lymphocyte this study reflect current population count and hematocrit, however, reflect demographics in which women outlive the nutrition of the older person, and their husbands and then live alone. The studies have linked nutrition with US Department of Health and Human immune status.333It is possible, thereServices Administration on Aging fore, that low TLC and hematocrit may reports that in 2000, the gender ratio of affect response to stressors, such as surwomen to men was 143 to 100.3l gery, and return to normal function Similarly,most of the men in this study after surgery. Sigruficantly,the sample lived with a spouse, while most of the also had a mean BMI indicating obesity? women lived alone. Older women are An increased BMI also may reflect the more likely to be poor, live alone, and nutritional state of participants, and it has a marked influence on mobility. have more chronic A 1995US Bureau of the Census pubClinically, this sample exhibited mean laboratory values for TLC and lication found that more than 80% of peohematocrit that are low- or below- ple older than age 65 have at least one normal for adults. Although immune chronic condition, and many have multisystem function in older adults tends to ple conditions.” All the patients in this decline with age and lymphocytes in study had at least one comorbid condiolder adults have shown impaired tion. The number of comorbid conditions function, no conclusive results exist to among the patients in this study was justify changing the values that delimit similar to a previous study in which an

TABLE10

Logistic Regression Results for Discharge Disposition Variables Age Gender Race Living arrangement Total lymphocyte count Hematucrit Comorbidities Body mass index Type of anesthesia Surgical time in minutes Type of postoperative analgesia Amount of analgesia in 48 hours Number of postoperative complications

* P < .ooz P c .05

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B

.37 1.89 1.65

-.46 .00

.oo .04 .09

-.34 .03 -.14

.02 .a7

R .29 .14 .06

.oo .oo .oo .oo .oo .oo .09 .oo .00 .08

df 1 1 1 1 1 1 1 1 1 1 1 1 1

Odds ratio 1.44+ 6.615 5.22 .63 1.oo 1.00 1.04 1.10

.71 1.04 .87 1.02

2.38

average of three comorbid conditionsper participant was found.%Clearly the risk of health problems and disabilityincreases with age, but assumptions about the link between comorbid illnesses and the ability to successfully undergo THA or TKA cannot be made. The majority of the sample had spinal/epidural anesthesia and received postoperative analgesia via epidural delivered by a PCA device. Although a Epidural analgesia via continues to be the desired outcome PCA acute postoperative pain relief of choice, but extenmost sive study of the efficacy of using this method of patients is pain therapy relative to discharge from other methods has not been done.3738 The average LOS was the acute care four days for this sample, facility directly which is fewer than the mean LOS that Medicare deems appropriatefor the to home, the diagnosis-related grouping for THA or TKA.%The majority of Medicare mean LOS for patients in this THA or TKA is 4.6 days and is the same for every study were facility across the United States." The shorter-thandischarged to a allowed by Medicare LOS may reflect the national subacute trend to shift the cost from expensive inpatient servrehabilitation ices to less expensive outpatient facility. Although a desired outcome for most patients is discharge from the acute care facility directlyvto home,23Bzthe majority of the patients in this study were discharged to a subacute or rehabilitation facility. Fewer than 10 patients were discharged to home without help. This finding is reflective of a general trend in THA and TKA surgeryBBThis trend may be

for

or

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occurring because Medicare reimbursement for rehabilitation in a subacutefacility is separate from acute care hospital charges and is available for up to 21 days after THA or TKA." This research was expected to identify key patient, clinical, and treatment factors that influence the patient's ability to return to stable function after a THA or TKA. Physiological and sociological variables were expected to account for differences in discharge disposition and to be predictors of outcomes for LOS, discharge disposition, and hospital charges. The patient and clinical factors or individual patient variables were found to be more predictive of THA or TKA outcomes than treatment factors or process variables, especially for discharge disposition. The few sigruficant results related to treatment factors found in literam and in this research study illustrate the difficulty in measuring the effect of treatments on outcomes. A treatment can be defined as a direct change in the patient's health environment designed to improve the patient's health status." A treatment includes both what was done (ie, process) and how well it was done (ie, skill). A surgical intervention must include all medications, nursing skills, and counseling or education sessions that are associated with the process. In other words, the treatment factors involved in hip or knee arthroplasty are numerous, and understanding the effect of various treatment factors on the outcomes must involve measurement of more variables than typically are examined. Differences in treatment skills among health care providers, whether mechanical, intellectual, or interpersonal,are other variables that modlfy the effect of the treatment on patient outcomes." Comparatively few treatment factors have been examined in relation to THA or TKA outcomes. The end result is that treatment

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Understanding the effects of the numerous treatment factors involved in hip or knee arthroplasty on outcomes must involve measurement of more variables than typically are examined. effects on the outcomes of THA or TKA are poorly explained.

equal in severity, and their impact on the outcomes can be different. Similarly, no distinction was made LIM~ATIONS regarding the strength of the various The conclusions drawn from this postoperative analgesic medications. study are limited by several method- The simple count method meant that ological factors. The sample was fentanyl, a highly potent, schedule IV drawn exclusively from one facility, narcotic administered via epidural, was limiting generalizability. Although the equivalent to an oral dose of propoxysample chosen appears to resemble phene napsylate, a much less potent national data fairly closely, one cannot analgesic. Dose amounts were not be sure whether the sample from this recorded and so could not be considsingle facility is representative of the ered in data analysis. Having to assume larger population of older people who for statistical purposes that different undergo hip and knee replacement analgesics and doses were equal surgery. decreased the precision of measurement This study also was limited by the and may have lessened measurable research design. The data collected were effects on the outcomes. retrospective and encompassed only the Finally, no data were collected about acute care hospitalization time period. types of prostheses. Procedure time for Retrospective designs rely on the accu- THA and TKA may vary sigruficantly racy of recorded data, and no validation according to the type of prosthesis used, or verification of the data can take place. so this constitutes an additional study Additionally, the acute care THA or limitation. TKA hospitalization period may not encompass all variables that ultimately CLNICIAL IMPUCAIIONS affect patients’ long-term recovery. The results of this investigation proIn this study, hip and knee surgeries vide an indication of the variables assowere analyzed as a single group. Al- ciated with good and poor outcomes though this has been done frequently in based on patient, clinical (ie, individsimilar research, an argument could be ual), and treatment (ie, process) factors. made that these surgeries are not the Some patient variables, such as age and same, and that findings related to the gender, cannot be changed; however, combined group may not be generaliz- knowledge of their effects provides able to either group alone. valuable information for the planning Another methodological limitation of patient services. Patients who are was the way in which comorbidities women, who are older, who live alone, and postoperative complications were and who are in poorer overall health measured. These variables were assess- likely will require more rehabilitation ed as a total count of Occurrences so that than that received in acute care facilieach occurrence was mathematically ties. Patients who have longer surgical equivalent to another. For example, the times and an increased number of postcomorbid condition of diabetes was operative complications can be expectequal to dermatitis in this study, and the ed to have l e n w e r hospital stays and postoperative complication of transfu- higher hospital charges. sion was weighted equally with the Practice guidelines or clinical pathpostoperative complication of dizzi- ways, which define the processes of care ness. Clearly, not all comorbid condi- that lead to the best patient outcomes, are tions or postoperative complicationsare being promoted to improve the quality of AORN JOURNAL

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Outcomes reseanh provides a foundation for evidence-based nursing practice that can improve the health, function, and well-being of older people who undergo hip and knee arthroplasties. care." Use of clinical pathways already has been shown to decrease LOS and hospital charges after THA and TKA."5It is reasonable to assume that refinement of clinical pathways and practice guidelines for both THA and TKA could improve the quality of care and lead to better outcomes for patients. Clinical pathways and practice guidelinescannot be formulated without objective data that identifies which patient, clinical, and treatment factors most influence the outcomes. This research has provided some of the data necessary to formulate clinical pathways. Clinical pathways and practice guidelines should include the primary intervention of preoperative nursing evaluations to identdy and prepare patients who are at increased risk for longer stays and lengtkuer rehabilitation. Older adult patients should be evaluated more extensively before surgery, and patients identified as being at increased risk for a poor result could be placed into a modified, patient-specific pathway. Practice guidelines also should include interdisciplinary discharge planning that considers patient, clinical, and treatment factors that affect patient reconstitution and return to independent living. The results of outcome studies could be used to refine and test clinical pathways so nurses could preempt problems and develop specific ways to optimize results after THAorTKA.

research also must address patientcentered outcomes, such as patient function and patient satisfaction with care. Further examination of psychological, functional, developmental, or spiritual variables needs to be done. Variables related to the patient's overall sense of well-being, including patient satisfaction at various postoperative intervals (eg, three months, six months, one year), would be a logical continuation of this research. Further research also needs to be performed to quantdy the results of THA or TKA among different health care settings. Shortening the LOS in acute care settings has resulted in a simultaneous increase in the use of other health care services, such as admission and recuperation in subacute units and the use of home health care services. The total cost of THA or TKA, including rehabilitation, needs to be examined. Assessment of the total THA or TKA period would allow researchers to capture the influence of the continuum of care, including access to care, use of resources, and total cost.& Specific strategies for reducing LOS, increasing the likelihood of discharge to home, and reducing hospital charges could include 0 reducing stays in the recovery room by evaluating the processes of recovering patients from different types of anesthesia or prostheses; 0 introducing and analyzing the use of step-down areas within the acute care setting to intensively monitor RESEARCHIMPLICATIONS high-risk older adult patients; Determination of the consequences of health care through outcomes 0 reevaluating the use of PCA methods; research provides a foundation for evidence-based nursing practice that will 0 clinically analyzing the effectiveness and use of various analgesicspostopimprove the health, function, and welleratively; and being of older people who undergo THA or TKA surgery. Although in this 0 reviewing the type, amount, and timing of physical therapy necessary in study only certain physiological and the acute, rehabilitation, or home setsociological variables were examined ting for successful rehabilitation. for their effect on patients, outcomes

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SUMMARYAND CONCLUSION The performance of hip and knee replacement surgeries has increased in frequency during the past 10 years." These arthroplasties are widely believed to enhance quality of life by reducing pain, increasing function, and easing performance of daily activities in older adults suffering from OA. Two groups of researchers, however, point out that uncertainty exists about the optimal process of care for these Variations in the care delivery process have developed for different reasons, and they are not always evidence based. For example, there appears to be no literature to support the efficacy of same-day admission for THA or TKA surgery, especially for the oldest and most at-risk patients. Additionally, there appears to be no definitive research regarding which method of surgical anesthesia results in the best postoperative rehabilitation." Findings from this and similar research could result in the improved design of age-appropriate clinical practice guidelines. For example, knowledge about the increased likelihood for women to be discharged to a subacute facility rather than to home could lead to specific clinical pathways designed for women. Similarly, patients with higher numbers of comorbidities are likely to be discharged to subacute facilities. Development of a comorbidityrisk instrument for nursing use might prove useful in designingpatient plans of care. The knowledge that the number of postoperative complications affects the outcomes of LOS and hospital charges also could prove useful if alternative clinical pathways or plans of care were developed for patients who experience particular complications. Given the ever-increasing population of older Americans and Medicare and private insurance mandates to reduce costs and decrease LOS, patient, clinical, and treatment factors that

affect "HA and TKA outcomes must be identified. Although research about factors that might correlate or predict L a , discharge disposition, and hospital charges has proliferated, definitive identification of individual and process variables that account for variance in outcomes has not occurred. Further research about individual and process variables related to THA and TKA must be extended so that appropriate, costeffective nursing interventions can be designed and implemented. 44 Cynthia D. Epps, RN, PhD, is an associate professor of nursing, State University of West Georgia, Carrollton, Ga. NOTES 1.M J Hall, C J DeFrances, "2001 national hos ital dischar e swey," Advance Data for VitaPand Health !?tatistics 332 (April 9,2003). Also available at Centers for Disease Control and Prevention, http:/lurww.cdc.gov/nchs /data/d/d332.pdf (accessed 24 Feb 2004). 2. G Forrest et al, "Factors affecting length of stay and need for rehabilitation after hip and knee arthroplasty," Journal of Arthroplasty 13 (Februa 1998) 186-190. 3. K E Thorpe, J ZKnickman, "Financing for health care," in Jonas and Kovner's Health Care Delivery in the United States, sixth ed, A R Kovner, S Jonas, eds (New York: Springer Publishing Co, 1999). 4. W L Healy et al, "Impact of cost reduction programs on short-term patient outcome and hospital cost of total knee arthrolasty," Journal of Bone and Joint Surgery M A March 2002) 348-353. 5. P Buerhaus, D Staiger, D Auerbach, "Why are shortages of hospital RNs concentrated in s ecialty care units?"Nursing Economic$18 PMa /June) 111-116. 6. B Messer, "Rec&cing lengths of stays in the total joint replacement population," Orthopaedic Nursing 17 no 2 suppl (March/ April 1998) 23-25. 7. A W Wojner, "Outcomes management: From theory to ractice," Critical Care Nursing Quarter y 19 (February 1997) 1-15. 8. V A Brander et al, "Outcome of hip and knee arthroplasv in ersons aged 80 years and older," Clinical &thopaedics and Related Research (December1997) 67-78. 9. R N Levy et al, "Outcome and long-term

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results following total hi replacement in elderly patients,” Clinica~orthopaedicsand Related Research (Jul 1995) 25-30. 10.K A Pettine, B ; A d d , M E Cabanela, ”Elective total hip arthroplasty in patients older than 80 ears of age,” Clinical Orthopaedicsand {elated Research (Ma 1991) 127-132. 11.J ~ s s a n e ns, Aro, P Paavolainen, ”Hospital-and patient-related characteristics determining length of hos ital stay for hip and knee re lacements,” nfernational Journalof Techno ogy Assessment in Health Care 12 (Spring 1996) 325-335. 12. A M Braeken et al, “Determinantsof 612 month post0 erative functional status and pain after e ective total hip replacement,” lntemational Journalfor Quali in Health Care 9 (December 1997) 413-4 8. 13. G C Del Savio et al, “Preoperativenutritional status and outcome of elective total hip replacement,” Clinical Orthopaedics and Related Research (Ma 1996) 153-161. 14.C J Lavemia, R {Sierra, L Baerga, “Nutritional parameters and short term outcome in arthro lasty,” Journal of the American College ofNutrifion 18 (June 1999) 274-278. 15.A Wan ,“Patient variability and the design of c k c a l pathways after primary total hip re lacement surgery,” Journal of Qualify in Ainical Practice 17 (September 1997) 123-129. 16.M R Brinker et al, ”Comparisonof general and epidural anesthesia in atients undergoing primary unilateral Orthopedics 20 (February 1997) 109-115. 17.D M McBeathanalgesia et al, ”Theand effect of patient controlled continuous e idural infusion on length of hospital stay aier total knee or total hip replacement1 aher total knee or total Gp replacement/ ' CRNA:TheClinical Forum for Nurse Anesthetists 6 (February1995) 31-36. 18.J J Neitzel et al, ”Improvingpain management after total ioint redacement sur&y,” Orthopaedic l h ~ ~ i n g(July/August i8 1999) 37-45,64. 19.M Nendick, “Patient satisfaction with post-o erative analgesia,“ Nursing Standard 14 (Fel!16-22.2000~ 32-37. 20.‘B E Bierbaum et al, “An analysis of blood management in patients havin a total hip or knee arthroplasty,”~ o u m ?of Bone and Joint Surgery 81 (Janu 1999) 2-10. 21.W J Gaine et al, “Wound Z d o n in hip and knee arthroplas ” Journal of Bone and Joint Surgery, Bntish volume 82 (May 2000) 561-565. 22. S Gherini et a1,”Delayed wound healing

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and nutritional deficienciesafter total hip arthro lasty,“ Clinical Orthopaedics and RelafefResearch (August 1993) 188-195. 23. M H Kelly, R M Ackerman, “Total joint arthroplasty: A com arison of postacute settings on patient ctional outcomes,” Orthopaedic Nursing 18 (September/October 1999) 75-84. 24. R W Bohannon, J Cooper, “Total knee arthro lasty: Evaluation of an acute care rehabfitation ro am,” Archives of Physical Medicine and &haktation 74 (October 1993) 1091-1094. 25.G P Forrest, J M Roque, S T Dawodu, “Decreasinglen of sta after total joint arthroplasty:E ect on re errals to rehabilitation units,’ Archives of Physical Medicine and Rehabilitation 80 (February 1999) 192-194. 26. M C Munin et al, ”Predicting discharge outcome after elective hip and knee arthroAmerican Journal of Physical Medicine 74 (July/August 1995) 294-301. 27. R C Wasielewski et al, ”Patient comorbidity: Relationshif to outcomes of total knee arthroplas Clinical Orthopaedics and Related Research?November 1998) 85-92. 28. S J Meyers et al, ”In atient cost of primary total joint arthropisty,” Journal of Arthroplasty 11 (A ril 1996) 281-285. 29. D K Lester, L Linn, “Variationin hospital charges for total joint arthroplasty: An investigation of physician efficiency,” Orthopedics 23 (February 2000) 137-140. 30. S H Stern, L B Singer, S E Weissman, “Analysis of hospital cost in total knee arthroplasty: Does length of stay matter?” Clinical Orthopaedics and Related Research (December 1995) 36-44. 31. D G Fowles, S Greenberg, A Profile of Older Americans:2002 (Washin on, DC: Administration on Aging, US partment of Health and Human Services, 2002). 32.A G Lueckenotte, Gerontologic Nursing, second ed (St. Louis: Mosby, 2000). 33.K A Kudsk et al, “A randomized trial of isonitrogenous enteral diets after severe trauma. An immune-enhancingdiet reduces septic complications,”Annals of S u r g ~ (October 4 1996) 531-540. 34. C endez et al, “Effects of an immuneenhancinF diet in critically injured patients, Journal of Trauma 42 (May 1997) 933-940. 35.US Bureau of the Census, Statistical Absfracfof the Unifed States, 115th ed (Washington,DC: US Government Printing Office, 1995). 36. M C Munin et al, “Early inpatient

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rehabilitation after elective hip and knee arthroplasty," JAMA 279 (March 18,1998) 847-852. 37. J E Edwards, "How to assess harm: Lessons from acute postoperative ain," in Pain 1999-An Updated Review: Rgesher course syllabus: IASP Refesher Courses on Pain Management Held in Conjunction with the 9th World Congress on Pain, August 22-27, 1999, Vienna,Austria, ed M Devor (Seattle: IASP Press, 1999) 411-421. 38. J L Plummer, "Clinical pharmacology of acute pain: Postoperative ain, acute myocardial infarction, an migraine," in Pain 1999-An Updated Review: Refresher course syllabus: IASP Refesher Courses on Pain Management Held in Conjunction zvith the 9th World Congress on Pain, August 22-27, 1999, Vienna,Austria, ed M Devor (Seattle: IASP Press, 1999)463-469. 39. T Nicholas, Basic ICD-9-CM Coding Handbook (Chicago:American Health Information Mana ement Association, 1996). 40.T Lee, persona communication with the author, Carrollton, Ga, 8 Au 2001. 41. L Shi, D A Singh, Delivering%ealth Care in America:A Systems Approach (Gaithers-

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bur Md As en,2001). 42.B A Stahf"Maximizing reimbursement for subacute care," Nursing Management 26 (April 1995) 16-19. 43.R L Kane, ed, UnderstandingHealth Care Outcomes Research (Gaithersburg,Md: Aspen Publishers, 1997). 44. A Wojner, Outcomes Management: A lications to Clinical Practice (St. Louis: Z s b y , Inc, 2001). 45. C Gregor et al, "Reduced len Of wi and improved appropriatenesso care a clinical path for total knee or hip arthrolasty," Joint CommissionJournal on Quality fmpmement 22 (September 1996) 617-628. 46.E A Lingard et al, "Management and care of atients undergoing total knee arthropasty: Variations across different health care settings," Arthritis Care and Research 13 (June 2OOO) 129-136. 47. F J Singelyn et al, "Effects of intravenous patient-controlledanal esia with morphine, continuous epiduraf analgesia, and continuous three-in-one block on postoperative pain and knee rehabilitation after unilateral total knee arthro lasty," Anesthesia and Analgesia 87 (July 1&) 88-92.

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Policy Affects Hiring of Foreign Health Care Workers major change i n federal policy will affect the hiring of foreign health care workers i n the United States, according t o a March 8, 2004, news release from the Commission on Graduates of Foreign Nursing Schools International Commission on Healthcare Professions. Nurses who are not US citizens are now required t o obtain a special health care worker visa certification t o practice i n the United States. The new regulations, which were issued by the US Department of Homeland Security, are intended t o ensure that foreign health care workers meet the professional training and standards necessary t o provide patient care i n US hospitals and health care facilities. The new rules apply t o foreign nurses who are seeking temporary or permanent occupational visas. Previous rules drafted by the Immigration and Naturalization Service applied only t o permanent occupational visas. The new rules also apply t o nurses from Mexico and Canada, who previously were exempt under the terms of the North

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American Free Trade Agreement. I n addition t o nurses, the new rules apply t o physical therapists, occupational therapists, speech-language pathologists, audiologists, medical technicians, medical laboratory technologists, and physician assistants. The new rules require that health care workers present this visa certification when entering the US t o work or applying for an extension of stay or on change of immigration status or employment. Although these rules went into effect on Sept 23, 2003, they include a transition period t o minimize disruption of the current US health care employment market, which defers their application until July 25, 2004. New Homeland Security Rules Mandate Screening of Foreign Workers Seeking Employment as Nurses in the US (news release, Philadehhia: Commission on Graduates of Foreign Nursing Schools International Commission on Healthcare Professions, March 8, 2004).

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