Upper Limits Of Agreement Research Articles

Do Measurements of Uterine Septum Using Three-Dimensional Ultrasound and Magnetic Resonance Imaging Agree?

ObjectiveTo evaluate the agreement between measurements of uterine septum by 3-D ultrasound (3-D US) and magnetic resonance imaging. MethodsFourteen women with a uterine septum underwent both a 3-D US and an MRI followed by hysteroscopic metroplasty in a tertiary care infertility clinic within a university teaching hospital. The agreement between 3-D US and MRI measurements of septum length (SL), septum width (SW) and the distance between fundal serosa and septal tip (SSD) was compared using the Bland Altman limit of agreement analysis. Results3-D US correctly identified all women who had a uterine septum identified with MRI. The mean difference in SL was 2.7mm (upper limit of agreement and lower limit of agreement were 10.3mm and −4.8mm, respectively). The mean difference in SW was 2.3mm (upper limit of agreement and lower limit of agreement of 10.4mm and −9.2mm, respectively). The SSD mean difference was 2.8mm (upper limit of agreement and lower limit of agreement of 10.6mm and −5mm, respectively). ConclusionsCategorical agreement in diagnosis was 100% and agreement between 3-D US and MRI measurements was good with narrow differences. Variations were unlikely to be greater than intra- and inter-observer variations anticipated in MRI readings. 3-D US can replace MRI for diagnosis and measurement of uterine septa.

Validity and reliability of the SPORTS score for shoulder instability.

athletes affected by shoulder instability cannot be judged solely according to the criteria used for non-athletes. In order to improve the assessment of shoulder instability surgery outcomes, the SPORTS score was tested in a cohort of athletes. ninety-eight athletes at an average follow-up of 4.6 years (range 1-9.2) after open or arthroscopic surgery for recurrent anterior shoulder instability were included in this study. The patients were asked to complete the SPORTS score questionnaire twice, with an interval of 2-3 weeks between the two assessments. The Bland-Altman method and the intra-class correlation coefficient were used to measure reliability. Criterion validity was assessed by calculating the Spearman correlation coefficient between the SPORTS score and the Western Ontario Shoulder Instability Index (WOSI) score, the Rowe score, the Oxford Shoulder Instability Score (OSIS), and the Subjective Shoulder Value (SSV). the SPORTS score showed excellent test-retest reliability. The systematic error between the first and the second assessment was 0.3 points (95% upper limit of agreement = 2.3 points). The criterion validity was found to be strong for the SPORTS score, which correlated best with the SSV and the "sport, recreation, and work" component of the WOSI score. The SPORTS score had an acceptable floor effect (8%). The ceiling effect was 46%, which was better than the ceiling effects seen with the Rowe, OSIS and WOSI scores. this study suggests that the SPORTS score is a valid score in the assessment of athletes after surgery for shoulder instability and that it adds important information to the currently available scores. Level III, diagnostic study of nonconsecutive patients.

Non-invasive cardiac output evaluation in postoperative cardiac surgery patients, using a new prolonged expiration-based technique

The gold standard methods to measure cardiac output (CO) are invasive and expose the patient to high risks of various complications. The aim of this study is to assess an innovative non-invasive method for CO monitoring in mechanically ventilated patients after cardiac surgery and its agreement with values obtained by thermodilution technique. Continuous monitoring of respiratory gas concentrations and airflow allows the estimation of CO through a newly developed algorithm derived from a modified version of the Fick equation. It consists of two phases: the first involves measurements during steady breathing state, and the second starts when a sudden perturbation into the carbon dioxide elimination process is introduced by a prolonged expiration. This prospective clinical study involved thirty-five adult patients, undergone cardiac surgery. The measurements were performed in curarized and haemodynamically stable patients, during the post-surgery recovery in intensive care unit. The study protocol, which lasted 1h for each patient, consisted of 20 measurements obtained by prolonged expiration-based method and 10 by thermodilution. The estimation of CO using the proposed method (COK) agreed with the thermodilution (COT) as demonstrated by: a low mean bias between COK and COT considering all patients (i.e., -0.11Lmin(-1)); a best fitting line having slope=0.98, r=0.81, p<0.0001; the lower and upper limits of agreement were -0.77 and +0.54Lmin(-1), respectively. COK shows a mean percentage error of 34%. In stable mechanically ventilated patients, undergone cardiac surgery, the proposed method is reliable if compared to the thermodilution. Considering the non-invasivity of the technique, further evaluations of its performances are encouraged.

Thoracic Staging in Lung Cancer: Prospective Comparison of 18F-FDG PET/MR Imaging and 18F-FDG PET/CT

Therapeutic decisions in non-small cell lung cancer (NSCLC) patients depend on the tumor stage. PET/CT with (18)F-FDG is widely accepted as the diagnostic standard of care. The purpose of this study was to compare a dedicated pulmonary (18)F-FDG PET/MR imaging protocol with (18)F-FDG PET/CT for primary and locoregional lymph node staging in NSCLC patients using histopathology as the reference. Twenty-two patients (12 men, 10 women; mean age ± SD, 65.1 ± 9.1 y) with histopathologically confirmed NSCLC underwent (18)F-FDG PET/CT, followed by (18)F-FDG PET/MR imaging, including a dedicated pulmonary MR imaging protocol. T and N staging according to the seventh edition of the American Joint Committee on Cancer staging manual was performed by 2 readers in separate sessions for (18)F-FDG PET/CT and PET/MR imaging, respectively. Results from histopathology were used as the standard of reference. The mean and maximum standardized uptake value (SUV(mean) and SUV(max), respectively) and maximum diameter of the primary tumor was measured and compared in (18)F-FDG PET/CT and PET/MR imaging. PET/MR imaging and (18)F-FDG PET/CT agreed on T stages in 16 of 16 of patients (100%). All patients were correctly staged by (18)F-FDG PET/CT and PET/MR (100%), compared with histopathology. There was no statistically significant difference between (18)F-FDG PET/CT and (18)F-FDG PET/MR imaging for lymph node metastases detection (P = 0.48). For definition of thoracic N stages, PET/MR imaging and (18)F-FDG PET/CT were concordant in 20 of 22 patients (91%). PET/MR imaging determined the N stage correctly in 20 of 22 patients (91%). (18)F-FDG PET/CT determined the N stage correctly in 18 of 22 patients (82%). The mean differences for SUV(mean) and SUV(max) of NSCLC in (18)F-FDG PET/MR imaging and (18)F-FDG PET/CT were 0.21 and -5.06. These differences were not statistically significant (P > 0.05). The SUV(mean) and SUV(max) measurements derived from (18)F-FDG PET/CT and (18)F-FDG PET/MR imaging exhibited a high correlation (R = 0.74 and 0.86, respectively; P < 0.0001). Size measurements showed an excellent correlation between (18)F-FDG PET/MR imaging and (18)F-FDG PET/CT (R = 0.99; P < 0.0001). The lower and upper limits of agreement between (18)F-FDG PET/CT and (18)F-FDG PET/MR imaging using Bland-Altman analysis were -2.34 to 3.89 for SUV(mean), -7.42 to 4.40 for SUV(max), and -0.59 to 0.83 for the tumor size, respectively. (18)F-FDG PET/MR imaging using a dedicated pulmonary MR imaging protocol, compared with (18)F-FDG PET/CT, does not provide advantages in thoracic staging in NSCLC patients.

Noninvasive hemoglobin measurement in pregnancy

Hemoglobin measurement is one of the most frequently requested laboratory tests in amaternity setting. Traditional laboratory estimation assesses hemoglobin at a given time point. However, recent advances enable the continuous and noninvasive measurement of total hemoglobin [1,2]. The ability to assess hemoglobin continuously is of particular value in an emergency setting, in the early detection of hemorrhage, and in the identification of cases that warrant intervention, fluid replacement, and blood transfusion. Rapid access to measurements via devices such as the SpHb Pulse CO-Oximeter (Masimo, Irvine, CA, USA) in a clinical outpatient setting also facilitates the identification of the need for additional blood investigations and the instigation of supplemental iron therapy earlier in pregnancy. The aim of the present study was to validate continuous and noninvasive hemoglobin assessment in an outpatient obstetric setting using the SpHb Pulse CO-Oximeter and to compare the valueswith traditional laboratory measurements of hemoglobin. Between August 2 and 31, 2010, 125 women were recruited from the prenatal clinic of the National Maternity Hospital, Dublin, Ireland, at the time of phlebotomy for standard prenatal laboratory hemoglobin estimation. The SpHb Pulse CO-Oximeter was calibrated and 3 noninvasive estimations of hemoglobin were taken and recorded, with consent. Approval was obtained from the institutional ethics committee. The comparison ofmeans between laboratory hemoglobin and SpHb estimation was carried out via t test and f test, as appropriate. A Bland– Altman plot was used to determine the accuracy and precision of the noninvasive test as an alternative to invasive testing in an outpatient clinical setting (Fig. 1). The mean difference between the 2 methods was 0.47 g/dL. The upper limit of agreement was 3.46 and the lower limit was −2.50. Seven (5.6%) of the 125 samples were outside these limits but only 1 result was outside the 95th confidence interval of the limits. The limits of agreement were sufficient to be confident that noninvasive hemoglobin assessment is accurate in the prenatal setting. The present study showed that noninvasive hemoglobin measurement from Pulse COOximetry provides clinically acceptable accuracy comparable to that of traditional hemoglobin testing. Anemia in pregnancy has implications for maternal, fetal, and neonatal wellbeing. The goal of early identification of anemic patients is to facilitate earlier intervention and prevention of serious sequelae. Prenatally, the SpHb Pulse CO-Oximeter could facilitate the earlier identification andmanagement of anemic patients because, traditionally, women in Ireland who are identified as being anemic are contacted by post following receipt of the blood report—a process that involves a variable time delay between identification and treatment. Further advantages of noninvasive continuous hemoglobin measurement in an obstetric setting include the potential for a more efficient patient triage system and, in a cost-conscious era, the possibility of limiting costly “out-of-hours” laboratory investigations. The identification of a subset of patients in any hospital population who require increased monitoring and early transfusion to avoid decompensation is the ideal.

Bioreactance is not reliable for estimating cardiac output and the effects of passive leg raising in critically ill patients

Bioreactance estimates cardiac output in a non-invasive way. We evaluated the ability of a bioreactance device (NICOM®) to estimate cardiac index (CI) and to track relative changes induced by volume expansion. In 48 critically ill patients, we measured CI estimated by the NICOM® device (CINicom) and by transpulmonary thermodilution (CItd, PiCCO2™ device) before and after a 500 ml saline infusion. Before volume expansion, we performed a passive leg raising (PLR) test and measured the changes it induced in CINicom and in pulse contour analysis-derived CI. Considering the values recorded before PLR and before and after volume expansion (n=144), the bias (lower and upper limits of agreement) between CItd and CINicom was 0.9 (-2.2 to 4.1) litre min(-1) m(-2). The percentage error was 82%. There was no significant correlation between the changes in CItd and CINicom induced by volume expansion (P=0.24). An increase in CI estimated by pulse contour analysis >9% during the PLR test predicted fluid responsiveness with a sensitivity of 84% (95% confidence interval 60-97%) and a specificity of 97% (95% confidence interval 82-100%). The area under the receiver operating characteristic curve constructed to test the ability of the PLR-induced changes in CINicom in predicting fluid responsiveness did not differ significantly from 0.5 (P=0.77). The NICOM® device cannot accurately estimate the cardiac output in critically ill patients. Moreover, it could not predict fluid responsiveness through the PLR test.

A clinical comparison between a non–invasive blood pressure monitor using high definition oscillometry (Memodiagnostic MD 15/90 Pro) and invasive arterial blood pressure measurement in anaesthetized dogs

ObjectiveTo compare high definition oscillometry (HDO) to invasive blood pressure measurement in anaesthetized dogs. Study designProspective, clinical trial. AnimalsFifty dogs weighing 1.95–79 kg (mean 23.5 kg). Materials and methodsAnaesthetic and peri–anaesthetic management was chosen according to each dog's physical status and anaesthetist's preference. Direct arterial blood pressure measurements were performed using a catheter placed in the dorsal pedal artery and an electronic pressure transducer connected to a multiparameter monitor. Non–invasive blood pressure measurements were performed using an appropriately sized cuff placed around the tail base. Comparisons between the two methods were made using Bland and Altman plots. The data are reported as mean bias (lower, upper limits of agreement). Further analysis was performed after separating the data into the following categories based on invasive mean arterial blood pressure (MAP): high (MAP > 100 mmHg), medium (70 mmHg < MAP < 100 mmHg) and low (MAP < 70 mmHg) blood pressure (BP). The two methods were compared as used clinically. ResultsEight hundred measurement pairs for invasive and HDO BP readings were compared. Overall, the HDO measured lower values for SAP and DAP but higher for MAP than the invasive method. The lowest bias (upper, lower limits of agreement) were obtained for MAP, −1 (−22, 19) mmHg. The biggest discrepancy between the methods was reflected by a large bias (limits of agreement) 5 (−34, 45) mmHg, was for SAP. The results for DAP were between those for SAP and MAP with a bias (limits of agreement) of 3 (−20, 27) mmHg. When the values were separated into the pressure range categories the HDO measured higher in the high, medium and low BP groups, with the exception of SAP in the low BP group. ConclusionsWhen considering the mean bias, the accuracy of HDO compared well with direct arterial blood pressure, but the precision was poor, as determined by wide limits of agreement. Clinical relevanceUsing trends and serial measurements rather than a single measurement for clinical decision making is recommended with both methods, when used as reported here.

Evaluation of cardiac output in intensive care using a non‐invasive arterial pulse contour technique (Nexfin®) compared with echocardiography

In this prospective study, cardiac output was measured in 38 intensive care unit patients before and after a fluid challenge, using both pulse contour analysis (Nexfin(®); BMEYE, Amsterdam, the Netherlands) and transthoracic echocardiography. The ability of the Nexfin device to detect significant changes in the velocity-time integral was evaluated. The pulse wave could not be detected by the Nexfin device in five patients (13%), leaving 33 patients for analysis. The Nexfin device adequately tracked changes in the velocity-time integral in 20 (61%) patients. Using a cut-off of a 10% increase in cardiac output estimated by the Nexfin or by echocardiography, the sensitivity of the Nexfin device to detect a response to fluid challenge was 47%, with specificity 81% and accuracy 64%. The percentage error between the Nexfin and echocardiography was 448%; lower limit of agreement -48% (95% CI -62 to -36%) and upper limit of agreement, 32% (95% CI 20-45%). We conclude that the Nexfin device does not adequately track changes in cardiac output in critically ill patients.

Native Acetabular Version: 3D CT Analysis of the Psoas Valley

Insufficient version has been demonstrated to be a significant factor in increasing metal-on-metal cup wear. Another implication is the impingement of the psoas tendon at the anatomical depression on the anterior acetabular rim, called the psoas valley. It is not known whether the psoas valley has any anatomical significance when measuring native version. The effect of this landmark on the measurement of acetabular version has not been assessed using 3D CT. Sixty five high resolution CT scans of non-diseased hips (performed for colonography) were used to measure the anatomical version angles of the bony acetabular rim. Our new method, using the psoas valley, was compared to the reference method, which used the full 320° of the acetabular rim. The measurement of acetabular version was highly reproducible between the methods. Both methods measured the angle of version over a wide range: 5° to 35° for males and 10° to 40° for females. There were no statistically significant differences between genders (p = 0.3670). The Bland-Altman 1.96 SD lower and upper limits of agreement between the two methods were +4.6° and -4.3°, respectively. Intra-observer and inter-observer reliability were high for the new method. This adds to our understanding of native bony anatomy, and specifically provides a landmark that 3D CT has demonstrated to be potentially useful in assessing native version.

Application of Bioimpedance Spectroscopy in Asian Dialysis Patients (ABISAD): serial follow-up and dry weight evaluation.

BackgroundMaintenance of the optimal fluid status in hemodialysis patients is still a challenging task in daily clinical practice. A bioelectric impedance technique has been applied for evaluation of hydration status in the dialysis population in recent years, but serial observations of its role in clinical dry weight determination are lacking. In this study, serial follow-up data of a body composition monitor based on bioimpedance spectroscopy (BCM-BIS) applied in dialysis patients were analyzed to define the technique's feasibility, precision and possible role in dry weight determination.MethodsBCM-BIS was applied monthly to 194 hemodialysis patients for 6 months. Intra-patient precision was analyzed. Bland–Altman analysis and repeated-measures analysis of variance (ANOVA) were used to define the relationship between the dry weights determined by BCM-BIS and by clinical judgment.ResultsThe coefficients of variation (CVs) of fluid parameters were <5%. Serial changes in dry weight differences were compared in groups with different post-dialysis hydration status and dry weight differences decreased gradually. Bland–Altman analysis revealed that the range of these differences was significantly narrower towards the latter part of the study. The upper limit of agreement with 95% confidence interval (CI) was 1.47 L and the lower limit was −3.02 L.ConclusionsBCM-BIS is precise and can be easily applied in the clinical setting. Discrepancy between the dry weights determined by BCM-BIS and by clinical judgment significantly decreased during the study. It is sensitive in dry weight determination, especially for those patients with obvious over-hydration (OH) by BCM-BIS. Patients with post-dialysis OH results beyond some critical values (>1.5 L or <−3 L) should be closely monitored.

Correlation between end-tidal and arterial carbon dioxide partial pressure in patients undergoing craniotomy

Background and Objective: Both end-tidal carbon dioxide pressure (ETCO2) is used routinely as an indicator of arterial partial pressure of carbon dioxide (PaCO2) and thus adequacy of ventilation. Accurate determination of the PaCO2 level in neuroanesthesia is quite important because of  its effect on cerebral blood flow and also hyperventilation is often used to reduce intracranial pressure in neurosurgical patients. This study was aimed to evaluate the relationship between ETCO2 and arterial PaCO2 in neurosurgical patients undergoing craniotomy to assess the predictive value of ETCO2 as an indicator of PaCO2 level. Methods: Forty-five consecutive adult patients with inclusion criteria, scheduled to undergo elective craniotomy surgery were enrolled in this prospective study. Measurements of PaCO2 and ETCO2 were performed at three different intervals: Time 1: 10 min after induction of general anesthesia; time 2: after cranium opening prior to dural incision; and at time 3: start of dural closure. All patients received the same anesthetic agent (propofol, sufentanil, atracurium, oxygen). Data were initially analyzed using Pearson’s Correlation to assess the relationship between PaCO2 and ETCO2 at different stages of the operation. A p-value (P) of less than 0.05 was considered significant. The agreement between the measures of CO2 was assessed using Bland-Altman method, where mean difference and average between PaCO2 and ETCO2 were calculated. The 95% confidence intervals for the lower and upper limits of agreement were presented. . Results: A total of 44 patients, aged 18 to 65 years, ASA grades 1 and 2 were participated in the study. Mean difference, standard deviation and correlation coefficient of the parameters were calculated for three time periods. The values for PaCO2, ETCO2, (PaCO2- ETCO2), and correlation coefficient for 10 min after anesthetic induction, prior to dural incision, and start of dural closure were 35.4 ± 3.2, 32.1 ± 3.2, 3.8 ± 2.1, and 0.565, 36.2 ± 3.1, 32.6 ± 3.2,4.8 ± 3.1, and 0.574, and 36.7 ± 2.4, 33 ± 3.2,3.8 ± 2.3, and 0.627, respectively (p< 0.01 for all analyses). The greatest mean difference occurred just prior to dural incision. The lowest mean difference was observed at 10 min post-anesthetic induction. Conclusion: to the present study was aimed to correlate between End-tidal and arterial carbon dioxide partial pressure in neurosurgical patients undergoing craniotomy. Findings of this study showed that ETCO2 consistently underestimates the value of PaCO2 during craniotomy indicating that ETCO2 value can be used instead of PaCO2.

Clinical evaluation of a new technique to monitor return electrode skin temperature during radiofrequency ablation

Return electrode burns occur occasionally in cardiac radiofrequency ablation and more frequently in tumor radiofrequency ablation. A return electrode incorporating a thermochromic liquid crystal (TLC) layer, which changes color with temperature, has been shown in sheep studies to accurately indicate underlying skin temperature. We aimed to validate the accuracy of TLC-coated return electrodes in indicating skin temperature in the clinical setting of cardiac radiofrequency ablation. The top layer of a standard return electrode was replaced with TLC. Fluoro-optic thermometer (FOT) probes were laid on the skin side of the return electrode, which was then placed on the left lateral mid-thigh of 18 patients (mean age = 61 ± 12 years, 12 men) undergoing cardiac radiofrequency ablation. Return electrode photographs were taken when FOT temperature exceeded 35 °C. TLC color changes, observed in 11 patients, were converted to temperature and compared with FOT temperature. TLC temperature correlated well with FOT temperature (Pearson's coefficient = 0.97 ± 0.03). Bland-Altman analysis showed good agreement (mean temperature difference = -0.04 ± 0.08 °C, upper limit of agreement = 0.11 ± 0.005 °C, lower limit of agreement = -0.19 ± 0.005 °C). The maximum FOT temperature recorded was 39.6 °C. There was no thermal injury at the return electrode site on any patients, when assessed immediately after and the day following the procedure. TLC-coated return electrodes accurately indicate underlying skin temperature in cardiac radiofrequency ablation and may help prevent burns. This technology might be essential in high energy radiofrequency ablation.

Reproducibility and accuracy of non-invasive measurement of infarct size in mice with high-resolution PET/CT

BackgroundThis study assessed the reproducibility and accuracy of 2-deoxy-2[18F]fluoro-d-glucose (18F-FDG) for non-invasive quantification of myocardial infarct size in mice by a high-resolution positron emission tomography (PET)/computed tomography (CT) system. Methods and ResultsMice were studied by 18F-FDG PET/CT 1 week after induction of myocardial infarction by permanent coronary occlusion or sham procedure. In a subset of mice, PET/CT was repeated 2 days apart to assess the reproducibility of infarct size measurements. Histological analysis was used as reference method to validate imaging data. The average difference in infarct size measurements between the first and the second study was −0.42% ± 2.07% (95% confidence interval −2.6 to 1.75) with a repeatability coefficient of 4.05%. At Bland-Altman analysis, the lower and upper limits of agreement between the two repeated studies were −4.46% and 3.63%, respectively, and no correlation between difference and mean was found (P = .89). The concordance correlation coefficient was 0.99 (P < .001) and the intraclass coefficient of correlation was 0.99. A high correlation between PET/CT and histology was found for measurement of infarct size (P < .001). Using Bland-Altman analysis, the mean difference in infarct size measurement (PET/CT minus histology) was 1.9% (95% confidence interval 0.94% to 2.86%). ConclusionsIn a mice model of permanent coronary occlusion non-invasive measurement of infarct size with high-resolution 18F-FDG, PET/CT has excellent reproducibility and accuracy. These findings support the use of this methodology in serial studies.

The estimation of cardiac output by the Nexfin device is of poor reliability for tracking the effects of a fluid challenge

IntroductionThe Nexfin device estimates arterial pressure by the volume clamp method through a finger pneumatic cuff. It also allows to estimate cardiac index (CInoninv) by pulse contour analysis of the non-invasive arterial pressure curve. We evaluated the ability of the device to track changes in cardiac index induced by a fluid challenge.MethodsWe included 45 patients for whom a volume expansion (500 mL of saline infused over 30 min) was planned. The volume expansion-induced changes in cardiac index measured by transpulmonary thermodilution (CIinv, PiCCO device) and in CInoninv were recorded.ResultsIn seven patients, the Nexfin could not record the arterial curve due to finger hypoperfusion. Considering both the values obtained before and after volume expansion (n = 76 pairs of measurements), the bias (lower and upper limits of agreement) between CIinv and CInoninv was 0.2 (-1.8 to 2.2) L/min/m2. The mean change in CInoninv was 10 ± 11%. The percentage error of CInoninv was 57%. The correlation between the changes in CIinv and CInoninv observed during volume expansion was significant (P = 0.0002) with an r2 = 0.31.ConclusionsThe estimation of CI by the Nexfin device in critically ill patients is not reliable, neither for estimating absolute values of CI nor for tracking its changes during volume expansion.

Accuracy of intraocular pressure measurements in dogs using two different tonometers and plano therapeutic soft contact lenses

To compare and evaluate the accuracy of intraocular pressure (IOP) measured through a therapeutic contact lens, using applanation (TonoPen XL(®)) and rebound (TonoVet(®)) tonometers in enucleated dog eyes. A total of 30 enucleated eyes from 15 beagle dogs. To measure accurate IOP, the anterior chamber of each enucleated eye was cannulated with two 26-gauge needles and two polyethylene tubes were connected vertically to an adjustable reservoir bag of normal saline and a pressure transducer. IOP was measured by the TonoPen XL(®) followed by the TonoVet(®) without a contact lens. After a contact lens was applied to the cornea, IOP was re-measured in the same order. Three consecutive IOP measurements were performed using both tonometers. Without the contact lens, the IOP values obtained by both tonometers correlated well according to the regression analysis (TonoVet(®): γ(2) = 0.98, TonoPen XL(®): γ(2) = 0.97, P < 0.001). The TonoPen XL(®) consistently underestimated values as transducer IOP increased; however, IOP values measured with the TonoPen XL(®) were in close agreement and were less variable than those determined with the TonoVet(®) when a contact lens was applied to the cornea. Bland-Altman analysis was used to determine the lower and upper limits of agreement (TonoVet(®): -29.7 and +21.1 mmHg, TonoPen XL(®): -3.9 and +3.6 mmHg) between the two devices. This study suggests that the TonoPen XL(®) is a useful tonometer for dogs wearing therapeutic contact lenses, and importantly, contact lenses would not need to be removed prior to IOP measurement.

Accuracy and inter-observer reliability of visual estimation compared to clinical goniometry of the elbow

To test the hypothesis that visual estimation by a trained observer is as accurate and reliable as clinical goniometry for measuring elbow range of motion. Instrument validity and inter-observer reliability of visual estimation was evaluated on a consecutive series of 50 elbow contractures. Four observers with different levels of elbow experience first estimated extension and flexion of the contracted elbows and then measured them with a blinded goniometer. Instrument validity for visually-based goniometry was extremely high. ICC scores were 0.97 for both extension and flexion estimations. Systematic error was negligible (1°) with upper limits of agreement being 9° (95% CI: 7°-11°) and 8° (95% CI: 6°-10°), respectively, for extension and flexion. For the expert surgeon, 92% of the visual estimates were within 5° of the value obtained by clinical goniometry. Between experienced observers (elbow surgeon and physician assistant), the ICC's were very high-0.96 for extension and 0.93 for flexion. The systematic errors were low, from -1° to 1° with upper limit of agreement being 11° (95% CI: 8°-14°). However, agreement was poor between an inexperienced study coordinator and the others (ICC's: 0.51-0.38, systematic errors: 8°-18°, upper limit of agreement: 32°-40°). The accuracy of the visual estimations made by the experienced elbow surgeon was as good as the measurements taken with a goniometer by the physician assistant or the clinical fellow and better than those taken by an inexperienced study coordinator. The trained human eye is highly capable of accurately estimating the range of motion of the elbow, compared to conventional clinical goniometry, depending on the experience of the observer. Diagnostic study, Level II.

Variation between hospitals in surgical margins after first breast-conserving surgery in the Netherlands

Surgical margin status after first breast-conserving surgery (BCS) is used as a quality indicator of breast cancer care in the Netherlands. The aim is to describe the variation in surgical margin status between hospitals. 7,345 patients with DCIS or invasive cancer (T1-2,N0-1,M0) diagnosed between July 1, 2008, and June 30, 2009, who underwent BCS as first surgery, were selected from the Netherlands Cancer Registry. Patients were treated in 96 hospitals. Maximum target values were 30% 'focally positive' or 'more than focally positive' for DCIS and 10% 'more than focally positive' for invasive carcinoma. Results per hospital are presented in funnel plots. For invasive carcinoma, multivariate logistic regression was used to adjust for case mix. Overall 28.5% (95% CI: 25.5-31.4%) of DCIS and 9.1% (95% CI: 8.4-9.8%) of invasive carcinoma had positive margins. Variation between hospitals was substantial. 6 and 10 hospitals, respectively, for DCIS and invasive cancer showed percentages above the upper limit of agreement. Case mix correction led to significant different conclusions for 5 hospitals. After case mix correction, 10 hospitals showed significant higher rates, while 7 hospitals showed significant lower rates. High rates were not related to breast cancer patient volume or type of hospital (teaching vs. non-teaching). Higher rates were related to hospitals where the policy is to aim for BCS instead of mastectomy. The overall percentage of positive margins in the Netherlands is within the predefined targets. The variation between hospitals is substantial but can be largely explained by coincidence. Case mix correction leads to relevant shifts.

Validity and reliability of the SPORTS score

Successful outcomes for an athlete usually consist of returning to their sport. The Subjective Patient Outcome for Return to Sports (SPORTS) score has been recently proposed as an easy to use score for evaluating an athlete's ability to return to their sport. The aim of this study was to test the reliability and validity of the SPORTS score in athletes 5-10 years after anterior cruciate ligament reconstruction. A total of 47 athletes (average age 30, range 15-45), 5-10 years, after an anterior cruciate reconstruction were included in this study. Athletes were asked to complete the SPORTS score with an intermediate period of 2 weeks in order to measure reliability by using the Bland-Altman method and the ICC score. The criterion validity was assessed by calculating the Spearman correlation coefficient between the SPORTS score and Lysholm score, KOOS score and the SF-36. The SPORTS score showed excellent reliability (ICC = 0.967). The systematic error was 0 points (95% upper limit of agreement = 1.8 points). A strong correlation was found between the SPORTS score and the sports and recreation component on the KOOS score (r = 0.55, P < 0.001). The floor effect was 9% and the ceiling effect 32%. This study suggests that the SPORTS score is a valid and reliable tool to assess and quantify return to sport.

Does femoral venous pressure measurement correlate well with intrabladder pressure measurement? A multicenter observational trial

To investigate if femoral venous pressure (FVP) measurement can be used as a surrogate measure for intra-abdominal pressure (IAP) via the bladder. This was a prospective, multicenter observational study. IAP and FVP were simultaneously measured in 149 patients. The effect of BMI on IAP was investigated. The incidences of intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) were 58 and 7% respectively. The mean APACHE II score was 22±10, SAPS 2 score 42±20, and SOFA score 9±4. The mean IAP was 11.2±4.5mmHg versus 12.7±4.7mmHg for FVP. The bias and precision for all measurements were -1.5 and 3.6mmHg respectively with the lower and upper limits of agreement being -8.6 and 5.7. When IAP was above 20mmHg, the bias between IAP and FVP was 0.7 with a precision of 2.0mmHg (lower and upper limits of agreement -3 and 4.6 respectively). Excluding those with ACS, according to the receiver operating curve analysis FVP=11.5mmHg predicted IAH with a sensitivity and specificity of 84.8 and 67.0% (AUC of 0.83 (95% CI 0.81-0.86) with P<0.001). FVP=14.5mmHg predicted IAP above 20mmHg with a sensitivity of 91.3% and specificity of 68.1% (AUC 0.85 (95% CI 0.79-0.91), P<0.001). Finally, at study entry, the mean IAP in patients with a BMI less then 30kg/m(2) was 10.6±4.0mmHg versus 13.8±3.8mmHg in patients with a BMI≥30kg/m(2) (P<0.001). FVP cannot be used as a surrogate measure of IAP unless IAP is above 20mmHg.

Development and validation of a timed urinary collection system for use in the cat

The aim of the study was to develop and validate a feline urinary collection system for accurate 24 h urine output measurement and glomerular filtration rate (GFR) evaluation. We hypothesized that precise identification of urination time improves the accuracy of the collection system. In a group of nine cats, urinary volume and micturition times were repeatedly recorded for up to 48 h using purpose-built collection trays containing a temperature data logger. Collection time was determined both with and without using the data loggers on 22 occasions and agreement between estimated 24 h urine outputs obtained with the two calculation methods was evaluated. GFR was repeatedly measured by endogenous urinary creatinine clearance on three occasions. Twenty-four-hour urine output was measured in 98.5% of the attempted collections (300 cat-sampling days). Sensitivity and specificity of the detection system were 97.8% and 100%, respectively. Mean 24 h urine output was 12.4 ± 4.94 mL/kg/day and mean intra-cat between-days coefficient of variation (CV) was 16.6 ± 5.6% when data loggers were used. The absolute relative volume error between the two calculation methods ranged from 0% to 131%. Median absolute relative [interquartile range] error was 9.1% [3.25-19.8]. Bias was -1.3% and lower and upper limits of agreement were -39.7% and 35.2%, respectively. Mean estimated GFR was lower than previously reported with comparable urinary clearance methods (1.92 ± 0.37 mL/min/kg) and mean within-cat CV was 12 ± 6.9%. The system was simple in design, readily affordable, allowed normal micturition behaviour and reduced intra-animal variability in 24 h feline urine collection.