Variation in Rheumatoid Hand and Wrist Surgery among Medicare Beneficiaries: A Population-based Cohort Study

DISCUSSION

RA remains common among older individuals, afflicting over 350,000 Medicare beneficiaries from 2006 to 2010. In our study, we identified a low rate of RA-related hand and wrist reconstructive procedures among the elderly population in the United States, but found substantial variation in RA-related hand and wrist procedures driven by patient and regional factors. Patients who lived in areas with a greater number of rheumatologists were less likely to undergo RA-related hand and wrist joint fusion and replacement. Additionally, younger, female, white patients with RA and patients who resided in rural areas were more likely to undergo both arthroplasty/arthrodesis of hand and wrist, and hand tendon reconstruction. Finally, in our cohort, patients of lower SES underwent fewer surgical procedures, including both joint and tendon reconstruction. Although the reasons for this are likely multifactorial, it is possible that individuals of lower SES lack access to appropriate specialist care, have additional comorbid conditions precluding aggressive medical or surgical intervention, or have fewer available financial resources. Since Alderman, et al¹² in 2002 described regional differences in rheumatoid hand and wrist reconstruction using national claims data, pronounced variation in RA treatment continues to persist. Our findings suggest the influence of providers on these differences. First, surgical rates may represent differential access to subspecialty care, particularly to rheumatologists with expertise in inflammatory arthropathies. In the United States, a relative shortage of rheumatologists exists, and many patients with RA are managed by providers who do not have subspecialty training, who may opt for less-aggressive immunosuppressive regimens, particularly among older individuals¹⁸. Individuals without access to newer DMARD may progress more quickly toward advanced deformities, resulting in higher rates of surgical therapy among those patients treated in areas with fewer rheumatologists. Additionally, our findings may represent differences in referral patterns for surgical intervention. Rheumatologists are often skeptical of the effectiveness of surgical interventions for RA, which influences referral rates for extremity surgery. Lower rates of surgery in some areas may reflect not only differences in aggressiveness of medical therapy, but also differences in treatment preferences^19,20.

The majority of patients are referred to rheumatologists by primary care physicians following the diagnosis of RA, and surgeons are rarely the initial treatment provider. In the United States, about 70% of hand surgeons are trained in orthopedic surgery, 20% in plastic surgery, and 10% in general surgery²¹. In our study, we identified a significant difference in rates of surgery by density of orthopedic surgeons. Surgeons often perceive that medical therapy is extended into advanced stages of RA, making it impossible to reconstruct functionally and aesthetically acceptable hands^12,19. To date, 1 of the largest prospective cohort studies of patients with rheumatoid hand deformities revealed that patients with RA treated with silicone metacarpophalangeal arthroplasty continue to experience longterm improvement in hand function and appearance compared with patients managed medically. Therefore, despite this controversy, surgery remains an important option to relieve pain and improve function, hand appearance, and quality of life among patients with RA²².

Geographic variation in care is common across the United States^23,24,25. Although such variation is thought to represent differences in quality of care, the reasons for this are multifactorial^23,26. Our analysis in Figure 1 represents the unadjusted rates across HRR in the United States. Our multivariate analysis does highlight several patient factors, such as age and sex, and regional factors, such as rheumatologist density, that explain the variation in rates. However, collectively, these factors explain only 0.3% of the variation, and unmeasured factors certainly exist. For example, our study lacks detail in clinical factors that may influence surgery, such as disease severity, and does not identify patient preferences for treatment¹⁹. It is also plausible that there is underlying geographic variation in the incidence of RA. An analysis of the Nurses’ Health Study revealed an increased incidence of RA among women in New England and the Midwest²⁷. Although the etiology of RA remains unknown, there is likely regional variation in risk factors, such as genetic pools or environmental factors that have yet to be identified²⁸.

Our study has several notable limitations. First, administrative data were subject to systematic coding errors and were not collected with the explicit purpose of examining practice patterns. However, we required at least 2 claims, including an RA diagnosis, to ensure the validity of our selected cohort, and a study comparing diagnoses between office records and Medicare claimed to have found a 90% correlation between diagnoses²⁹. Owing to the stringency of our criteria, it was possible that patients with RA with limited access to care could be excluded from the cohort. Additionally, we excluded Medicare Part C enrollees (16–24% of all Medicare beneficiaries) because their outpatient services may not be found in administrative claims data. Our study sample included only adults aged ≥ 65 years, and our findings may not have been generalizable to younger individuals with RA³⁰. Finally, we were not able to examine the effect of disease severity or chronicity on surgical rates, given the lack of granular detail of claims data at this level. Without clinical data, such as laboratory findings, symptomatology, and radiographic progression, we could not account for the influence of disease severity on rates of surgery. Nonetheless, Medicare data have been widely used to examine treatment patterns and provide robust data because of large, population-based samples. Compared with clinical trials or observational registries that are biased toward tertiary care centers, CMS claims data reflect real-world clinical practice^29,31,32,33.

Despite these limitations, our findings reveal significant variation in RA treatment pattern by availability of rheumatologists, and highlight important areas for future investigation. First, access to appropriate healthcare resources has been central to healthcare reform initiatives in the United States. Several interventions, such as the expansion of prescription drug coverage through Medicare Part D and the expansion of Medicaid (low-income) coverage from the Patient Protection and Affordable Care Act, may minimize disparities in access to care for chronic diseases. For example, the initiation of Medicare Part D coverage of biologic DMARD therapy for RA has improved use among vulnerable groups^34,35. Additionally, healthcare reform initiatives have included specific provisions for comparative effectiveness research. Given the controversy that remains regarding the effectiveness of medical and surgical therapy for rheumatoid hand deformities, future studies that directly compare the effectiveness of surgical therapy in the setting of advanced medical therapies, such as biologic DMARD, may allow for better integration of treatment options between rheumatologists and surgeons.

Surgical reconstruction of rheumatoid hand deformities varies across the United States because of the availability of rheumatologists and patient characteristics. Future efforts that directly examine access to healthcare services, surgery referral pattern, and effectiveness of medical and surgical treatment options, as well as health policy interventions aimed at improving access to care, can minimize unwarranted variation in the management of rheumatoid hand and wrist deformities.