Joint arthroplasty is done to reduce patient pain and suffering, increase quality of life (QOL), and improve productivity. Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are the most commonly performed procedures. They are safe and cost-effective treatments for alleviating pain and restoring physical function in patients who do not respond to nonsurgical therapy.1 Numerous studies have documented racial and ethnic disparities in utilization of these procedures and have shown that joint arthroplasty is underutilized by African American and Hispanic patients.2–6
Arthritis, the leading cause of disability in the United States, is the main indication for THA and TKA. Veterans of the armed forces are more likely than nonveterans to report physician-diagnosed arthritis, and patients in the Veterans Affairs (VA) health care system have a higher prevalence of physician-diagnosed arthritis than do veterans who are not in this system.7 Three types of studies have been done on racial and ethnic disparities in THA and TKA in the VA system: estimates of joint arthroplasty utilization, postoperative outcomes, and patient factors that may influence utilization.
The VA health care system primarily serves honorably discharged veterans who meet financial need criteria, have service-related disabilities, or are a part of certain special veterans groups (eg, reservists and National Guard members who served in combat operations). Other honorably discharged veterans also may receive services, but at a lower priority or subject to additional copayments.8 An estimated 2.5 million veterans receive care annually.9 The VA health care system is the largest health care program in the world and is designed to function as an integrated national system of care based on national policies and standard guidelines for care,8–10 thus minimizing the issue of quality of care. The VA system is a leader in electronic recordkeeping, including computerized medical records, information technology, and special databases intended for in-depth evaluation of services and for research. For example, VA databases are used to conduct health services research designed to improve the quality of health care received by veterans. The VA system conducts clinical trials through the VA Cooperative Studies Program.
Joint Arthroplasty Utilization by Race and Ethnicity
Jones et al11 used two national VA databases, the 1999 VA Outpatient Clinic Files and the 2000–2001 VA Patient Treatment Files, to estimate the racial disparity in TKA. The Patient Treatment File is an administrative database that contains information on all hospitalizations. In 1999, a total of 260,856 outpatients aged 50 years and older who had osteoarthritis (OA), classified as code 715.x in the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), were eligible for the study. Data on comorbidity were collected using components of the Deyo-Modified Charlson Comorbidity Index. Comorbidity was prevalent in both African American and white patient populations. Study results were analyzed for racial and ethnic differences in TKA (CPT code 27447) procedures for a 2-year period. After adjusting for age, sex, and number of comorbidities, African American patients were significantly less likely than white patients to have received TKA (odds ratio [OR], 0.72; 95% confidence interval [CI], 0.65–0.80). Similar results were found when the study population was restricted to the 46,207 patients who had been referred to rheumatology or orthopaedic clinics for specialty care.
The study by Jones et al11 is unique because, by combining the VA Outpatient Clinic Files and the VA Patient Treatment Files, the authors captured data from all patients diagnosed with OA who were potential candidates for TKA prospectively and examined surgical outcomes. This study design allowed the calculation of the true rates, defined as the number of persons who underwent surgery divided by the population at risk. As noted by Katz and Losina,12 the most useful denominator for estimating utilization rates is the population at risk for TKA (ie, patients with advanced arthritis). The disparity in utilization of TKA is estimated using the risk ratio, defined as the risk of TKA surgery in one racial or ethnic group divided by the risk of TKA surgery in the dominant racial or ethnic group. When administrative databases such as Medicare are used to examine disparities in TKA utilization rates, the general population of enrollees is used as the surrogate for the population at risk because prospective identification of outpatients with severe arthritis is not feasible. Unfortunately, the authors did not make the best use of the prospective study design when analyzing the data because the rates of TKA were not broken down according to different racial and ethnic groups.
Racial and Ethnic Differences in Postoperative Outcomes
Two VA-based studies on health outcomes following THA and TKA used data from the National Surgical Quality Improvement Program (NSQIP).13,14 NSQIP is a nationally validated surgical quality assurance and data collection program on major surgeries within 123 VA hospitals.13–15 This database has many advantages over administrative databases (eg, Medicare). Data are collected prospectively by staff who are trained in using standardized procedures to collect information from medical records and from patient and physician interviews. Preoperative, intraoperative, and 30-day postoperative variables are collected, and a five-point complexity score is used to rate all surgeries.13,15 Since initiation of the NSQIP 30-day assessment in 1994, postoperative morbidity has declined by 45%, and 30-day mortality has declined by 27%.16 This improvement in outcomes supports the assumption that a strong quality assurance program can minimize differences in the quality of care based on race and ethnicity.
Weaver et al13 used 1991–1997 NSQIP data merged with national VA discharge data to report on 30-day morbidity and mortality and readmission rates that occurred within 1 year of surgery. Hip and knee arthroplasty included both total and partial replacements (defined as Current Procedural Terminology [CPT] codes 27125 and 27130 [hip] and 27437 to 27447 [knee]). Race was dichotomized as white or nonwhite; approximately 22% of hip arthroplasty patients and 18% of knee arthroplasty patients were nonwhite. In this study, women constituted 2.6% of hip arthroplasty patients and 3.2% of knee arthroplasty patients. The authors classified morbidity as minor complications (urinary tract infection, prolonged ileus, superficial wound infection, deep vein thrombosis) or major complications (all other) and then further rated these using the Deyo-Modified Charlson Comorbidity Index.
Nonwhite patients experienced longer postoperative hospitalization for both hip arthroplasty and knee arthroplasty and had a higher likelihood of complications with knee arthroplasty. Mortality rates were low for all procedures and were not reported by race.13 Although this study reports an independent association between race and longer hospital stay as well as between race and elevated TKA complications, it is overly speculative in interpreting the meaning of the findings, noting illogically that the findings “are consistent with other work that found less improvement in pain and function in blacks … and evidence that Hispanic ethnicity is related to increased risk of wound-healing problems.”13
Ibrahim et al14 used NSQIP data to analyze 30-day postoperative morbidity and mortality in a sample of patients from 107 VA hospitals that performed TKA (CPT codes 27437 to 27447) and THA (CPT code 27130) between 1996 and 2000. Morbidity was classified as non-infection-related, infection-related, or none. Overall 30-day morbidity and mortality after TKA was low in all patient groups. However, the adjusted analysis demonstrated that, compared with white patients, both African American and Hispanic patients had a higher risk of infectionrelated complications (relative risk [RR] = 1.42, P = 0.02; RR = 1.64, P = 0.02, respectively). Compared with white patients, African American patients also had a higher risk (RR = 1.50, P = 0.02) of non-infectionrelated complications. Morbidity after THA was low and was similar for African American, Hispanic, and white patients. Overall 30-day mortality was 0.6% for patients who underwent TKA and 0.7% for patients who underwent THA. There were no significant racial and ethnic disparities with regard to mortality.14
This study demonstrated no disparity in 30-day surgical mortality. Overall 30-day morbidity was low in the VA population, which is known to have a high prevalence of comorbid conditions before surgery, but African Americans had a 42% higher risk of infection-related complications and a 50% higher risk of non-infection-related complications, compared with white patients, after undergoing TKA. Hispanic patients had a 62% higher risk of infection after undergoing TKA compared with white patients. THA was not associated with disparity according to race or ethnicity. The higher rate of complications among racial and ethnic minority patients who undergo TKA needs to be examined further.
Several patient-level factors that may influence health disparities in the utilization of joint arthroplasty were examined in a cross-sectional survey conducted between 1997 and 2000 of men attending primary care clinics at the Louis Stokes Cleveland VA Medical Center in Cleveland, OH.17–22 These factors included racial and ethnic differences in patterns of self-care, familiarity with joint replacement procedures, expectations of postoperative outcomes, QOL, the influence of prayer on willingness to undergo surgery, and perception of symptoms.
Patients aged 50 years and older who had no history of hip or knee arthroplasty were screened for chronic hip or knee pain using the Lequesne osteoarthritis severity index. Among the 1,351 men screened, 57% met the criteria; the first 600 men who agreed to participate were selected for the target sample size. Demographic information was collected via questionnaire, and comorbidity data were collected via medical record review and scored using the Charlson Comorbidity Index. All patients had hip or knee radiographs, which were used to confirm the diagnosis of OA. Other standardized measures included the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index, the Geriatric Depression Index, the Efficacy of Specific Treatment Questionnaire (ie, Bill-Harvey questionnaire), and the Global QOL Questionnaire. In addition, the investigators included a religiosity scale and questions about familiarity with joint arthroplasty; expectations of postoperative hospital stay, pain, and disability; and willingness to consider joint arthroplasty.
Demographic data demonstrated notable differences in patients according to their race and ethnicity. African American men, compared with white men, were less likely to have a high school education, be married, and be employed. African American men were more likely to have a household income <$10,000. No significant differences were found in comorbidity scores, severity of radiologic findings, WOMAC Index score, and depression scores between African American and white men. African American men scored significantly higher on religiosity than did white men (P ≤ 0.001).
African American men were more likely than white men to rely on self-care practices, such as over-the-counter drugs, seeking advice from a friend or family member, reducing activities, or applying a medicated cream. In addition, African American men were more likely than white men to perceive traditional treatments (eg, physical therapy, acetaminophen) and complementary treatments (eg, herbal medicine, massage, copper or metal bracelets) as useful17 (Table 1). African American men were significantly less likely than white men to know someone who had undergone joint replacement surgery (OR, 0.39; CI, 0.26–0.61) and to report a good understanding of joint replacement as a form of treatment (OR, 0.62; CI, 0.42–0.92). African American men were more likely to expect a longer hospital stay (OR, 4.09; CI 2.57–6.54); to expect moderate to extreme postoperative pain (OR, 2.61; CI 1.74–3.89); and to expect moderate to severe difficulty walking after surgery (OR, 2.76; CI, 1.83–4.16).18 These factors explained why African American men were less likely than white men to be willing to consider joint arthroplasty.19 Global QOL was rated lower for African American men than for white men. This contradicts the hypothesis that low QOL increases patient preference for joint arthroplasty and increases the likelihood of physician recommendation for surgery.20
Another analysis demonstrated that African American men were twice as likely as white men to perceive prayer as helpful in the management of arthritis.21 Among those who perceived prayer to be helpful, notably fewer African Americans were willing to consider surgery. In contrast, no difference in willingness to consider surgery was found among African American and white men who did not use prayer.21 The final study found no racial or ethnic differences in pain and function when measured by severity of radiologic findings.22
These studies indicate a need for patient education about the benefits of joint arthroplasty, the typical hospital course, and the long-term improvement in pain, function, and QOL. The study results are limited, however, because they are based on the survey of patients in a clinic; therefore, the findings cannot be linked to actual use of surgery. It would be useful to know whether willingness to undergo joint arthroplasty surgery differed across racial and ethnic groups among eligible patients who were offered surgery.
These VA-based studies of racial and ethnic differences in utilization of joint arthroplasty surgery explored many of the factors that have been hypothesized to explain health care disparities (eg, estimates of joint arthroplasty utilization, postoperative outcomes, patient-related factors). The VA population is a convenient group to study, and VA research is useful as a beginning in developing a systematic approach to research that estimates the disparities in health care utilization and defines the determinants of these disparities. However, VA studies are limited because of the unique nature of the VA population. Studies of VA patients do not capture a representative sample of the US population, even among men, because VA patients tend to have lower income and education levels than the US population overall.
Research on health care disparities must focus on differences between populations. Clinician researchers usually approach research by collecting information on individuals; however, individuals cluster in populations based on any number of socioeconomic, racial, ethnic, and other factors. In the case of racial and ethnic disparities, many of the existing studies on health care disparities are based on historical scientific categories that lead to systematic disadvantage for the specific racial or ethnic group. For example, a 2003 report from the Institute of Medicine23 notes that “racial discrimination persists in a wide range of American life” and that the legacy of segregated and inferior health care continues to affect African American and American Indian groups today.
Future studies should systematically define the population of study, in addition to the research questions and methodologic approaches to be used in examining health care disparities in joint arthroplasty. Unlike traditional biomedical research that explores cause and treatment at the individual patient level, outcomes in health care disparities research cluster according to different patient populations; thus, the population in these studies must be described clearly.
This work was supported by EXPORT grant 1 R24 MD000500–01 from the National Center on Minority Health and Health Disparities, National Institutes of Health, and a grant from the J. Robert Gladden Orthopaedic Society.
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