A Framework for Studying Healthcare Equity in Adolescent Idiopathic Scoliosis: Scoping Review and Meta-Analysis of Existing Literature.

INTRODUCTION: Health inequities remain a notable barrier for pediatric patients, especially in conditions such as adolescent idiopathic scoliosis (AIS), where the efficacy of nonsurgical treatment is dependent on early diagnosis and referral to a specialist. Social determinants of health (SDOH) are nonmedical factors that affect health outcomes, such as economic stability, neighborhood environment, and discrimination. Although these factors have been studied throughout the AIS literature, considerable inconsistencies remain across studies regarding the investigation of SDOH for this population. Through a scoping review, we analyze the existing literature to propose a comprehensive framework to consider when designing future prospective and retrospective studies of healthcare equity in AIS. METHODS: A systematic review was executed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. A meta-analysis was performed for each reported SDOH (race, ethnicity, insurance provider, and socioeconomic status) including only studies with complete and consistent variables and outcomes. Cobb angle measurements were aggregated and summarized as the weighted mean difference with 95% confidence interval using a fixed or random-effects model (substantial heterogeneity identified). RESULTS: Of 7,539 studies reviewed, nine studies met all the inclusion criteria. As expected, considerable inconsistencies were found across the nine studies making it difficult to aggregate data. Within the meta-analyses, the mean difference between White non-Hispanic and Hispanic patients was statistically significant (1.71; 95% confidence interval 0.78 to 2.65; P < 0.001). No other statistically significant differences were identified among the SDOH and presenting main Cobb angle magnitude. CONCLUSION: These studies provide insight into healthcare inequities in AIS, although notable inconsistencies make it difficult to aggregate data and draw the conclusions needed to drive necessary public health changes. However, our proposed framework can provide a guideline for future prospective and retrospective studies to standardize data reporting and allow for improved collaboration, study design, and future systematic reviews and meta-analyses.

A Validated Pre-operative Risk Prediction Tool for Extended Inpatient Length of Stay Following Primary Total Hip or Knee Arthroplasty.

BACKGROUND: As value-based reimbursement models mature, understanding the potential trade-off between inpatient lengths of stay and complications or need for costly postacute care becomes more pressing. Understanding and predicting a patient's expected baseline length of stay may help providers understand how best to decide optimal discharge timing for high-risk total joint arthroplasty (TJA) patients. METHODS: A retrospective review was conducted of 37,406 primary total hip (17,134, 46%) and knee (20,272, 54%) arthroplasties performed at two high-volume, geographically diverse, tertiary health systems during the study period. Patients were stratified by 3 binary outcomes for extended inpatient length of stay: 72 + hours (29%), 4 + days (11%), or 5 + days (5%). The predictive ability of over 50 sociodemographic/comorbidity variables was tested. Multivariable logistic regression models were created using institution #1 (derivation), with accuracy tested using the cohort from institution #2 (validation). RESULTS: During the study period, patients underwent an extended length of stay with a decreasing frequency over time, with privately insured patients having a significantly shorter length of stay relative to those with Medicare (1.9 versus 2.3 days, P < .0001). Extended stay patients also had significantly higher 90-day readmission rates (P < .0001), even when excluding those discharged to postacute care (P < .01). Multivariable logistic regression models created from the training cohort demonstrated excellent accuracy (area under the curve (AUC): 0.755, 0.783, 0.810) and performed well under external validation (AUC: 0.719, 0.743, 0.763). Many important variables were common to all 3 models, including age, sex, American Society of Anesthesiologists (ASA) score, body mass index, marital status, bilateral case, insurance type, and 13 comorbidities. DISCUSSION: An online, freely available, preoperative clinical decision tool accurately predicts risk of extended inpatient length of stay after TJA. Many risk factors are potentially modifiable, and these validated tools may help guide clinicians in preoperative patient counseling, medical optimization, and understanding optimal discharge timing.

Racial and Ethnic Differences in Maternal Social Support and Relationship to Mother-Infant Health Behaviors.

OBJECTIVE: To examine racial and ethnic differences in maternal social support in infancy and the relationship between social support and mother-infant health behaviors. METHODS: Secondary analysis of baseline data from a multisite obesity prevention trial that enrolled mothers and their 2-month-old infants. Behavioral and social support data were collected via questionnaire. We used modified Poisson regression to determine association between health behaviors and financial and emotional social support, adjusted for sociodemographic characteristics. RESULTS: Eight hundred and twenty-six mother-infant dyads (27.3% non-Hispanic Black, 18.0% Non-Hispanic White, 50.1% Hispanic and 4.6% Non-Hispanic Other). Half of mothers were born in the United States; 87% were Medicaid-insured. There were no racial/ethnic differences in social support controlling for maternal nativity. US-born mothers were more likely to have emotional and financial support (rate ratio [RR] 1.14 95% confidence interval [CI]: 1.07, 1.21 and RR 1.23 95% CI: 1.11, 1.37, respectively) versus mothers born outside the United States. Mothers with financial support were less likely to exclusively feed with breast milk (RR 0.62; 95% CI: 0.45, 0.87) yet more likely to have tummy time ≥12min (RR 1.28; 95% CI: 1.02, 1.59) versus mothers without financial support. Mothers with emotional support were less likely to report feeding with breast milk (RR 0.82; 95% CI: 0.69, 0.97) versus mothers without emotional support. CONCLUSIONS: Nativity, not race or ethnicity, is a significant determinant of maternal social support. Greater social support was not universally associated with healthy behaviors. Interventions may wish to consider the complex nature of social support and population-specific social support needs.

A Daily, Respiratory Therapist Assessment of Readiness to Liberate From Venovenous Extracorporeal Membrane Oxygenation in Patients With Acute Respiratory Distress Syndrome.

We assessed the effect of implementing a protocol-directed strategy to determine when patients can be liberated from venovenous extracorporeal membrane oxygenation on extracorporeal membrane oxygenation duration, time to initiation of first sweep-off trial, duration of mechanical ventilation, ICU length of stay, hospital length of stay, and survival to hospital discharge. DESIGN: Single-center retrospective before and after study. SETTING: The medical ICU at an academic medical center. PATIENTS: One-hundred eighty patients with acute respiratory distress syndrome managed with venovenous extracorporeal membrane oxygenation at a single institution from 2013 to 2019. INTERVENTIONS: In 2016, our institution implemented a daily assessment of readiness for a trial off extracorporeal membrane oxygenation sweep gas ("sweep-off trial"). When patients met prespecified criteria, the respiratory therapist performed a sweep-off trial to determine readiness for discontinuation of venovenous extracorporeal membrane oxygenation. MEASUREMENTS AND MAIN RESULTS: Sixty-seven patients were treated before implementation of the sweep-off trial protocol, and 113 patients were treated after implementation. Patients managed using the sweep-off trial protocol had a significantly shorter extracorporeal membrane oxygenation duration (5.5 d [3-11 d] vs 11 d [7-15.5 d]; p < 0.001), time to first sweep-off trial (2.5 d [1-5 d] vs 7.0 d [5-11 d]; p < 0.001), duration of mechanical ventilation (15.0 d [9-31 d] vs 25 d [21-33 d]; p = 0.017), and ICU length of stay (18 d [10-33 d] vs 27.0 d [21-36 d]; p = 0.008). There were no observed differences in hospital length of stay or survival to hospital discharge. CONCLUSIONS: In patients with acute respiratory distress syndrome managed with venovenous extracorporeal membrane oxygenation at our institution, implementation of a daily, respiratory therapist assessment of readiness for a sweep-off trial was associated with a shorter time to first sweep-off trial and shorter duration of extracorporeal membrane oxygenation. Among survivors, the postassessment group had a reduced duration of mechanical ventilation and ICU lengths of stay. There were no observed differences in hospital length of stay or inhospital mortality.

Resilience and pain catastrophizing among patients with total knee arthroplasty: a cohort study to examine psychological constructs as predictors of post-operative outcomes.

BACKGROUND: Patients' psychological health may influence recovery and functional outcomes after total knee arthroplasty (TKA). Pain catastrophizing, known to be associated with poor function following TKA, encompasses rumination, magnification, and helplessness that patients feel toward their pain. Resilience, however, is an individual's ability to adapt to adversity and may be an important psychological construct that supersedes the relationship between pain catastrophizing and recovery. In this study we sought to identify whether pre-operative resilience is predictive of 3-month postoperative outcomes after adjusting for pain catastrophizing and other covariates. METHODS: Patients undergoing TKA between January 2019 and November 2019 were included in this longitudinal cohort study. Demographics and questionnaires [Brief Resilience Scale (BRS), Pain Catastrophizing Scale (PCS), Knee injury and Osteoarthritis Outcome Score, Junior (KOOS, JR.) and Patient-Reported Outcomes Measurement Information System Physical and Mental Health (PROMIS PH and MH, respectively)] were collected preoperatively and 3 months postoperatively. Multivariable regression was used to test associations of preoperative BRS with postoperative outcomes, adjusting for PCS and other patient-level sociodemographic and clinical characteristics. RESULTS: The study cohort included 117 patients with a median age of 67.0 years (Q1-Q3: 59.0-72.0). Fifty-three percent of patients were women and 70.1% were white. Unadjusted analyses identified an association between resilience and post-operative outcomes and the relationship persisted for physical function after adjusting for PCS and other covariates; in multivariable linear regression analyses, higher baseline resilience was positively associated with better postoperative knee function (ß = 0.24, p = 0.019) and better general physical health (ß = 0.24, p = 0.013) but not general mental health (ß = 0.04, p = 0.738). CONCLUSIONS: Our prospective cohort study suggests that resilience predicts postoperative knee function and general physical health in patients undergoing TKA. Exploring interventions that address preoperative mental health and resilience more specifically may improve self-reported physical function outcomes of patients undergoing TKA.

Duration of Dermatitis Before Patch Test Appointment Is Associated With Distance to Clinic and County Poverty Rate.

BACKGROUND: Contact dermatitis is a common disease that is associated with impaired quality of life. OBJECTIVE: We examined the effect of travel distance and other socioeconomic factors on duration of dermatitis before presentation at the Duke Contact Dermatitis and Patch Testing Center. METHODS: This is a retrospective study of patients who underwent patch testing from March 1, 2012, to August 1, 2018. Associations between duration of dermatitis, distance to clinic, and socioeconomic factors (age, race, payor group, county poverty rate, rural-urban status) were examined. RESULTS: The median duration of dermatitis was 14 months (Q1 = 7 months; Q3 = 36 months), and the median distance to clinic was 18 miles (Q1 = 7 miles; Q3 = 45.9 miles). For a 50-mile increase in the distance from the patient's zip code to the clinic, the median duration of dermatitis increased by 17.9% (P < 0.001). For every 5% increase in the county poverty rate, the median duration of dermatitis increased by 16.3% (n = 29; P = 0.032). Trends were noted for a longer duration of dermatitis based on insurance payor, rural-urban status, and race. CONCLUSIONS: Distance to patch test provider and county poverty status are important measures of access for patients with dermatitis.

Effects of Virtual Exercise Rehabilitation In-Home Therapy Compared with Traditional Care After Total Knee Arthroplasty: VERITAS, a Randomized Controlled Trial.

BACKGROUND: Financial burden for patients, providers, and payers can reduce access to physical therapy (PT) after total knee arthroplasty (TKA). The purpose of the present study was to examine the effect of a virtual PT program on health-care costs and clinical outcomes as compared with traditional care after TKA. METHODS: At least 10 days before unilateral TKA, patients from 4 clinical sites were enrolled and randomized 1:1 to the virtual PT program (involving an avatar [digitally simulated] coach, in-home 3-dimensional biometrics, and telerehabilitation with remote clinician oversight by a physical therapist) or to traditional PT care in the home or outpatient clinic. The primary outcome was total health-care costs for the 12-week post-hospital period. Secondary (noninferiority) outcomes included 6 and 12-week Knee injury and Osteoarthritis Outcome Score (KOOS); 6-week knee extension, knee flexion, and gait speed; and 12-week safety measures (patient-reported falls, pain, and hospital readmissions). All outcomes were analyzed on a modified intent-to-treat basis. RESULTS: Of 306 patients (mean age, 65 years; 62.5% women) who were randomized from November 2016 to November 2017, 290 had TKA and 287 (including 143 in the virtual PT group and 144 in the usual care group) completed the trial. Virtual PT had lower costs at 12 weeks after discharge than usual care (median, $1,050 compared with $2,805; p < 0.001). Mean costs were $2,745 lower for virtual PT patients. Virtual PT patients had fewer rehospitalizations than the usual care group (12 compared with 30; p = 0.007). Virtual PT was noninferior to usual PT in terms of the KOOS at 6 weeks (difference, 0.77; 90% confidence interval [CI], -1.68 to 3.23) and 12 weeks (difference, -2.33; 90% CI, -4.98 to 0.31). Virtual PT was also noninferior to usual care at 6 weeks in terms of knee extension, knee flexion, and gait speed and at 12 weeks in terms of pain and hospital readmissions. Falls were reported by 19.4% of virtual PT patients and 14.6% of usual care patients (difference, 4.83%; 90% CI, -2.60 to 12.25). CONCLUSIONS: Relative to traditional home or clinic PT, virtual PT with telerehabilitation for skilled clinical oversight significantly lowered 3-month health-care costs after TKA while providing similar effectiveness. These findings have important implications for patients, health systems, and payers. Virtual PT with clinical oversight should be considered for patients managed with TKA. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Patch Test Practice Patterns of Members of the American Contact Dermatitis Society.

BACKGROUND: Patch testing is the criterion standard for diagnosis and management of allergic contact dermatitis. Limitations on the number of allergens tested can negatively impact patient care. OBJECTIVE: This study reports clinical practice patterns of American Contact Dermatitis Society (ACDS) members. METHODS: In October and November 2018, the US-based members of the ACDS received an electronic survey regarding their procedures and experiences with patch testing. We evaluated the type of practice, number of patients tested, type of screening and supplemental series, number of allergens tested, and billing and reimbursement concerns. RESULTS: There were 149 respondents; 62% use ACDS Core 80, 70% "sometimes" or "always" test with supplemental series, and 70% "sometimes" or "always" test patient products. Participants estimated that supplemental series identify relevant allergens 35% of the time. Approximately 66% most commonly test more than 81 allergens per patient, and 78% expressed concerns regarding fair reimbursement. CONCLUSIONS: Most ACDS members routinely test more than 81 allergens per patient. Barriers to fair payment for beyond a fixed number of patches at any one visit may impede the diagnosis of allergic contact dermatitis, prolong suffering, and worsen outcomes.

Clinical Impact of Routine Complete Blood Counts Following Total Knee Arthroplasty.

BACKGROUND: Routine laboratory studies are generally obtained following total knee arthroplasty (TKA), and often continued daily until discharge. This study aims to investigate the utility and cost-effectiveness of complete blood count (CBC) tests following TKA. METHODS: Retrospective review identified 484 patients who underwent primary TKA under a tourniquet at a single institution. Preoperative and postoperative CBC values were collected along with demographic data, use of tranexamic acid (TXA), and transfusion rates. Logistic regression models were calculated for all variables. RESULTS: Twenty-five patients required transfusion following TKA (5.2%). Patients requiring transfusion had significantly lower preoperative hemoglobin compared to patients who did not require transfusion (11.47 vs 13.58 g/dL, P = .005). Risk of transfusion was 5.2 times higher in patients with preoperative anemia (95% confidence interval 2.90-9.35, P < .001). Without TXA, patients were 2.75 times more likely to receive transfusion (95% confidence interval 1.43-5.30, P < .001). An average of 2.9 CBC tests were collected per patient who did not receive medical intervention, costing a total of $144,773.80 in associated hospital charges ($316.10 per patient). CONCLUSION: Ensuring quality, cost-effective patient care following total joint arthroplasty is essential in the era of bundled payments. Routine postoperative CBCs do not add value for patients with normal preoperative hemoglobin who receive TXA during TKA performed under tourniquet. Patients who are anemic preoperatively or do not receive TXA should obtain a postoperative CBC test. Daily CBCs are unnecessary if the first postoperative CBC does not prompt intervention.

The Utility of Basic Metabolic Panel Tests After Total Joint Arthroplasty.

INTRODUCTION: Routine laboratory studies are often obtained daily after total joint arthroplasty (TJA) regardless of medical management. The purpose of this study was to investigate the utility of routine basic metabolic panel (BMP) tests after TJA. Furthermore, the goal was to identify factors that may predispose patients to abnormal laboratory values that require medical intervention. METHODS: A retrospective review was performed on 767 patients who underwent primary TJA at a single institution. Preoperative and postoperative potassium, sodium, creatinine, and glucose values were collected along with demographic data, comorbidities, and procedural characteristics. Multivariable logistic regression models were used to determine independent risk factors for abnormal postoperative laboratory values. RESULTS: Diabetes was associated with abnormal glucose (odds ratio [OR] 23.4, 95% confidence interval [CI] 10.7-51.0, P < .001), while chronic kidney disease was associated with abnormal creatinine (OR 3.1, 95% CI 1.7-5.8, P < .001) and potassium (OR 1.8, 95% CI 1.1-2.8, P = .014) requiring medical intervention. An abnormal preoperative laboratory value was also associated with medical treatment for each of sodium, potassium, and creatinine (all P < .001). Average number of BMP tests collected for patients who did not receive medical intervention was 2.8. This equated to $472,372.56 in total hospital charges. CONCLUSION: Cost containment while maintaining high-quality patient care is critical. Routine postoperative BMP tests in patients with normal preoperative values without major medical comorbidities do not contribute to actionable information. Patients with diabetes, chronic kidney disease, or with abnormal preoperative values should obtain a BMP after TJA.

Preoperative Patient Profile in Total Hip and Knee Arthroplasty: Predictive of Increased Medicare Payments in a Bundled Payment Model.

BACKGROUND: The shift toward value-based bundled payment models in total joint arthroplasty highlights the need for identification of modifiable risk factors for increased spending as well as opportunities to mitigate perioperative treatment of chronic disease. The purpose of this study was to identify preoperative comorbidities that result in an increased financial burden using institutional data at a single institution. METHODS: We conducted a retrospective review of total joint arthroplasty patients and collected payment data from the Center for Medicare and Medicaid Services for each patient up to 90 days after surgery in accordance with the regulations of the Comprehensive Care for Joint Replacement initiative. Statistical analysis and comparison of preoperative profile and Medicare payments as a surrogate for cost were completed. RESULTS: Six hundred ninety-four patients were identified over a 4-year time period who underwent surgery before adoption of the Comprehensive Care for Joint Replacement but that met criteria for inclusion. The median total payment per patient episode of care was $20,048. Preoperative diagnosis of alcoholism, anemia, diabetes, and obesity was found to have a statistically significant effect on total payments. The model predicted a geometric mean increase from $1425 to $9308 for patients bearing these comorbidities. CONCLUSION: With Medicare payments as a surrogate for cost, we demonstrate that specific patient comorbidities and a cumulative increase in comorbidities predict increased costs. This study was based on institutional data rather than administrative data to gain actionable information on an institutional level and highlight potential flaws in research based on administrative data.

Dual Diagnosis and Total Hip Arthroplasty.

The co-occurrence of a mental illness and a substance abuse disorder (SUD) is common and has been referred to as a "dual diagnosis" (DD). Although studies have independently investigated mental illness alone and SUD alone, few have examined the effects of these entities combined on complications. A search of the Medicare database from 2005 to 2012 identified 2000 DD patients who underwent total hip arthroplasty (THA). They were compared with 86,976 patients with mental illness only and 590,689 controls (no mental illness or SUD). Medical comorbidities and postoperative complications at 30-day, 90-day, and minimum 2-year time points were analyzed. There was a significant increase (P<.001) in 7 (53.8%) of 13 recorded postoperative medical complications, including acute renal failure (odds ratio [OR], 1.78), postoperative anemia (OR, 1.31), and blood transfusion (OR, 1.24), at the 90-day time point. In addition, there was a statistically significant increase overall in periprosthetic infection (periprosthetic joint infection OR, 4.30; P<.001), periprosthetic fracture (OR, 2.80; P<.001), dislocation (OR, 6.38; P<.001), and the need for THA revision (OR, 3.58; P<.001). When compared with patients with mental illness only, DD patients remained at significantly (P<.001) increased risk for 90-day and overall postoperative surgical complications, including dislocation, periprosthetic joint infection, and THA revision. Patients with a DD were at significant risk for perioperative complications compared with both control patients and patients with mental illness only. Studies investigating only psychiatric disease or only SUD may miss a vulnerable cohort. Further investigation is needed to exactly define to what extent DD amplifies complication rates. [Orthopedics. 2018; 41(3):e321-e327.].

Psychiatric disorders increase complication rate after primary total knee arthroplasty.

BACKGROUND: Psychiatric disease is difficult to screen preoperatively and the incidence of mental health disorders in patients undergoing total knee arthroplasty (TKA) may be underappreciated. The purpose of this study is to evaluate the perioperative complication profile in patients with psychiatric disorders. METHODS: A search of the entire Medicare database from 2005 to 2011 was performed to identify patients who underwent primary TKA with bipolar disorder (20,972), depression (187,448), and schizophrenia (7607). A cohort of 1,271,464 patients as controls with minimum 2.5-year follow-up. Medial and surgical complications at 30-days, 90-days, and overall were compared between the two cohorts. RESULTS: Patients with any psychiatric disease were more likely to be younger (age<65 OR 5.5, p<0.001), female (OR 2.61, p<0.001), and more medically complex (significant increase in 28/28 Elixhauser medical comorbidities, p<0.05). There was a significant increase (p<0.001) in 11/14 (78.5%) of recorded postoperative medical complication rates at 90-days. There was a statistically significant increase in periprosthetic infection (OR 2.17 p<0.001), periprosthetic fracture (OR 2.40, p<0.001), revision TKA (OR 2.06, p<0.001), and extensor mechanism rupture (OR 2.41, p<0.001) at 90day and overall time points. CONCLUSIONS: Patients with psychiatric disorders who undergo elective primary TKA have significantly increased medical and surgical complication rates in the global period and short term follow-up. An ideal screening tool is yet to be determined and these patients need to be counseled appropriately regarding the increased complication rates before proceeding with TKA.

Use of stress testing and diagnostic catheterization after coronary stenting: association of site-level patterns with patient characteristics and outcomes in 247,052 Medicare beneficiaries.

OBJECTIVES: The aim of this study was to determine diagnostic testing patterns after percutaneous coronary intervention (PCI). BACKGROUND: Little is known about patterns of diagnostic testing after PCI in the United States or the relationship of these patterns to clinical outcomes. METHODS: Centers for Medicare and Medicaid Services inpatient and outpatient claims were linked to National Cardiovascular Data Registry CathPCI Registry data from 2005 to 2007. Hospital quartiles of the cumulative incidence of diagnostic testing use within 12 and 24 months after PCI were compared for patient characteristics, repeat revascularization, acute myocardial infarction, and death. RESULTS: A total of 247,052 patients underwent PCI at 656 institutions. Patient and site characteristics were similar across quartiles of testing use. There was a 9% and 20% higher adjusted risk for repeat revascularization in quartiles 3 and 4 (highest testing rate), respectively, compared with quartile 1 (lowest testing rate) (p = 0.020 and p < 0.0001, respectively). The adjusted risk for death or acute myocardial infarction did not differ among quartiles. CONCLUSIONS: Although patient characteristics were largely independent of rates of post-PCI testing, higher testing rates were not associated with lower risk for myocardial infarction or death, but repeat revascularization was significantly higher at these sites. Additional studies should examine whether increased testing is a marker for improved quality of post-PCI care or simply increased health care utilization.

Patterns and predictors of stress testing modality after percutaneous coronary stenting: data from the NCDR(®).

OBJECTIVES: We evaluated temporal trends and geographic variation in choice of stress testing modality after percutaneous coronary intervention (PCI), as well as associations between modality and procedure use after testing. BACKGROUND: Stress testing is frequently performed post-PCI, but the choices among available modalities (electrocardiography only, nuclear, or echocardiography; pharmacological or exercise stress) and consequences of such choices are not well characterized. METHODS: CathPCI Registry(®) data were linked with identifiable Medicare claims to capture stress testing use between 60 and 365 days post-PCI and procedures within 90 days after testing. Testing rates and modality used were modeled on the basis of patient, procedure, and PCI facility factors, calendar quarter, and Census Divisions using Poisson and logistic regression. Post-test procedure use was assessed using Gray's test. RESULTS: Among 284,971 patients, the overall stress testing rate after PCI was 53.1 per 100 person-years. Testing rates declined from 59.3 in quarter 1 (2006) to 47.1 in quarter 4 (2008), but the relative use of modalities changed little. Among exercise testing recipients, adjusted proportions receiving electrocardiography-only testing varied from 6.8% to 22.8% across Census Divisions; and among exercise testing recipients having an imaging test, the proportion receiving echocardiography (versus nuclear) varied from 9.4% to 34.1%. Post-test procedure use varied among modalities; exercise electrocardiography-only testing was associated with more subsequent stress testing (13.7% vs. 2.9%; p < 0.001), but less catheterization (7.4% vs. 14.1%; p < 0.001) than imaging-based tests. CONCLUSIONS: Modest reductions in stress testing after PCI occurring between 2006 and 2008 cannot be ascribed to trends in use of any single modality. Additional research should assess whether this trend represents better patient selection for testing or administrative policies (e.g., restricted access for patients with legitimate testing needs). Geographic variation in utilization of stress modalities and differences in downstream procedure use among modalities suggest a need to identify optimal use of the different test modalities in individual patients.

Assessment of derived 12-lead electrocardiograms using general and patient-specific reconstruction strategies at rest and during transient myocardial ischemia.

Twelve-lead ST-segment monitoring is a widely used tool for capturing focal ischemia and transient intermittent episodes. However, continuous registration of all 10 electrodes is impractical in clinical settings. This study investigated the accuracy of 2 derived 12-lead strategies that required 6 electrodes, including all limb leads, and 2 precordial leads by using population-based (generalized) and individualized (patient-specific) reconstruction coefficients to derive the additional 4 chest leads. A total of 26,880 simultaneous digital conventional 12-lead generalized and patient-specific electrocardiograms were monitored over 112 hours in 39 patients during percutaneous coronary intervention, including 159 balloon occlusions in 63 arteries, to test accuracy at rest and during ischemia. Occlusion duration was 78 seconds (range 42 to 96) in the left main coronary in 2 patients, the left anterior descending artery in 15, the right coronary artery in 10, the circumflex artery in 2, and graft segments in 5 patients. Average summated 12-lead ST deviation over the study population at baseline was 377 microV (range 104 to 1,718), which increased at peak ischemia to an average of 1,086 microV (range 282 to 4,099). Median absolute differences at peak ischemic ST deviation were 25 microV in lead V(1), 0 microV in lead V(2), 35 microV in lead V(3), 34 microV in lead V(4), 0 microV in lead V(5), 11 microV in lead V(6), and 114 microV for summated 12-lead ST deviation with the generalized method and 7 microV in lead V(1), 4 microV in lead V(2), 1 muV in lead V(3), 5 microV in lead V(4), 4 microV in lead V(5), 9 microV in lead V(6), and 83 microV for the summated 12-lead ST deviation with the patient-specific method. Limb leads (I, II, III, aVR, aVL, and aVF) were identical in all patients. Thus, generalized and patient-specific methods derived from 12-lead electrocardiography using actual limb and 2 precordial electrodes accurately derived the additional chest leads at rest and during ischemia. These approaches appear to be more practical than conventional 10-electrode monitoring but preserve high accuracy.