Factors associated with oral anticoagulant prescription status among patients with a new diagnosis of atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is the most common sustained arrhythmia in adults and increases stroke risk. Treatment with oral anticoagulants (OACs) may reduce this risk however many patients do not receive OAC therapy. This study aimed to use electronic health record data to identify newly diagnosed AF patients at high risk for stroke and not anticoagulated as well as factors associated with OAC prescription. HYPOTHESIS: Timely prescription of OACs among patients with newly diagnosed AF is poor. METHODS: We performed a retrospective study of patients with a new diagnosis of AF. We assessed stroke risk with the CHA2 DS2 -VASc score. The primary outcome was prescription of an OAC within 6 months following diagnosis. We used logistic regression to see how the odds of being prescribed an OAC differs for 17 independent variables. RESULTS: We identified 18 404 patients with a new diagnosis of AF. Among patients at high risk for stroke, 41.3% received an OAC prescription within 6 months. Male sex, Caucasian compared to African American race, stroke, obesity, congestive heart failure, vascular disorder, current antiplatelet, beta blocker, or calcium channel blocker prescription, and increasing CHA2 DS2 -VASc score were positively associated with receiving an OAC. Whereas anemia, renal dysfunction, liver dysfunction, antiarrhythmic drug use and increasing HAS-BLED score were negatively associated. CONCLUSIONS: Most newly diagnosed AF patients at high stroke risk do not receive an OAC prescription in the first 6 months following diagnosis. Our analysis suggests that patient sex, race, comorbidities, and additional prescriptions are associated with rates of OAC prescribing.

Ordering Characteristics Predictive of Noncontrast CT Head Positivity in the Emergency Department.

RATIONALE AND OBJECTIVES: Recent decades have seen a steady increase in noncontrast head CT utilization in the emergency department with a concurrent rise in the practice of physician assistants (PAs) and nurse practitioners (NPs). The goal of this study was to identify ordering and patient characteristics predictive of positive noncontrast head CTs in the ED. We hypothesized NP/PAs would have lower positivity rates compared to physicians, suggestive of relative overutilization. MATERIALS AND METHODS: We retrospectively identified ED patients who underwent noncontrast head CTs at a single institution: a nonlevel 1 trauma center, during a 7-year period, recording examination positivity, ordering provider training/experience, and multiple additional ordering/patient attributes. Exam positivity was defined as any intracranial abnormality necessitating a change in acute management, such as acute hemorrhage, hydrocephalus, herniation, or worsening prior findings. RESULTS: 6624 patients met inclusion criteria. 4.6% (280/6107) of physician exams were positive while 3.7% (19/517) of NP/PA exams were positive; however, differences were not significant. Increasing provider experience was not associated with positivity. Attributes with increased positivity were patient age (p < 0.001), daytime exam (p < 0.05), and indications regarding malignancy (p < 0.001) or focal neurologic deficit (p = 0.001). Attributes with decreased positivity were indications of trauma (p < 0.001) or vertigo/dizziness (p < 0.05). CONCLUSION: We found no significant difference in rates of exam positivity between physicians and NP/PAs, even accounting for years of experience. This suggests increasing utilization of head CTs in the ED is not due to the increasing presence of NP/PAs, and may be reflective of general practice trends and clear diagnostic algorithms leading to head CT.

Dig Deeper: A Case Report of Finding (and Fixing) the Root Cause of Add-On Laboratory Failures.

BACKGROUND: Venipunctures and the testing they facilitate are clinically necessary, particularly for hospitalized patients. However, excess venipunctures lead to patient harm, decreased patient satisfaction, and waste. OBJECTIVES: We sought to identify contributors to excess venipunctures at our institution, focusing on electronic health record (EHR)-related factors. We then implemented and evaluated the impact of an intervention targeting one of the contributing factors. METHODS: We employed the quality improvement (QI) methodology to find sources of excess venipunctures, specifically targeting add-on failures. Once an error was identified, we deployed an EHR-based intervention which was evaluated with retrospective pre- and postintervention analysis. RESULTS: We identified an error in how the EHR evaluated the ability of laboratories across a health system to perform add-on tests to existing blood specimens. A review of 195,263 add-on orders placed prior to the intervention showed that 165,118 were successful and 30,145 failed, a failure rate of 15.4% (95% confidence interval [CI]: 15.1-15.6). We implemented an EHR-based modification that changed the criteria for add-on testing from a health-system-wide query of laboratory capabilities to one that incorporated only the capabilities of laboratories with feasible access to existing patient samples. In the 6 months following the intervention, a review of 87,333 add-on orders showed that 77,310 were successful, and 10,023 add-on orders failed resulting in a postintervention failure rate of 11.4% (95% CI: 11.1, 11.8) (p < 0.001). CONCLUSION: EHR features such as the ability to identify possible add-on tests are designed to reduce venipunctures but may produce unforeseen negative effects on downstream processes, particularly as hospitals merge into health systems using a single EHR. This case report describes the successful identification and correction of one cause of add-on laboratory failures. QI methodology can yield important insights that reveal simple interventions for improvement.

Assessing the performance of different outcomes for tumor growth studies with animal models.

The consistency of reporting results for patient-derived xenograft (PDX) studies is an area of concern. The PDX method commonly starts by implanting a derivative of a human tumor into a mouse, then comparing the tumor growth under different treatment conditions. Currently, a wide array of statistical methods (e.g., t-test, regression, chi-squared test) are used to analyze these data, which ultimately depend on the outcome chosen (e.g., tumor volume, relative growth, categorical growth). In this simulation study, we provide empirical evidence for the outcome selection process by comparing the performance of both commonly used outcomes and novel variations of common outcomes used in PDX studies. Data were simulated to mimic tumor growth under multiple scenarios, then each outcome of interest was evaluated for 10 000 iterations. Comparisons between different outcomes were made with respect to average bias, variance, type-1 error, and power. A total of 18 continuous, categorical, and time-to-event outcomes were evaluated, with ultimately 2 outcomes outperforming the others: final tumor volume and change in tumor volume from baseline. Notably, the novel variations of the tumor growth inhibition index (TGII)-a commonly used outcome in PDX studies-was found to perform poorly in several scenarios with inflated type-1 error rates and a relatively large bias. Finally, all outcomes of interest were applied to a real-world dataset.

Lost to Follow-Up: A Nationwide Analysis of Patients With Transient Ischemic Attack Discharged From Emergency Departments With Incomplete Imaging.

PURPOSE: Imaging guidelines for transient ischemic attack (TIA) recommend that patients undergo urgent brain and neurovascular imaging within 48 hours of symptom onset. Prior research suggests that most patients with TIA discharged from the emergency department (ED) do not complete recommended TIA imaging workup during their ED encounters. The purpose of this study was to determine the nationwide percentage of patients with TIA discharged from EDs with incomplete imaging workup who complete recommended imaging after discharge. METHODS: Patients discharged from EDs with the diagnosis of TIA were identified from the Medicare 5% sample for 2017 and 2018 using International Classification of Diseases, tenth rev, Clinical Modification codes. Imaging performed was identified using Current Procedural Terminology codes. Incomplete imaging workup was defined as a TIA encounter without cross-sectional brain, brain-vascular, and neck-vascular imaging performed within the subsequent 30 days of the initial ED encounter. Patient- and hospital-level factors associated with incomplete TIA imaging were analyzed in a multivariable logistic regression. RESULTS: In total, 6,346 consecutive TIA encounters were analyzed; 3,804 patients (59.9%) had complete TIA imaging workup during their ED encounters. Of the 2,542 patients discharged from EDs with incomplete imaging, 761 (29.9%) completed imaging during the subsequent 30 days after ED discharge. Among patients with TIA imaging workup completed after ED discharge, the median time to completion was 5 days. For patients discharged from EDs with incomplete imaging, the odds of incomplete TIA imaging at 30 days after discharge were highest for black (odds ratio, 1.84; 95% confidence interval, 1.27-2.66) and older (≥85 years of age; odds ratio, 2.41; 95% confidence interval, 1.78-3.26) patients. Reference values were age cohort 65 to 69 years; male gender; white race; no co-occurring diagnoses of hypertension, hyperlipidemia, or diabetes mellitus; household income > $63,029; hospital in the Northeast region; urban hospital location; hospital size > 400 beds; academically affiliated hospital; and facility with access to MRI. CONCLUSIONS: Most patients discharged from EDs with incomplete TIA imaging workup do not complete recommended imaging within 30 days after discharge.

Factors Associated with Retention and Adherence in a Comprehensive, Diverse HIV Pre-Exposure Prophylaxis Clinic.

Retention in HIV pre-exposure prophylaxis (PrEP) care and adherence to PrEP have been suboptimal in some populations, despite evidence that high adherence dramatically enhances PrEP efficacy. A comprehensive PrEP Clinic with a retention specialist and clinical pharmacist could impact patient's retention and adherence in PrEP care. A retrospective electronic medical record review of patients attending an academic PrEP Clinic was conducted between June 2018 and June 2019 (at least one visit attended for PrEP was required). Retention was defined as a medical or laboratory visit every 3 months ±30 days, as recommended by CDC guidelines, but was analyzed using the number of visits and time between visits via multivariate regression analyses. PrEP adherence was calculated using a Medication-Possession Ratio (MPR) and compared between patient characteristics using Kruskal-Wallis tests. One hundred twenty-two patients were identified by chart review, 96 had sufficient data for follow-up and were included in at least one analysis. The population was primarily cisgender men who have sex with men and over half were African American or Hispanic. Overall, patient retention was 43%. The retention analysis demonstrated that individuals who self-identified as gay were more likely to be retained than those who identified as heterosexual (53% vs. 18%, hazard ratio = 1.75, 95% confidence interval = [1.01-3.03], p = .045). Although not statistically significant, African Americans and cisgender women were less likely to be retained in care. The adherence analysis identified higher median MPRs among patients not reporting previous incarceration (80% vs. 35%, p < .01). Although not statistically significant, there was lower adherence among youth 18-24 (11% vs. 54% MPR >80, p = .058). Despite comprehensive PrEP clinical care, heterosexual individuals were less likely to be retained in PrEP care than those who self-identified as gay and previously incarcerated individuals were less likely to be adherent to PrEP.

Mass-Like Fat at the Medial Midfoot: A Common Pseudolesion.

Background Fatty masses are common and may be encountered in the foot and ankle. In some cases, normal subcutaneous fat may be mistaken for a discrete mass. Aims The aim of this study was to evaluate the common finding of prominent subcutaneous fat at the medial midfoot resembling a lipoma and to determine the prevalence of this pseudolesion by applying a series of potential size cutoff criteria. Materials and Methods Three musculoskeletal radiologists retrospectively evaluated 91 sequentially performed magnetic resonance imaging examinations of the ankle to measure fat resembling a discrete lipoma at the medial midfoot. Each blinded reader measured the largest area of continuous subcutaneous fat in orthogonal axial, coronal craniocaudal, and coronal transverse dimensions. Patient age, sex, and study indications were also recorded. Statistical analysis was performed with R and SAS 9.4 software Results A discrete fatty pseudolesion as defined by measuring at least 1 cm in all planes by measurements of at least two of three readers was present in 87% of cases (79 of 91). When a size criterion of 1.5 cm was used, a pseudolesion was documented in 14% of cases (13 of 91). There was a significant correlation between larger pseudolesion size and female sex in the axial plane; however, there was no correlation in the coronal craniocaudal and coronal transverse dimensions. Conclusions Subcutaneous fat at the medial midfoot often has a mass-like appearance that could be mistaken for a lipoma. It is important to recognize this pseudolesion variant and not to confuse the imaging appearance for a discrete mass.

Small target repeatability of 68Ga and 18F: effects of target concentration and imaging time on SUV measurements in clinically relevant phantoms.

Quantification of tumor uptake using PET imaging is important for the evaluation of therapy response. For 18F FDG PET scans, a change in uptake of 25% is commonly considered significant. For scans using novel radiopharmaceuticals, the threshold of significance is unclear. Factors including imaging time, tumor size, activity concentration, and radiopharmaceutical may affect the repeatablity of uptake metrics. This work evaluates the effect of these parameters on the repeatablity of maximum SUV (SUVmax) and mean SUV (SUVmean) in phantoms using 18F and 68Ga. An Esser PET phantom (Data Spectrum, Durham NC) was scanned on a Biograph Horizon PET/CT scanner (Siemens Medical Solutions, Malvern PA) using 18F and 68Ga. Data were acquired for 5 minutes with reconstructions between 0.5-5 minutes. The background activity mimicked clinical scans with target-to-background (T/B) ratios from 1.7-19.8. The SUVmax and SUVmean were measured for 5 slices. The mean, standard deviation, and coefficient of variation (COV) were calculated. The effects of radionuclide, imaging time, activity concentration, and target size on COV were evaluated using multivariate gamma regressions. COV for 68Ga was 40% higher and 54% higher on average than for 18F for SUVmax and SUVmean, respectively. Decreased lesion size, imaging time, and activity concentration were significantly associated with increased COV for both metrics (P < 0.001). COV was substantially reduced at high T/B for 68Ga. At the highest T/B the COV for SUVmax and SUVmean was within the typical range seen for 18F. COV is relatively high for small targets (8 mm) but is dramatically reduced with high radiotracer uptake.

Implementation and 1-year follow-up of the cardiovascular ICU standardised handover.

BACKGROUND: Miscommunication during clinical handover can lead to partial information transfer and healthcare provider dissatisfaction. We hypothesised that a quality improvement project to standardise the cardiovascular intensive care unit (CVICU) handover could improve healthcare provider satisfaction and reduce information omission. METHODS: After institutional review board approval, the operating room (OR) to CVICU handover was audited prior, post and 1 year after standardisation implementation. The medical information transferred, healthcare provider participation and satisfaction, and patient outcome data were collected. Additionally, surveys were sent to the OR and CVICU staff by email. RESULTS: There were 68 handover processes observed. The odds of greater satisfaction with handover for providers were 18 times higher with the process post implementation (p<0.0001) and 26 times higher 1 year after implementation (p<0.0001). There was statistically significant difference between intensive care unit resident presence (45% vs 76% vs 91%, p=0.004), surgical faculty presence (10% vs 36% vs 45%, p=0.034) and surgical fellow presence (15% vs 64% vs 62%, p=0.001) between the three time periods. More information related to the surgeon (5% vs 52% vs 27%, p=0.002), the medical history (65% vs 96% vs 91%, p=0.014) and the cardiopulmonary bypass (47% vs 88% vs 76%, p=0.017) was conveyed. The duration of mechanical ventilation was shorter after implementation (2.2±2.6 days vs 1.2±1.9 days vs 0.5±1.2 days, p=0.026). CONCLUSIONS: One year after the OR to CVICU standardised handover implementation, the healthcare provider satisfaction remained increased, more team members participated and the information transfer increased. Although some clinical outcomes improved, further studies are recommended to prove causality.

Alvimopan as part of the Enhanced Recovery After Surgery protocol following radical cystectomy is associated with decreased hospital stay.

OBJECTIVE: To study the effect of alvimopan and the Enhanced Recovery After Surgery protocol on length of hospital stay in patients undergoing radical cystectomy. METHODS: Our retrospective study involved 296 consecutive patients undergoing radical cystectomy for bladder cancer at our institution from 2010 through 2018. Patients were grouped according to three stages of the Enhanced Recovery After Surgery protocol implementation: (i) pre-Enhanced Recovery After Surgery (group A; n = 146); (ii) pre-alvimopan Enhanced Recovery After Surgery (group B; n = 102); and (iii) Enhanced Recovery After Surgery plus alvimopan (group C; n = 48). The primary outcome was the length of hospital stay. Secondary outcomes were time to first bowel movement, time to tolerate a regular diet, the incidence of postoperative ileus, postoperative complications and 30-day readmission rate. RESULTS: Group C showed a significantly shorter median length of hospital stay (7 days, P = 0.003), shorter gastrointestinal recovery time (4 days, P = 0.018) and a lower rate of postoperative ileus (14.6%, P = 0.005). The reduction in length of hospital stay, gastrointestinal recovery time and a lower rate of postoperative ileus was significant after controlling for other confounders on multivariable regression analysis. With the open approach, group C showed a significantly shorter length of hospital stay and gastrointestinal recovery time (P = 0.005, P = 0.001, respectively); however, in robotic cohorts, no significant differences were observed. There was no difference among groups in the 30-day readmission rate or postoperative complications. CONCLUSIONS: Patients undergoing radical cystectomy and managed by an Enhanced Recovery After Surgery protocol experience a significantly shorter length of hospital stay when receiving alvimopan as part of the protocol. Patients seem to derive the optimum benefits of alvimopan when it is used with an open approach; however, these benefits become less obvious with the robotic approach.

Effects of acetate on cerebral blood flow, systemic inflammation, and behavior in alcohol use disorder.

BACKGROUND: Alcohol use disorders (AUDs) are associated with altered regulation of physiological processes in the brain. Acetate, a metabolite of ethanol, has been implicated in several processes that are disrupted in AUDs including transcriptional regulation, metabolism, inflammation, and neurotransmission. To further understand the effects of acetate on brain function in AUDs, we investigated the effects of acetate on cerebral blood flow (CBF), systemic inflammatory cytokines, and behavior in AUD. METHODS: Sixteen participants with AUD were recruited from a nonmedical, clinically managed detoxification center. Each participant received acetate and placebo in a randomly assigned order of infusion and underwent 3T MR scanning using quantitative pseudo-continuous arterial spin labeling. Participants and the study team were blinded to the infusion. CBF values (ml/100 g/min) extracted from thalamus were compared between placebo and acetate using a mixed effect linear regression model accounting for infusion order. Voxel-wise CBF comparisons were set at threshold of p < 0.05 cluster-corrected for multiple comparisons, voxel-level p < 0.0001. Plasma cytokine levels and behavior were also assessed between infusions. RESULTS: Fifteen men and 1 woman were enrolled with Alcohol Use Disorders Identification Test (AUDIT) scores between 13 and 38 with a mean of 28.3 ± 9.1. Compared to placebo, acetate administration increased CBF in the thalamus bilaterally (Left: 51.2 vs. 68.8, p < 0.001; Right: 53.7 vs. 69.6, p = 0.001), as well as the cerebellum, brainstem, and cortex. Older age and higher AUDIT scores were associated with increases in acetate-induced thalamic blood flow. Cytokine levels and behavioral measures did not differ between placebo and acetate infusions. CONCLUSIONS: This pilot study in AUD suggests that during the first week of abstinence from alcohol, the brain's response to acetate differs by brain region and this response may be associated with the severity of alcohol dependence.

Influence of Weight Loss on Obesity-Associated Complications After Metabolic and Bariatric Surgery in Adolescents.

OBJECTIVE: Following metabolic and bariatric surgery (MBS), most adolescents experience weight loss and improvement of many obesity-associated complications (OACs). The relationship between weight loss and remission of OACs after MBS in adolescents has not been well described. METHODS: The Teen Longitudinal Assessment of Bariatric Surgery (Teen-LABS) is a multi-institutional prospective observational study of adolescents who underwent MBS between 2007 and 2012. Lower-weight-loss responders (LWLRs) were defined as having <20% total body weight loss (TBWL) and higher-weight-loss responders (HWLRs) were defined as having ≥20% TBWL at 5 years after MBS. The prevalence of OACs was compared at baseline and 5 years after MBS. RESULTS: Both LWLRs (n = 114) and HWLRs (n = 78) lost significant weight within the first year following MBS; however, the TBWL at 5 years for the LWLRs was 8.6% ± 9.5% compared with 33.8% ± 9.2% for the HWLRs. Those in the HWLR group were more likely to experience durable remission of composite dyslipidemia at 5 years, whereas there were no differences between groups in remission rates of all other OACs. CONCLUSIONS: Greater weight loss after MBS in adolescents was associated with greater remission of composite dyslipidemia; however, remission of other OACs was not dependent on major sustained weight loss.

Excess skin problems among adolescents after bariatric surgery.

BACKGROUND: Bariatric surgery results in significant and durable weight loss and improved health in severely obese adolescents. An important adverse consequence of the massive weight loss after bariatric surgery is excess skin and soft tissue. The prevalence and clinical characteristics of excess skin-related symptoms have been described in adults undergoing bariatric surgery but not in adolescents. Although the higher skin elasticity of adolescents may result in fewer excess skin problems compared with adults, this hypothesis remains untested. OBJECTIVES: The purpose of the present study was to describe the natural history of excess skin and its associated complications among severely obese adolescents undergoing bariatric surgery. SETTING: University Hospitals, United States. METHODS: We evaluated data from the Teen-Longitudinal Assessment of Bariatric Surgery cohort, a prospective, multiinstitutional study of adolescents (13-19 yr) undergoing bariatric surgery. Abdominal pannus severity (graded 0-5) and excess skin symptoms were evaluated preoperatively and for the first 5 years after bariatric surgery. RESULTS: Among the 217 study participants, 198 (90%) had an abdominal pannus and 16 (7%) reported pannus-related symptoms at the time of bariatric surgery. Preoperative symptoms included intertriginous infections (n = 12, 75%), recurrent cellulitis (n = 5, 31%), and superficial cutaneous ulcerations (n = 1, 6%). Participants with a higher pannus grade preoperatively experienced both a greater reduction in pannus severity (P < .0001) and a higher incidence of pannus-related symptoms (P = .002) postoperatively. Changes in pannus severity occurred during the first 24 months after bariatric surgery; mean pannus severity remained unchanged beyond 24 months. CONCLUSIONS: Severely obese adolescents who undergo bariatric surgery often present with an abdominal pannus at the time of surgery with associated symptoms. Higher preoperative pannus grade is associated with more pannus related symptoms after surgery. Counseling about need for body contouring surgery should be considered in this group.

Body contouring in adolescents after bariatric surgery.

BACKGROUND: Bariatric surgery leads to sustained weight loss and resolution of obesity-associated co-morbidities in severely obese adolescents. However, one consequence of massive weight loss is excess skin and soft tissue. Many details regarding the timing, outcomes, and barriers associated with body contouring surgery (BCS) in youth who have undergone bariatric surgery are unknown. OBJECTIVES: Describe the incidence and effect of BCS following bariatric surgery among adolescents. SETTING: University Hospitals. METHODS: Teen-Longitudinal Assessment of Bariatric Surgery is a prospective multi-institutional study of 242 adolescents who underwent bariatric surgery from 2007 to 2012. Utilization of BCS was analyzed in this population with comparison of anthropometrics and excess skin-related symptoms between those who did and those who did not undergo BCS. RESULTS: Among the 198 study participants with BCS data available, 25 (12.6%) underwent 41 body contouring procedures after bariatric surgery. The most common BCS was panniculectomy (n = 23). Presence of pannus-related symptoms at baseline and the magnitude of weight loss within the first year after bariatric surgery were independently associated with subsequent panniculectomy (P = .04 and P = .03, respectively). All adolescents who underwent panniculectomy experienced resolution of pannus-related symptoms. At 5 years after bariatric surgery, 74% of those who did not undergo panniculectomy reported an interest in the procedure, and 58% indicated that cost/insurance coverage was the barrier to obtaining BCS. CONCLUSION: Few adolescents who underwent bariatric surgery later underwent BCS procedures. Panniculectomy effectively treated pannus-related symptoms. Disparities in access to surgical care for adolescents who desire BCS warrants further investigation.

Collagen Allografts Compared With Autologous Tissue in Tympanoplasty.

OBJECTIVE: There are no direct comparisons between the success of collagen allografts versus traditional autografts for tympanic membrane (TM) repair. We sought to compare success rates in a large series of patients undergoing tympanoplasty using collagen allografts versus autologous tissues. STUDY DESIGN: Retrospective review. SETTING: Academic medical center. SUBJECTS AND METHODS: Single institution retrospective chart review was performed for adult subjects with TM perforation undergoing tympanoplasty. Demographic, clinical, and surgical data were collected. Statistical analysis was completed using Rstudio. Each factor was examined to assess effect on graft success rate using logistic regression. RESULTS: Two hundred sixty-five surgeries met criteria with four main grafting materials or combinations thereof. The overall graft success rate was 81.1% with failure rate of 18.9%. There was no significant association between failure rates and: age, sex, perforation cause, size, and location, primary or revision status, middle ear status (wet or dry), concomitant procedures (mastoidectomy or ossiculoplasty), presence of active cholesteatoma, or surgical technique. Although not statistically significant, the odds of success for perichondrium + cartilage were 7.5 times higher than collagen allografts (p = 0.07, 95% confidence interval [CI] = 0.81-69.6). The odds of success for the postauricular (odds ratio [OR] = 6.4) and transcanal approaches (OR = 24.8) were significantly greater than for endaural (p = 0.007 and p = 0.008, respectively). CONCLUSION: In tympanoplasty surgeries performed on patients with TM perforation, we found no statistically significant difference in graft failure rates between collagen allograft and other grafting materials or combinations, though the higher odds ratio of success with cartilage + perichondrium may be clinically relevant.