Tag: pubmed

Diabetes Care. 2021 Sep 2:dc211107. doi: 10.2337/dc21-1107. Online ahead of print.

ABSTRACT

OBJECTIVE: Early menopause may be associated with higher cardiovascular disease (CVD) risk. Type 2 diabetes mellitus (T2DM), coupled with early menopause, may result in even greater CVD risk in women. We examined CVD risk in women with early compared with normal-age menopause, with and without T2DM overall, and by race/ethnicity.

RESEARCH DESIGN AND METHODS: We pooled data from the Atherosclerosis Risk in Communities study, the Multi-Ethnic Study of Atherosclerosis, and the Jackson Heart Study. We included women with data on menopausal status, menopausal age, and T2DM, excluding pre- or perimenopausal women and those with prevalent CVD. Outcomes included incident coronary heart disease (CHD), stroke, heart failure (HF), and atherosclerotic cardiovascular disease (ASCVD) (CHD or stroke). We estimated the risk associated with early (<45 years) compared with normal-age menopause using Cox proportional hazards models. Covariates included age, race/ethnicity, education, BMI, blood pressure, cholesterol, smoking, alcohol consumption, antihypertensive medication, lipid-lowering medication, hormone therapy use, and pregnancy history.

RESULTS: We included 9,374 postmenopausal women for a median follow-up of 15 years. We observed 1,068 CHD, 659 stroke, 1,412 HF, and 1,567 ASCVD events. T2DM significantly modified the effect of early menopause on CVD risk. Adjusted hazard ratios for early menopause and the outcomes were greater in women with T2DM versus those without (CHD 1.15 [95% CI 1.00, 1.33] vs. 1.09 [1.03, 1.15]; stroke 1.21 [1.04, 1.40] vs. 1.10 [1.04, 1.16]; ASCVD 1.29 [1.09, 1.51] vs. 1.10 [1.04, 1.17]; HF 1.18 [1.00, 1.39] vs. 1.09 [1.03, 1.16]). The modifying effect of T2DM on the association between early menopause and ASCVD was only statistically significant in Black compared with White women.

CONCLUSIONS: Early menopause was associated with an increased risk for CVD in postmenopausal women. T2DM may further augment the risk, particularly in Black women.

PMID:34475032 | DOI:10.2337/dc21-1107

Stat Med. 2021 Sep 2. doi: 10.1002/sim.9187. Online ahead of print.

ABSTRACT

In this article, we consider the density estimation for data with a mixture structure, where the component densities are assumed unknown, but for each observation, the probabilities of its membership to the subpopulations are known or estimable from other resources. Data of this kind arise from practice and have wide applications. Motivated from the classical kernel density estimation method for a single population, we propose a weighted kernel density estimation method to estimate the component density functions nonparametrically. Within the framework of the EM algorithm, we derive an algorithm that computes our proposed estimates effectively. Via extensive simulation studies, we demonstrate that our methods outperform the existing methods in most occasions. We further compare our methods with existing methods by real data examples.

PMID:34474504 | DOI:10.1002/sim.9187

Korean J Med Educ. 2021 Sep;33(3):191-201. doi: 10.3946/kjme.2021.199. Epub 2021 Aug 27.

ABSTRACT

PURPOSE: This study aims to design that using formative assessment as an instructional strategy in real-time online classes, and to explore the application of Bloom’s taxonomy in the development of formative assessment items.

METHODS: We designed the instruction using formative assessment in real-time online classes, developed the items of formative assessment, analyzed the items statistically, and investigated students’ perceptions of formative assessment through a survey.

RESULTS: It is designed to consist of 2-3 learning outcomes per hour of class and to conduct the formative assessment with 1-2 items after the lecture for each learning outcome. Formative assessment was 31 times in the physiology classes (total 48 hours) of three basic medicine integrated. There were nine “knowledge” items, 40 “comprehension” items, and 55 “application” items. There were 33 items (31.7%) with a correct rate of 80% or higher, which the instructor thought was appropriate. As a result of the survey on students’ perceptions of formative assessment, they answered that it was able to concentrate on the class and that it was helpful in achieving learning outcomes.

CONCLUSION: The students focused during class because they had to take formative assessment immediately after the learning outcome lecture. “Integration of lesson and assessments” was maximized by solving the assessment items as well as through the instructor’s immediate explanation of answers. Through formative assessment, the students were able to utilize metacognition by learning what content they understood or did not understand. Items that consider Bloom’s taxonomy allow students to remember, understand, and apply to clinical contexts.

PMID:34474526 | DOI:10.3946/kjme.2021.199

Stat Med. 2021 Sep 2. doi: 10.1002/sim.9184. Online ahead of print.

ABSTRACT

Current status data arise when each subject is observed only once and the failure time of interest is only known to be either smaller or larger than the observation time rather than observed exactly. For the situation, due to the use of imperfect diagnostic tests, the failure status could often suffer misclassification or one observes misclassified data, which may result in severely biased estimation if not taken into account. In this article, we discuss regression analysis of such misclassified current status data arising from the additive hazards model, and a simulation-extrapolation (SIMEX) approach is developed for the estimation. Furthermore, the asymptotic properties of the proposed estimators are established, and a simulation study is conducted to assess the empirical performance of the method, which indicates that the proposed procedure performs well. In particular, it can correct the estimation bias given by the naive method that ignores the existence of misclassification. An application to a medical study on gonorrhea is also provided.

PMID:34474502 | DOI:10.1002/sim.9184

J Reconstr Microsurg. 2021 Sep 2. doi: 10.1055/s-0041-1733994. Online ahead of print.

ABSTRACT

BACKGROUND: Free flaps have become a highly valuable tool for complex reconstructive surgeries. The requirement of red blood cell transfusion (RBCT) during the perioperative period is common and its effect on the free flap survival is debatable. The aim of this study was to determine the relationship between perioperative RBCT and vascular pedicle thrombosis (VPT).

METHODS: For this study 302 free flaps performed between January 2006 and December 2019 were retrospectively analyzed. It included their characteristics from before, during, and after the surgical procedure. The incidence of VPT and flap survival were calculated based on Kaplan Meier’s method and the relationship between VPT and perioperative variables were analyzed by Cox regression models.

RESULTS: The transfusion group was represented by 62 flaps (20.5%) and no transfusion by 240 flaps. The overall transfusion requirement was 20.5% and the cumulative incidence of VPT was 9.11%. A statistically significant relationship was not demonstrated between flap survival and transfusion status (HR = 1.73 IC 95%: 0.5 to 3.96; p = 0.192) (p = 0.192) independently from the number of units transfused, the preoperative diagnosis of anemia, and the type of flap used and did not establish an increased risk of VPT.

CONCLUSIONS: This study did not demonstrate an association between RBCT during preoperative period and the risk for VPT or microvascular free flap survival rate on postoperative follow up.

PMID:34474496 | DOI:10.1055/s-0041-1733994

Stat Med. 2021 Sep 2. doi: 10.1002/sim.9185. Online ahead of print.

ABSTRACT

The potential benefit of using a surrogate marker in place of a long-term primary outcome is very attractive in terms of the impact on study length and cost. Many available methods for quantifying the effectiveness of a surrogate endpoint either rely on strict parametric modeling assumptions or require that the primary outcome and surrogate marker are fully observed that is, not subject to censoring. Moreover, available methods for quantifying surrogacy typically provide a proportion of treatment effect explained (PTE) measure and do not directly address the important questions of whether and how the trial can be ended earlier using the surrogate marker. In this article, we specifically address these important questions by proposing a PTE measure to quantify the feasibility of ending trials early based on endpoint information collected at an earlier landmark point $t_0$ in a time-to-event outcome setting. We provide a framework for deriving an optimally predicted outcome for individual patients at $t_0$ based on a combination of surrogate marker and event time information in the presence of censoring. We propose a non-parametric estimator for the PTE measure and derive the asymptotic properties of our estimators. Finite sample performance of our estimators are illustrated via extensive simulation studies and a real data application examining the potential of hemoglobin A1c and fasting plasma glucose to predict treatment effects on long term diabetes risk based on the Diabetes Prevention Program study.

PMID:34474500 | DOI:10.1002/sim.9185

Spine (Phila Pa 1976). 2021 Aug 31. doi: 10.1097/BRS.0000000000004215. Online ahead of print.

ABSTRACT

STUDY DESIGN: This was a dual-center study over an eight-year period on patients undergoing single level fusion surgery with either posterior- (PLIF) or transforaminal lumbar interbody fusion (TLIF). We analyzed prospectively collected pre- and postoperative data from the national Danish surgical spine database (DaneSpine).

OBJECTIVE: To compare clinical and patient-reported outcome (PRO) two years after TLIF or PLIF in patients with symptomatic lumbar mechanical disc degeneration.

SUMMARY OF BACKGROUND DATA: PLIF and TLIF are well-described techniques for treating lumbar mechanical disc degeneration but whether the theoretical differences between the two techniques translate to different clinical outcomes is unknown.

METHODS: The primary outcome was Oswestry Disability Index (ODI) score at two-year follow-up. Secondary outcome measures were scores on the European Quality of Life-5 Dimensions (EQ-5D) and visual analog scale (VAS) and the rate of intraoperative complications. To minimize baseline differences between the groups, propensity-score matching was employed in a 1:1 fashion, balancing the groups on preoperative factors including age, sex, back and leg pain, ODI, EQ-5D and previous spine surgery.

RESULTS: The matched cohort included 211 patients in each cohort. There was no significant difference between the groups in the mean score on the ODI at two years (PLIF: 33 ± 20 vs. TLIF: 35 ± 20, p = 0.328). We found no statistically significant differences in EQ-5D score (0.54 ± 0.35 vs. 0.51 ± 0.34, p = 0.327), VAS score for back pain (47 ± 32 vs. 48 ± 29, p = 0.570) or leg pain (42 ± 33 vs.41 ± 32, p = 0.936) between the PLIF and TLIF groups, respectively at two-year follow-up. Dural tears occurred in 9.5% in the PLIF group and 1.9% in the TLIF group (p = 0.002) corresponding to a relative risk of 5.0 (95%CI 1.7-14.4).

CONCLUSIONS: We found no significant difference in PRO at two-year follow-up between PLIF and TLIF for the treatment of lumbar disc degeneration. PLIF is associated with a five-times higher risk of dural tears.Level of evidence: 3.

PMID:34474454 | DOI:10.1097/BRS.0000000000004215

J Glaucoma. 2021 Sep 2. doi: 10.1097/IJG.0000000000001935. Online ahead of print.

ABSTRACT

PRECIS: Glaucoma can cause disturbance in psychological and emotional functioning of patients, leading to anxiety and depression, even early in the disease. Identification and management of these problems should be included as a part of the holistic approach for patient care.

PURPOSE: To assess the prevalence of anxiety and depression in patients with primary glaucoma using a standard validated questionnaire.

METHODS: A cross-sectional prevalence study was carried out on 200 patients attending the glaucoma outpatient clinic at a tertiary care eye hospital in Pune, India. After obtaining written consent, all patients underwent a thorough ophthalmic examination. Those with primary glaucoma were included in the study and classified on the basis of the Hodapp-Parrish-Anderson criteria. Participants were asked to respond to the Hospital Anxiety and Depression Scale (HADS) questionnaire and responses were analyzed statistically.

RESULTS: Mean HADS- Anxiety (HADS-A) score was 4.5 (SD 3.4) while HADS-Depression (HADS-D) was 4.1 (SD 3.8). Severity of disease was associated with significantly higher HADS scores. Mean HADS-A scores were 3.1 (SD 2.9) mild glaucoma, 4.4 (SD 2.6) for moderate and 7.7 (SD 3.0) for advanced disease (P<0.001). Similarly mean HADS-D scores were 2.0 (SD 2.6), 4.2 (SD 3.0) and 8.3 (SD 3.3) respectively for mild, moderate and severe glaucoma (P<0.001). Based on HADS scores, a quarter of patients (25.5%) were symptomatic for anxiety or depression, out of which 25 (12.5%) could be classified as definite cases. Duration of treatment had no association with HADS scores.

CONCLUSION: An association exists between the amount of visual loss among patients with glaucoma, and symptoms of anxiety and depression, irrespective of disease duration. This information may help to choose treatment approaches most likely to be beneficial to the patients.

PMID:34474423 | DOI:10.1097/IJG.0000000000001935

Spine (Phila Pa 1976). 2021 Aug 31. doi: 10.1097/BRS.0000000000004214. Online ahead of print.

ABSTRACT

STUDY DESIGN: A retrospective cross-sectional study.

OBJECTIVE: This study aims to evaluate the effect size of postoperative glycemic variability on surgical outcomes among patients who have undergone one- to three-level lumbar fusion.

SUMMARY OF BACKGROUND DATA: While numerous patient characteristics have been associated with surgical outcomes after lumbar fusion, recent studies have described the measuring of postoperative glycemic variability as another promising marker.

METHODS: A total of 850 patients were stratified into tertiles (low, moderate, high) based on degree of postoperative glycemic variability defined by coefficient of variation (CV). Surgical site infections were determined via chart review based on the CDC definition. Demographic factors, surgical characteristics, inpatient complications, readmissions, and reoperations were determined by chart review and telephone encounters.

RESULTS: Overall, a statistically significant difference in 90-day adverse outcomes was observed when stratified by postoperative glycemic variability. In particular, patients with high CV had higher odds of readmission (OR = 2.19 [1.17, 4.09]; P = 0.01), experiencing a surgical site infection (OR = 3.22 [1.39, 7.45]; P = 0.01), and undergoing reoperations (OR = 2.65 [1.34, 5.23]; P = 0.01) compared with patients with low CV. No significant association was seen between low and moderate CV groups. Higher CV patients were more likely to experience longer hospital stays (β: 1.03; P = 0.01). Among the three groups, high CV group experienced the highest proportion of complications.

CONCLUSION: Our study establishes a significant relationship between postoperative glycemic variability and inpatient complications, length of stay, and 90-day adverse outcomes. While HbA1c has classically been used as the principal marker to assess blood glucose control, our results show CV to be a strong predictor of postoperative adverse outcomes. Future high-quality, prospective studies are necessary to explore the true effect of CV, as well as its practicality in clinical practice. Nevertheless, fluctuations in blood glucose levels during the inpatient stay should be limited to improve patient results.Level of Evidence: 4.

PMID:34474452 | DOI:10.1097/BRS.0000000000004214

J Glaucoma. 2021 Sep 2. doi: 10.1097/IJG.0000000000001934. Online ahead of print.

ABSTRACT

PRECIS: Bruch membrane opening minimum rim width (BMO-MRW) is overall a useful parameter for diagnosing early glaucoma in myopic eyes.

PURPOSE: The aim of this study was to determine the diagnostic value of BMO-MRW compared with peripapillary retinal nerve fiber layer (pRNFL) thickness for detecting early glaucoma in patients with moderate to severe myopia.

METHODS: One eye was randomly selected from each of the 253 subjects (127 normal controls, 82 with glaucoma suspect, and 44 with early glaucoma). All patients underwent visual acuity testing, refractive error assessment, slit-lamp inspection, intraocular pressure measurement, fundus photography, perimetry. BMO-MRW and pRNFL thickness data were obtained using spectral-domain optical coherence tomography. Area under the receiver operating characteristic curves (AUC) for global and sectoral thickness parameters were calculated.

RESULTS: Global analyses for the discrimination of early glaucoma in all myopic subjects showed comparable AUCs between BMO-MRW and pRNFL thickness [AUC 0.952 (95% confidence interval, 0.918-0.975) and 0.934 (95% confidence interval, 0.896-0.961), respectively, P=0.345]. However, in sectoral analysis, BMO-MRW showed significantly better diagnostic performance than pRNFL thickness except for the superotemporal sector. The AUC for discriminating early glaucoma from glaucoma suspect, BMO-MRW showed statistically better diagnostic performance in the inferotemporal, inferonasal, superonasal, and nasal sectors. When dividing the subject based on a threshold Bruch membrane opening (BMO) area of 2.5 mm2, the diagnostic power of BMO-MRW was generally lower except for the inferonasal sector in the subgroup with a large BMO area.

CONCLUSIONS: BMO-MRW was overall a useful parameter for diagnosing early glaucoma in myopic eyes. However, its diagnostic performance was decreased in myopic eyes with large BMO and there were no significant differences from pRNFL thickness.

PMID:34474421 | DOI:10.1097/IJG.0000000000001934