Decreasing medical complications for total knee arthroplasty: effect of critical pathways on outcomes.

BACKGROUND: Studies on critical pathway use have demonstrated decreased length of stay and cost without compromise in quality of care. However, pathway effectiveness is difficult to determine given methodological flaws, such as small or single center cohorts. We studied the effect of critical pathways on total knee replacement outcomes in a large population-based study. METHODS: We identified hospitals in four US states that performed total knee replacements. We sent a questionnaire to surgical administrators in these hospitals including items about critical pathway use and hospital characteristics potentially related to outcomes. Patient data were obtained from Medicare claims, including demographics, comorbidities, 90-day postoperative complications and length of hospital stay. The principal outcome measure was the risk of having one or more postoperative complications. RESULTS: Two hundred ninety five hospitals (73%) responded to the questionnaire, with 201 reporting the use of critical pathways. 9,157 Medicare beneficiaries underwent TKR in these hospitals with a mean age of 74 years (+/- 5.8). After adjusting for both patient and hospital related variables, patients in hospitals with pathways were 32% less likely to have a postoperative complication compared to patients in hospitals without pathways (OR 0.68, 95% CI 0.50-0.92). Patients managed on a critical pathway had an average length of stay 0.5 days (95% CI 0.3-0.6) shorter than patients not managed on a pathway. CONCLUSION: Medicare patients undergoing total knee replacement surgery in hospitals that used critical pathways had fewer postoperative complications than patients in hospitals without pathways, even after adjusting for patient and hospital related factors. This study has helped to establish that critical pathway use is associated with lower rates of postoperative mortality and complications following total knee replacement after adjusting for measured variables.

Neighborhoods matter: use of hospitals with worse outcomes following total knee replacement by patients from vulnerable populations.

BACKGROUND: Neighborhood sociodemographic characteristics are associated with health care utilization across many conditions. There has been little study of whether total knee replacement (TKR) recipients from vulnerable populations, including racial and ethnic minorities, the poor, the elderly, and the less well educated, are more likely to use low-volume hospitals (LVHs). METHODS: We used Medicare claims and census data to identify a national cohort of Medicare beneficiaries who had elective TKR. We defined an LVH as a center performing fewer than 26 TKRs per year, and we used geocoding to identify "bypassers" (patients who had a high-volume hospital closer to their residence than the one where they had TKR). We used multivariate logistic regression to examine the association of patient and neighborhood characteristics with utilization of LVHs and bypassing. We derived a summative measure of neighborhood vulnerability that included 4 high-risk characteristics (factors were high proportions of residents who are minority individuals, who have foreign-born status, with low income, and with low education). RESULTS: Of 113 015 TKR recipients, 13 120 (11.6%) used LVHs. Of all the TKR recipients, 9815 (8.7%) bypassed a center with a higher TKR volume than the one they used. Multivariate analyses showed that nonwhite (odds ratio [OR], 1.24; 95% confidence interval [CI], 1.16-1.33), poor (OR, 1.94; 95% CI, 1.83-2.08), and nonurban (OR, 1.94; 95% CI, 1.87-2.01) subjects were more likely to use LVHs. The TKR recipients from neighborhoods with 3 or 4 vulnerability factors were more likely than patients in neighborhoods with no vulnerability factors to use an LVH and bypass a high-volume hospital. CONCLUSION: Efforts to inform patients about the association of volume with TKR outcomes should target rural areas and vulnerable populations in urban settings.

Deep infection after total knee replacement: impact of laminar airflow systems and body exhaust suits in the modern operating room.

We investigated the relationship between the risk of deep infection and intraoperative use of laminar airflow systems and body exhaust suits during 8,288 total knee replacements performed in 256 hospitals. The overall 90-day cumulative incidence of deep infection requiring subsequent operation was 0.34% (28 procedures). In all combinations of laminar airflow systems and body exhaust suits, the 90-day cumulative incidence of infection requiring subsequent operation was 0.27%-0.43%. The risk ratio was 1.57 (95% confidence interval, 0.75-3.31) for laminar airflow systems and 0.75 (95% confidence interval, 0.34-1.62) for body exhaust suits suits. The risk was not statistically associated with use of either method, but infections were rare.

Direct observation of computer workplace risk factors of college students.

Recently, researchers have reported high musculoskeletal symptom prevalence at several US colleges. Since ergonomic interventions have been shown to prevent and reduce disability, it is important to identify the risk factors for developing symptoms among college students. A nested case-control study was completed to determine computer-related ergonomic risks associated with musculoskeletal symptoms. A trained observer completed ergonomic assessments on 52 randomly selected cases and controls. More than 75 percent (cases and controls combined) of the population was exposed to nine potential postural strains including: arms not along side during keying or mousing; lower back not supported; not having chair accessories; computer monitor not adjustable; mouse being too high or low; hand/wrist/forearm in contact with the desk edge; lack of wrist support; and keyboard not being adjustable. Cases and controls were equally likely to have substantially elevated risks but because the sample was small and lacked power, no risks were statistically significant. Since many known risk factors were prevalent in cases and controls, more research is required to evaluate and prevent injury in this population.

Infection control practices to reduce airborne bacteria during total knee replacement: a hospital survey in four states.

OBJECTIVE: To describe the use of laminar airflow, body exhaust, and ultraviolet lights during total knee replacement (TKR) in four U.S. states. DESIGN: Survey of healthcare facilities. SETTING: Hospitals in Illinois, North Carolina, Ohio, and Tennessee that performed TKR during 2000 as identified by Medicare claims data. PARTICIPANTS: Hospitals responding to a mailed questionnaire. RESULTS: Two hundred ninety-five (73%) of 405 eligible hospitals that performed 18,374 primary and revision TKR procedures responded to the questionnaire. Among responding hospitals, 30% reported regular use (for > 75% of procedures) of laminar airflow, 42% reported regular use of body exhaust, and 5% reported regular use of ultraviolet lights. Among hospitals providing complete data, 150 (58%) performing 66% of procedures reported regular use of at least one of these techniques. On regression analyses, laminar airflow was used more often by hospitals with a TKR volume greater than 25 procedures per year (odds ratio [OR], 2.0; 95% confidence interval [CI95], 1.1-3.7) and orthopedic residency programs (OR, 2.8; CI95, 1.3-6.3), but its use was not significantly related to hospital setting or ownership status. CONCLUSIONS: Although these clean air practices are not recommended by any U.S. governmental or professional organization, they are used in nearly two-thirds of TKR procedures. Better information about their impact on current practice and more explicit guidelines may aid decisions about the use of these resource-intensive infection control practices.

An assessment of willingness to participate in a randomized trial of arthroscopic knee surgery in patients with osteoarthritis.

Identifying barriers to recruitment into a randomized clinical trial can help researchers adjust recruitment strategies to maximize enrollment. To determine barriers to enrollment of patients in trials of knee osteoarthritis treatments, we recruited from three centers patients over age 45 who had both knee osteoarthritis and a meniscal tear. We described a hypothetical randomized trial of arthroscopic partial meniscectomy versus non-operative management and assessed patients' willingness to participate in such a trial. We elicited preferences for treatment along with information on age, sex, education level, race, work status, and pain. We examined the association between these factors and willingness to participate in the trial. Orthopedic surgeons identified 106 eligible osteoarthritis patients, of whom 12 could not be reached, 6 refused and 88 (83%) completed interviews. 63% were female, 55% were college graduates, 23% were non-white and mean age was 60+/-8. The mean WOMAC pain score was 56+/-23. 22% of patients stated that they were definitely willing to participate in the hypothetical trial, and 24% stated they were probably willing. Subjects lacking strong preferences for treatment stated a greater willingness to participate than those with strong preferences (36-14% definitely willing, chi(2) for trend, p=0.005). WOMAC pain score, age, education, work status and race were not associated with willingness to participate. Males were more likely than females to state a willingness to participate (39-11% definitely willing, p=0.005). Since OA affects females disproportionately, a better understanding of barriers to females' participation in trials may enhance future research on treatment of osteoarthritis. Effectively addressing a priori treatment preferences through patient education about the advantages and drawbacks of treatments may increase willingness to participate in trials.

Predictors of successful work role functioning after carpal tunnel release surgery.

This study identified the clinical, individual, and workplace predictors of successful work role functioning (WRF) after carpal tunnel release surgery (CTRS). A community-based cohort (n = 197) was followed for 6 months post-CTRS. Predictors of successful WRF were analyzed prospectively using ordinal logistic regression. Baseline WRF predicted successful WRF at 2 months, whereas being depressed and a workers' compensation claimant predicted being out of work. Baseline WRF, improved self-efficacy, and a supportive organization predicted 6-month successful WRF. Supportive organizations have an impact on the effectiveness of medical interventions for CTS. The significance of improved self-efficacy at 6 months and depression at 2 months postsurgery highlights the importance of psychosocial management of musculoskeletal disorders.

Longer distal motor latency predicts better outcomes of carpal tunnel release.

The association of preoperative median nerve distal latencies with surgical outcomes of carpal tunnel release is unclear. A total of 109 surgically treated workers with carpal tunnel syndrome across the state of Maine completed questionnaires assessing preoperative levels of symptom and functional limitations and general physical health (SF-12). A second questionnaire assessed the 6-month postoperative outcomes of symptom severity, functional limitations, and satisfaction with surgery. Univariate analyses indicated that longer preoperative distal motor and sensory latencies were associated with less postoperative levels of symptom, less postoperative functional limitations, and more satisfaction with surgery. The associations persisted in multiple linear regression analysis; however, better general health preoperatively was a better predictor of favorable outcomes. The results suggest that workers with prolonged preoperative distal motor latencies and who are in good general health preoperatively have a higher rate of successful carpal tunnel release surgery.

Predictors of exercise behavior in patients with rheumatoid arthritis 6 months following a visit with their rheumatologist.

BACKGROUND AND PURPOSE: When factors that influence exercise behavior are known, health care professionals can more likely design and modify patient education materials targeted to promote exercise behavior. This study aimed to identify predictors of exercise behavior in patients with rheumatoid arthritis 6 months after a visit with their rheumatologist. SUBJECTS AND METHODS: Twenty-five rheumatologists and 132 patients with rheumatoid arthritis participated. One hundred thirteen patients (85.6%) completed the 6-month follow-up. Rheumatologists and patients completed baseline questionnaires and were audiotaped during a subsequent visit. Physical function and exercise behavior were ascertained via questionnaire 6 months following the visit. Multivariate logistic regression identified predictors of exercise behavior at 6 months. Eighty-nine patients (79%) were female. The average age was 54.8 years (SD=14.4, range=20-94). The mean duration of illness was 9.8 years (SD=8.7, range= <1-35). Patients were moderately impaired (mean Medical Outcomes Study 36-Item Short-Form Health Survey [SF-36] function score=49.3, SD=27.5). Thirty-four patients (27%) were exercising 6 months after visiting their rheumatologist. More than 50% of the rheumatologists had 5 or more years of clinical experience, 18 (72%) were male, and 10 (42%) reported they exercised regularly. RESULTS: Predictors of exercise behavior at 6 months were patients' past history of exercise (odds ratio=6.8, 95% confidence interval=3.1-15) and rheumatologists' current exercise behavior (odds ratio=0.26, 95% confidence interval=0.09-0.77). DISCUSSION AND CONCLUSION: Patients were nearly 7 times more likely to exercise 6 months after visiting their rheumatologist if they participated in exercise in the past. If a patient's rheumatologist was currently performing aerobic exercise, the patient was 26% more likely to be engaged in exercise at follow-up. These data may be useful in understanding patient motivation to participate in exercise.

Upper extremity musculoskeletal symptoms and functional impairment associated with computer use among college students.

PURPOSE: Occupational computer use has been associated with upper extremity musculoskeletal disorders among working-age adults, but little is known about computer-related musculoskeletal problems among college students. We carried out a descriptive epidemiological study of computer use-associated symptoms, functional limitations, and medication and health care utilization in this population. SUBJECTS AND METHODS: Cross-sectional survey of 240 undergraduates in the second through fourth years at a residential dormitory at a four-year college with random housing assignments. RESULTS: 194 students returned useable surveys (81% response rate). 42% reported upper extremity pain or discomfort when using a computer in the preceding two weeks. 41% said this pain or discomfort caused functional limitation and 9% said that these symptoms hindered academic or extracurricular performance. 23% reported taking medications for upper extremity pain related to computing (4% regularly) and 16% had seen a health care provider for computer-related symptoms. Female students, students of racial/ethnic minority groups, and students who experienced symptoms with < or = 1 hour of computer use were more likely to report symptom-related functional limitation than others. CONCLUSION: College students report high rates of computer use-associated upper extremity musculoskeletal symptoms and symptom-related functional limitation. Future studies should more closely examine exposure, demographic, and ergonomic correlates of these symptoms and outcomes.

A randomized controlled trial of an internal family systems-based psychotherapeutic intervention on outcomes in rheumatoid arthritis: a proof-of-concept study.

OBJECTIVE: To conduct a proof-of-concept randomized trial of an Internal Family Systems (IFS) psychotherapeutic intervention on rheumatoid arthritis (RA) disease activity and psychological status. METHODS: Patients with RA were randomized to either an IFS group for 9 months (n = 39) or an education (control) group (n = 40) that received mailed materials on RA symptoms and management. The groups were evaluated every 3 months until intervention end and 1 year later. Self-assessed joint pain (RA Disease Activity Index joint score), Short Form-12 physical function score, visual analog scale for overall pain and mental health status (Beck Depression Inventory, and State Trait Anxiety Inventory) were assessed. The 28-joint Disease Activity Score-C-reactive Protein 4 was determined by rheumatologists blinded to group assignment. Treatment effects were estimated by between-group differences, and mixed model repeated measures compared trends between study arms at 9 months and 1 year after intervention end. RESULTS: Of 79 participants randomized, 68 completed the study assessments and 82% of the IFS group completed the protocol. Posttreatment improvements favoring the IFS group occurred in overall pain [mean treatment effects -14.9 (29.1 SD); p = 0.04], and physical function [14.6 (25.3); p = 0.04]. Posttreatment improvements were sustained 1 year later in self-assessed joint pain [-0.6 (1.1); p = 0.04], self-compassion [1.8 (2.8); p = 0.01], and depressive symptoms [-3.2 (5.0); p =0.01]. There were no sustained improvements in anxiety, self-efficacy, or disease activity. CONCLUSION: An IFS-based intervention is feasible and acceptable to patients with RA and may complement medical management of the disease. Future efficacy trials are warranted. ClinicalTrials.gov identifier: NCT00869349.

Clinical course and management of a consecutive series of patients with "healed temporal arteritis".

OBJECTIVE: To describe the clinical course and management of patients with a pathologic diagnosis of "healed" giant cell arteritis (GCA), and to determine whether previously published histological descriptions of healed arteritis can identify patients with a greater likelihood of clinically significant arteritis. METHODS: All temporal artery biopsy reports between 1994 and 2003 were examined for a diagnosis of "healed arteritis." Two rheumatologists abstracted the medical record for presenting features, physical findings, comorbid conditions, and data on treatment and outcomes. One pathologist, blinded to the clinical data, reviewed all specimens and reinterpreted the biopsies according to published histological descriptions of healed arteritis. RESULTS: Forty-seven patients with an initial pathologic diagnosis of healed arteritis were identified. In 54% of these patients, corticosteroid therapy did not change after the diagnosis of healed arteritis was documented in the pathology report. Seventy percent were ultimately treated with no corticosteroids or low-moderate corticosteroid regimens. Only 32% of the initial cases were confirmed upon review of the biopsies using standardized histological criteria. Patients with confirmed healed arteritis were more likely to have a documented history of polymyalgia rheumatica/GCA and a longer duration of corticosteroid treatment before biopsy. These patients were not more likely to have adverse outcomes. CONCLUSION: In this case series, the diagnosis of healed arteritis had little effect on treatment decisions. In most cases, the initial pathologic diagnosis of healed arteritis was not confirmed when biopsies were reviewed by a single pathologist using uniform histological criteria.

The relationship between disease activity, sleep, psychiatric distress and pain sensitivity in rheumatoid arthritis: a cross-sectional study.

INTRODUCTION: Despite recent advances in anti-inflammatory therapy, rheumatoid arthritis (RA) patients continue to rate pain as a priority. The etiology of RA pain is likely multifactorial, including both inflammatory and non-inflammatory components. In this study, we examine the association between disease activity, sleep, psychiatric distress and pain sensitivity in RA. METHODS: Fifty-nine female RA patients completed questionnaires and underwent pressure pain threshold testing to assess hyperalgesia/allodynia at joint and non-joint sites. Blood samples were taken to measure C-reactive protein (CRP). The association between disease activity, sleep problems, psychiatric distress and pain threshold was assessed using Pearson/Spearman correlations and multivariable linear regression. Disease activity levels, sleep problems and psychiatric distress were compared between RA patients with fibromyalgia and RA patients without fibromyalgia. RESULTS: In unadjusted analyses, CRP was not correlated with pain threshold, but tender joint count was inversely correlated with pain threshold at all sites (P < or = 0.004). Sleep problems were associated with low pain threshold at all sites (P < or = 0.0008). Psychiatric distress was associated with low pain threshold at the wrist and thumbnail (P < or = 0.006). In multivariable linear regression models, CRP was inversely associated with wrist pain threshold (P = 0.003). Sleep problems were inversely associated with pain threshold at all sites (P < or = 0.01), but psychiatric distress was not. Despite differences in pain threshold, CRP levels and sleep problems between RA patients with fibromyalgia and those without fibromyalgia, associations between these variables did not change when patients with fibromyalgia were excluded. CONCLUSIONS: Multivariable models are essential in analyses of pain. Among RA patients, inflammation is associated with heightened pain sensitivity at joints. In contrast, poor sleep is associated with diffuse pain sensitivity, as noted in central pain conditions such as fibromyalgia. Future studies examining pain sensitivity at joint and non-joint sites may identify patients with different underlying pain mechanisms and suggest alternative approaches to treating RA pain.

Association of hospital and surgeon procedure volume with patient-centered outcomes of total knee replacement in a population-based cohort of patients age 65 years and older.

OBJECTIVE: To study the association between procedure volume and patient-centered outcomes such as functional status. METHODS: We performed an observational study of a stratified random sample of Medicare beneficiaries who underwent primary total knee replacement (TKR) in 2000. Low-volume surgeons were defined as surgeons performing < or =6 TKRs per year in the Medicare population, and low-volume centers were defined as those in which < or =25 TKRs per year were performed. The primary outcome was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) functional status score (0-100 scale; 100 = best) 2 years after TKR. We defined a WOMAC functional status score of <60 as a poor functional outcome. Analyses were adjusted for sociodemographic factors, preoperative functional status, and comorbidities. RESULTS: Fifty-eight percent of 1,597 eligible patients agreed to participate. Twelve percent of participating patients had a WOMAC score <60 2 years following TKR. Patients operated upon by low-volume surgeons in low-volume hospitals were twice as likely to have a poor WOMAC functional status score as patients operated upon by higher volume surgeons and in higher volume hospitals (odds ratio 2.1, 95% confidence interval 1.1-4.2). CONCLUSION: Patients operated upon in low-volume hospitals by low-volume surgeons had worse functional outcomes 2 years after TKR. These findings add a new and important dimension to the discussion of whether to promote selective referral of procedures such as TKR to high-volume centers.

Effect of glutathione S-transferase polymorphisms and proximity to hazardous waste sites on time to systemic lupus erythematosus diagnosis: results from the Roxbury lupus project.

OBJECTIVE: The high prevalence of systemic lupus erythematosus (SLE) among African American women may be due to environmental exposures, genetic factors, or a combination of factors. Our goal was to assess association of residential proximity to hazardous waste sites and genetic variation in 3 glutathione Stransferase (GST) genes (GSTM1, GSTT1, and GSTP1) with age at diagnosis of SLE. METHODS: Residential histories were obtained by interviewing 93 SLE patients from 3 predominantly African American neighborhoods in Boston. Residential addresses and locations of 416 hazardous waste sites in the study area were geocoded using ArcView software. Time-varying Cox models were used to study the effect of residential proximity to hazardous sites, GST genotype, and interaction between genotype and exposure in determining age at diagnosis. RESULTS: The prevalence of SLE among African American women in these neighborhoods was 3.56 SLE cases per 1,000. Homozygosity for GSTM1-null and GSTP1 Ile105Val in combination was associated with earlier SLE diagnosis (P = 0.03), but there was no association with proximity to 416 hazardous sites. Available data on specific site contaminants suggested that, at a subset of 67 sites, there was higher potential risk for exposure to volatile organic compounds (P < 0.05 with Bonferroni correction). GST genotypes had a significant interaction with proximity (P = 0.03) in analyses limited to these sites. CONCLUSION: There was no independent association between residential proximity to hazardous waste sites and the risk of earlier SLE diagnosis in this urban population. However, analysis of a limited number of sites indicated that the risk of earlier SLE associated with proximity to hazardous sites might be modulated by GST polymorphisms.

Development of a preliminary index that predicts adverse events after total knee replacement.

OBJECTIVE: We undertook this study to assess the relationships between hospital characteristics, volume of procedures, and perioperative outcomes after total knee replacement (TKR), and to use this information to construct a simple predictive index for perioperative outcomes that incorporates hospital- and patient-level characteristics. METHODS: We studied Medicare beneficiaries who underwent TKR in 4 US states in 2000. Orthopedic surgery administrators from hospitals caring for patients in this sample were surveyed about a range of hospital characteristics. The relationships between these hospital characteristics, patient variables, and 90-day postoperative adverse events (including death, pulmonary embolus, pneumonia, deep wound infection, and acute myocardial infarction) were assessed using generalized estimating equations adjusting for hospital volume. These relationships were assessed in low- and high-risk patient groups. Variables from the final multivariate model were used to create an index that was tested against 90-day adverse event rates. RESULTS: Three hundred twenty-seven (3.6%) of the patients undergoing TKR in our sample experienced an adverse event. In the final multivariate regression models, variables that predicted adverse perioperative events included low hospital volume (fewer than 23 TKRs in the Medicare population per year), absence of a preoperative teaching program, fewer TKRs conducted in a dedicated orthopedic surgery operating room, patient age >70 years, male sex, and at least 1 comorbid condition. The effect of volume on perioperative adverse events was evident both in patients with few risk factors and in patients with several risk factors. An index including the 6 patient and hospital variables discriminated well, with adverse events occurring in 2.0% (95% confidence interval [95% CI] 1.4-2.7%) of patients in the lowest risk category and in 7.4% (95% CI 4.5-12.3%) of patients in the highest risk category (P for trend < 0.001). The index predicted adverse event rates both in hospitals with a low volume of TKRs and in those with a high volume of TKRs. CONCLUSION: Characteristics of hospital care, procedure volume, and patient-level factors are all associated with perioperative outcomes of TKR. A preliminary index combining hospital characteristics and volume is moderately predictive of adverse perioperative outcomes. The index is predictive of outcome in low- and high-volume hospitals.

Extent of followup care after elective total hip replacement.

OBJECTIVE: To estimate the extent of radiographic and orthopedic followup among recipients of total hip replacement (THR), and to identify patients who are less likely to have consistent followup over 6 years postoperatively. METHODS: We studied a population-based sample of 622 patients who received THR in 1995. We developed a multivariate ordinal regression model with the extent of radiographic followup as the dependent variable (none, early, and consistent), adjusting for demographic and preoperative clinical characteristics, and hospital and surgeon volume. RESULTS: Ninety-four (15%) patients indicated that they had no followup radiographs, 269 (43%) had early followup only, and 259 (42%) had consistent followup radiographs over 6 years. Ninety percent of those with consistent followup orthopedic visits also had consistent followup radiographs over 6 years. Multivariate analyses revealed that older patients were less likely to have radiographic followup than younger patients (OR 0.76, 95% CI 0.65, 0.89) per each 5-year increase in age. Subjects with no college education were less likely to have radiographic followup than those with more education (OR 0.58, 95% CI 0.41, 0.83), and those with lower income were less likely to have radiographic followup than those with a higher income (OR 0.50, 95% CI 0.27, 0.92). CONCLUSION: Only 42% of THR recipients reported consistent radiographic followup. Older patients, patients with lower income, and those with lower education level were less likely to have consistent radiographic followup over 6 years after THR. These population groups can serve as targets for interventions to improve followup after elective THR.

Geographic diversity of low-volume hospitals in total knee replacement: implications for regionalization policies.

BACKGROUND/OBJECTIVES: Centers performing low volumes of total knee replacements (TKR) have worse outcomes of TKR than higher volume centers. Regionalization policies that shift patients to higher volume centers are being considered as a means of improving TKR outcomes. We sought to describe geographic diversity in the distribution of low-volume centers and examine state level characteristics associated with states that have a higher proportion of low-volume centers and/or a higher proportion of TKRs performed in low-volume centers. METHODS: We used U.S. Census data and geocoded Medicare claims to ascertain state-level demographic factors, procedure volume, and TKR rates and to conduct our state level analysis. We defined 2 outcomes: 1) proportion of all hospitals with a low annual TKR volume (<26 per year in the Medicare population); and 2) proportion of all TKRs in the Medicare population performed in low-volume centers. We examined linear associations among the 2 outcomes and state factors, and used multivariate regression to identify factors associated independently with these outcomes. RESULTS: Half of hospitals performing TKR in the Medicare population were low-volume centers, accounting for 13% of TKRs. Multivariate analysis revealed lower TKR rates, higher proportion of rural areas and larger state area were associated with a higher proportion of low-volume hospitals in a state. Lower proportion of elderly residents, higher population density and higher proportion of rural areas predicted a higher proportion of TKRs performed in low-volume centers. CONCLUSIONS: The distribution of low-volume hospitals among U.S. states varies substantially. Regionalization of TKR may require different strategies in states with small and large numbers of low-volume centers.

Determinants of work absence following surgery for carpal tunnel syndrome.

BACKGROUND: The objective was to identify factors across multiple domains associated with return to work in a community-based cohort of workers with carpal tunnel syndrome. METHODS: Workers scheduled for carpal tunnel release were recruited into this prospective study. Subjects completed questionnaires preoperatively and at 2, 6, and 12 months postoperatively. The questionnaires contained demographic, clinical, and psychosocial factors and physical and psychosocial workplace stressors. Predictors of work absence at 6 and 12 months were examined in bivariate and multivariate logistic regression analyses. RESULTS: Six months following surgery of 181 subjects, 29 (19%) were out of work. Twelve months postoperatively 33 subjects (22%) were out of work. In bivariate analyses, the factors associated with work absence at 6 months, at P < or = 0.01, included preoperative physical functional status, change in self-efficacy between preoperative assessment and 2 months, lower income, workers' compensation, representation by an attorney, work exposure to force and repetition, higher psychological job demands and lower control, lower social support by coworkers, lower job security and more supportive organizational policies and practices. The factors associated with work absence at 12 months in bivariate analyses included preoperative physical functional status, lower self-efficacy at 2 months, workers' compensation, and less supportive organizational policies and practices. Multivariate analyses documented a multidimensional model, with predictors from multiple domains. CONCLUSIONS: Clinical, demographic, economic, and workplace factors were associated with work absence. Strategies to reduce work absence following carpal tunnel release should address multiple dimensions of the worker and workplace.

Offering patients the opportunity to choose their hospital for total knee replacement: impact on satisfaction with the surgery.

OBJECTIVE: To describe the extent to which patients were offered a choice between 2 or more hospitals for total knee replacement (TKR); to examine the association between having a choice of hospital for TKR and satisfaction with the surgery; and to identify population groups less likely to be offered a choice. METHODS: We studied a population-based sample of 932 Medicare beneficiaries who underwent elective TKR in 2000. We surveyed patients about their participation in choosing a hospital and their satisfaction with surgery. We examined whether lack of hospital choice influenced satisfaction with surgery after adjusting for age, sex, preoperative function, and socioeconomic status. RESULTS: Among 932 TKR recipients (mean age 74 years, 67% women), more than half (53%) reported having a lack of hospital choice. After adjusting for socioeconomic status, patients reporting lack of choice were approximately twice as likely to be dissatisfied with the results of surgery as patients who reported choosing among 2 or more hospitals for TKR (odds ratio [OR] 2.09, 95% confidence interval [95% CI] 1.13-3.87). Results of logistic regression revealed that patients reporting lack of choice were more likely to be women (OR 1.52, 95% CI 1.14-2.04), >80 years of age (as compared with 65-70 years; OR 1.63, 95% CI 1.03-2.57), living in suburban areas (OR 1.68, 95% CI 1.23-2.30), nonwhite (OR 1.57, 95% CI 0.86-2.87), and were less likely to have TKR performed by a high-volume surgeon (OR 0.71, 95% CI 0.53-0.96). CONCLUSION: More than half of the patients did not have a choice in selecting the hospital where they had TKR. Patients reporting lack of choice were more likely to be dissatisfied with surgery. Interventions to address preferences for hospital may improve satisfaction with care for patients with advanced knee arthritis.