Category: Statistics

Bone. 2021 Jun 30:116096. doi: 10.1016/j.bone.2021.116096. Online ahead of print.

ABSTRACT

BACKGROUND: Prior data demonstrated three weeks of sleep restriction and concurrent circadian disruption uncoupled bone turnover markers (BTMs), indicating decreased bone formation and no change or increased bone resorption. The effect of insufficient sleep with or without ad libitum weekend recovery sleep on BTMs is unknown.

METHODS: BTMs were measured in stored serum from 20 healthy adults randomized to one of three study groups consisting of a control group (N = 3 men; 9 h/night) or one of two nocturnal sleep restriction groups in an inpatient laboratory environment. One Sleep Restriction group (“SR”; N = 9; 4 women) had 5 h sleep opportunity per night for nine nights. The other sleep restriction group had an opportunity for ad libitum Weekend Recovery sleep (“WR”; N = 8; 4 women) after four nights of 5 h sleep opportunity per night. Food intake was energy balanced at baseline and ad libitum thereafter. Fasted morning BTM levels and hourly 24 h melatonin levels were obtained on study days 3 (baseline), 5 (after 1 night of sleep restriction for WR and SR), and 11 (after a sleep restricted workweek with weekend recovery sleep in WR or 7 nights of sleep restriction in SR). Linear mixed-effects modeling was used to examine the effect of study duration (e.g., change over time), study condition, age, and sex on BTMs. Pearson correlations were used to determine associations between changes in BTMs and changes in weight and morning circadian misalignment (i.e., duration of high melatonin levels after wake time).

RESULTS: There was no significant difference between the three study groups in change over time (p ≥ 0.4 for interaction between assigned group and time for all BTMs), adjusted for age and sex. There was no significant change in N-terminal propeptide of procollagen type I (P1NP), osteocalcin, or C-telopeptide of type I collagen (CTX) from baseline to day 11 (all p ≥0.3). In women <25 years old, there was a non-significant decline in P1NP from day 3 to day 5 (-15.74 ± 7.80 ng/mL; p = 0.06). Change in weight and morning circadian misalignment from baseline to day 11 were correlated with statistically non-significant changes in BTMs (all p ≤ 0.05).

CONCLUSION: In this small secondary analysis, we showed that nine nights of prescribed sleep restriction with or without weekend recovery sleep and ad libitum food intake did not alter BTMs. It is possible that age, sex, weight change and morning circadian misalignment modify the effects of sleep restriction on bone metabolism.

PMID:34216838 | DOI:10.1016/j.bone.2021.116096

Orthop Traumatol Surg Res. 2021 Jun 30:103001. doi: 10.1016/j.otsr.2021.103001. Online ahead of print.

ABSTRACT

INTRODUCTION: The tip-apex distance (TAD) is the only predictor for mechanical failure after internal fixation of trochanteric fractures. The main objective of our study was to assess whether the intraoperative visual estimation of the TAD concurred with the measurement taken on postoperative digital X-rays. We hypothesized that there was a good concordance between these 2 different methods of measurement.

MATERIALS AND METHODS: Patients with an isolated trochanteric fracture were included in our study. A hardcopy of the intraoperative X-rays were printed, and the TAD was calculated manually. Radiological and clinical follow-ups were scheduled at 6 weeks, 3 months and 6 months during which numerical measurements of the TAD were taken. We also recorded the fracture type (AO/OTA classification), degree of osteoporosis (Singh index), surgeon experience, age and ASA score.

RESULTS: A total of 98 patients were included in our study. Of these, 70 had a 6-month follow-up and interpretable postoperative X-rays. The mean age was 87 years, with 77.14% women and a mean ASA score of 3. The coefficient of concordance between the intra and postoperative TAD was 0.7202 (95% CI = 0.4905-0.9499). The secondary displacement rate was 3.28%. The univariate analysis showed no statistically significant association between an intraoperative TAD > 25 mm and fracture type (P = .7290), degree of osteoporosis (P = .5701) and surgeon experience (P = 1).

DISCUSSION/CONCLUSIONS: There was a high degree of concordance between intraoperative visual estimation of the TAD and its measurement on postoperative digital X-rays. The treatment of unstable fractures in osteoporotic bone by junior surgeons was not a risk factor for intraoperative TAD > 25 mm. It is therefore important to educate young surgeons on the concept of TAD and its intraoperative visual estimation technique as it ensures that the cephalic screw is positioned properly during the fixation of trochanteric fractures.

LEVEL OF EVIDENCE: II.

PMID:34216841 | DOI:10.1016/j.otsr.2021.103001

Clin Gastroenterol Hepatol. 2021 Jun 30:S1542-3565(21)00691-1. doi: 10.1016/j.cgh.2021.06.027. Online ahead of print.

ABSTRACT

BACKGROUND: Epidemiological studies from Europe and North America report an increasing incidence of microscopic colitis (MC) in the late twentieth century followed by a plateau. This population-based study assessed recent incidence trends and the overall prevalence of MC over the past decade.

METHODS: Residents of Olmsted County, Minnesota diagnosed with collagenous colitis (CC) or lymphocytic colitis (LC) between January 1, 2011 and December 31, 2019 were identified using the Rochester Epidemiology Project. Clinical variables were abstracted by chart review. Incidence rates were age- and sex-adjusted to the 2010 US population. Associations between incidence and age, sex, and calendar periods were evaluated using Poisson regression analyses.

RESULTS: A total of 268 incident cases of MC were identified with a median age at diagnosis of 64 years (range, 19-90); 207 (77%) were women. The age- and sex-adjusted incidence of MC was 25.8 (95% confidence interval [CI] 22.7-28.9) cases per 100,000 person-years. The incidence of LC was 15.8 (95% CI, 13.4-18.2) and CC 9.9 (95% CI, 8.1-11.9) per 100,000 person-years. A higher MC incidence was associated with increasing age and female sex (p<0.01). There was no significant trend in age- and sex-adjusted incidence rate over the study period (p=0.92). On December 31, 2019, the prevalence of MC, LC, and CC (including cases diagnosed before 2011) was 246.2, 146.1, and 100.1 per 100,000 persons, respectively.

CONCLUSION: The incidence of MC and its subtypes was stable between 2011-2019, but its prevalence is higher than in previous periods. MC incidence continues to be associated with increasing age and female sex.

PMID:34216819 | DOI:10.1016/j.cgh.2021.06.027

Clin Gastroenterol Hepatol. 2021 Jun 30:S1542-3565(21)00699-6. doi: 10.1016/j.cgh.2021.06.035. Online ahead of print.

ABSTRACT

BACKGROUND AND AIMS: We developed and validated a magnetic resonance imaging (MRI-)based index to predict Crohn’s disease (CD) post-operative recurrence (POR).

METHODS: Patients with CD having undergone a post-operative evaluation for recurrence (with colonoscopy and MRI no longer than 105 days apart) were included between 2006 and 2016 in university hospital of Nancy, France. MRI-items with good levels of intra and inter-rater agreement (Gwet’s coefficient ≥0.5) were selected. The MONITOR index’s performance was assessed in terms of the area under the receiver operating characteristic curve (AUROC) and accuracy, by considering the Rutgeerts score as the gold standard. The MONITOR index was validated with a bootstrap method and an independent cohort.

RESULTS: Seventy-three MRI datasets were interpreted by two radiologists. Seven items (bowel wall thickness, contrast enhancement, T2 signal increase, diffusion-weighted signal increase, edema, ulcers, and the length of the diseased segment) had a Gwet’s coefficient ≥0.5 and were significantly associated with the Rutgeerts score, leading to their inclusion in the MONITOR index. All the items had a weighting of 1, except the “ulcers” item weighting 2.5, reflecting the higher adjusted odds ratio. The AUROC [95% confidence interval] for the prediction of endoscopic POR (Rutgeerts score >i1) was 0.80 [0.70; 0.90]. The optimal threshold was a MONITOR index ≥1, giving a sensitivity of 79%, a specificity of 55%, a predictive positive value of 68%, and a predictive negative value of 68%. The bootstrap validation gave an AUROC of 0.85 [0.73; 0.97]. In the validation cohort, a MONITOR index ≥1 gave a sensitivity of 87%, a specificity of 75%, a predictive positive value of 84,6%, and a predictive negative value of 75%.

CONCLUSIONS: The MONITOR index is an efficient, reliable, easy-to-apply tool that can be used in clinical practice to predict the POR of CD.

PMID:34216820 | DOI:10.1016/j.cgh.2021.06.035

Neuroimage. 2021 Jun 30:118323. doi: 10.1016/j.neuroimage.2021.118323. Online ahead of print.

ABSTRACT

Axon diameter mapping using diffusion MRI in the living human brain has attracted growing interest with the increasing availability of high gradient strength MRI systems. A systematic assessment of the consistency of axon diameter estimates within and between individuals is needed to gain a comprehensive understanding of how such methods extend to quantifying differences in axon diameter index between groups and facilitate the design of neurobiological studies using such measures. We examined the scan-rescan repeatability of axon diameter index estimation based on the spherical mean technique (SMT) approach using diffusion MRI data acquired with gradient strengths up to 300 mT/m on a 3T Connectom system in 7 healthy volunteers. We performed statistical power analyses using data acquired with the same protocol in a larger cohort consisting of 15 healthy adults to investigate the implications for study design. Our study revealed a high degree of repeatability in voxel-wise restricted volume fraction estimates and tract-wise estimates of axon diameter index derived from high-gradient diffusion MRI data. On the region of interest (ROI) level across white matter tracts in the whole brain, the Pearson’s correlation coefficient of the axon diameter index estimated between scan and rescan experiments was r = 0.72 with an absolute deviation of 0.18 μm. For an anticipated 10% effect size in studies of axon diameter index, most white matter regions required a sample size of less than 15 people to observe a measurable difference between groups using an ROI-based approach. To facilitate the use of high-gradient strength diffusion MRI data for neuroscientific studies of axonal microstructure, the comprehensive multi-gradient strength, multi-diffusion time data from all individuals included in this work will be made publicly available, in support of open science and increasing the accessibility of such data to the greater scientific community.

PMID:34216774 | DOI:10.1016/j.neuroimage.2021.118323

J Shoulder Elbow Surg. 2021 Jun 30:S1058-2746(21)00527-9. doi: 10.1016/j.jse.2021.05.028. Online ahead of print.

ABSTRACT

BACKGROUND: Treatment of posterior shoulder instability (PSI) associated with excessive glenoid retroversion is a rare, challenging problem in shoulder surgery. One proposed technique is posterior opening wedge glenoid osteotomy to correct excessive glenoid retroversion as described by Scott. However, this operation is rarely performed and limited long-term outcomes using this approach are available. It was the goal to analyze long-term outcome of posterior open wedge glenoid osteotomy for PSI associated with excessive glenoid retroversion.

METHODS: Six consecutive patients (7 shoulders) with a mean age of 24 (range, 19-34) years were treated with posterior open wedge glenoid osteotomy for PSI associated with a glenoid retroversion greater than 15° and followed-up clinically and radiographically at a mean of 15 (range, 10-19) years.

RESULTS: Recurrent, symptomatic PSI was observed in 6 out of 7 shoulders (86%). One necessitated revision with a posterior (iliac crest) bone block procedure and was rated as a failure and excluded from functional analysis. One patient rated his result as excellent, 3 as good, 1 as fair and 1 as unsatisfactory. Mean relative Constant Score (CS%) was unchanged from preoperatively to final follow-up (CS%: 72%) and pain did not significantly decrease (Constant pain scale: 7 to 10 points; p=0.969). The mean Subjective Shoulder Value (SSV) was improved postoperatively but with 7 patients the improvement did not reach statistical significance (SSV: 42% to 67%; p=0.053) and the total WOSI score averaged 30% at the final follow-up. Mean glenoid retroversion of all 7 shoulders was corrected from 20° (Range, 16-26°) to 3° (range, (-)3-(+)8°; p=0.018). In the five shoulders with preoperative static posterior subluxation of the humeral head (PSH), the humeral head was not recentered. All seven shoulders showed progression of glenoid arthritic changes.

CONCLUSIONS: Posterior open wedge glenoid osteotomy for PSI associated with excessive glenoid retroversion did neither reliably restore shoulder stability nor recenter the joint or prevent progression of osteoarthritis. Alternative treatments for PSI associated with excessive glenoid retroversion have to be developed and evaluated.

PMID:34216782 | DOI:10.1016/j.jse.2021.05.028

J Biomed Inform. 2021 Jun 30:103855. doi: 10.1016/j.jbi.2021.103855. Online ahead of print.

ABSTRACT

Aging is a major risk factor for various eye diseases, such as cataract, glaucoma, and age-related macular degeneration. Age-related changes are observed in almost all structures of the human eye. Considerable individual variations exist within a group of similarly aged individuals, indicating the need for more informative biomarkers for assessing the aging of the eyes. The morphology of the anterior segment has been reported to vary across age groups, focusing on only a few corneal parameters, such as keratometry and thickness of the cornea, which could not provide accurate estimation of age. Thus, the association between eye aging and the morphology of the anterior segment remains elusive. In this study, we aimed to develop a predictive model of age based on a large number of anterior segment morphology-related features, measured via the high-resolution Pentacam. This approach allows for an integrated assessment of age-related changes in corneal morphology, and the identification of important morphological features associated with different eye aging patterns. Three machine learning methods (neural networks, Lasso regression and extreme gradient boosting) were employed to build predictive models using 276 anterior segment features of 63,753 participants from 10 ophthalmic centers in 10 different cities of China. The best performing age prediction model achieved a median absolute error of 2.80 years and a mean absolute error of 3.89 years in the validation set. An external cohort of 100 volunteers was used to test the performance of the prediction model. The developed neural network model achieved a median absolute error of 3.03 years and a mean absolute error of 3.4 years in the external cohort. In summary, our study revealed that the anterior segment morphology of the human eye may be an informative and non-invasive indicator of eye aging. This could prompt doctors to focus on age-related medical interventions on ocular health.

PMID:34216803 | DOI:10.1016/j.jbi.2021.103855

Eur J Pain. 2021 Jul 3. doi: 10.1002/ejp.1835. Online ahead of print.

ABSTRACT

This journal recently published a paper by Rong et al., entitled “Persistent moderate to severe pain and long-term cognitive decline.” (Rong et al., 2021). The authors demonstrate that, to a small but statistically significant degree, older adults with persistent moderate-to-severe pain (an approximation for chronic pain) experience a faster rate of late-life cognitive decline than older adults without pain. Given these findings, should clinicians be alert for accelerated cognitive decline in older adults with chronic pain? Rong and colleagues argue yes. But, interestingly, using the same data source, an earlier study by Veronese and colleagues concluded that there was no evidence for an effect (Veronese et al., 2018). What are we to make of this?

PMID:34216525 | DOI:10.1002/ejp.1835

Colorectal Dis. 2021 Jul 3. doi: 10.1111/codi.15801. Online ahead of print.

ABSTRACT

We read with interest the paper by Park et al [1]. The authors analyzed a population of 107 patients with mid-transverse colon cancer (MTCC), who underwent either extended hemicolectomy (EC=70) or segmental colectomy (SC=37) [1]. No statistically significant difference was found in perioperative and long-term outcomes, following propensity score matching [1]. In particular, the authors underlined the lack of significant differences in 3-year disease-free survival (DFS; 86.5% vs. 90.9%, p = 0.675) and 5-year overall survival (OS; 87.4% vs. 93.0%, p = 0.349) [1].

PMID:34216529 | DOI:10.1111/codi.15801

J Vet Emerg Crit Care (San Antonio). 2021 Jul 3. doi: 10.1111/vec.13085. Online ahead of print.

ABSTRACT

OBJECTIVE: To compare hemostatic variables performed on blood samples obtained from indwelling jugular catheters or direct venipuncture over a 72-hour period.

DESIGN: Prospective experimental study.

SETTING: University research laboratory.

ANIMALS: Five healthy neutered male purpose-bred Beagle dogs.

INTERVENTIONS: Each dog was sedated to facilitate placement of a long-stay 20-Ga polyurethane IV catheter into the jugular vein. Blood samples were obtained from the preplaced catheters at 4 time points corresponding to 0, 24, 48, and 72 hours relative to placement. Blood samples were also obtained by direct venipuncture of a peripheral vein using a 21-Ga butterfly catheter and evacuated blood tubes at the same time points. Platelet count, platelet closure time, prothrombin time, activated partial thromboplastin time, fibrinogen, and kaolin-activated thromboelastography were performed on these paired samples at each time point. The patency of the indwelling catheters was maintained by flushing every 6 hours with heparinized saline.

MEASUREMENTS AND MAIN RESULTS: No significant differences were identified in any of the hemostatic variables obtained by either blood collection technique at any time point during the study (P > 0.05). There was also no significant day-to-day variation in any catheter-derived hemostatic variable obtained from individual dogs identified over the course of the study.

CONCLUSIONS: These data suggest that accurate hemostatic variables may be obtained using blood collected from indwelling jugular catheters, maintained with heparinized saline for at least 72 hours, in healthy dogs.

PMID:34216531 | DOI:10.1111/vec.13085