Predictors of Patient-Reported Pain and Functional Outcomes Over 10 Years After Primary Total Knee Arthroplasty: A Prospective Cohort Study.

Background This study aimed to identify preoperative predictors of patient-reported outcomes after total knee replacement (TKR) and to investigate their association with the outcomes over time. Methods We used data from 2,080 patients from the Knee Arthroplasty Trial (KAT) who received primary TKR in the UK between July 1999 and January 2003. The primary outcome measure was the Oxford Knee Score (OKS) collected annually over 10 years after TKR. Preoperative predictors included a range of patient characteristics and clinical conditions. Mixed-effects linear regression model analysis of repeated measurements was used to identify predictors of OKS overall score, pain and function subscale scores over 10 years, separately. Results Worse preoperative OKS score, worse mental well-being, BMI>35 kg/m^2, living in the most deprived areas, higher American Society of Anaesthesiologists grade, presence of comorbidities, and history of previous knee surgery were associated with worse OKS overall score over 10 years after surgery. The same predictors were identified for pain and function subscale scores, and for both long-term (10 years) and short-/mid-term outcomes (1 and 5 years). However, fitted models explained more variations in function and shorter-term outcomes than in pain and longer-term outcomes, respectively. Conclusion The same predictors were identified for pain and functional outcomes over both short-tomedium term and long term after TKR. Within the factors identified, functional and shorter-term outcomes were more predictable than pain and longer-term outcomes, respectively. Regardless of their preoperative characteristics, on average, patients achieved substantial improvement in pain over time, though improvement for function was less prominent. </p

Atmospheric Heating and Wind Acceleration: Results for Cool Evolved Stars based on Proposed Processes

A chromosphere is a universal attribute of stars of spectral type later than ~F5. Evolved (K and M) giants and supergiants (including the zeta Aurigae binaries) show extended and highly turbulent chromospheres, which develop into slow massive winds. The associated continuous mass loss has a significant impact on stellar evolution, and thence on the chemical evolution of galaxies. Yet despite the fundamental importance of those winds in astrophysics, the question of their origin(s) remains unsolved. What sources heat a chromosphere? What is the role of the chromosphere in the formation of stellar winds? This chapter provides a review of the observational requirements and theoretical approaches for modeling chromospheric heating and the acceleration of winds in single cool, evolved stars and in eclipsing binary stars, including physical models that have recently been proposed. It describes the successes that have been achieved so far by invoking acoustic and MHD waves to provide a physical description of plasma heating and wind acceleration, and discusses the challenges that still remain.Comment: 46 pages, 9 figures, 1 table; modified and unedited manuscript; accepted version to appear in: Giants of Eclipse, eds. E. Griffin and T. Ake (Berlin: Springer

Ethnic and gender differences in applicants' decision-making processes: An application of the theory of reasoned action

Contains fulltext : 54483.pdf (publisher's version ) (Closed access)11 p

Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc

Sudden cardiac death prediction in arrhythmogenic right ventricular cardiomyopathy: a multinational collaboration

Background:Arrhythmogenic right ventricular cardiomyopathy (ARVC) is associated with ventricular arrhythmias (VA) and sudden cardiac death (SCD). A model was recently developed to predict incident sustained VA in patients with ARVC. However, since this outcome may overestimate the risk for SCD, we aimed to specifically predict life-threatening VA (LTVA) as a closer surrogate for SCD.Methods:We assembled a retrospective cohort of definite ARVC cases from 15 centers in North America and Europe. Association of 8 prespecified clinical predictors with LTVA (SCD, aborted SCD, sustained, or implantable cardioverter-defibrillator treated ventricular tachycardia >250 beats per minute) in follow-up was assessed by Cox regression with backward selection. Candidate variables included age, sex, prior sustained VA (>= 30s, hemodynamically unstable, or implantable cardioverter-defibrillator treated ventricular tachycardia; or aborted SCD), syncope, 24-hour premature ventricular complexes count, the number of anterior and inferior leads with T-wave inversion, left and right ventricular ejection fraction. The resulting model was internally validated using bootstrapping.Results:A total of 864 patients with definite ARVC (40 +/- 16 years; 53% male) were included. Over 5.75 years (interquartile range, 2.77-10.58) of follow-up, 93 (10.8%) patients experienced LTVA including 15 with SCD/aborted SCD (1.7%). Of the 8 prespecified clinical predictors, only 4 (younger age, male sex, premature ventricular complex count, and number of leads with T-wave inversion) were associated with LTVA. Notably, prior sustained VA did not predict subsequent LTVA (P=0.850). A model including only these 4 predictors had an optimism-corrected C-index of 0.74 (95% CI, 0.69-0.80) and calibration slope of 0.95 (95% CI, 0.94-0.98) indicating minimal over-optimism.Conclusions:LTVA events in patients with ARVC can be predicted by a novel simple prediction model using only 4 clinical predictors. Prior sustained VA and the extent of functional heart disease are not associated with subsequent LTVA events.Cardiolog

Sudden Cardiac Death Prediction in Arrhythmogenic Right Ventricular Cardiomyopathy: A Multinational Collaboration

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is associated with ventricular arrhythmias (VA) and sudden cardiac death (SCD). A model was recently developed to predict incident sustained VA in patients with ARVC. However, since this outcome may overestimate the risk for SCD, we aimed to specifically predict life-threatening VA (LTVA) as a closer surrogate for SCD. METHODS: We assembled a retrospective cohort of definite ARVC cases from 15 centers in North America and Europe. Association of 8 prespecified clinical predictors with LTVA (SCD, aborted SCD, sustained, or implantable cardioverter-defibrillator treated ventricular tachycardia >250 beats per minute) in follow-up was assessed by Cox regression with backward selection. Candidate variables included age, sex, prior sustained VA (≥30s, hemodynamically unstable, or implantable cardioverter-defibrillator treated ventricular tachycardia; or aborted SCD), syncope, 24-hour premature ventricular complexes count, the number of anterior and inferior leads with T-wave inversion, left and right ventricular ejection fraction. The resulting model was internally validated using bootstrapping. RESULTS: A total of 864 patients with definite ARVC (40±16 years; 53% male) were included. Over 5.75 years (interquartile range, 2.77-10.58) of follow-up, 93 (10.8%) patients experienced LTVA including 15 with SCD/aborted SCD (1.7%). Of the 8 prespecified clinical predictors, only 4 (younger age, male sex, premature ventricular complex count, and number of leads with T-wave inversion) were associated with LTVA. Notably, prior sustained VA did not predict subsequent LTVA (P=0.850). A model including only these 4 predictors had an optimism-corrected C-index of 0.74 (95% CI, 0.69-0.80) and calibration slope of 0.95 (95% CI, 0.94-0.98) indicating minimal over-optimism. CONCLUSIO

A new prediction model for ventricular arrhythmias in arrhythmogenic right ventricular cardiomyopathy

AIMS: Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVC) is characterized by ventricular arrhythmias (VAs) and sudden cardiac death (SCD). We aimed to develop a model for individualized prediction of incident VA/SCD in ARVC patients. METHODS AND RESULTS: Five hundred and twenty-eight patients with a definite diagnosis and no history of sustained VAs/SCD at baseline, aged 38.2 ± 15.5 years, 44.7% male, were enrolled from five registries in North America and Europe. Over 4.83 (interquartile range 2.44-9.33) years of follow-up, 146 (27.7%) experienced sustained VA, defined as SCD, aborted SCD, sustained ventricular tachycardia, or appropriate implantable cardioverter-defibrillator (ICD) therapy. A prediction model estimating annual VA risk was developed using Cox regression with internal validation. Eight potential predictors were pre-specified: age, sex, cardiac syncope in the prior 6 months, non-sustained ventricular tachycardia, number of premature ventricular complexes in 24 h, number of leads with T-wave inversion, and right and left ventricular ejection fractions (LVEFs). All except LVEF were retained in the final model. The model accurately distinguished patients with and without events, with an optimism-corrected C-index of 0.77 [95% confidence interval (CI) 0.73-0.81] and minimal over-optimism [calibration slope of 0.93 (95% CI 0.92-0.95)]. By decision curve analysis, the clinical benefit of the model was superior to a current consensus-based ICD placement algorithm with a 20.6% reduction of ICD placements with the same proportion of protected patients (P < 0.001). CONCLUSION: Using the largest cohort of patients with ARVC and no prior VA, a prediction model using readily available clinical parameters was devised to estimate VA risk and guide decisions regarding primary prevention ICDs (www.arvcrisk.com)

Determinants of revision and functional outcome following unicompartmental knee replacement.

SummaryObjectiveUnicompartmental Knee Replacement (UKR) has important advantages over total knee replacement (TKR) but has a higher revision rate. Outcomes vary between centres, suggesting that risk factors for revision may be modifiable with changes to patient selection or operative technique. The objective of this study was to determine factors affecting revision, patient-reported outcome and satisfaction following UKR.Method25,982 cases from three national databases were analysed. Multilevel multivariable regression models were used to examine the effect of patient and surgical factors on implant survival, patient-reported outcome and satisfaction at 6 months and 8 years following UKR.ResultsOf the 25,982 cases, 3862 (14.9%) had pre-operative and 6-month Oxford Knee Scores (OKS). Eight-year survival was 89.1% (95% confidence intervals (CI) 88.3–89.9). OKS increased from 21.9 (SD 7.6) to 37.5 (SD 9.5). Age (Hazard ratio (HR) 0.96 (95% CI 0.96–0.97) per year), male gender (HR 0.86 (95% CI 0.76–0.96)), unit size (HR 0.92 (95% CI 0.86–0.97) per case up to 40 cases/year) and operating surgeon grade (HR 0.78 (95% CI 0.67–0.91) if consultant) predicted improved implant survival. Older patients (≥75 years), and those with lower deprivation levels had superior OKS and satisfaction (adjusted mean difference 0.14 (95% CI 0.09–0.20) points per year of age and 0.93 (95% CI 0.60–1.27) per quintile of deprivation). Ethnicity, anxiety and co-morbidities also affected patient-reported outcome.ConclusionsThis study has identified important predictors of revision and patient-reported outcome following UKR. Older patients, who are least likely to be offered UKR, may derive the greatest benefits. Improved understanding of these factors may improve the long-term outcomes of UKR

The aesthetic outcome of surgical correction for sagittal synostosis can be reliably scored by a novel method of preoperative and postoperative visual assessment.

BACKGROUND: Aims of surgical correction for isolated sagittal synostosis are functional and aesthetic. Multiple surgical techniques exist; however, reliable assessment of aesthetic outcome is poorly documented, limiting direct comparisons. The pinched appearance of the temporal regions is particularly challenging to correct. A visual analogue scale was designed to grade skull shape in patients who had total or subtotal calvarial remodeling for isolated sagittal synostosis. METHODS: Twenty-two assessors graded preoperative and postoperative photographs from 42 consecutive cases of sagittal synostosis under a single surgeon. Five aspects were graded (i.e., narrow elongated skull, frontal bossing, temporal pinching, occipital bullet, and overall shape) from 0 (normal) to 100 (severe). Interobserver and intraobserver agreement were analyzed by calculating within-subject standard deviation, coefficient of variation, and intraclass correlation coefficient. Linear regression analysis determined predictors of outcome. RESULTS: Surgery improved outcome dramatically across all five aspects of skull shape, with a 72.6 to 76.4 percent decrease in severity score. Improvements in severity score were greater after total calvarial remodeling, and type of calvarial remodeling (total versus subtotal) was an independent predictor of outcome in all aspects of skull shape (p≤0.001). Temporal pinching was improved in a subset of patients who also had onlay bone grafts in this region. CONCLUSIONS: Calvarial remodeling is a powerful technique for improving skull shape. A panel can detect gross and subtle aesthetic changes after surgical correction of sagittal synostosis using a visual analogue scale, with moderate interobserver and intraobserver agreement. This provides a tool for future outcome assessment. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV