Per Liv

Is what you see what you get? Standard inclinometry of set upper arm elevation angles

Previous research suggests inclinometers (INC) underestimate upper arm elevation. This study was designed to quantify possible bias in occupationally relevant postures, and test whether INC performance could be improved using calibration. Participants were meticulously positioned in set arm flexion and abduction angles between 0° and 150°. Different subject-specific and group-level regression models comprising linear and quadratic components describing the relationship between set and INC-registered elevation were developed using subsets of data, and validated using additional data. INC measured arm elevation showed a downward bias, particularly above 60°. INC data adjusted using the regression models were superior to unadjusted data; a subject-specific, two-point calibration based on measurements at 0° and 90° gave results closest to the true set angles. Thus, inclinometer measured arm elevation data required calibration to arrive at true elevation angles. Calibration to a common measurement scale should be considered when comparing arm elevation data collected using different methods.

Hypertrophic Cardiomyopathy and Implantable Defibrillators in Sweden: Inappropriate Shocks and Complications Requiring Surgery.

The expanded use of implantable cardioverter‐defibrillators (ICDs) to prevent sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM) based on risk stratification in individuals without known previous ventricular arrhythmia is justified by an acceptable risk of device‐related adverse events. Such complications, leading to surgical procedures or inappropriate electrical shocks, may impact mortality, morbidity, quality of life, and cost‐effectiveness.

Causes of death and mortality in hypertrophic cardiomyopathy patients with implantable defibrillators in Sweden.

Aims Implantable defibrillators (ICDs) successfully terminate ventricular arrhythmias in hypertrophic cardiomyopathy (HCM), protect against bradycardia, and monitor atrial arrhythmias. This may alter the natural history and causes of death. Methods This nationwide observational longitudinal retrospective study of all HCM patients implanted during 1995–2012 obtained data from the Swedish ICD Registry, the National Patient Register, the Cause of Death Register, and were validated by review of medical records. Results Of 342 patients (mean age 51.8 years, 70.8% males), 45 died during a total follow-up of 1847 years (mean 5.4 years). Mean age at death was 68.2 years (range 21–83 years; 12 were ≥75 years). Mean follow-up time among the deceased was 4.9 years (quartiles 1.4–7.4 years). All-cause mortality was higher in HCM patients compared with the age and sex-matched Swedish general population (standardized mortality ratio 3.4; 95% confidence interval 2.4–4.5; Pu200a<u200a0.001). Main cause of death was heart failure (nu200a=u200a27), stroke (nu200a=u200a5), cancer (nu200a=u200a3), myocardial infarction (nu200a=u200a2), sepsis (nu200a=u200a2), and others (nu200a=u200a4). Two patients died suddenly, one after the ICD was turned off because of inappropriate shocks, and one patient whose device system was removed after infection. HCM was the main cause of death in 76% of the cases, mainly because of progressive heart failure. Conclusion For HCM patients, ICDs almost eliminate premature arrhythmic death and result in a shift to heart failure as the cause of death in the majority of cases. Still, mortality in HCM patients remains elevated and management of heart failure and comorbidities must be improved to increase survival.

A novel method for superimposition and measurements on maxillary digital 3D models-studies on validity and reliability.

BackgroundnSerial 3D models can be used to analyze changes, but correct superimposition is crucial before measurements can be assessed. Earlier studies show that every palatal structure changes due to growth or treatment. Here, we describe a new method that uses an algorithm-based analysis to perform superimpositions and measurements in maxillary 3D models. This method can be used to identify deformations. In a second step, only unchanged areas are used for superimposition.nnnObjectivesnThis study investigates the validity and reliability of this novel method.nnnMethodsnDigital 3D models from 16 cases were modified by an independent 3D engineer to simulate space closure and growth. True values for tooth movements were available as reference. Measurements and repeated measurements were performed by four observers.nnnResultsnThe total tooth movement had an absolute mean error of 0.0225 mm (SD 0.03). The intraclass correlation coefficient (ICC) was 0.9996. Rotational measurements had an absolute mean error of 0.0291 degrees (SD 0.04 degrees) and an ICC of 0.9999.nnnLimitationsnSerial models need to be taken with a moderate interval (1 to 2 years). Obvious changed areas in the palate need to be cropped before processing the models.nnnConclusionnThe tested method is valid and reliable with excellent accuracy and precision even when changes through growth or orthodontic treatment occur.

A Comparison of Two Strategies for Building an Exposure Prediction Model.

Cost-efficient assessments of job exposures in large populations may be obtained from models in which true exposures assessed by expensive measurement methods are estimated from easily accessible and cheap predictors. Typically, the models are built on the basis of a validation study comprising true exposure data as well as an extensive collection of candidate predictors from questionnaires or company data, which cannot all be included in the models due to restrictions in the degrees of freedom available for modeling. In these situations, predictors need to be selected using procedures that can identify the best possible subset of predictors among the candidates. The present study compares two strategies for selecting a set of predictor variables. One strategy relies on stepwise hypothesis testing of associations between predictors and exposure, while the other uses cluster analysis to reduce the number of predictors without relying on empirical information about the measured exposure. Both strategies were applied to the same dataset on biomechanical exposure and candidate predictors among computer users, and they were compared in terms of identified predictors of exposure as well as the resulting model fit using bootstrapped resamples of the original data. The identified predictors were, to a large part, different between the two strategies, and the initial model fit was better for the stepwise testing strategy than for the clustering approach. Internal validation of the models using bootstrap resampling with fixed predictors revealed an equally reduced model fit in resampled datasets for both strategies. However, when predictor selection was incorporated in the validation procedure for the stepwise testing strategy, the model fit was reduced to the extent that both strategies showed similar model fit. Thus, the two strategies would both be expected to perform poorly with respect to predicting biomechanical exposure in other samples of computer users.

The prognostic value of pre-treatment thrombocytosis in two cohorts of patients with non-small cell lung cancer treated with curatively intended chemoradiotherapy

Chemoradiotherapy is the standard of care for inoperable stage III non-small cell lung cancer (NSCLC). This treatment, however, offers only a small chance of cure and is associated with many side effects. Little research has been made concerning which patients benefit most/least from the treatment. The present study evaluates the prognostic value of anemia, leukocytosis and thrombocytosis at diagnosis in this treatment setting. In the present study, data were collected retrospectively for 222 patients from two different phase II studies conducted between 2002-2007 in Sweden with patients treated with chemoradiotherapy for stage IIIA-IIIB NSCLC. Clinical data and the serum values of hemoglobin (Hgb), White blood cells (WBC) and Platelets (Plt) at enrollment were collected for all patients and studied in relation to overall survival using Kaplan-Meier product-limit estimates and a multivariate Cox proportional hazards regression model. The results showed that patients with thrombocytosis (Plt > 350 x 109/L) had a shorter median overall survival (14.5 months) than patients with normal Plt at baseline (23.7 months). Patients with leukocytosis (WBC > 9 x 109/L) had a shorter median survival (14.9 months) than patients with a normal WBC at baseline (22.5 months). However, in a multivariate model including all lab parameters and clinical factors, only thrombocytosis and performance status displayed a prognostic significance. In Conclusion, thrombocytosis showed to be an independent prognostic marker associated with shorter overall survival in stage III NSCLC treated with curatively intended chemoradiotherapy. This knowledge can potentially be used together with established prognostic factors, such as performance status when choosing the optimal therapy for the individual patient in this clinical setting.

Observer performance in estimating upper arm elevation angles under ideal viewing conditions when assisted by posture matching software.

Selecting a suitable body posture measurement method requires performance indices of candidate tools. Such data are lacking for observational assessments made at a high degree of resolution. The aim of this study was to determine the performance (bias and between- and within-observer variance) of novice observers estimating upper arm elevation postures assisted by posture matching software to the nearest degree from still images taken under ideal conditions. Estimates were minimally biased from true angles: the mean error across observers was less than 2°. Variance between observers was minimal. Considerable variance within observers, however, underlined the risk of relying on single observations. Observers were more proficient at estimating 0° and 90° postures, and less proficient at 60°. Thus, under ideal visual conditions observers, on average, proved proficient at high resolution posture estimates; further investigation is required to determine how non-optimal image conditions, as would be expected from occupational data, impact proficiency.

Chemotherapy Treatment of Elderly Patients (≥70 Years) with Non-Small Cell Lung Cancer: A Seven-Year Retrospective Study of Real-Life Clinical Practice at Karolinska University Hospital, Sweden.

An increasing proportion of cancer patients are aged >65 years and many are aged >70 years. Treatment of the elderly with lung cancer has, therefore, become an important issue; so we performed a retrospective study of our patients to demonstrate how elderly patients with NSCLC are treated in real-life, clinical practice. All patients aged ≥70 years with NSCLC at our department were reviewed retrospectively. In total, 1059 patients (50.8% of all NSCLC patients). Of these patients, 243 (22.9%) received chemotherapy, 164 (70.4%) of whom were treated with a platinum doublet using carboplatin. Second- and third-line chemotherapy were given to 31.4% and 13.9% of patients, respectively. Median overall survival was 289 and 320 days for male and female patients, respectively. Patients with performance status (PS) 0 experienced significantly better survival than patients with PS1 or PS 2: 410, 314, and 204 days, respectively. Age was of less importance, with patients aged 70–79 years versus those aged ≥80 years. Treatment of elderly NSCLC patients with chemotherapy is feasible if they have a good PS and appears to prolong survival. In this study, we found no significant differences in survival either between age groups or genders.

Placement of Cardiac PacemaKEr Trial (POCKET) – Rationale and Design: A Randomized Controlled Trial:

Background A pacemaker system consists of one or two leads connected to a device that is implanted into a pocket formed just below the collarbone. This pocket is typically subcutaneous, that is, located just above the pectoral fascia. Even though the size of pacemakers has decreased markedly, complications due to superficial implants do occur. An alternative technique would be intramuscular placement of the pacemaker device, but there are no randomized controlled trials (RCTs) to support this approach, which is the rationale for the Placement Of Cardiac PacemaKEr Trial (POCKET). The aim is to study if intramuscular is superior to subcutaneous placement of a pacemaker pocket. Methods In October 2016, we started to enroll 200 consecutive patients with an indication for bradycardia pacemaker implantation. Patients are randomized to random block sizes, stratified by age group (cut-off: 65 years) and sex, and then randomized to either subcutaneous or intramuscular implant. A concealed allocation procedure is employed, using sequentially numbered, sealed envelopes. Pocket site is blinded to the patient and in all subsequent care. The primary endpoint is patient overall satisfaction with the pocket location at 24 months as measured using a visual analog scale (VAS) 0-10. Secondary endpoints are: complications, patient-reported satisfaction at 1, 12, and 24 months (overall satisfaction, pain, discomfort, degree of unsightly appearance, movement problems, and sleep problems due to device). Conclusions POCKET is a prospective interventional RCT designed to evaluate if intramuscular is superior to subcutaneous placement of a bradycardia pacemaker during a two-year follow-up.

Risk Markers and Appropriate Implantable Defibrillator Therapy in Hypertrophic Cardiomyopathy

Risk stratification of sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM) is mainly based on evaluations from patients at highly specialized centers.