The Journal of Arthroplasty Vol. 24 No. 5 2009

Patient Expectations Predict Greater Pain Reliefwith Joint Arthroplasty

Rajiv Gandhi, MD, John Roderick Davey, MD, and Nizar Mahomed, MD

Abstract: We examined the relationship between patient expectations of total jointarthroplasty and functional outcomes. We surveyed 1799 patients undergoingprimary hip or knee arthroplasty for demographic data and Western OntarioMcMaster University Osteoarthritis Index scores at baseline, 3 months, and 1 year offollow-up. Patient expectations were determined with 3 survey questions. Thepatients with the greatest expectations of surgery were younger, male, and had alower body mass index. Linear regression modeling showed that a greaterexpectation of pain relief with surgery independently predicted greater reportedpain relief at 1 year of follow-up, adjusted for all relevant covariates (P b .05). Patientexpectation of pain relief after joint arthroplasty is an important predictor ofoutcomes at 1 year. Key words: arthroplasty, expectations, outcomes, hip, knee.© 2009 Elsevier Inc. All rights reserved.

Patient expectations of hip, knee, and back surgeryencompass the domains of pain relief, improvementin function, and psychological well-being [1-5].These expectations may be based on personalexperience with surgery or information they havegathered through discussions with their health careproviders. Not all patients present for surgery withthe same level of expectations.The outcomes literature in total joint arthroplasty

(TJA) has looked at the influence of both systemfactors and patient level factors. System factors suchas surgeon and hospital volume appear to have apositive correlation to clinical outcomes [6-8].Patient level factors such as preoperative function[9-11] and preoperative psychological distress[11-15] have been shown to predict clinical out-comes. Many authors have examined the effect of

From the Toronto Western Hospital, Division of Orthopedic Surgery,Toronto, Ontario, Canada.

Submitted February 5, 2008; accepted May 11, 2008.No benefits or funds were received in support of the study.Reprint requests: Rajiv Gandhi, MD, Toronto Western

Hospital, 399 Bathurst St, Toronto, Ontario, Canada M5T 2S8.© 2009 Elsevier Inc. All rights reserved.0883-5403/08/2405-0010$36.00/0doi:10.1016/j.arth.2008.05.016

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age, comorbidity, and obesity; however, there islittle evidence for a strong effect for any of thesefactors [16-21]. Studies evaluating preoperativepatient expectations have shown that those withthe greatest expectations of surgery demonstrate thebest outcomes when undergoing heart surgery,abdominal hysterectomy, and lumbar spine surgery[22-24]. Other authors have stressed that patientsshould have realistic expectations of surgery [4]because fulfillment of these expectations may leadto greater patient satisfaction [1,2,25].

The primary objective of our study was toexamine the relationship between patient expecta-tions of TJA and their preoperative functional status.Our secondary objective was to determine the effectof patient expectations at predicting surgical out-comes at 1 year.

Methods

Study Sample

Study patients were recruited from a singleCanadian Academic Institution, the Toronto Wes-tern Hospital, before undergoing primary hip orknee arthroplasty. Our inclusion criteria for the

Patient Expectations Predict Greater Pain Relief with Joint Arthroplasty � Gandhi et al 717

study were age of 18 years old and above and adiagnosis of primary or secondary osteoarthritis. Allpatients gave informed consent to participate in thestudy. All data were collected by an independentassessor not involved in the medical care of thepatients. The study protocol was approved by thelocal ethics committee.

Collection of Data

Baseline demographic data of age, sex, body massindex (BMI) were collected. Highest level ofeducation was recorded as either higher educationlevel (university or above) or low education level(high school or below). Baseline medical health wasscored on the Charlson Comorbidity Illness Index[26]. The Charlson index was developed in 1987based on 1-year mortality data and encompasses 19medical conditions weighted on a scale from 1 to 6.A lower score represents a better health state. Giventhe low frequency of comorbidity in this sample,the data were collapsed in 4 categories: a score of 0,1, 2, or 3 or higher. Functional status and pain levelwere assessed preoperatively, at 3 months, and at1 year of follow-up with the Western OntarioMcMaster University Osteoarthritis Index(WOMAC) function and pain scores, respectively[27]. A greater score on the WOMAC scalerepresents poorer function or greater pain. Patientquality of life was assessed by the Medical Out-comes Study Short Form 36 (SF-36) preoperatively[28-30]. A lower score on the SF-36 scale indicatesa poorer quality of life. Eight hundred eighty-twopatients (49%) in our cohort were retired at thetime of surgery, whereas 432 (24%) were stillworking. One hundred eighty-two patients (10%)were on disability at the time of joint arthroplasty.The remainders were either unemployed ordescribed themselves as homemakers.

Table 1. Demographic Data and Baseline SF-36 Scores Comparto Full Recovery f

Question 1 High expectations

How long to recover from surgery? n = 502

Mean age (SD) 70.0 (11.9)% Men 43.3%Mean BMI (kg/m2) (SD) 29.9 (6.1)% Higher education 51.9%Charlson index (%)0 57.2%1 27.6%2 8.9%≥3 6.3%SF-36, preoperativePhysical function 20.0 (11.0)Role physical 8.6 (4.3)

Patient expectations were assessed with 3 surveyquestions under the domains of time to fully recoverfrom surgery, level of pain expected after surgery,and ability to perform his/her usual activities.Responses were collapsed into those with high,moderate, and low expectations and comparedacross an appropriate component of the WOMACscore. For the question of time to fully recover fromsurgery, high expectations was defined as 3 months orless; moderate expectations, 4 to 12 months; and lowexpectations, 12 months or more. For the question of“how painful do you expect your hip/knee to bewhen fully recovered,” high expectations wasdefined as no pain; moderate expectations, slightlyto moderately painful; and low expectations, veryextremely painful. For the question of “how limiteddo you expect to be in your usual activities whenfully recovered from surgery,” high expectationswas defined as no limitations (able to perform high-impact activities such as running, doubles, tennis, orhiking); moderate expectations, slightly to moder-ately limited (walking a distance of 1 hour or playinggolf); and low expectations, very totally limited(walking, maximum of 20 minutes).

Patient satisfaction was assessed at 1 year offollow-up with a single survey question asking “howsatisfied are you with the results of your surgery.”Responses of very satisfied and somewhat satisfiedwere collapsed into a satisfied group, and responsesof somewhat dissatisfied and very dissatisfied werecollapsed into a dissatisfied group.

Statistical Analysis

Continuous data such as age, BMI, and WOMACscores were compared between groups using t testsor 1-way analysis of variance for comparisons acrossmultiple groups. Means and standard deviations arereported for all continuous variables. Categorical

ed Across Groups for the Question of Expectation of Timerom Surgery

Moderate expectations Low expectations

Pn = 1203 n = 94

69.0 (12.3) 73.9 (10.2) .0440.0% 20.0% .0230.6 (6.8) 33.1 (7.0) .0653.3% 34.5% .13

52.7% 43.3% .1030.8% 26.7%11.5% 23.3%5.0% 6.7%

21.3 (11.8) 23.8 (11.7) .00311.9 (4.8) 17.7 (8.2) b.001

Table 2. WOMAC Scores Compared Across Groups for Expectation of Time to Recover From Surgery

Question 1 High expectations Moderate expectations Low expectations

PHow long to recover from surgery? n = 502 n = 1203 n = 94

Preoperative WOMAC scores 50.5 (18.7) 54.1 (17.3) 62.9 (16.9) b.00112-wk WOMAC scores 23.2 (16.0) 27.5 (16.9) 37.8 (22.0) b.0011-y WOMAC scores 17.9 (16.4) 22.5 (16.9) 34.5 (21.4) b.001WOMAC change score, preoperative, 12 wk 27.2 (17.1) 27.6 (17.6) 28.9 (18.2) .84WOMAC change score, preoperative, 1 y 32.6 (19.3) 31.6 (18.1) 28.4 (24.6) .333% Satisfied 93.4% 93.5% 95% .919

718 The Journal of Arthroplasty Vol. 24 No. 5 August 2009

data such as sex, education, Charlson index, andsatisfaction are reported with frequencies, andgroups were compared with the χ2 test.Multivariate linear regression modeling was

performed to determine the impact of patientlevel of expectations on the correspondingWOMAC change scores. WOMAC change score isdefined as the absolute difference in score frombaseline to the particular time period of follow-up.Separate models were constructed for each of the 3expectation questions. The relevant covariatesentered into the models were age, sex, BMI,education, and Charlson index.All statistical analysis was done with SPSS version

13.0 (Chicago, Ill). β Coefficients for regressionmodeling and their 95% confidence intervals (CIs)are reported. All reported P values are 2-tailed, withan α of .05.

Results

In our registry, we had complete data on 1799(76.6%) of 2350 patients that comprised our studycohort. Participants and nonparticipants were notsignificantly different in terms of age, BMI, sex, orCharlson index.Demographic data compared across groups

defined by the expectations question on time tofully recover from surgery are shown in Table 1. Thepatients with the lowest expectations were signifi-cantly older at a mean age of 73.9 years (P = .04) andmore commonly female (P = .02) than those with

Table 3. WOMAC Pain Scores Compared Across Groups for Ex

Question 2 High expectations

How much pain do you expect to have? n = 1095

Preoperative WOMAC pain scores 10.3 (3.9)12-wk WOMAC pain scores 4.0 (3.7)1-y WOMAC pain scores 2.0 (2.4)WOMAC pain change score, preoperative, 1 y 8.3 (3.5)% Satisfied 93.7%

high expectations. There was a strong trend that thepatients with the lowest expectations had a greaterBMI at 33.1 kg/m2, as compared to 29.9 kg/m2 inthe high expectations group (P = .06). There wereno significant differences in level of education andcomorbidity between groups (P N .05).

Patients with the greatest expectations of surgerydemonstrated the best quality of score scores on theSF-36 domains of physical function (P = .003) androle physical (P b .001), as compared to these withmoderate and low expectations.

In response to the first expectations question,28% (502/1799) of patients had high expectationsof recovery, whereas 5.2% (94/1799) of patientshad low expectations of recovery. Table 2 showsthat, as expectations of surgery became greater,patients demonstrated significantly better overallfunctional scores at all time points (P b .001). Therewere no differences in recovery patterns betweengroups as the WOMAC change scores at 12 weeksand 1 year were no different (P N .05). There was nodifference in satisfaction between each of the 3expectation groups (P = .919).

In response to the second expectation question,60.9% (1095/1799) of patients had high expecta-tions of recovery, whereas 1.8% (33/1799) ofpatients had low expectations of pain relief.Table 3 shows that, as expectations became greater,patients demonstrated significantly better overallpain scores at all time points (P b .05). The groupwith the highest expectations showed a signifi-cantly greater WOMAC pain change score ascompared to the other groups (P b .05). There

pectation of Pain Relief After Full Recovery from Surgery

Moderate expectations Low expectations

Pn = 671 n = 33

11.2 (3.8) 11.8 (3.7) b.0015.7 (3.8) 5.4 (3.6) .0014.6 (3.7) 5.2 (4.1) .0126.6 (4.5) 6.6 (4.1) b.001

92.9% 94.8% .616

Table 4. WOMAC Function Scores Compared Across Groups for Expectation of Ability to Perform Their UsualDaily Activities

Question 3 High expectations Moderate expectations Low expectations

PHow limited will you be in your usual activities? n = 521 n = 1189 n = 89

Preoperative WOMAC function scores 40.1 (15.2) 43.2 (14.1) 45.3 (13.7) b.00112-wk WOMAC function scores 19.2 (13.0) 22.7 (13.7) 30.7 (17.7) b.0011-y WOMAC function scores 14.9 (13.3) 18.7 (14.0) 20.9 (14.2) b.001WOMAC function change score, preoperative, 1 y 25.2 (15.6) 24.5 (14.7) 24.4 (18.3) .721% Satisfied 94.7% 92.9% 94.8% .282

Patient Expectations Predict Greater Pain Relief with Joint Arthroplasty � Gandhi et al 719

were no differences in satisfaction between groups(P = .616).In response to the third expectation question,

29.0% (521/1799) of patients had high expectationsof the ability to perform their usual activities afterfully recovered surgery, whereas 4.9% (89/1799) ofpatients had low expectations. Table 4 shows that, aspatient expectations became greater, they demon-strated significantly better overall WOMAC functionscores at all time points, as compared to those withlesser expectations (P b .001). There were nodifferences in WOMAC function change scores(P = .721) or satisfaction between each of the 3expectation groups (P = .282).Linear regressionmodeling was used to determine

the impact of expectation level on predicting thecorresponding WOMAC change score. Patientexpectations of time to fully recover from surgeryor level of function were not significant predictors ofthe corresponding WOMAC change scores (P N .05).Higher patient expectation of pain relief was asignificant predictor for a greater WOMAC painchange score adjusted for age, sex, BMI, comorbid-ity, and education (P b .001). The β coefficient and95% CIs for the level of expectation variable areshown in Table 5.

Table 5. Linear RegressionModel for PredictingWOMACPain Change Scores Adjusted for Age, Sex, BMI, Charlson

Index, and Education

β Coefficient (95% CI) for predictingWOMAC pain change scores P

Level of patientexpectations

0.79 (0.36-1.21) b.001

Discussion

Our study demonstrates that patient expectationsof joint arthroplasty correlate well with baselinefunctional status. Our patients had realistic expecta-tions of surgery because those with the bestpreoperative functional status demonstrated thehighest expectations and those with the poorestpreoperative function demonstrated the lowestexpectations of surgery. We believe that becauseour patients had set realistic goals for themselvesfollowing surgery, we found no difference in level ofsatisfaction between groups on any of the expecta-tions questions. Overall, we report a 93.5% satisfac-tion rate for hip and knee arthroplasty.Optimal clinical outcomes may be predicted by

objective measures such as preoperative functional

status [9-11], patient age [31], sex [32], and level ofhome social support [32]. Consistent with the workof others, we found that preoperative functionpredicted postoperative function in our cohort ofpatients. The importance of subjective measuressuch as socioeconomic status [9] and patientexpectations in predicting clinical outcomes hasbeen gaining attention. Our search of the literatureidentified only one other study that examined theinfluence of patient expectations on functionalrecovery after knee arthroplasty. Much of theliterature on this question focuses on hip arthro-plasty [2,22,33,34]. These studies showed thatsome patients present for hip arthroplasty withunrealistic expectations [22], and unfilled expecta-tions may lead to less satisfaction with outcomes[2]. In our study, we found that the expectation ofgreater pain relief from surgery independentlypredicted a greater reported improvement inWOMAC pain scores. This finding agrees withthat of another study done in joint arthroplastypatients with 6 months follow-up data [1] and is inopposition to findings from a study done in patientsundergoing lumbar spine surgery where thoseauthors reported that a greater expectation ofpain relief was associated with less reported painrelief at 6 months [4].

Another important finding of our study is that thepatients with the highest expectations of recoverywere found to be younger, men, and having a lowerBMI. Obese patients demonstrate poorer preopera-tive functional scores at the time of TJA [32,35] andhave higher complication rates with TJA [36-38];however, they do gain significant benefit fromsurgery [39,40]. Our finding of patients with a

720 The Journal of Arthroplasty Vol. 24 No. 5 August 2009

greater BMI having lesser expectations of surgeryhas important implications for preoperative coun-seling. Other authors have failed to identify anysociodemographic factors that influence patientexpectations [1].One potential limitation of our study is the 76.6%

response rate among our participants; however, wedemonstrated no difference in responders andnonresponders in terms of age, sex, BMI, or baselinemedical comorbidity, and we believe our conclu-sions remain valid.In conclusion, we find that our patients presented

with appropriate levels of expectations and subse-quently demonstrated high levels of satisfactionwith surgery. Moreover, having high expectations ofpain relief was associated with a greater reportedpain relief at 1 year. Future work should be directedtoward understanding the pathway by whichpatients with high expectations achieve greaterpain relief such as self-efficacy or participationin rehabilitation.

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