Interpreting regression models in clinical outcome studies

The transepicondylar distance is a reliable and easily measured parameter for estimating femoral cartilage surface area using MRI

PURPOSE

Different cartilage repair techniques are widely used to regenerate cartilage, such as autologous chondrocyte implantation (ACI), osteochondral autograft transfer, microfracturing and minced cartilage. Defect size is a key parameter for selecting the best procedure to repair cartilage. However, the defect's size is not related to the patient's total cartilage surface. This is because assessing the femoral cartilage surface area is time-consuming and therefore unsuitable in the daily clinical routine. It has been proposed that the femur's total cartilage area correlates positively with the transepicondylar distance (TEA).

METHODS

The knees of 40 subjects were analysed. Their average age was 30.1 ± 8.6 years. Twenty-four female and 16 male subjects were examined. Their mean body height was 176.2 ± 8.8 cm. MRI scans were performed via 3-Tesla MRI. These data were postprocessed and quantified using the browser-based, customizable SATORI platform (Fraunhofer MEVIS). This software computed the femoral cartilage surface area (FeCA), the patella cartilage surface area (PCA), the TEA and the patella length.

RESULTS

Body height reveals a good correlation (r = 0.722, p < 0.001) with the distal femur's cartilage area surface. However, regression analysis shows only moderate dependence (R2: 0.514). A very good correlation (r = 0.830, p < 0.001) was observed between the TEA distance and the total cartilage surface area of the distal femur. The regression analysis yields a good value (R2: 0.684). The cranio-caudal length of the patella was chosen as a suitably measurable two-dimensional parameter for correlation analysis with the patella's total cartilage surface area. Those results yield a poor correlation (r = 0.577, p < 0.001) between the two parameters, and regression analysis reveals a low value (R2: 0.384).

CONCLUSION

The TEA is a reliable parameter for estimating the femur's cartilage area using MRI. A simple determination of this parameter allows the estimation of the femur's total cartilage area as well as the surface-corrected defect size (SCDS) in daily routine.

LEVEL OF EVIDENCE

Level II.

Population reference equations for handheld peak expiratory flow in older U.S. adults

BACKGROUND

Peak expiratory flow (PEF) is a simple, inexpensive measure of respiratory effort and is a valuable predictor of health outcomes in older adults. Yet, there is a lack of epidemiological data validating PEF prediction equations among older adult populations, especially those ≥80 years. The National Health and Aging Trends Study (NHATS) is a large, nationally representative sample of U.S. adults ages ≥65 years that offers a unique opportunity to develop PEF population reference equations.

METHODS

Using a healthy subsample from the NHATS 2011 cohort (N = 1740; 68.9 % female; mean [SD] age = 77.0 [7.9] years), sex-specific reference equations were generated for PEF, measured via a handheld flow meter, using height and age as predictors. Reference equations for both sexes were validated against the NHATS 2015 cohort by testing measured vs. predicted PEF values. Additionally, new reference equations were compared to spirometry PEF reference equations from the National Health and Nutrition Examination Survey (NHANES).

RESULTS

After applying NHATS 2011 reference equations to the NHATS 2015 cohort, measured vs. predicted PEF values were not significantly different (Ps > 0.05). The NHANES equations tended to slightly overestimate handheld PEF measurements in the NHATS 2015 cohort by an average of 29.3 L/min and 10.1 L/min in males and females, respectively.

CONCLUSIONS

Results demonstrate the comparability of PEF reference equations from a handheld meter to spirometry reference equations in older adults. New reference equations can be applied to a traditionally undersampled population with an easily obtained and low-cost measure.

Prediction Of Palmaris Longus Tendon Length And Thickness Through Simple Anthropometric Measurements

OBJECTIVE

This study aimed to test whether palmaris longus tendon (PLT) length and thickness can be predicted from simple anthropometric measurements.

MATERIALS AND METHODS

120 healthy volunteers with bilateral PL muscles were enrolled in this prospective study. PLT length and thickness were measured by ultrasonographic examination. Anthropometric measurements included body height, weight, forearm length, and wrist circumference. Correlation, linear regression, and Bland-Altman plot were used for analysis.

RESULTS

The mean PLT length and thickness were 10.8±1.4 cm and 4.0±0.9 mm, respectively. Body height and PLT length had a moderate positive correlation (r:0.407, p:0.001), and forearm length and PLT thickness had a weak positive correlation (r:0.229, p:0.001). The regression analysis showed that body height was the best predictor for PLT length, and forearm length was the best predictor for PLT thickness. The regression equations were as follows: PLT length=0.276+(0.062×height) (r2=0.165, p<0.001) and PLT thickness=1.373+(0.108×forearm length) (r2=0.052, p<0.001). The predicted PLT lengths and thicknesses were calculated using these regression formulas and compared with the actual thicknesses and lengths using the Bland-Altman plot. The upper and lower limits of agreement (95% CI) ranged from -2.54 cm to 2.51 cm for actual PLT length and predicted PLT length and from -1.76 mm to 1.74 mm for actual PLT thickness and predicted PLT thickness in the Bland-Altman plot with a weak agreement and proportional bias.

CONCLUSIONS

These findings indicate that height and forearm length have limited accuracy in predicting PLT length and thickness. The preoperative ultrasonographic examination can provide valuable assistance, particularly in cases that require grafts with precise length and thickness requirements.

Handrim kinetics and quantitative ultrasound parameters for assessment of subacromial impingement in wheelchair users with pediatric-onset spinal cord injury

BACKGROUND

Most manual wheelchair users with pediatric-onset spinal cord injury (SCI) will experience shoulder pain or pathology at some point in their life. However, guidelines for preservation of the upper limb in children with SCI are limited.

RESEARCH QUESTION

What are the relationships between manual wheelchair handrim kinetics and quantitative ultrasound parameters related to subacromial impingement in individuals with pediatric-onset SCI?

METHODS

Subacromial impingement risk factors including supraspinatus tendon thickness (SST), acromiohumeral distance (AHD), and occupation ratio (OR; SST/AHD) were measured with ultrasound in 11 manual wheelchair users with pediatric-onset SCI. Handrim kinetics were acquired during the stroke cycle, including peak resultant force (FR), peak rate of rise of resultant force (ROR) and fractional effective force (FEF). Variability of handrim kinetics was computed using the coefficient of variation and linear regression was performed to assess correlations between handrim metrics and quantitative ultrasound parameters.

RESULTS

Peak resultant force significantly increased 1.4 % and variability of FEF significantly decreased 8.0 % for every 0.1 cm increase in AHD. FEF decreased 3.5 % for every 0.1 cm increase in SST. Variability of peak resultant force significantly increased 3.6 % and variability of peak ROR of resultant force significantly increased 7.3 % for every 0.1 cm increase in SST. FEF variability significantly decreased 11.6 % for every 0.1 cm increase in SST. Peak ROR significantly decreased 1.54 % with every 10 % increase in OR. FEF variability significantly decreased 1.5 % with every 10 % increase in OR.

SIGNIFICANCE

This is the first study to investigate relationships among handrim kinetics and shoulder structure in manual wheelchair users with pediatric-onset SCI. Associations were identified between subacromial impingement risk factors and magnitude and variability of wheelchair handrim kinetics. These results indicate the critical need to further explore the relationships among wheelchair handrim kinetics, shoulder joint dynamics, and shoulder pathology in manual wheelchair users with pediatric-onset SCI.

Sensory Profiles Predict Symptoms of Central Sensitization in Low Back Pain: A Predictive Model Research Study

Background: Acute low back pain has a high prevalence, and when persisting into chronicity, it results in enormous socio-economic consequences. Sensory preferences may be key factors in predicting central sensitization as the main mechanism of nociplastic pain and chronicity. Objectives: Build a model to predict central sensitization symptoms using sensory profiles based on the PROGRESS framework. Methods: A Prognostic Model Research study was carried out to predict central sensitization symptoms at 12 weeks, using baseline sensory profiles, based on 114 patients with acute low back pain. Independent variables were sensory profiles, state and trait anxiety, age, duration, pain severity, depressive symptoms, and pain catastrophizing. Results: This model, based on continuous data, significantly predicts central sensitization symptoms at 12 weeks. It contains two significantly contributing variables: sensory profile Sensory Sensitive (unstandardized B-value = 0.42; p = 0.01) and trait anxiety (unstandardized B-value = 0.53; p ≤ 0.001). The model has a predictive value of R2 = 0.38. Conclusions: This model significantly predicts central sensitization symptoms based on sensory profile Sensory Sensitive and trait anxiety. This model may be a useful tool to intervene in a bottom-up and top-down approaches to prevent chronicity in clinical practice, including individual sensory preferences and behavioral responses to sensory stimulation in rehabilitation strategies.

Exploring CrossFit performance prediction and analysis via extensive data and machine learning

BACKGROUND

The analysis of athletic performance has always aroused great interest from sport scientist. This study utilized machine learning methods to build predictive models using a comprehensive CrossFit (CF) dataset, aiming to reveal valuable insights into the factors influencing performance and emerging trends.

METHODS

Random forest (RF) and multiple linear regression (MLR) were employed to predict performance in four key weightlifting exercises within CF: clean and jerk, snatch, back squat, and deadlift. Performance was evaluated using R-squared (R2) values and mean squared error (MSE). Feature importance analysis was conducted using RF, XGBoost, and AdaBoost models.

RESULTS

The RF model excelled in deadlift performance prediction (R2=0.80), while the MLR model demonstrated remarkable accuracy in clean and jerk (R2=0.93). Across exercises, clean and jerk consistently emerged as a crucial predictor. The feature importance analysis revealed intricate relationships among exercises, with gender significantly impacting deadlift performance.

CONCLUSIONS

This research advances our understanding of performance prediction in CF through machine learning techniques. It provides actionable insights for practitioners, optimize performance, and demonstrates the potential for future advancements in data-driven sports analytics.

An Innovative EEG-Based Pain Identification and Quantification: A Pilot Study

OBJECTIVE

The present pilot study aimed to propose an innovative scale-independent measure based on electroencephalographic (EEG) signals for the identification and quantification of the magnitude of chronic pain.

METHODS

EEG data were collected from three groups of participants at rest: seven healthy participants with pain, 15 healthy participants submitted to thermal pain, and 66 participants living with chronic pain. Every 30 s, the pain intensity score felt by the participant was also recorded. Electrodes positioned in the contralateral motor region were of interest. After EEG preprocessing, a complex analytical signal was obtained using Hilbert transform, and the upper envelope of the EEG signal was extracted. The average coefficient of variation of the upper envelope of the signal was then calculated for the beta (13-30 Hz) band and proposed as a new EEG-based indicator, namely Piqβ, to identify and quantify pain.

MAIN RESULTS

The main results are as follows: (1) A Piqβ threshold at 10%, that is, Piqβ ≥ 10%, indicates the presence of pain, and (2) the higher the Piqβ (%), the higher the extent of pain.

CONCLUSIONS

This finding indicates that Piqβ can objectively identify and quantify pain in a population living with chronic pain. This new EEG-based indicator can be used for objective pain assessment based on the neurophysiological body response to pain.

SIGNIFICANCE

Objective pain assessment is a valuable decision-making aid and an important contribution to pain management and monitoring.

The relationship between trust and outcomes during physical therapy care for chronic low back pain

INTRODUCTION

Enhancing the therapeutic alliance has been associated with improved outcomes for patients with chronic low back pain (CLBP). Qualitatively trust has been described to be part of the therapeutic alliance, but it has not been measured quantitatively within the physical therapy literature.

OBJECTIVE

Examine the relationship between trust and outcomes during physical therapy for CLBP.

METHODS

Observational study of patients with CLBP being seen for physical therapy were assessed through self-report measures. The Primary Care Assessment Survey (PCAS) trust measurement scale was completed by patients at initial, post-initial, and discharge visit. These measurements were compared for correlations with patient reported outcome measures for pain and function recorded at initial visit and discharge.

RESULTS

A convenience sample of 29 patients (49.3 ± 15 years old) with CLBP were measured. The PCAS showed correlations for changes in trust throughout treatment for improvements in pain and discharge pain rating. Average discharge pain rating correlated to changes in the PCAS (rs = -0.692, p < .001), with lower pain ratings relating to higher changes in trust over time. Average change in pain (rs = 0.745, p < .001) throughout treatment also correlated with higher changes in trust. Higher trust scores at discharge also correlated with improved Global Rating of Change and Oswestry Disability Index scores at discharge. The linear regression model showed adjusted R2 values for the trust scores and outcomes varied between 0.247 and 0.642.

CONCLUSION

Both increases in trust throughout the treatment and end trust scores during physical therapy were related to improved outcomes for patients with CLBP.

Trochleoplasty Provides Good Outcomes for Recurrent Patellofemoral Dislocations with No Clear Superiority across Different Techniques

Background: Literature is sparse on outcome comparisons between different trochleoplasty techniques in the treatment of patella instability. To date, it is unclear whether there is a technique that offers superior outcomes. This systematic review and meta-analysis aims to compare and evaluate the outcomes of trochleoplasty techniques in the treatment of patellofemoral instability in trochlea dysplasia to establish whether there is an ideal choice of trochleoplasty technique for superior outcomes. Methods: 21 studies involving 880 knees were included. The mean age of the patients was 21.7 years (range 8-49 years). Mean follow-up timeframe of 43.5 months (range 8.8-100 months). Clinical outcomes assessed included rates of recurrence of patellofemoral dislocation, patient satisfaction, Kujala score, International Knee Documentation Committee (IKDC) score, Tegner score, and Lysholm score. Egger's test showed no publication bias across all outcomes assessed. Results: Favourable results were seen across all outcomes assessed and patient satisfaction. Improvements were seen with Kujala, IKDC, and Lysholm scores. Tegner scores showed good return to function. Post-operative dislocation and complication rates were low across the different techniques. Meta-regression for Kujala and IKDC scores showed good outcomes regardless of trochleoplasty technique used (Kujala, p = 0.549, relative risk 492.06; IKDC, p = 0.193, RR 0.001). The exact risk that trochleoplasty poses to the cartilage remains uncertain, as no study had a conservatively managed arm for comparison. Conclusions: Trochleoplasty yielded good outcomes irrespective of technique used with no clear superiority demonstrated in any technique in terms of outcome scores, satisfaction, post-operative dislocation rates or complications.

Determining whether biomechanical variables that describe common 'safe lifting' cues are associated with low back loads

Lift technique training programs have been implemented to help reduce injury risk, but the underlying content validity of cues used within these programs is not clear. The objective of this study was to determine whether biomechanical variables, that commonly used lifting cues aim to elicit, are associated with resultant low back extensor moment exposures. A sample of 72 participants were recruited to perform 10 repetitions of a floor-to-waist height barbell lift while whole-body kinematics and ground reaction forces were collected. Kinematic, kinetic, and energetic variables representative of characteristics commonly targeted by lifting cues were calculated as predictor variables, while peak and cumulative low back moments were calculated as dependent measures. Multiple regression revealed that 56.6-59.2% of variance in low back moments was explained by predictor variables. From these regression models, generating motion with the legs (both greater hip and knee work), minimizing the horizontal distance of the body to the load, maintaining a stable body position, and minimizing lift time were associated with lower magnitudes of low back moments. These data support that using cues targeting these identified variables may be more effective at reducing peak low back moment exposures via lift training.

Making immotile sperm motile using high-frequency ultrasound

Sperm motility is a natural selection with a crucial role in both natural and assisted reproduction. Common methods for increasing sperm motility are by using chemicals that cause embryotoxicity, and the multistep washing requirements of these methods lead to sperm DNA damage. We propose a rapid and noninvasive mechanotherapy approach for increasing the motility of human sperm cells by using ultrasound operating at 800 mW and 40 MHz. Single-cell analysis of sperm cells, facilitated by droplet microfluidics, shows that exposure to ultrasound leads to up to 266% boost to motility parameters of relatively immotile sperm, and as a result, 72% of these immotile sperm are graded as progressive after exposure, with a swimming velocity greater than 5 micrometer per second. These promising results offer a rapid and noninvasive clinical method for improving the motility of sperm cells in the most challenging assisted reproduction cases to replace intracytoplasmic sperm injection (ICSI) with less invasive treatments and to improve assisted reproduction outcomes.

Epilepsy in Canadian households: The financial pinch

BACKGROUND

It has long been recognized that epilepsy has a substantial economic impact on populations including health care costs and employment impact. There is a paucity of data on the individual and household impact of epilepsy on financial income.

METHODS

Canadian data on households containing persons with epilepsy were derived from the National Population Health Survey of Neurological Conditions within the Canadian Community Health Survey (CCHS), a Canadian population-based cross-sectional survey that collects information related to health status (2010-2011). We determined the number of households in Canada reporting at least one member with epilepsy. We examined the difference in reported household income between households reporting at least one member with epilepsy with those not reporting any members with epilepsy. We then developed a model of reported household income within Canada in order to adjust the estimated impact on household income of having at least one member with epilepsy.

RESULTS

In 2010-2011, 122,911 respondents to the CCHS identified 1,254 households containing individuals with epilepsy, representing ∼ 594,200 households in Canada (95 % CI: 534,900-650,500). These respondents reported that household income for households with members with epilepsy was reduced by CDN$ 14,000 when compared to the mean reported household income of CDN$ 83,000, (p < 0.001). In a model of income, the adjusted impact of a household member with epilepsy was CDN$ 14,700 (95 % CI: 10,000-19,500).

CONCLUSION

The financial impact on Canadian households of persons with epilepsy is profound. While we can only speculate on the rationale driving this, the differential in average household income in households living with an individual with epilepsy is clear. This places an additional financial burden on persons with epilepsy (PWE) who may already face substantial medication, health care and caregiver costs.

Employing direct electromagnetic coupling to assess acute fracture healing: An ovine model assessment

OBJECTIVES

This study explored the efficacy of collecting temporal fracture site compliance data via an advanced direct electromagnetic coupling (DEC) system equipped with a Vivaldi-type antenna, novel calibration technique, and multi-antenna setup (termed maDEC) as an approach to monitor acute fracture healing progress in a translational large animal model. The overarching goal of this approach was to provide insights into the acute healing dynamics, offering a promising avenue for optimizing fracture management strategies.

METHODS

A sample of twelve sheep, subjected to ostectomies and intramedullary nail fixations, was divided into two groups, simulating normal and impaired healing scenarios. Sequential maDEC compliance or stiffness measurements and radiographs were taken from the surgery until euthanasia at four or eight weeks and were subsequently compared with post-sacrifice biomechanical, micro-CT, and histological findings.

RESULTS

The results showed that the maDEC system offered straightforward quantification of fracture site compliance via a multiantenna array. Notably, the rate of change in the maDEC-measured bending stiffness significantly varied between normal and impaired healing groups during both the 4-week (p = 0.04) and 8-week (p = 0.02) periods. In contrast, radiographically derived mRUST healing measurements displayed no significant differences between the groups (p = 0.46). Moreover, the cumulative normalized stiffness maDEC data significantly correlated with post-sacrifice mechanical strength (r2 = 0.80, p < 0.001), micro-CT measurements of bone volume fraction (r2 = 0.60, p = 0.003), and density (r2 = 0.60, p = 0.003), and histomorphometric measurements of new bone area fraction (r2 = 0.61, p = 0.003) and new bone area (r2 = 0.60, p < 0.001).

CONCLUSIONS

These data indicate that the enhanced maDEC system provides a non-invasive, accurate method to monitor fracture healing during the acute healing phase, showing distinct stiffness profiles between normal and impaired healing groups and offering critical insights into the healing process's progress and efficiency.

A systematic review and meta-analysis on the correlation between HIV infection and multidrug-resistance tuberculosis

Background

The emergence of multidrug-resistant tuberculosis (MDR-TB) in HIV-positive people poses a significant challenge to international efforts to eradicate tuberculosis (TB). Many studies found conflicting results when examining the correlation between HIV and MDR-TB. The purpose of the present investigation was to comprehensively review the literature on the association between HIV infection and MDR-TB in order to evaluate the impact of HIV on MDR-TB worldwide.

Methods

Utilizing the databases PubMed, Scopus, Google Scholar, and ScienceDirect, studies published between January 2000 and March 2023 that are eligible for meta-analysis were selected. Using the random-effects model, the aggregated odds ratio of the empirical relationship between HIV and MDR-TB was calculated, along with a confidence interval ranging from 0 to 95 %. Examining the asymmetry of the funnel plot and utilizing Egger's and Begg's test, the possibility of publication bias was investigated. The extent of heterogeneity was determined using the I2 statistics.

Results

Through a database search, we identified 1214 studies, from which we ultimately selected 15 studies involving 9667 patients. The odds ratio of 2.78 (95 % confidence interval: 1.07-7.20) between HIV/AIDS and MDR-TB indicates a significant positive correlation. Tau 2 = 3.46, chi 2 = 1440.46, df = 14, I2 = 99.0 %, z = 2.10, and p 0.05 indicate that there is substantial heterogeneity among pooled studies. Since I2 is 99 % (>50 %), a random effect model was employed. The percentage of multidrug-resistant HIV-positive patients across all included studies follows a normal distribution, as shown by a Box and whisker plot with a symmetric skewness and a mesokurtic tail and a scatter plot with a significant R2 value below 1 [R2 = 0.2476] showed the positive correlation between multidrug resistance and HIV infection.

Conclusion

HIV infection increases MDR-TB risk, and the preceding pooled analysis showed an increased risk trend. Thus, MDR-TB, especially in HIV-positive patients, requires early case detection, quality-assured bacteriology diagnosis, and an effective infection control program.

The Use of Practical Measures to Determine Body Composition of Older People

Background

Older adults frequently experience body composition changes-decreased lean body mass (LBM) and bone mineral content (BMC), along with increased body fat mass (FM)-which affect their health and independence. However, the need for standard complex and costly imaging modalities could delay the detection of these changes and retard treatment effectiveness. Thus, this study explored the ability of practical measures, including simple muscle strength tests and demographic data, to determine the body composition of older adults.

Methods

Participants (n = 111, with an average age of 77 years old) were cross-sectionally assessed for the outcomes of the study, including upper limb loading during a seated push-up test (ULL-SPUT), hand grip (HG) strength test and body composition.

Results

The ULL-SPUT significantly correlated with body composition (r or rs, = 0.370-0.781; P < 0.05), particularly for female participants and was higher than that found for the HG strength test (rs = 0.340-0.614; P < 0.05). The ULL-SPUT and HG strength test, along with gender and body mass index (BMI), could accurately determine the LBM and BMC of the participants up to 82%.

Conclusion

The ULL-SPUT along with gender and BMI can be used as a practical strategy to detect the LBM and BMC of older adults in various settings. Such a strategy would facilitate timely managements (i.e. standard confirmation or appropriate interventions) in various settings.

Robustness of pulmonary nodule radiomic features on computed tomography as a function of varying radiation dose levels-a multi-dose in vivo patient study

OBJECTIVE

Analysis of textural features of pulmonary nodules in chest CT, also known as radiomics, has several potential clinical applications, such as diagnosis, prognostication, and treatment response monitoring. For clinical use, it is essential that these features provide robust measurements. Studies with phantoms and simulated lower dose levels have demonstrated that radiomic features can vary with different radiation dose levels. This study presents an in vivo stability analysis of radiomic features for pulmonary nodules against varying radiation dose levels.

METHODS

Nineteen patients with a total of thirty-five pulmonary nodules underwent four chest CT scans at different radiation dose levels (60, 33, 24, and 15 mAs) in a single session. The nodules were manually delineated. To assess the robustness of features, we calculated the intra-class correlation coefficient (ICC). To visualize the effect of milliampere-second variation on groups of features, a linear model was fitted to each feature. We calculated bias and calculated the R2 value as a measure of goodness of fit.

RESULTS

A small minority of 15/100 (15%) radiomic features were considered stable (ICC > 0.9). Bias increased and R2 decreased at lower dose, but shape features seemed to be more robust to milliampere-second variations than other feature classes.

CONCLUSION

A large majority of pulmonary nodule radiomic features were not inherently robust to radiation dose level variations. For a subset of features, it was possible to correct this variability by a simple linear model. However, the correction became increasingly less accurate at lower radiation dose levels.

CLINICAL RELEVANCE STATEMENT

Radiomic features provide a quantitative description of a tumor based on medical imaging such as computed tomography (CT). These features are potentially useful in several clinical tasks such as diagnosis, prognosis prediction, treatment effect monitoring, and treatment effect estimation.

KEY POINTS

• The vast majority of commonly used radiomic features are strongly influenced by variations in radiation dose level. • A small minority of radiomic features, notably the shape feature class, are robust against dose-level variations according to ICC calculations. • A large subset of radiomic features can be corrected by a linear model taking into account only the radiation dose level.

Classification and regression model to manage the hospitalization for laparoscopic cholecystectomy

Gallstone disease (GD) is one of the most common morbidities in the world. Laparoscopic Cholecystectomy (LC) is currently the gold standard, performed in about 96% of cases. The most affected groups are the elderly, who generally have higher pre- and post-operative morbidity and mortality rates and longer Length of Stay (LOS). For this reason, several indicators have been defined to improve quality and efficiency and contain costs. In this study, data from patients who underwent LC at the "San Giovanni di Dio e Ruggi d'Aragona" University Hospital of Salerno in the years 2010-2020 were processed using a Multiple Linear Regression (MLR) model and Classification algorithms in order to identify the variables that most influence LOS. The results of the 2352 patients analyzed showed that pre-operative LOS and Age were the independent variables that most affected LOS. In particular, MLR model had a R2 value equal to 0.537 and the best classification algorithm, Decision Tree, had an accuracy greater than 83%. In conclusion, both the MLR model and the classification algorithms produced significant results that could provide important support in the management of this healthcare process.

Association Between First Attempt Buffalo Concussion Treadmill Test and Days to Recovery in 855 Children With Sport-Related Concussion: A Historical Cohort Study and Prognostic Factors Analysis

OBJECTIVE

Little is known about the prognostic value of the Buffalo Concussion Treadmill Test (BCTT) after the acute phase of sport-related concussion (SRC). We examined the added prognostic value of the BCTT performed 10 to 21 days after SRC in children, in addition to participant, injury, and clinical process characteristics on days to recovery.

DESIGN

Historical clinical cohort study.

SETTING

Network of approximately 150 Canadian multidisciplinary primary-care clinics.

PARTICIPANTS

855 children (mean age 14 years, range 6-17 years, 44% female) who presented between January 2016, and April 2019 with SRC.

ASSESSMENT OF RISK FACTORS

Participant, injury, and clinical process characteristics, with focus on BCTT exercise intolerance assessed 10 to 21 days after injury.

OUTCOME

Days to clinical recovery.

RESULTS

Children who were exercise intolerant experienced an increase of 13 days to recovery (95% CI, 9-18 days). Each additional day between SRC and first BCTT was associated with a recovery delay of 1 day (95% CI, 1-2 days), and prior history of concussion was associated with a recovery delay of 3 days (95% CI, 1-5 days). Participant, injury, and clinical process characteristics, and the first attempt BCTT result explained 11% of the variation in recovery time, with 4% accounted for by the BCTT.

CONCLUSION

Exercise-intolerance assessed 10 to 21 days after SRC was associated with delayed recovery. However, this was not a strong prognostic factor for days to recovery.

Factors Related to Expectations in Individuals Waiting for Total Knee Arthroplasty

Purpose

There is no consensus on how age and expectations influence planning for total knee arthroplasty (TKA). This study developed and evaluated a new expectation questionnaire and assessed the relationship between preoperative expectations and patient characteristics.

Method

The questionnaire evaluated expectations for mobility, pain, participation, and rate of recovery after surgery. Fifty-five participants completed a 6-minute walk test and expectation questionnaire prior to TKA; 17 participants repeated the questionnaire one week later for reliability testing. Analysis of the questionnaire included intra-class correlation coefficient (ICC), homoscedasticity, skewness, kurtosis, multicollinearity, and descriptive measures. A four-step hierarchical linear regression was completed to determine the relationship of patient age, BMI, previous contralateral TKA, and 6-minute walk test scores to expectations.

Results

The questionnaire showed good/high test-retest reliability (ICC 0.84; 95% CI: 0.57, 0.94; p > 0.001). The final model was significant in predicting expectation scores R2 = 0.19 (p = 0.017).

Conclusions

This questionnaire reliably measures patient expectations before TKA; however, further research is needed. Although we anticipated younger age to be related to higher expectations, higher function prior to TKA appears to be more strongly associated with higher expectations.

Responsible Imputation of Missing Speech Perception Testing Data & Analysis of 4,739 Observations and Predictors of Performance

OBJECTIVE

To address outcome heterogeneity in cochlear implant (CI) research, we built imputation models using multiple imputation by chained equations (MICEs) and K-nearest neighbors (KNNs) to convert between four common open-set testing scenarios: Consonant-Nucleus-Consonant word (CNCw), Arizona Biomedical (AzBio) in quiet, AzBio +5, and AzBio +10. We then analyzed raw and imputed data sets to evaluate factors affecting CI outcome variability.

STUDY DESIGN

Retrospective cohort study of a national CI database (HERMES) and a nonoverlapping single-institution CI database.

SETTING

Multi-institutional (32 CI centers).

PATIENTS

Adult CI recipients (n = 4,046 patients).

MAIN OUTCOME MEASURES

Mean absolute error (MAE) between imputed and observed speech perception scores.

RESULTS

Imputation models of preoperative speech perception measures demonstrate a MAE of less than 10% for feature triplets of CNCw/AzBio in quiet/AzBio +10 (MICE: MAE, 9.52%; 95% confidence interval [CI], 9.40-9.64; KNN: MAE, 8.93%; 95% CI, 8.83-9.03) and AzBio in quiet/AzBio +5/AzBio +10 (MICE: MAE, 8.85%; 95% CI, 8.68-9.02; KNN: MAE, 8.95%; 95% CI, 8.74-9.16) with one feature missing. Postoperative imputation can be safely performed with up to four of six features missing in a set of CNCw and AzBio in quiet at 3, 6, and 12 months postcochlear implantation using MICE (MAE, 9.69%; 95% CI, 9.63-9.76). For multivariable analysis of CI performance prediction, imputation increased sample size by 72%, from 2,756 to 4,739, with marginal change in adjusted R2 (0.13 raw, 0.14 imputed).

CONCLUSIONS

Missing data across certain sets of common speech perception tests may be safely imputed, enabling multivariate analysis of one of the largest CI outcomes data sets to date.

Multiple logistic regression model to predict bile leak associated with subtotal cholecystectomy

BACKGROUND

There are no prediction models for bile leakage associated with subtotal cholecystectomy (STC). Therefore, this study aimed to generate a multivariable prediction model for post-STC bile leakage and evaluate its overall performance.

METHODS

We analysed prospectively managed data of patients who underwent STC by a single consultant surgeon between 14 May 2013 and 21 December 2021. STC was schematised into four variants with five subvariants and classified broadly as closed-tract or open-tract STC. A contingency table was used to detect independent risk factors for bile leakage. A multiple logistic regression analysis was used to generate a model. Discrimination and calibration statistics were computed to assess the accuracy of the model.

RESULTS

A total of 81 patients underwent the STC procedure. Twenty-eight patients (35%) developed bile leakage. Of these, 18 patients (64%) required secondary surgical intervention. Multivariable logistic regression revealed two independent predictors of post-STC bile leak: open-tract STC (odds ratio [OR], 7.07; 95% confidence interval [CI], 2.191-25.89; P = 0.0170) and acute cholecystitis (OR, 5.449; 95% CI, 1.584-23.48; P = 0.0121). The area under the receiver-operating characteristic curve was 82.11% (95% CI, 72.87-91.34; P < 0.0001). Tjur's pseudo-R2 was 0.3189 and the Hosmer-Lemeshow goodness-of-fit statistic was 4.916 (P = 0.7665).

CONCLUSIONS

Open-tract STC and acute cholecystitis are the most reliable predictors of bile leakage associated with STC. Future prospective, multicentre studies with higher statistical power are needed to generate more specific and externally validated prediction models for post-STC bile leaks.

The seventh cervical vertebra is an appropriate landmark for thoracic kyphosis measures using distance from the wall

Background

Hyperkyphosis is frequently found nowadays due to the change in current lifestyles and age-related system decline. A simple hyperkyphosis measurement can be made easily using the perpendicular distance from the landmark to the wall. However, the existing evidence applied two different landmarks [occiput and the seventh cervical vertebra (C7)] and the measurement using rulers was susceptible to error due to their misalignment.

Objective

To assess an appropriate landmark for thoracic kyphosis measurement using distance from the wall (KMD), by comparing between occiput and C7, as measured using rulers and verified using data from a specially developed machine, the so-called infrared-gun kyphosis wall distance tool (IG-KypDisT), and the Cobb angles.

Methods

Community-dwelling individuals with a risk of thoracic hyperkyphosis (age ≥ 10 years, n = 43 ) were cross-sectionally assessed for their thoracic hyperkyphosis using the perpendicular distance from the landmarks, occiput and C7, to the wall using rulers and IG-KypDisT. Then the Cobb angles of these participants were measured within seven days.

Results

The outcomes from both landmarks differed by approximately 0.8 cm (p =  0.084). The outcomes derived from C7 were more reliable (ICCs>0.93, p < 0.001), with greater concurrent validity with the radiologic data (r =  0.738, p < 0.001), with the overall variance predicted by the regression models for the Cobb angles being higher than that from the occiput (47-48% from C7 and 38-39% from occiput). The outcomes derived from rulers and IG-KypDisT showed no significant differences.

Conclusion

The present findings support the reliability and validity of KMD assessments at C7 using rulers as a simple standard measure of thoracic hyperkyphosis that can be used in various clinical, community, and research settings.

Fetal heart rate changes and labor neuraxial analgesia: a machine learning approach

BACKGROUND

Neuraxial labor analgesia has been associated with fetal heart rate changes. Fetal bradycardia is multifactorial, and predicting it poses a significant challenge to clinicians. Machine learning algorithms may assist the clinician to predict fetal bradycardia and identify predictors associated with its presentation.

METHODS

A retrospective analysis of 1077 healthy laboring parturients receiving neuraxial analgesia was conducted. We compared a principal components regression model with tree-based random forest, ridge regression, multiple regression, a general additive model, and elastic net in terms of prediction accuracy and interpretability for inference purposes.

RESULTS

Multiple regression identified combined spinal-epidural (CSE) (p = 0.02), interaction between CSE and dose of phenylephrine (p < 0.0001), decelerations (p < 0.001), and the total dose of bupivacaine (p = 0.03) as associated with decrease in fetal heart rate. Random forest exhibited good predictive accuracy (mean standard error of 0.92).

CONCLUSION

Use of CSE, presence of decelerations, total dose of bupivacaine, and total dose of vasopressors after CSE are associated with decreases in fetal heart rate in healthy parturients during labor. Prediction of changes in fetal heart rate can be approached with a tree-based random forest model with good accuracy with important variables that are key for the prediction, such as CSE, BMI, duration of stage 1 of labor, and dose of bupivacaine.

Validity and clinical applicability of the 60-secondecond sit-to-stand test in people with acute exacerbations of COPD

BACKGROUND

The 60-second sit-to-stand test (60STS) is a simple and increasingly popular test of physical function, however evidence to support its appropriateness for assessing people with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) is lacking.

AIMS

To evaluate the concurrent, convergent, predictive and discriminant validity, and responsiveness of the 60STS against the six-minute walk test (6MWT) in people hospitalised due to AECOPD.

METHODS

Prospective cohort study involving 54 inpatients with AECOPD (53% males, mean age 69.0 years, FEV1 46.5% predicted). 60STS was performed 30 min after a six-minute walk test (6MWT) upon discharge, with follow-up testing repeated one-month later (n = 39). Outcome measures included 60STS repetitions (60STSr), six-minute walk distance (6MWD), heart rate, oxyhaemoglobin saturation (SpO2), perceived dyspnoea (Borg scale), and rate of perceived exertion (RPE). Concurrent validity was assessed via correlation, convergent validity via Bland-Altman plots, predictive validity via multivariate linear regression (adjusted for confounders), discriminant validity via unpaired t tests and responsiveness via Chi (Jenkins, 2007) [2] tests.

RESULTS

Discharge 60STSr and 6MWD were strongly correlated (r = 0.61). Bland-Altman plots for nadir SpO2, peak HR, Borg and RPE scores showed acceptable agreement in terms of mean differences, but wide limits of agreement. Poor 60STSr performers were older, had weaker quadriceps, and had lower 6MWD than high performers (p < 0.05 for all). 60STSr was not retained as a significant predictor of 6MWD in multivariate regression analyses. 80% of 60STSr improvers also improved >30m on 6MWT at follow-up.

CONCLUSION

The 60STS demonstrates satisfactory validity and responsiveness as a measure of exercise performance in people with AECOPD.

Skin drug delivery using lipid vesicles: A starting guideline for their development

Lipid vesicles can provide a cost-effective enhancement of skin drug absorption when vesicle production process is optimised. It is an important challenge to design the ideal vesicle, since their properties and features are related, as changes in one affect the others. Here, we review the main components, preparation and characterization methods commonly used, and the key properties that lead to highly efficient vesicles for transdermal drug delivery purposes. We stand by size, deformability degree and drug loading, as the most important vesicle features that determine the further transdermal drug absorption. The interest in this technology is increasing, as demonstrated by the exponential growth of publications on the topic. Although long-term preservation and scalability issues have limited the commercialization of lipid vesicle products, freeze-drying and modern escalation methods overcome these difficulties, thus predicting a higher use of these technologies in the market and clinical practice.

Similarity assessment and model migration for measurement processes

Purpose

The determination of the measurement uncertainty is relevant for all measurement processes. In production engineering, the measurement uncertainty needs to be known to avoid erroneous decisions. However, its determination is associated to high effort due to the expertise and expenditure that is needed for modelling measurement processes. Once a measurement model is developed, it cannot necessarily be used for any other measurement process. In order to make an existing model useable for other measurement processes and thus to reduce the effort for the determination of the measurement uncertainty, a procedure for the migration of measurement models has to be developed.

Design/methodology/approach

This paper presents an approach to migrate measurement models from an old process to a new “similar” process. In this approach, the authors first define “similarity” of two processes mathematically and then use it to give a first estimate of the measurement uncertainty of the similar measurement process and develop different learning strategies. A trained machine-learning model is then migrated to a similar measurement process without having to perform an equal size of experiments.Similarity assessment and model migration

Findings

The authors’ findings show that the proposed similarity assessment and model migration strategy can be used for reducing the effort for measurement uncertainty determination. They show that their method can be applied to a real pair of similar measurement processes, i.e. two computed tomography scans. It can be shown that, when applying the proposed method, a valid estimation of uncertainty and valid model even when using less data, i.e. less effort, can be built.

Originality/value

The proposed strategy can be applied to any two measurement processes showing a particular “similarity” and thus reduces the effort in estimating measurement uncertainties and finding valid measurement models.

Race, employment, and the pandemic: An exploration of covariate explanations of COVID-19 case fatality rate variance

We derive a simple asymptotic approximation for the long-run case fatality rate of COVID-19 (alpha and delta variants) and show that these estimations are highly correlated to the interaction between US State median age and projected US unemployment rate (Adj. r2 = 60%). We contrast this to the high level of correlation between point (instantaneous) estimates of per state case fatality rates and the interaction of median age, population density and current unemployment rates (Adj. r2 = 50.2%). To determine whether this is caused by a "race effect," we then analyze unemployment, race, median age and population density across US states and show that adding the interaction of African American population and unemployment explains 53.5% of the variance in COVID case fatality rates for the alpha and delta variants when considering instantaneous case fatality rate. Interestingly, when the asymptotic case fatality rate is used, the dependence on the African American population disappears, which is consistent with the fact that in the long-run COVID does not discriminate on race, but may discriminate on access to medical care which is highly correlated to employment in the US. The results provide further evidence of the impact inequality can have on case fatality rates in COVID-19 and the impact complex social, health and economic factors can have on patient survival.

Association Between Cannabis and Violence in Community-Dwelling Patients With Severe Mental Disorders: A Cross-sectional Study Using Machine Learning

The objective of this cross-sectional study was to identify cannabis-related features and other characteristics predictive of violence using a data-driven approach in patients with severe mental disorders (SMDs). A Least Absolute Shrinkage and Selection Operator regularization regression model was used on the database consisting of 97 patients with SMD who completed questionnaires measuring substance use and violence. Cannabis use, particularly related to patients' decision to consume or time spent using, was a key predictor associated with violence. Other patterns of substance use and personality traits were identified as strong predictors. Regular patterns of cannabis use and interpersonal issues related to cannabis/stimulant abuse were inversely correlated to violence. This study identified the effect of several predictors correlated to violence in patients with SMD using a regularization regression model. Findings open the door to better identify the profiles of patients that may be more susceptible to perpetrate violent behaviors.

Do mean values tell the full story? Cardiac cycle and biological sex comparisons in temporally derived neurovascular coupling metrics

Previous reports have noted cerebrovascular regulation differs across the cardiac cycle, with greater regulation occurring within systole. However, this methodological notion has not been meticulously scrutinized during temporally deduced neurovascular coupling (NVC) metrics with additional respect to biological sex. Analyses of 111 healthy individuals (40 females/71 males) were performed where participants engaged in the "Where's Waldo?" paradigm. All NVC parameters were quantified in the posterior and middle cerebral arteries at 310 unique timepoints. Several individuals completed repeat testing which enabled for between-day (3 timepoints) and within-day (7 timepoints) reliability comparisons in 17 and 11 individuals, respectively. One-way analysis of variance compared NVC metrics between diastole, mean, and systole values, as well as differences between biological sexes. Greater absolute cerebral blood velocity (CBv; baseline and peak) and total activation (area under the curve) were noted within systole for both posterior cerebral artery (PCA; P < 0.001) and middle cerebral artery (MCA; P < 0.001) values; however, the relative percent increase in CBv was greater within diastole (P < 0.001). Females had an elevated diastolic and mean CBv and a greater diastolic cerebrovascular conductance (P < 0.050). No sex differences were present for systolic CBv measures and within parameters quantifying the NVC response (area under the curve/relative CBv increase) across the cardiac cycle (P > 0.072). Future investigations seeking to differentiate cerebral regulatory mechanisms between clinical populations may benefit by performing their analyses across the cardiac cycle, as certain pathogenesis may affect one aspect of the cardiac cycle independently. Minimal differences were noted between females and males for metrics characterizing the NVC response across the cardiac cycle.NEW & NOTEWORTHY Neurovascular coupling (NVC) studies commonly assess the mean cerebral hemodynamic response with little consideration for diastole, systole, and biological sex. Greater total activation expressed as the area under the curve was seen within systole compared with mean and diastole. Resting cerebral blood velocity sex differences were more prevalent during diastole when the cerebrovasculature was pressure-passive. Future studies should assess the NVC response across the cardiac cycle as it may help delineate the underlying pathophysiology of various clinical populations.

Radiologists' Contribution to Variation in Detecting Clinically Significant Prostate Cancer in Men With Prostate MRI

OBJECTIVE

Assess radiologists' contribution to variation in clinically significant prostate cancer (csPCa) detection in patients with elevated prostate-specific antigen (PSA) and multiparametric MRI (mpMRI).

METHODS

This institutional review board-approved, retrospective cohort study was performed at a tertiary, academic, National Cancer Institute-designated Comprehensive Cancer Center with a multidisciplinary prostate cancer program. Men undergoing mpMRI examinations from January 1, 2015, to December 31, 2019, with elevated PSA (≥4 ng/mL) and biopsy within 6 months pre- or post-MRI or prostatectomy within 6 months post-mpMRI were included. Univariate and multivariable hierarchical logistic regression assessed impact of patient, provider, mpMRI examination, mpMRI report, and pathology factors on the diagnosis of Grade Group ≥ 2 csPCa.

RESULTS

Study cohort included 960 MRIs in 928 men, mean age 64.0 years (SD ± 7.4), and 59.8% (555 of 928) had csPCa. Interpreting radiologist was not significant individually (P > .999) or combined with mpMRI ordering physician and physician performing biopsy or prostatectomy (P = .41). Prostate Imaging Reporting and Data System (PI-RADS) category 2 (odds ratio [OR] 0.18, P = .04), PI-RADS category 4 (OR 2.52, P < .001), and PI-RADS category 5 (OR 4.99, P < .001) assessment compared with no focal lesion; PSA density of 0.1 to 0.15 ng/mL/cc (OR 2.46, P < .001), 0.15 to 0.2 ng/mL/cc (OR 2.77, P < .001), or ≥0.2 ng/mL/cc (OR 4.52, P < .001); private insurance (reference = Medicare, OR 0.52, P = .001), and unambiguous extraprostatic extension on mpMRI (OR 2.94, P = .01) were independently associated with csPCa. PI-RADS 3 assessment (OR 1.18, P = .56), age (OR 0.99, P = .39), and African American race (OR 0.90, P = .75) were not.

DISCUSSION

Although there is known in-practice variation in radiologists' interpretation of mpMRI, in our multidisciplinary prostate cancer program we found no significant radiologist-attributable variation in csPCa detection.

Effects of anode position on pedicle screw testing during lumbosacral spinal fusion surgery

OF BACKGROUND DATA

Pedicle screws are commonly placed with lumbar/lumbosacral fusions. Triggered electromyography (tEMG), which employs the application of electrical current between the screw and a complementary anode to determine thresholds of conduction, may be utilized to confirm the safe placement of such implants. While previous research has established clinical thresholds associated with safe screw placement, there is variability in clinical practice of anode placement which could lead to unreliable measurements.

PURPOSE

To determine the variance in pedicle screw stimulation thresholds when using four unique anode locations (ipsilateral/contralateral and paraspinal/gluteal relative to tested pedicle screws).

STUDY DESIGN

Prospective cohort study. Tertiary medical center.

PATIENT SAMPLE

Twenty patients undergoing lumbar/lumbosacral fusion with pedicle screws using tEMG OUTCOME MEASURES: tEMG stimulation return values are used to assess varied anode locations and reproducibility based on anode placement.

METHODS

Measurements were assessed across node placement in ipsilateral/contralateral and paraspinal/gluteal locations relative to the screw being assessed. R² coefficients of correlation were determined, and variances were compared with F-tests.

RESULTS

A total of 94 lumbosacral pedicle screws from 20 patients were assessed. Repeatability was verified using two stimulations at each location for a subset of the screws with an R² of 0.96. Comparisons between the four anode locations demonstrated R² values ranging from 0.76 to 0.87. F-tests comparing thresholds between each anode site demonstrated all groups not to be statistically different.

CONCLUSION

The current study, a first-of-its-kind formal evaluation of anode location for pedicle screw tEMG testing, demonstrated very strong repeatability and strong correlation with different locations of anode placement. These results suggest that there is no need to change the side of the anode for testing of left versus right screws, further supporting that placing an anode electrode into gluteal muscle is sufficient and will avoid a sharp ground needle in the surgical field.

Neurovascular coupling on trial: How the number of trials completed impacts the accuracy and precision of temporally derived neurovascular coupling estimates

Standard practices for quantifying neurovascular coupling (NVC) with transcranial Doppler ultrasound (TCD) require participants to complete one-to-ten repetitive trials. However, limited empirical evidence exists regarding how the number of trials completed influences the validity and reliability of temporally derived NVC metrics. Secondary analyses was performed on 60 young healthy participants (30 females/30 males) who completed eight cyclical eyes-closed (20-seconds), eyes-open (40-seconds) NVC trials, using the "Where's Waldo?" visual paradigm. TCD data was obtained in posterior and middle cerebral arteries (PCA and MCA, respectively). The within-day (n = 11) and between-day (n = 17) reliability were assessed at seven- and three-time points, respectively. Repeat testing from the reliability aims were also used for the concurrent validity analysis (n = 160). PCA metrics (i.e., baseline, peak, percent increase, and area-under-the-curve) demonstrated five trials produced excellent intraclass correlation coefficient (ICC) 95% confidence intervals for validity and within-day reliability (>0.900), whereas between-day reliability was good-to-excellent (>0.750). Likewise, 95% confidence intervals for coefficient of variation (CoV) measures ranged from acceptable (<20%) to excellent (<5%) with five-or-more trials. Employing fewer than five trials produced poor/unacceptable ICC and CoV metrics. Future NVC, TCD-based research should therefore have participants complete a minimum of five trials when quantifying the NVC response with TCD via a "Where's Waldo?" paradigm.

A behavioural study of hydrothermally derived novel alumina/magnesia/hydroxyapatite (Al2O3/MgO/HA) bioceramic nanocomposite

Regeneration and regrowth of human bones is a gradual and time-consuming process. Therefore scaffolds are required to hold the bones in position and give them time to heal well. Though hydroxyapatite (HA) is a potential candidate, its weak mechanical nature has made it undesirable. To overcome this hurdle, a novel nanocomposite of HA with alumina (Al₂O₃) and magnesia (MgO) was prepared by hydrothermal method in this study. The constitution, composition and conformation of the Al₂O₃/MgO/HA nanocomposite were affirmed via X-ray Diffraction (XRD), Fourier-Transform Infra-Red (FTIR) and imaging tests. Vicker's hardness test evinces the mechanical calibre of the nanocomposite. A perspective load-displacement analysis was done by means of Onitsch and Kick's power laws. The nanocomposite excelled above par with a hardness of 5.19 GPa and fracture toughness of 1.27 MPam^1/2. This holistic progress makes this nanocomposite a very desirable bone implant material.

Reliability of non-invasive arterial blood pressure measurement in patients with aneurysmal subarachnoid haemorrhage

Objective Invasively measured arterial blood pressure (ABP) is associated with complications, while non-invasively measured ABP is generally considered risk-free. This study aimed to investigate the reliability of non-invasive ABP measured using finger-cuff volume-clamp device compared to invasive ABP measured by an arterial catheter in patients with aneurysmal subarachnoid haemorrhage (SAH). Approach In 30 patients admitted for neurointensive care with SAH, invasive and non-invasive ABP were recorded simultaneously. Reliability was assessed for mean, diastolic and systolic ABP separately using intraclass correlation coefficient (ICC) agreement for each full period and each 3-second average. Main results A median of 3 (IQR: 2-3) periods were included for each participant. The full periods (n = 81) showed an ICC of 0.34 (95% CI: 0.14-0.52), 0.31 (95% CI: 0.10 to 0.49), and 0.20 (95% CI: 0.00 to 0.39) for mean, diastolic, and systolic ABP, respectively. Three-second averages (n = 33,786) for mean (ICC: 0.35; 95% CI: 0.33 to 0.36), diastolic (ICC: 0.25; 95% CI: 0.25 to 0.28), and systolic ABP (ICC: 0.26; 95% CI: 0.18 to 0.33) yielded similar findings. Pearson's correlation coefficient showed an R2 of 0.15 (p < 0.001), 0.15 (p < 0.001), 0.06 (p = 0.027) for mean, diastolic and systolic ABP, respectively. Significance In patients with SAH, non-invasive measurement of ABP using the widely used Nano system from Finapres Medical Systems - a finger-cuff volume-clamp device (Finapres, Chennai, India) showed poor reliability and therefore cannot be used interchangeably with invasively measured ABP.

Assessing Conservation and Mitigation Banking Practices and Associated Gains and Losses in the United States

Conservation and mitigation banks allow their proponents to buy credits to offset the negative residual impacts of their development projects with the goal of no net loss (NNL) in the ecosystem function and habitat area. However, little is known about the extent to which these bank transactions achieve NNL. We synthesized and reviewed 12,756 transactions in the United States which were related to meeting area and ecological equivalence (n = 4331) between the approved negative impact and offset. While most of these transactions provided an offset that was equal to or greater than the impacted area, approximately one quarter of the transactions, especially those targeting wetlands, did not meet ecological equivalence between the impact and offset. This missing ecological equivalence was often due to the significantly increasing use of preservation, enhancement, and rehabilitation over creating new ecosystems through establishment and re-establishment. Stream transactions seldom added new ecosystem area through creation but mainly used rehabilitation in order to add offset benefits, in many cases leading to a net loss of area. Our results suggest that best practice guidance on habitat creation as well as the incentivization of habitat creation must increase in the future to avoid net loss through bank transactions and to meet the ever-accelerating global changes in land use and the increased pressure of climate change.

Forecasting the rate of hand injuries in Singapore

Purpose

This study aims to analyse the correlation between the incidence rate of hand injuries and various major economic indicators in Singapore. We hypothesise that the number of hand injuries is correlated to activity in the construction and manufacturing industries in Singapore.

Methods

Twenty thousand seven hundred sixty-four patients who underwent hand surgeries in a tertiary institution between 2012 to 2018 were reviewed. Two independent, blinded observers extracted the frequency of hand surgeries performed from Electronic Medical Records. Economic indicators pertinent to Singapore’s economic activity were collected and smoothed by simple moving average of the prior 3 months. Results were analysed using IBM SPSS v25.0.

Results

Significant independent univariate variables were Purchasing-Manager-Index and Industrial-Production-Index. Multiple linear regression of quarterly reported figures showed that Total-Livestock-Slaughtered, Total-Seafood-Handled, Purchasing-Manger-Index, Industrial-Production-Index, Gas-Tariffs, Construction-Index, Consumer-Price-Index, Total-Air-Cargo-Handled, Total-Container-Throughput, Total-Road-Traffic-Accident-Casualties, Food-&-Beverage-Services-Index were significantly correlated (p < 0.05) with hand injuries, with R² = 62.3%.

Conclusion

Quarterly economic indicators from major economic industries can be used to predict the incidence of hand injuries with a 62.3% correlation. These findings may be useful for anticipating healthcare resource allocation to treat hand injuries.

Type of study and level of evidence

Economic and decision, Level II.

Risk Factors for Potential Mental Illness Among Brazilians in Quarantine Due To COVID-19

BACKGROUND

During quarantine, both physical and mental health are a concern. To the same extent that physicians are a scarce resource during this crisis, psychiatrists and psychologists are also limited in number. To help practitioners and public managers decide where to invest their resources, the present research investigated the relationships of stress, depression and state anxiety levels with sociodemographic and behavioural variables.

METHODS

Data were collected in Brazil between March, 18 and 22, 2020 in 1,468 volunteers during quarantine. Participants with a history of or current mental health illnesses were excluded leaving 1,460 individuals in the final sample. The online assessment included instruments for psychological stress, depression and state anxiety. A sociodemographic and behavioural questionnaire with 15 items was used to assess other factors. Multiple linear regression was performed for each psychological outcome to determine a hierarchy of significant predictors.

FINDINGS

Stress, depression and state anxiety levels were all predicted by gender (women higher than men), quality of nutrition, attendance in tele-psychotherapy, exercise frequency, presence of elderly persons in quarantine with the person, obligation to work outside the home, level of education (more educated, lesser risk for mental illness) and age (younger age, greater risk). Having a perceived risk factor for COVID-19 predicted depression and state anxiety, but not stress. Finally, the presence of children in quarantine with the participant was a protective factor for depression.

INTERPRETATION

Even though this research is limited by its cross-sectional design, it is possible to infer that mental health varies by demographic attributes, obligations and health behaviours. Those who report higher distress must work outside the home during quarantine, live with an elderly person and carry a risk factor for COVID-19, among other factors. Identifying those who are most vulnerable would help to prioritize those who may need the greatest psychological aid and assist public health practitioners in developing support strategies.

PROMIS Scores Should Not be Used in Isolation to Measure Outcomes in Lumbar Stenosis Patients

STUDY DESIGN

Retrospective cross-sectional analysis.

OBJECTIVE

The aim of this study was to establish the strength of relationship between the Patient-reported Outcomes Measurement Information System (PROMIS) Adult Depression (AD), Physical Function (PF), and Pain Interference (PI) with the Swiss Spinal Stenosis Questionnaire (SSSQ) in assessing lumbar spinal stenosis (LSS).

SUMMARY OF BACKGROUND DATA

In 2009, there were >35,000 surgeries for LSS, which amounted to $1.65 billion in health care cost. By 2021, there will be >2.4 million people in the United States with symptomatic LSS. There is an increasing emphasis on patient-reported outcomes (PROs) to define value in medicine. Therefore, it would be beneficial to compare PROMIS, a universal PRO, against the SSSQ, the "criterion standard" for assessing LSS.

METHODS

Eighty-two patients with LSS completing the PROMIS and SSSQ were enrolled. Per existing institutional protocol, PROMIS AD, PF, and PI were completed at every clinic visit. Linear regression analysis was then performed to evaluate how well the SSSQ and PROMIS scores correlated to each other.

RESULTS

When linear regression was performed for pre-treatment values, the R2 value for the SSSQ PF versus PROMIS PF was 0.14 (P = 0.0008), whereas the R2 value for the SSSQ symptom severity versus PROMIS PI was 0.03 (P = 0.13). The R2 value for the combined SSSQ physical function and symptom severity versus PROMIS AD was 0.07 (P = 0.02). When post-treatment SSSQ satisfaction scores were correlated to postoperative PROMIS AD, PI, and PF scores, the R2 values for a good linear fit were 0.13, 0.25, and 0.18 respectively (P values: 0.01, 0.003, and 0.003).

CONCLUSION

Pre-treatment PROMIS scores do not adequately capture the disease-specific impact of spinal stenosis, but postoperative PROMIS scores better reflect outcomes after surgery for LSS. PROMIS scores should not be used in isolation to assess outcomes in patients with LSS.Level of Evidence: 4.

Personalized prediction of rehabilitation outcomes in multiple sclerosis: a proof-of-concept using clinical data, digital health metrics, and machine learning

Predicting upper limb neurorehabilitation outcomes in persons with multiple sclerosis (pwMS) is essential to optimize therapy allocation. Previous research identified population-level predictors through linear models and clinical data. This work explores the feasibility of predicting individual neurorehabilitation outcomes using machine learning, clinical data, and digital health metrics. Machine learning models were trained on clinical data and digital health metrics recorded pre-intervention in 11 pwMS. The dependent variables indicated whether pwMS considerably improved across the intervention, as defined by the Action Research Arm Test (ARAT), Box and Block Test (BBT), or Nine Hole Peg Test (NHPT). Improvements in ARAT or BBT could be accurately predicted (88% and 83% accuracy) using only patient master data. Improvements in NHPT could be predicted with moderate accuracy (73%) and required knowledge about sensorimotor impairments. Assessing these with digital health metrics over clinical scales increased accuracy by 10%. Non-linear models improved accuracy for the BBT (+ 9%), but not for the ARAT (-1%) and NHPT (-2%). This work demonstrates the feasibility of predicting upper limb neurorehabilitation outcomes in pwMS, which justifies the development of more representative prediction models in the future. Digital health metrics improved the prediction of changes in hand control, thereby underlining their advanced sensitivity.

Graphical Abstract

Optimization of substrate composition for pectinase production from Satkara (Citrus macroptera) peel using Aspergillus niger-ATCC 1640 in solid-state fermentation

Pectinase is an enzyme having a broad industrial and commercial application. However, higher production costs may be the major constraint for the wide-scale application of pectinase. Therefore, researchers are trying to reduce the pectinase production cost for subsequent application in the industrial processes by using a unique substrate and optimizing the fermentation medium components and process conditions. The main purpose of the current study was to optimize medium composition for pectinase production using Aspergillus niger-ATCC 1640 in the solid-state fermentation. The Response Surface Methodology (RSM) was performed to evaluate the effects of variables, specifically the concentrations of Satkara peel, urea, (NH₄)₂PO₄, NH₄NO₃, KH₂PO₄, ZnSO₄, and MgSO₄.7H₂O on pectinase production in the solid substrate. Firstly, a two-factorial design, Plackett-Burman design (PBD) was applied to screen the variables that significantly influenced the pectinase production. After finding the critical variables, 15 experimental runs were carried out using a Box-Behnken design (BBD) to derive a statistical model for optimizing the concentrations of the selected variables. The PBD model revealed that Satkara peel, urea, and (NH₄)₂SO₄ significantly affected the pectinase production. RSM results indicated that the predicted response for pectinase production was in good agreement with experimental data (R² = 0.9836). Under the optimized condition of Satkara peel (8.4 g/L), urea (0.5 g/L), and (NH₄)₂SO4 (2.7 g/L), the pectinase activity was predicted to be 0.6178 μmol/mL. In the present study, the experimental pectinase production achieved 0.6045 μmol/mL. The study revealed that optimization through RSM could improve the pectinase production from Satkara peel.

Continuous diagnostic models for volume deficit in patients with acute diarrhea

Background

Episodes of acute diarrhea lead to dehydration, and existing care algorithms base treatment around categorical estimates for fluid resuscitation. This study aims to develop models for the percentage dehydration (fluid deficit) in individuals with acute diarrhea, to better target treatment and avoid the potential sequelae of over or under resuscitation.

Methods

This study utilizes data from two prospective cohort studies of patients with acute diarrhea in Dhaka, Bangladesh. Data were collected on patient arrival, including weight, clinical signs and symptoms, and demographic information. Consecutive weights were obtained to determine the true volume deficit of each patient. Data were entered into two distinct forward stepwise regression logistic models (DHAKA for under 5 years and NIRUDAK for 5 years and over).

Results

A total of 782 patients were included in the final analysis of the DHAKA data set, and 2139 were included in the final analysis of the NIRUDAK data set. The best model for the DHAKA data achieved an R² of 0.27 and a root mean square error (RMSE) of 3.7 (compared to R² of 0.06 and RMSE of 5.5 with the World Health Organization child care algorithm) and selected 6 predictors. The best performance model for the NIRUDAK data achieved an R² of 0.28 and a RMSE of 2.6 (compared to R² of 0.08 and RMSE of 4.3 with the World Health Organization adolescent/adult care algorithm) and selected 7 predictors with 2 interactions.

Conclusions

These are the first mathematical models for patients with acute diarrhea that allow for the calculation of a patient’s percentage dehydration (fluid deficit) and subsequent targeted treatment with fluid resuscitation. These findings are an improvement on existing World Health Organization care algorithms.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41182-021-00361-9.

Examining the factors influencing adoption of over the top (OTT) services among Indian consumers

Purpose

The purpose of this paper is to identify and predict the key factors that influenced the usage intention of over the top (OTT) services by consumers. This was done by applying the modified unified theory of acceptance and use of technology 2 (UTAUT2) model.

Design/methodology/approach

An online survey questionnaire assessed the proposed motivational factors for the adoption of OTT services. Confirmatory factor analysis and structural equation modelling were conducted on collected data (n = 598) to demonstrate the reliability and validity of the measurement and structural model.

Findings

The model consisted of nine factors, namely, value expectancy (VE), ease of effort (EE), social influence (SI), favourable infrastructure conditions (FIC), hedonistic motivation for usage (HMU), favourable economic position (FEP), content quality (CQ), habitual behaviour (HB) and security conditions (SC). SC, VE, SI, HB and EE were the antecedent variables. FEP, CQ and FIC were the mediating variables and HMU was the dependant variable. SI and CQ of OTT services were positively associated with HMU of OTT services, FEP had no significant effects on HMU. The results also supported the explanatory strength and predictability of UTAUT2 as a model. It further extended UTAUT2 boundaries and paved the way for an extended UTAUT2 model to be developed.

Originality/value

The promising role of OTT services in the entertainment and media industry had gained consumer attention, however, limited empirical investigations had been conducted on explicating how user attitude and usage intention were shaped regarding the use of OTT services in the Indian context. This study served as one of the first attempts to empirically examine the adoption process, with implications for the HMU regarding OTT services. This was one of the first studies to extend the UTAUT2 theoretical model.

Genetic Variations Associated with Long-Term Treatment Response in Bipolar Depression

Several pharmacogenetic-based decision support tools for psychoactive medication selection are available. However, the scientific evidence of the gene-drug pairs analyzed is mainly based on pharmacogenetic studies in patients with major depression or schizophrenia, and their clinical utility is mostly assessed in major depression. This study aimed at evaluating the impact of individual genes, with pharmacogenetic relevance in other psychiatric conditions, in the response to treatment in bipolar depression. Seventy-six patients diagnosed with bipolar disorder and an index major depressive episode were included in an observational retrospective study. Sociodemographic and clinical data were collected, and all patients were genotyped using a commercial multigene pharmacogenomic-based tool (Neuropharmagen^®, AB-Biotics S.A., Barcelona, Spain). Multiple linear regression was used to identify pharmacogenetic and clinical predictors of efficacy and tolerability of medications. The pharmacogenetic variables response to serotonin-norepinephrine reuptake inhibitors (SNRIs) (ABCB1) and reduced metabolism of quetiapine (CYP3A4) predicted patient response to these medications, respectively. ABCB1 was also linked to the tolerability of SNRIs. An mTOR-related multigenic predictor was also associated with a lower number of adverse effects when including switch and autolytical ideation. Our results suggest that the predictors identified could be useful to guide the pharmacological treatment in bipolar disorder. Additional clinical studies are necessary to confirm these findings.

Symptom response to mobilization and outcomes in patients with subacromial pain syndrome: A cohort study

OBJECTIVES

The objectives of this study were the following: (1) to determine if there was a difference in outcomes between immediate responders to glenohumeral mobilizations at the initial evaluation, 2-week, 4-week, and 6-month follow-up as compared to those that do not respond in participants with subacromial pain syndrome; (2) to see if there were statistically significant differences in outcomes within these groups between these time frames of interest, and (3) to see if symptom response at the initial evaluation was predictive of a favorable recovery.

METHODS

This was a prospective, single-group observational design. Clinicians pragmatically identified positive responders as improving at least two points on the Numeric Pain Rating Scale and/or a 20° improvement in shoulder active range of motion (AROM) following shoulder mobilization at the initial evaluation. Data were collected for the subjective and objective variables of interest at the initial evaluation, 2-week, 4-week, and 6-month follow-up.

RESULTS

The prevalence of responders at the initial evaluation was 99 (81.8%). There were no statistically significant between-group differences for the variables of interest except for the Global Rating of Change (GRoC; f = 2.79, p = 0.006). The shoulder abduction AROM between-group difference exceeded the minimal detectable change at 4 weeks. The pair-wise comparison showed statistically significant differences for the outcomes of interest at each time point except for the GRoC between 4 weeks and 6 months. There was a statistically significant correlation between responders at the initial evaluation and shoulder abduction AROM at the 4-week follow-up (r_pb (112) = 0.27, p = 0.004).

CONCLUSION

Individuals with SAPS may benefit from shoulder mobilization independent of their within-session response to shoulder mobilization at the initial evaluation. Future research should seek to differentiate if these improvements are related to the within-session positive treatment response at the initial evaluation in individuals who are randomized to receive shoulder mobilization or not.

Predicting height from ulna length for the determination of weight status in New Zealand adolescents: A cross-sectional study

BACKGROUND

The measurement of height is crucial for weight status assessment. When standing height is difficult to measure, ulna length may offer a convenient and accurate surrogate of height measure. Adolescence is a period of accelerated linear growth; hence, the validation of age-specific equations that predict height from ulna length in adolescents is warranted. The present study aimed to develop and validate age- and sex-specific equations for predicting height from ulna length in New Zealand adolescents.

METHODS

Height, weight and ulna length were measured in 364 adolescents (n = 110 males, n = 254 females) aged 15.0-18.8 years, who were enrolled in the SuNDiAL (Survey of Nutrition Dietary Assessment and Lifestyle) project, a cross-sectional survey performed in 2019 and 2020. Regression models were used to determine equations to predict height from ulna length. Agreement between measured and predicted height, body mass index (BMI) and BMI z-score was assessed with intra-class correlation coefficients (ICC) and Bland-Altman plots. Sensitivity and specificity were calculated for classifying obesity.

RESULTS

Strong agreement was found between predicted and measured height (ICC = 0.78; mean difference = 0; 95% confidence interval = -0.5 to 0.5 cm) and BMI (ICC = 0.95; mean difference = 0; 95% confidence interval = -0.1 to 0.1 kg m^-2 ). Predicted height was 88.1% accurate when classifiying weight status, showing high sensitivity (93.8%) and specificity (99.4%) for classifying obesity.

CONCLUSIONS

Ulna length measurement can accurately estimate height and subsequently weight status in New Zealand adolescents aged 15-18 years.

Use of shear wave elastography on the maternal cervix to recognise cervical insufficiency using a transabdominal ultrasound approach

INTRODUCTION

The ramifications of preterm birth on society and the role of cervical length in identifying cervical insufficiency are well known. The main goal of this work was to apply shear wave elastography to the maternal cervix to assess the stiffness of the cervix and identify cervical insufficiency, using a transabdominal ultrasound approach.

METHODS

Measurements of shear wave speed were obtained using a transabdominal ultrasound approach, at the anterior and posterior portions of the internal and external cervical os on 504 participants. A total of 455 participants were contacted following the expected date of birth of the fetus and birth details were obtained.

RESULTS

The anterior and posterior portions of the internal os showed a significant correlation between shear wave speed and time until delivery of the fetus for women who gave birth spontaneously, with R 2 Linear being 0.024 (P = 0.012) and 0.017 (P = 0.05) respectively, and these correlations increased for the group of participants that were scanned between the 18th and end of the 20th week of pregnancy to R 2 Linear = 0.043 (P = 0.001) and 0.021 (P = 0.040) respectively. A ratio of internal os/external os anteriorly also showed a correlation of R 2 Linear = 0.030 (P = 0.009).

CONCLUSION

A transabdominal ultrasound technique has identified a reduction in shear wave speeds at the internal os in the mid-trimester, in women who had a subsequent preterm birth.

The validity and reliability of ultra-short-term heart rate variability parameters and the influence of physiological covariates

Ultra-short-term (UST) heart rate variability (HRV) metrics have increasingly been proposed as surrogates for short-term HRV metrics. However, the concurrent validity, within-day reliability, and between-day reliability of UST HRV have yet to be comprehensively documented. Thirty-six adults (18 males, age: 26 ± 5 yr, BMI: 24 ± 3 kg/m²) were recruited. Measures of HRV were quantified in a quiet-stance upright orthostatic position via three-lead electrocardiogram (ADInstruments, FE232 BioAmp). All short-term data recordings were 300 s in length and five UST time points (i.e., 30 s, 60 s, 120 s, 180 s, and 240 s) were extracted from the original 300-s recording. Bland-Altman plots with 95% limits of agreement, repeated measures ANOVA and two-tailed paired t tests demarcated differences between UST and short-term recordings. Linear regressions, coefficient of variation, intraclass correlation coefficients, and other tests examined the validity and reliability in both time- and frequency domains. No group differences were noted between all short-term and UST measures, for either time- (all P > 0.202) or frequency-domain metrics (all P > 0.086). A longer recording duration was associated with augmented validity and reliability, which was less impacted by confounding influences from physiological variables (e.g., respiration rate, carbon dioxide end-tidals, and blood pressure). Conclusively, heart rate, time-domain, and relative frequency-domain HRV metrics were acceptable with recordings greater or equal to 60 s, 240 s, and 300 s, respectively. Future studies employing UST HRV metrics should thoroughly understand the methodological requirements to obtain accurate results. Moreover, a conservative approach should be utilized regarding the minimum acceptable recording duration, which ensures valid/reliable HRV estimates are obtained.NEW & NOTEWORTHY A one size fits all methodological approach to quantify HRV metrics appears to be inappropriate, where study design considerations need to be conducted upon a variable-by-variable basis. The present results found 60 s (heart rate), 240 s (time-domain parameters), and 300 s (relative frequency-domain parameters) were required to obtain accurate and reproducible metrics. The lower validity/reliability of the ultra-short-term metrics was attributable to measurement error and/or confounding from extraneous physiological influences (i.e., respiratory and hemodynamic variables).

Cyanocobalamin Ultraflexible Lipid Vesicles: Characterization and In Vitro Evaluation of Drug-Skin Depth Profiles

Atopic dermatitis (AD) and psoriasis are the most common chronic inflammatory skin disorders, which importantly affect the quality of life of patients who suffer them. Among other causes, nitric oxide has been reported as part of the triggering factors in the pathogenesis of both conditions. Cyanocobalamin (vitamin B₁₂) has shown efficacy as a nitric oxide scavenger and some clinical trials have given positive outcomes in its use for treating skin pathologies. Passive skin diffusion is possible only for drugs with low molecular weights and intermediate lipophilicity. Unfortunately, the molecular weight and hydrophilicity of vitamin B₁₂ do not predict its effective diffusion through the skin. The aim of this work was to design new lipid vesicles to encapsulate the vitamin B₁₂ to enhance its skin penetration. Nine prototypes of vesicles were generated and characterized in terms of size, polydispersity, surface charge, drug encapsulation, flexibility, and stability with positive results. Additionally, their ability to release the drug content in a controlled manner was demonstrated. Finally, we found that these lipid vesicle formulations facilitated the penetration of cyanocobalamin to the deeper layers of the skin. The present work shows a promising system to effectively administer vitamin B₁₂ topically, which could be of interest in the treatment of skin diseases such as AD and psoriasis.