Wilcoxon Matched-pairs Signed-rank Test Research Articles

A multi-center nested case-control study on hospitalization costs and length of stay due to healthcare-associated infection

BackgroundIn 2018, the Chinese government demanded nationwide implementation of medical insurance payment methods based on Single-Disease Payment (SDP), but during the operation process the medical insurance system did not fully consider the extra economic burden caused by healthcare-associated infection (HAI). HAIs can prolong the length of stay and increase the hospitalization costs, but only a few studies have been conducted in Sichuan province, China. We evaluated the hospitalization costs and length of stay due to HAI in Sichuan province based on the prevalence survey, and provided data reference for China’s medical insurance reform.MethodsIn the hospitals surveyed on the prevalence of HAI, a multi-center nested case-control study was performed by a paired method. The study period was from 6 September 2016 to 30 November 2016. Binary outcomes were tested using χ2 test, continuous outcomes were tested using Wilcoxon matched-pairs signed rank test, intra-group comparisons were tested using multiple linear regression analysis.ResultsA total of 225 pairs/450 patients were selected in 51 hospitals, and 170 pairs/350 patients were successfully matched. The case fatality rate was 5.14% for the HAIs patients and 3.43% for non-HAs patients, there was no significant difference (χ2 = 0.627, P = 0.429); the median length of stay in patients with HAIs was 21 days, longer than that of patients with non-HAI 16 days, the median of the difference between matched-pairs was 5 days, the difference was statistically significant (Z = 4.896, P = 0.000). The median hospitalization costs of patients with HAI were €1732.83, higher than that of patients with non-HAI €1095.29, the median of the difference between matched-pairs were €431.34, the difference was statistically significant (Z = 6.413, P = 0.000). Multiple linear regression results showed that HAIs at different sites have caused different economic burdens, but in different economic regions, the difference was not statistically significant.ConclusionsIn Sichuan, the hospitalization costs and length of stay caused by HAI should be given special attention in the current medical insurance reform. The proportion and scope of medical payment for patients with HAI at different sites should be different. Efforts need to be taken to incentivize reduction of HAI rates which will reduce hospitalization costs and length of stay.

A covert field-intervention experiment to determine how heating controls that conserve energy affect thermal comfort.

A field-intervention study was carried out in 106 households in Sweden. Without informing the householders, a retrofitted heat pump controller was twice disabled for 1week at a time over a 4-week period during the heating season, using a single-blind cross-over design with two pseudorandomly selected groups of householders, each experiencing different conditions at any given time. Thermal comfort was assessed by observing the total number of times that householders made adjustments to their set point temperature under each condition. A within-household, repeated-measures analysis was performed to determine whether this indicator was positively or negatively affected when the secondary controller was disabled so the heat pump system operated as designed. While over 80% of households showed no effect, among those that did respond to the imposed changes, a Wilcoxon matched-pairs signed-ranks test indicates that disabling the retrofitted controller had a negative effect on thermal comfort (P<0.05 for a 2-tail test), in that it resulted in significantly more thermostat adjustments. A concurrent increase in the variance of indoor temperature about the household mean was significant (P<0.001) but small: The range within which indoor temperatures were maintained for 95% of the time (2.5K) was increased by only 0.3K (16%), indicating the sensitivity of the approach.

An economical strategy for early medical education in ultrasound

BackgroundA movement to include ultrasound training in undergraduate medical education is slowly taking place. However, many educational institutions are hesitant to include formal ultrasound training as a part of their curricula due to curricular time constraints, high cost of ultrasound equipment, and a lack of sufficient faculty skilled with ultrasound. We suggest that an economical ultrasound training strategy is needed to resolve these obstacles and enable hesitant medical programs to include ultrasound training.MethodsTwenty-eight first year medical students volunteered to attend extra-curricular ultrasound training sessions covering topics related to 11 commonly used sonographical imaging categories. Study assessments included subjective pre/post-training skill evaluation surveys, and objective numerical scores awarded by the session instructor during real-time evaluation of each participant’s performance in obtaining each target ultrasound view.ResultsA Wilcoxon matched-pairs signed rank test was performed to evaluate the difference between pre-training and post-training survey questions. P values < 0.05 were considered significant. Moreover, following analysis the p value for all test was found to be < 0.0001. Of the 308 total ultrasound-related tasks attempted collectively by all 28 participants, only 7 (2.3%) tasks were deemed unsuccessful by an instructor.ConclusionsThe training program presented in this study requires one faculty member, a single ultrasound machine, and time to conduct six 30-min training sessions with small groups of students over 4 weeks. Many medical schools are concerned that they don’t have adequate time or resources to include ultrasound training in their curricula. Our intention is to negate these concerns by providing a simple and practical training method that is both temporally and fiscally economical.

The impact of demonetization on Indian firms’ performance: does company’s age make a difference?

The main aim of this paper is to evaluate the impact of demonetization on Indian firm’s quarterly financial performance before and after demonetization period (March-December, 2017), and to find out if companies’ age helps to face financial disruption. Four variables, which are net sales, total income, net profit after tax, and earnings per share, were taken as proxies for analyzing the quarterly financial performance of 2,892 companies listed on Bombay Stock Exchange (BSE), National Stock Exchange (NSE), and Calcutta Stock Exchange (CSE). Nonparametric test, particularly Wilcoxon Matched-Pairs Signed Rank Test and Kruskal-Wallis one-way analysis of variance, were applied in analyzing the data. Results reveal that there is a statistically significant difference between the financial performance before and after demonetization at 5% level of significance. It was also found that the decrease/increase in the financial performance of all the firms was affected by the demonetization process, irrespective of their ages. The findings could be useful for financial managers and financial consultants, as they would be able to focus on the issues that matter most at the time of financial disruption.

Validity of Wearable Electromyographical Compression Shorts to Predict Lactate Threshold During Incremental Exercise in Healthy Subjects.

Snarr, RL, Tolusso, DV, Hallmark, AV, and Esco, MR. Validity of wearable electromyographical compression shorts to predict lactate threshold during incremental exercise in healthy subjects. J Strength Cond Res 35(3): 702-708, 2021-Determination of lactate threshold (LT) is an important variable in improving cardiovascular endurance and performance. Unfortunately, monitoring LT during exercise uses a costly, invasive blood analysis. Recently, electromyography (EMG) has been deemed a potential method of monitoring exercise intensity and may provide a noninvasive technique to monitor lactate during exercise. The purpose of this investigation was to determine if wearable surface EMG technology, acquired from specialized compression shorts, could estimate the LT work rate during incremental cycling. Thirteen men (n = 9) and women (n = 4) completed a maximal exercise test on a cycle ergometer. Blood lactate was measured every minute, whereas EMG was recorded throughout at the site of the vastus lateralis. Lactate and EMG thresholds were calculated using the Dmax method and compared using a Wilcoxon matched-pairs signed-rank test. Results demonstrated no significant differences between lactate and EMG thresholds in regards to work output (p = 0.83), percent maximal heart rate (p = 0.13; Cohen's d = 0.43), or percent peak oxygen consumption (p = 0.64; Cohen's d = 0.09). This confirms that both lactate and EMG exhibit similar properties (i.e., increasing exponential values) during incremental exercise. A possible mechanism includes the rise in blood lactate concentration, which increases motor unit recruitment in an attempt to maintain proper cadence and force output during incremental exercise. Thus, a coincidental, exponential increase in EMG amplitude may occur. Therefore, wearable EMG compression gear may provide a viable field tool for monitoring training intensity and predicting LT work rates.

Blocking neuromuscular junctions to impair muscle overactivity enhances neurological heterotopic ossifications (NHO) development in a mouse model of spinal cord injury

To ascertain a role for muscle spasticity in the development of NHO, by blocking neuromuscular signalling using botulinum toxin during spinal cord injury-induced NHO formation in a murine model. Spinal Cord Injury (SCI) was performed on 5–6-week-old C57BL/6 mice. To promote NHO development, cardiotoxin (CDTX) dose injections were administered at the time of the surgery to the right and left hamstring muscles. Botulinum toxin A (BTA) injections were administered at the site of NHO formation in the right hamstrings to block neuromuscular signalling, and mock equivalent volume of PBS was injected in the contralateral site 4 days prior to SCI, and weekly for 3 weeks. Twenty-one days post SCI, quantitative assessment of NHO volume and density within each hamstrings muscle were performed using Micro-computed tomography scan. μCTscan analysis revealed the development of NHO in 100% of mice in both hamstrings. NHO volume average was 1.6 mm 3 (± 1.0) in the left hamstrings injected with PBS in contrast to 3.3 mm 3 (± 1.4) in the right hamstrings with BTA. This doubling of NHO volume in BTA-treated hamstrings was statistically significant (Wilcoxon matched-pairs signed rank test, P = 0.013). Furthermore, NHO were more compact in muscles injected with BTA with a density of 1244.6 mg/cm 3 (± 10.4) and was significantly denser compared to NHO in the PBS-treated contralateral side density of 1231.2 mg/cm 3 (± 20.1) (Wilcoxon matched-pairs signed rank test, P = 0.027). In our murine model of SCI-induced NHO, we demonstrated a doubling of the NHO volume, and increased density burden when treated locally with BTA. These results demonstrate that local administration of BTA exacerbates NHO development leading to an overall increase in bone formation. The outcome suggests that in contrast to risk spasticity, resulting from defective neuromuscular signalling, may be an inhibitor of local NHO development.

The influence of endorectal filling on rectal cancer staging with MRI.

To assess the influence of endorectal filling (EF) on rectal cancer staging. 47 patients who underwent a staging MRI of rectal cancer in the period from 2011 to 2014 were included. The MRI protocol included T2 weighted fast spin echo sequences without and with EF at 3 T (EF-MRI). Images were scored by two readers for T-stage, distance of the lower pole of the tumour to the anorectal junction, distance to the mesorectal fascia (MRF),and number of (suspicious) lymph nodes. Agreement in T-staging was calculated using the Cohen's κ value. Comparison of continuous variables was performed using Wilcoxon matched pairs signed-rank test. The interobserver agreement for T-staging with and without EF-MRI showed a poor agreement between both readers (weighted κ = 0.156, weighted κ = 0.037, respectively). Tumours tended to be overstaged more prominently with EF-MRI. The accuracy of predicting the pathological T-stage slightly improved from 55% with EF to 64% without EF for Reader 1 and from 59 to 68% for Reader 2, respectively. The distance of the tumour to the anorectal junction increased from 33.9 to 49.3 mm (p < 0.001) after EF for Reader 2. EF-MRI did not significantly influence the number of (suspicious) lymph nodes and distance to the mesorectal fascia. EF-MRI did not lead to an improved tumour staging and it has the potential to influence the distance to a key anatomical landmark. EF-MRI is therefore not recommended in primary staging rectal cancer. Advances in knowledge: EF-MRI may not be used as an additional tool to stage rectal cancer patients, as it does not seem to facilitate in locoregionally staging the disease.

Urine IP-10 as a biomarker of therapeutic response in patients with active pulmonary tuberculosis

BackgroundPrior to clinical trials of new TB drugs or therapeutic vaccines, it is necessary to develop monitoring tools to predict treatment outcomes in TB patients. Urine interferon gamma inducible protein 10 (IP-10) is a potential biomarker of treatment response in chronic hepatitis C virus infection and lung diseases, including tuberculosis. In this study, we assessed IP-10 levels in urine samples from patients with active TB at diagnosis, during treatment, and at completion, and compared these with levels in serum samples collected in parallel from matched patients to determine whether urine IP-10 can be used to monitor treatment response in patients with active TB.MethodsIP-10 was measured using enzyme-linked immunosorbent assays in urine and serum samples collected concomitantly from 23 patients with active TB and 21 healthy adults (44 total individuals). The Mann-Whitney U test and Wilcoxon matched-pairs signed rank test were used for comparisons among healthy controls and patients at three time points, and LOESS regression was used for longitudinal data.ResultsThe levels of IP-10 in urine increased significantly after 2 months of treatment (P = 0.0163), but decreased by the completion of treatment (P = 0.0035). Serum IP-10 levels exhibited a similar trend, but did not increase significantly after 2 months of treatment in patients with active TB.ConclusionsUnstimulated IP-10 in urine can be used as a biomarker to monitor treatment response in patients with active pulmonary TB.

PMH58 - A Community-Wide Education Program on Drug Addiction: Stakeholder Knowledge, Beliefs, and Opportunities for Interprofessional Collaboration

Few studies have focused on interdisciplinary efforts to prevent drug misuse and overdose across health systems and communities. Thus, the purpose of this study was to increase health professionals’ and community stakeholders’ knowledge about drug and opioid abuse and ability to collaborate interprofessionally. A quasi-experimental pretest-posttest design was employed using mixed-methods. Prescribers, pharmacists, law enforcement, regulatory agencies, and community members in Alabama were recruited for a day-long, in-person drug addiction and abuse education program via email and online advertisements. Outcomes were measured via online surveys at baseline and post-training. Primary outcome measures included: 1) change in knowledge score (percent correct on a 9-item scale); 2) beliefs regarding the most effective way to address Alabama’s drug abuse problem; and 3) opportunities for interprofessional collaboration. Participants were matched pre and post-training and changes in knowledge score were analyzed using the Wilcoxon Matched-Pairs Signed Rank test. Beliefs about effective solutions and interprofessional collaboration were measured via free-response at post-training and analyzed using qualitative thematic analysis. A total of 838 people attended the education program, most of whom were pharmacists (42.3%) and nurses/physicians (20.2%). Survey completion rates were high at baseline (65.87%, n=552) and post-training (76.61%, n=642). Mean overall knowledge score increased by 20.7% (p <0.0001) from baseline to post-training. The most frequently discussed ways to address Alabama’s drug abuse problem were education of the public/community (n=121, 22.4%) and seeking/prescribing non-opioid treatments for pain (n=120, 22.3%). Most frequently discussed methods for interprofessional collaboration included more joint educational events (n=221, 41.1%) and improved communication channels between health professionals, law enforcement, and state Boards of Medicine/Pharmacy (n=212, 39.4%). This interprofessional education program was effective at increasing participants’ knowledge about drug abuse in Alabama. Key stakeholders supported future studies aimed at improving communication modalities between health professionals, law enforcement, and regulatory agencies.

Three‐Dimensional Infraorbital Foramen Location Relative to Facial Landmarks: Preliminary Results

Infraorbital nerve block injections are performed by either an intraoral approach per the oral vestibule or an extraoral approach through the skin near the infraorbital foramen. Many studies have assessed the location of the IOF relative to bony landmarks, teeth, as well as soft tissue landmarks with mixed results. Few studies have assessed the location of the IOF in three dimensions. This study analyzed the location of the IOF relative to a midpoint between the inferolateral nasal aperture and inferolateral orbital rim via three‐dimensional models rendered from 18 adult crania. The distance from the midpoint to the IOF averaged 4.16±1.43 mm (mean±SD) on the left and 3.93±1.43 mm on the right. Wilcoxon matched‐pairs signed rank tests revealed no significant difference among sides (p=0.325). This report also addresses differences among the x, y, and z axes. These preliminary data demonstrate the utility of three‐dimensional analysis for the assessment of IOF location. Understanding the location of the IOF in three dimensions may aid in determining the best patient‐specific approach for infraorbital nerve block.Support or Funding InformationWV Research Challenge Fund [HEPC.dsr.17.06] and [HEPC.dsr.14.13]This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Self-reported home exercise adherence – fact or fiction? A validity and reliability study using concealed accelerometry among people with knee osteoarthritis

Purpose: The benefits of exercise for older adults with knee osteoarthritis (OA) are undisputed. Given the chronic nature of OA, home exercise programs provide an economic and sustainable intervention option. However, for these programs to be beneficial, patient adherence is crucial. Self-reported adherence measures such as exercise diaries and simple self-rated scales are commonly used both clinically and in research, yet it has been acknowledged that these measures are vulnerable to reporting bias, particular over increasing periods of recall, and little evidence exists demonstrating their validity or reliability. The objectives of this study were threefold: (i) to examine concurrent validity of adherence over 12 weeks measured via an exercise diary compared to adherence simultaneously measured using a concealed accelerometer in a cuff weight, among a cohort of older adults with chronic knee pain undertaking a home strengthening program; (ii) to examine the validity of a self-rated adherence scale with increasing duration of recall from 2-12 weeks compared to accelerometer measured adherence; and (iii) to evaluate test-retest reliability of the self-rated adherence scale. Methods: 54 adults aged 45 years or older with self-reported painful knee OA completed a physiotherapist-prescribed quadriceps strengthening program using an ankle cuff weight. Over 12 weeks participants completed daily home exercise diaries (from which exercise volume was calculated by multiplying the number of exercise sessions recorded (possible range of 0-10 for each 2-week period) by the number of exercises performed in each session recorded (possible range of 1-4 exercises)) and at fortnightly appointments rated their agreement with the statement “I have been doing my exercises exactly as I was asked to by my physiotherapist” since Week 0 on an 11-point Numeric Rating Scale (0 = Strongly disagree to 10 = Strongly agree). A triaxial accelerometer and data logger were concealed (without the participant's knowledge) in the ankle cuff weight used for exercises. To enable evaluation of test-retest reliability of the NRS at Week 2 participants repeated the scale at home the day following their physiotherapy session. Data were analysed using descriptive statistics, Spearman rank-order correlations, the Wilcoxon matched-pairs signed-rank test and the Bland-Altman method to assess agreement. Intra-class correlation coefficients (ICC's) were used to assess test-retest reliability. Results: Adherence was significantly overestimated in exercise diaries over the 12 weeks compared to accelerometer recordings (Diary median = 220 exercises; Accelerometer median = 176; z = 6.2; P<0.00). A Bland-Altman plot indicated large between-participant variability in level of agreement between these measures. Neither self-reported measure met the optimal level of correlation (r>0.80). Adherence recorded in exercise diaries showed a moderate correlation with accelerometer data over 12 weeks (r = 0.52 (95%CI 0.26–0.69)). Correlations between self-rated adherence and accelerometer data over 2-12 weeks were little to fair with wide confidence intervals (r = 0.23 (95%CI 0.003–0.47) – r = 0.39 (95%CI 0.14–0.58)). No pattern of correlation was evident with increasing recall time periods. On the two occasions one day apart at Week 2, self-rated adherence neared, but did not meet minimal acceptable levels of reliability (ICC = 0.79, lower 1-sided 95% CI 0.68). Conclusions: Both exercise diaries and self-rated scales demonstrated questionable validity in measuring home exercise adherence when compared with the objective accelerometer measured exercise completion. The self-rated adherence scale was also found to have limited test-retest reliability. Consequently neither of the adherence measures examined in this study can be confidently recommended for clinicians or researchers to use.

Test-Retest Reliability of EQ-5D-5L Valuation Techniques: The Composite Time Trade-Off and Discrete Choice Experiments

ObjectivesTo explore the test-retest reliability of the composite time trade-off (C-TTO) and discrete choice experiment (DCE) used in the Indonesian five-level EuroQol five-dimensional questionnaire (EQ-5D-5L) valuation study. MethodsA representative sample aged 17 years and older was recruited from the Indonesian general population by stratified quota sampling with respect to residence, sex, and age. Trained interviewers conducted computer-assisted face-to-face interviews using the EuroQol valuation technology. Each respondent valued 10 health states using C-TTO and 7 pairs of health states in a DCE exercise. The retest interview was conducted after 2 weeks by the same interviewer. The Wilcoxon matched-pairs signed-rank test, intraclass correlation coefficient, and multilevel regression were applied in comparing the C-TTO test and retest data. For DCE, the analysis of proportions was used. ResultsA total of 226 respondents with characteristics similar to the Indonesian population completed the retest interview. For C-TTO, 82 (95.3%) of 86 health states had no significant mean value differences between test and retest. The mean value of the second test was statistically significantly higher than that of the first test by 0.042. For DCE, 72.5% of responses were identical. DCE retest showed a different pattern concerning the relative importance of the dimensions, whereas the C-TTO remained the same. ConclusionsC-TTO is stable over time, whereas in DCE the relative values of the dimensions shift. The results support the use of the C-TTO, in particular the Indonesian EQ-5D-5L value set, and suggest a critical examination of the reliability of DCE results over time.

Values clarification workshops to improve abortion knowledge, attitudes and intentions: a pre-post assessment in 12 countries

BackgroundWomen’s access to abortion care is often denied or hampered due to a range of barriers, many of which are rooted in abortion stigma. Abortion values clarification and attitude transformation (VCAT) workshops are conducted with abortion providers, trainers, and policymakers and other stakeholders to mitigate the effects of abortion stigma and increase provision of and access to abortion care. This study assesses changes in knowledge, attitudes, and behavioral intentions of VCAT workshop participants.MethodsPre- and post-workshop surveys from 43 VCAT workshops conducted in 12 countries in Asia, Africa, and Latin America between 2006 and 2011 were analyzed to assess changes in three domains: knowledge, attitudes and behavioral intentions related to abortion care. A score was created for each domain (range: 0-100), and paired t-tests or Wilcoxon matched-pairs signed-ranks tests were used to test for significant differences between the pre- and post-workshop scores overall and by region and participant type (providers, trainers, and policymakers/other stakeholders). We also assessed changes in pre- and post-workshop scores for participants with the lowest knowledge and negative attitudes on the pre-workshop survey.ResultsOverall, the mean knowledge score increased significantly from 49.0 to 67.1 (p < 0.001) out of a total possible score of 100. Attitudes and behavioral intentions showed more modest, but still statistically significant improvements between the pre- and post-workshop surveys. The mean attitudes score increased from 78.2 to 80.9 (p < 0.001), and the mean behavioral intentions score rose from 82.2 to 85.4 (p = 0.03). Among participants with negative attitudes pre-workshop, most shifted to positive attitudes on the post-workshop survey, ranging from 35.2% who switched to supporting unrestricted access to second-trimester abortion to 90.9% who switched to feeling comfortable working to increase access to contraceptive services in their country. Participants who began the workshop with the lowest level of knowledge experienced the greatest increase in mean knowledge score from 20.0 to 55.0 between pre- and post-workshop surveys (p < 0.001).ConclusionsVCAT workshop participants demonstrated improvements in knowledge, attitudes, and behavioral intentions related to abortion care. Participants who entered the workshops with the lowest levels of knowledge and negative attitudes had the greatest gains in these domains.

Determination of reference intervals and comparison of venous blood gas parameters using a standard and nonstandard collection method in 51 dogs.

The aim of this study was to determine reference intervals (RI) for venous blood parameters determined with the RAPIDPoint 500 (RP500) blood gas analyzer using blood gas syringes (BGS) and to determine whether immediate analysis of venous blood collected into lithium heparin (LH) tubes can replace anaerobic blood sampling into BGS. The null hypothesis was that canine venous blood samples collected in BGS and in LH tubes are comparable. Jugular blood was collected from 51 healthy dogs into a BGS and a LH tube. The BGS was immediately analyzed followed by the LH tube. The RI were calculated from BGS results. The BGS and LH tubes results were compared using paired t-test or Wilcoxon matched-pairs signed-rank test and Bland-Altman analysis. To assess clinical relevance, the bias between BGS and LH tubes was compared with the allowable total error (TEa). Values derived from LH tubes showed no significant difference for standard bicarbonate (HCO3std), whole blood base excess (BE B), Na, K, Cl, glucose and hemoglobin (tHb). The pH, partial pressure of carbon dioxide and oxygen, actual bicarbonate, extracellular base excess, ionized Ca, anion gap and lactate were significantly (p.

Respiratory pump maintains cardiac stroke volume during hypovolemia in young, healthy volunteers.

Spontaneous breathing has beneficial effects on the circulation, since negative intrathoracic pressure enhances venous return and increases cardiac stroke volume. We quantified the contribution of the respiratory pump to preserve stroke volume during hypovolemia in awake, young, healthy subjects. Noninvasive stroke volume, cardiac output, heart rate, and mean arterial pressure (Finometer) were recorded in 31 volunteers (19 women), 19-30 yr old, during normovolemia and hypovolemia (approximating 450- to 500-ml reduction in central blood volume) induced by lower-body negative pressure. Control-mode noninvasive positive-pressure ventilation was employed to reduce the effect of the respiratory pump. The ventilator settings were matched to each subject's spontaneous respiratory pattern. Stroke volume estimates during positive-pressure ventilation and spontaneous breathing were compared with Wilcoxon matched-pairs signed-rank test. Values are overall medians. During normovolemia, positive-pressure ventilation did not affect stroke volume or cardiac output. Hypovolemia resulted in an 18% decrease in stroke volume and a 9% decrease in cardiac output ( P < 0.001). Employing positive-pressure ventilation during hypovolemia decreased stroke volume further by 8% ( P < 0.001). Overall, hypovolemia and positive-pressure ventilation resulted in a reduction of 26% in stroke volume ( P < 0.001) and 13% in cardiac output ( P < 0.001) compared with baseline. Compared with the situation with control-mode positive-pressure ventilation, spontaneous breathing attenuated the reduction in stroke volume induced by moderate hypovolemia by 30% (i.e., -26 vs. -18%). In the patient who is critically ill with hypovolemia or uncontrolled hemorrhage, spontaneous breathing may contribute to hemodynamic stability, whereas controlled positive-pressure ventilation may result in circulatory decompensation. NEW & NOTEWORTHY Maintaining spontaneous respiration has beneficial effects on hemodynamic compensation, which is clinically relevant for patients in intensive care. We have quantified the contribution of the respiratory pump to cardiac stroke volume and cardiac output in healthy volunteers during normovolemia and central hypovolemia. The positive hemodynamic effect of the respiratory pump was abolished by noninvasive, low-level positive-pressure ventilation. Compared with control-mode positive-pressure ventilation, spontaneous negative-pressure ventilation attenuated the fall in stroke volume by 30%.

Evaluating the traditional day and night shift in an acute care surgery fellowship: Is the swing shift a better choice?

Fellowship trainees in acute care surgery require experience in the management of complex and operative trauma cases. Trauma center staffing usually follows standard 12-hour or 24-hour shifts, with resident and fellow trainees following a similar schedule. Although trauma admissions can be generally unpredictable, we analyzed temporal trends of trauma patient arrival times to determine the best time frame to maximize trainee experience during each day. We reviewed 10 years (2007-2016) of trauma registry data for blunt and penetrating trauma activations. Hourly volumetric trends were observed, and three specific events were chosen for detailed analysis: (1) trauma activation with Injury Severity Score (ISS) greater than 15, (2) laparotomy for trauma, and (3) thoracotomy for trauma. A retrospective shift log was created, which included day (7:00 AM to 7:00 PM), night (7:00 PM to 7:00 AM), and swing (noon to midnight) shifts. A swing shift was chosen because it captures the peak volume for all three events. Means and 95% confidence intervals were calculated, and comparisons were made between shifts using the Wilcoxon matched-pairs signed rank test with Bonferroni correction, and p less than 0.05 considered significant. During the 10-year study period, 28,287 patients were treated at our trauma center. This included the evaluation and management of 7,874 patients with ISS greater than 15, performance of 1,766 laparotomies, and 392 thoracotomies for trauma. Swing shift was superior to both day and night shifts for ISS greater than 15 (p < 0.001). Both swing and night shifts were superior to day shift for laparotomies (p < 0.001). Swing shift was superior to both day shift (p < 0.001) and night shift (p = 0.031). Shifts with the highest yield of ISS greater than 15, laparotomies, and thoracotomies include night and swing shifts on Fridays and Saturdays. Projected experience of acute care surgery fellows in managing complex trauma patients increases with the integration of swing shifts into the schedule. Daily trauma volume follows a temporal pattern which, when used correctly, can increase trainee exposure to complex and operative trauma cases. We encourage other centers to analyze their volume and adjust trainee schedules accordingly to maximize their educational experience. Therapeutic study, level IV.

Efficiency of Er:YAG utilization in accelerating deep bite orthodontic treatment.

The long duration of orthodontic treatment is a major patients' concern. A noninvasive method of accelerating tooth movement in a physiological manner is needed. The aim of the study was to evaluate the effects of Er:YAG laser application during orthodontic treatment of deep bite and to evaluate its analgesic effect during that movement. A prospective randomized controlled clinical trial (RCT) was performed on 30 patients with deep bite. Sample was divided into two groups: (A), 15 patients (orthodontic treatment-control group) and (B), 15 patients (orthodontic treatment and Er:YAG Laser - laser group). The tooth movement was evaluated as the primary outcome variable by measuring angular and linear changes on three progress lateral cephalometeric radiographs (T1, T2 and T3); Lateral cephalograms were taken before treatment (T1), immediately after finishing the stage of leveling and alignment (T2) and after completion of the intrusion stage (T3).Laser parameters were 400 mJ/10 Hz/4 W and 400 mJ/15 Hz/6 W, depending on the handpiece used. The levels of pain and discomfort were evaluated and ranked according to a visual analog scale. Paired t-tests or Wilcoxon matched-pairs signed-rank tests were used to detect significant differences. The main findings of the treatment were (1) significant positive difference in the rates of tooth intrusion movement on the experimental group compared with the control group at the baseline to T2 and T3 interval and the tooth movement rate was approximately 3 times faster in the experimental group. (2) The pain score in the experimental group was significantly lower compared with the control group on day 3 as on day 7. The application of Er:YAG laser is an effective mean to speed orthodontic tooth movement with a significant reduction in pain and discomfort after application.

Serum VEGF levels in the early diagnosis and severity assessment of non-small cell lung cancer.

Background: Effective biomarkers are essential to the differential diagnosis and severity assessment of non-small cell lung cancer (NSCLC). This study explored the use of the serum vascular endothelial growth factor (VEGF) levels as a biomarker with the aim of achieving better management of NSCLC.Methods: Serum VEGF levels were assayed via enzyme-linked immunosorbent assay in 180 patients with NSCLC, 136 patients with benign pulmonary nodules, and 119 healthy controls. We additionally detected the serum concentration of three traditional biomarkers—carcinoembryonic antigen (CEA), cancer antigen (CA)-125, and cytokeratin 19 fragments (Cyfra 21-1)—to comparatively evaluate the efficiency and diagnostic value of VEGF in patients with NSCLC. We further evaluated the relationship between serum VEGF levels and clinicopathologic parameters. VEGF levels were compared between pro- and post-surgical patients using the Wilcoxon matched-pairs signed-rank test. DNA was isolated from the primary tumors. EGFR mutations were detected by Scorpions amplification refractory mutation system (ARMS).Results: Patients with NSCLC had significantly higher serum concentration of VEGF, compared to those with benign pulmonary nodules and healthy controls (P <0.0001). As a diagnostic biomarker of NSCLC, VEGF had area under the curve values of 0.824 and 0.839, sensitivities of 75.0% and 75.0%, and specificities of 93.3% and 95.6% when compared with healthy people and patients with benign pulmonary nodules, respectively; notably, these values were greater than those of CA125, Cyfra 21-1 and CEA. Furthermore, a model in which VEGF was combined with CEA, CA125, and Cyfra 21-1 was more effective for NSCLC diagnosis than VEGF alone (sensitivity, 85.0% and 84.4; specificity, 90.0% and 91.9% vs. healthy controls and patients with benign pulmonary nodules, respectively). When use to identify early-stage NSCLC, VEGF showed a better diagnostic efficacy than other biomarkers. The pro-surgical VEGF levels were significantly higher than those measured 25-30 days after surgery. Moreover, VEGF concentration differed significantly among cases according to TNM stages and malignant grades (P <0.0001). EGFR mutations and the size of benign pulmonary nodules did not affect the level of serum VEGF significantly.Conclusion: The serum VEGF levels exhibited relatively high sensitivity and specificity for NSCLC, and may therefore be a useful diagnostic biomarker. Furthermore, the serum VEGF levels could be used to assess prognosis and curative effects.

Urodynamic outcomes of tamsulosin in the treatment of primary bladder neck obstruction in men.

Introduction:Alpha blockers are widely used in the treatment of primary bladder neck obstruction; however, evidence for objective urodynamic efficacy is scarce. We studied the effect of the uroselective α1-blocker tamsulosin on urodynamic parameters in male patients with type I primary bladder neck obstruction.Methods:A single center prospective observational study was carried out from July 2013 to February 2015. Male patients (18–50 years) with type 1 primary bladder neck obstruction were recruited. Selected patients were started on tablet tamsulosin 0.4 mg once daily for 3 months. International prostate symptom score (IPSS), uroflow and urodynamic studies were done pre- and post-treatment. Primary outcome was decreased in minimum detrusor pressure at maximum flow rate by 15%. Wilcoxon-matched pair signed-rank test was used.Results:Of 39 patients recruited, 21 patients completed the follow-up as per protocol and were analyzed. Mean age was 41 years. 57% patients achieved the primary outcome (median detrusor pressure pre- and post-treatment were 71 and 56 cm of water, P < 0.001). Similarly, median values for bladder outlet obstruction index (BOOI) and IPSS decreased from 59 to 38 (P < 0.001) and 22 to 12 (P < 0.001), respectively. Median maximum flow rate increased from 8 to 10 ml (P = 0.05). Pretreatment BOOI of >60 was associated with poor outcomes.Conclusions:Tamsulosin 0.4 mg once a day is effective in reducing bladder outlet obstruction on pressure flow studies in patients with primary bladder neck obstruction type 1.

Effects of a Physical Activity and Brain Exercise Program on Cognitive Ability of Healthy Thai Elders

This study used a quasi-experimental single-group time series design to compare the effects of a physical activity and brain exercise program on the cognitive ability of healthy Thai elders. It was conducted from December 2015 to May 2016. A purposive sample of 23 people of over 60 years of age was used. The research instruments consisted of 1) the Mini-Mental State Examination Thai 2002 (MMSE-Thai 2002), 2) the Montreal Cognitive Assessment (MoCA, Thai version), and 3) the physical activity and brain exercise program devised for this research. The program components were validated and reviewed by 3 experts and yielded a content validity index (CVI) of 0.96. Participants attended the program 8 times (3 h each) over 5 consecutive weeks. Subsequently, participant follow-up progress reviews were done in weeks 10, 14, and 18. Data were analyzed using descriptive statistics and ANOVA with Wilcoxon matched-pairs signed-rank test and repeated measures ANOVA. Results revealed that the average score for cognitive ability (Mental State and cognitive function) in weeks 10 and 14 and at follow-up in week 18 were statistically significantly higher (p &lt; .05) than the baseline. Recommendation: the physical activity and brain exercise program could improve cognitive ability and should be included in health promoting activities in elders’ clubs or senior schools in the future.