Category: Statistics

Methods Mol Biol. 2021;2249:213-227. doi: 10.1007/978-1-0716-1138-8_12.

ABSTRACT

When analyzing the results of a trial, the primary outcome variable must be kept in clear focus. In the analysis plan, consideration must be given to comparing the characteristics of the subjects, taking account of differences in these characteristics, intention-to-treat analysis, interim analyses and stopping rules, mortality comparisons, composite outcomes, research design including run-in periods, factorial, stratified and crossover designs, number needed to treat, power issues, multivariate modeling, subgroup analysis, competing risks, and hypothesis-generating analyses.

PMID:33871846 | DOI:10.1007/978-1-0716-1138-8_12

Ann Nucl Med. 2021 Apr 19. doi: 10.1007/s12149-021-01612-9. Online ahead of print.

ABSTRACT

OBJECTIVE: Astatine (²¹¹At) is a promising alpha emitter as an alternative to iodine (¹³¹I). We are preparing the first-in-human (FIH) clinical trial of targeted alpha therapy for differentiated thyroid cancer in consultation with Pharmaceuticals and Medical Devices Agency. Here, we performed an extended single-dose toxicity examination under a reliability standard, as a preclinical safety assessment of [²¹¹At]NaAt to determine the FIH dose.

METHODS: [²¹¹At]NaAt solution was injected into normal 6-week-old mice (male (n = 50) and female (n = 50), body weight: male 33.2 ± 1.7 g, female 27.3 ± 1.5 g), which were then divided into four groups: 5 MBq/kg (n = 20), 20 MBq/kg (n = 20), 50 MBq/kg (n = 30), saline control (n = 30). The mice were followed up for 5 days (primary evaluation point for acute toxicity: n = 80) or 14 days (n = 20: evaluation point for recovery) to monitor general condition and body weight change. At the end of the observation period, necropsy, blood test, organ weight measurement, and histopathological examination were performed. For body weight, blood test, and organ weight, statistical analyses were performed to compare data between the control and injected groups.

RESULTS: No abnormal findings were observed in the general condition of mice. In the 50 MBq/kg group, males (days 3 and 5) showed a significant decrease in body weight compared with the control. However, necropsy did not differ significantly beyond the range of spontaneous lesions. In the blood test, males (50 MBq/kg) and females (50 MBq/kg) showed a decrease in white blood cell and platelet counts on day 5, and recovery on day 14. In the testis, a considerable weight decrease was observed on day 14 (50 MBq/kg), and multinucleated giant cells were observed in all mice, indicating a significant change related to the administration of [²¹¹At]NaAt.

CONCLUSIONS: In the extended single-dose toxicity study of [²¹¹At]NaAt, administration of high doses resulted in weight loss, transient bone marrow suppression, and pathological changes in the testis, which require consideration in the FIH clinical trial.

PMID:33871803 | DOI:10.1007/s12149-021-01612-9

Spine Deform. 2021 Apr 19. doi: 10.1007/s43390-020-00283-2. Online ahead of print.

ABSTRACT

OBJECTIVES: To study factors causing postoperative change of PI after surgical correction of ASD and to assess the effect of this variability on postoperative PI-LL mismatch.

BACKGROUND: PI is used as an individual constant to define lumbar lordosis (LL) correction goal (PI-LL < 10). Postoperative changes of PI were shown but with opposite vectors. The impact of the PI variability on the postoperative PI-LL has not been studied.

METHODS: The medical and radiographic data analyzed for patients who underwent long posterior instrumented spinal fusion. Inclusion criteria are age, ≥ 20 years old; ASD due to degenerative disk disease (DDD) or scoliosis (DS); ≥ 3 levels fused; and 2-year follow-up or revision. Studied parameters are LL (L1-S1), PI, sacral slope (SS), pelvic tilt (PT), and PI-LL. Measurement error and postoperative changes were defined. Statistical analysis includes ANOVA, correlation, regression, and risk assessment by odds ratio; P ≤ 0.05 considered statistically significant.

RESULTS: Eighty patients were included: mean age, 62.4 years-old (SD, 11.1); female, 63.7%; mean body mass index (BMI), 27.1 (SD, 5.6). Distribution of patients by follow-ups includes preoperative 100%; postoperative (1-3 weeks), 100%; 11-13 months. 90%; 22-26 months, 58%; and revision: 24%. Pre- versus postoperative PI (∆PI) changed both positively and negatively and the absolute value of change|∆PI| exceeded measurement error (P ≤ 0.05) reaching as high as 31°, and progressed with time; R² dropped from 0.73 to 0.45 (P < 0.001); ∆PI depended on disproportional changes of SS and PT, preoperative PI, and change of LL. Obesity, DS, and absence of sacroiliac fixation increased |∆PI|. The risk of LL insufficient correction (PI-LL > 10°) associated with a |∆PI|> 6°, P = 0.05. Sacroiliac fixation diminished PI variability only during the first postoperative year.

CONCLUSION: Preoperative variability and postoperative instability of PI diminish the applicability of the PI-LL < 10° goal to plan correction of LL. An alternative method is offered.

LEVEL OF EVIDENCE: IV.

PMID:33871832 | DOI:10.1007/s43390-020-00283-2

Methods Mol Biol. 2021;2249:1-16. doi: 10.1007/978-1-0716-1138-8_1.

ABSTRACT

Clinical epidemiology is the science of human disease investigation with a focus on diagnosis, prognosis, and treatment. The generation of a reasonable question requires definition of patients, interventions, controls, and outcomes. The goal of research design is to minimize error, ensure adequate samples, measure input and output variables appropriately, consider external and internal validities, limit bias, and address clinical as well as statistical relevance. The hierarchy of evidence for clinical decision-making places randomized controlled trials (RCT) or systematic review of good-quality RCTs at the top of the evidence pyramid. Prognostic and etiologic questions are best addressed with longitudinal cohort studies.

PMID:33871835 | DOI:10.1007/978-1-0716-1138-8_1

Endocrine. 2021 Apr 19. doi: 10.1007/s12020-021-02730-0. Online ahead of print.

ABSTRACT

PURPOSE: Sodium-glucose cotransporter 2 inhibitors increase glucagon secretion by pancreatic alpha cells and the susceptibility to ketoacidosis. On the other hand, growth hormone (GH) stimulates peripheral lipolysis and provides free fatty acids (FFA) for ketogenesis; however, it remains unresolved whether GH directly impacts hepatic ketogenesis. We aimed to investigate the role of physiologic GH levels in promoting ketogenesis in prediabetic or type 2 diabetic patients under empagliflozin treatment.

METHODS: Sixteen patients (11 women, 5 men) with prediabetes or type 2 diabetes mellitus, aged 55.6 ± 4.7 years and with a mean BMI of 30.7 ± 4.8 kg/m² and HbA1c 7.1 ± 1.6% (means ± SD), participated in this study. All of them were submitted to three mixed-meal tests: they received placebo at -60 min (test 1), and empagliflozin 25 mg (test 2, 21st day) and empagliflozin 25 mg plus pegvisomant 30 mg were administered subcutaneously 36 h before (test 3, 28th day). After test 1, all patients were instructed to take empagliflozin 25 mg daily.

RESULTS: The empagliflozin treatment decreased the plasma concentrations of glucose by 14% (P < 0.01), FFA by 23% (P < 0.01), and the insulin/glucagon ratio by 26% (P < 0.01), and it increased β-hydroxybutyrate by 44% (P < 0.05). The GH receptor block by pegvisomant restored the plasma β-hydroxybutyrate to baseline levels.

CONCLUSIONS: We conclude that GH has a direct effect on promoting the ketogenesis environment in patients treated with empagliflozin.

PMID:33871793 | DOI:10.1007/s12020-021-02730-0

J Gastrointest Cancer. 2021 Apr 19. doi: 10.1007/s12029-021-00641-x. Online ahead of print.

ABSTRACT

PURPOSE: Gastric and small intestine are the most common gastrointestinal stromal tumors (GISTs). There are few studies of patients who underwent surgical treatment with disparate findings. We aimed to evaluate the differences between groups and the risk factors for recurrence and mortality.

METHODS: A retrospective study of 96 gastric and 60 small intestine GIST was performed between 1995 and 2015. Both groups were compared in terms of clinicopathologic features, morbidity, recurrence, and mortality. Statistical analysis was performed with SPSS®.

RESULTS: Eighty-one gastric GISTs and 56 small intestine GISTs underwent surgical treatment. Gastrointestinal bleeding was the most common cause of emergency surgery being more frequent in gastric GIST (P = 0.009); however, emergency surgery was indicated more frequently in the small intestinal GIST (P = 0.004) and was mostly due to perforation (P = 0.009). With a median follow-up of 66.9 (39.7-94.8) months, 28 (20.4%) patients had recurrence. A mitotic index > 5 (P ≤ 0.001) and the intestinal location (P = 0.012) were significantly associated to recurrence. Tumor size > 15 cm (P = 0.001) and an age of ≥ 75 years (P = 0.014) were associated to mortality. On univariate analysis, higher mean values of Ki-67 were associated to higher mortality (P = 0.0032). Small intestine GIST presented lower disease-free survival (DFS) than that of gastric GIST (65.7% vs 90.8%) with P = 0.003. The overall survival (OS) of gastric and small intestine GIST was 74.7% and 71.6%, respectively (P = 0.68).

CONCLUSION: Small intestine GIST received emergency surgery more frequently showing lower DFS and same OS than that of gastric GIST. We found that Ki-67 could be a prognostic factor. Further studies are necessary to assess whether Ki-67 is a prognostic risk factor for GISTs.

PMID:33871798 | DOI:10.1007/s12029-021-00641-x

J Cancer Surviv. 2021 Apr 19. doi: 10.1007/s11764-021-01036-4. Online ahead of print.

ABSTRACT

PURPOSE: Prognostication in cancer is growing in importance as increasingly accurate tools are developed. Prognostic accuracy intensifies ethical concerns that a poor prognosis could be psychologically harmful to survivors. Uveal melanoma (UM) prognostication allows survivors to be reliably told that life expectancy is either normal (good prognosis) or severely curtailed because of metastatic disease (poor prognosis). Treatment cannot change life expectancy. To identify whether prognosis is associated with psychological harm, we compared harm in UM survivors with good and poor prognoses and those who declined testing and compared these outcomes to general population norms.

METHODS: Non-randomized 5-year study of a consecutive series of 708 UM survivors (51.6% male, mean age 69.03, SD=12.12) with observations at 6, 12, 24, 36, 48 and 60 months. We operationalized psychological harm as anxiety and depression symptoms, worry about cancer recurrence (WREC) and poor quality of life (QoL).

RESULTS: Compared to other groups, survivors with poor prognoses showed initially elevated anxiety and depression and consistently elevated worry about local or distant recurrence over 5 years. Good prognoses were not associated with outcomes. Generally, no prognostic groups reported anxiety, depression and WREC or QoL scores that exceeded general population norms.

CONCLUSIONS: Using a large sample, we found that harm accruing from a poor prognosis was statistically significant over 5 years, but did not exceed general non-cancer population norms.

IMPLICATIONS FOR CANCER SURVIVORS: Survivors desire prognostic information. At a population level, we do not believe that our findings show sufficiently strong links between prognostication outcome and psychological harm to deny patients the option of knowing their prognosis. Nonetheless, it is important that patients are informed of potential adverse psychological consequences of a poor prognosis.

PMID:33871760 | DOI:10.1007/s11764-021-01036-4

J Clin Monit Comput. 2021 Apr 19. doi: 10.1007/s10877-021-00704-1. Online ahead of print.

ABSTRACT

Almost since its introduction pulse oximetry was known to overestimate oxygen saturation in cases of carbon monoxide poisoning or elevated methemoglobin (metHb) levels. To eliminate this dangerous behavior some manufacturers have added additional LED emitters to try to increase the number of measured hemoglobin species and to improve measurement accuracy, but have not been very successful. We hypothesized that the use of narrow-band laser light sources would make accurate and precise measurement of the four primary species of hemoglobin possible, even in cases of elevated levels of carboxyhemoglobin (COHb). Calibration and verification studies were performed on a tissue simulator that employed an artificial finger pulsating with whole human blood. This simulator allowed safe generation of 165 different combinations of the levels of oxyhemoglobin (O₂Hb), COHb, metHb, and reduced hemoglobin (RHb) for calibration of the laser-based pulse oximeter. A follow-on study used 56 mixed hemoglobin levels for verification and statistical analysis of the performance of this device. This laser-based pulse oximeter measured all four species of hemoglobin accurately and precisely (A_RMS ≤ 1.8%) for metHb levels in the clinically normal range. At elevated metHb levels the device continued to provide accurate and precise measurements of metHb and RHb (A_RMS ≤ 1.7%). The use of monochromatic laser light sources can create a new generation of highly accurate, multi-parameter, pulse oximeters.

PMID:33871764 | DOI:10.1007/s10877-021-00704-1

Heart Vessels. 2021 Apr 19. doi: 10.1007/s00380-021-01857-4. Online ahead of print.

ABSTRACT

New and clinically useful markers of cardiovascular risk are of great importance in patients with type 2 diabetes since cardiovascular disease is a major cause of death in these patients. We analyzed inflammatory markers and other risk factors for heart disease in 761 patients who participated in the CARDIPP-study, Cardiovascular Risk factors in Patients with Diabetes-a Prospective study in Primary care. All participants had type 2 diabetes and were 55-66 years old at recruitment during the years 2005-2008. Patients were followed for incidence of stroke, myocardial infarction, or death from cardiovascular disease until the end of the year 2018 using the national Swedish Cause of Death and Hospitalization Registries. Besides traditional risk-markers for vascular disease, we also measured carotid-femoral pulse-wave velocity and intima-media thickness of carotid arteries. During a median period of 13 years, 165 men and 65 women died or were hospitalized for ischemic heart disease and stroke. TNFrII showed statistically significance as a risk factor for stroke, ischemic heart disease, and total mortality in male patients with diabetes type 2, independently of age, diabetes duration, BMI, Hba1c, systolic blood pressure, triglycerides, IMT and PWV (p = 0.002, HR 2.70, CI 1.42:5.13, p = 0.002). Circulating TNFrII levels failed to present a similar correlation in women (p = 0.48, CI 0.48:4.84). TNFrII stayed significant in males when HDL/LDL-ratio, CRP and smoking were added to the statistical analysis. Our data support the use of serum TNFrII in male type 2 diabetes patients to add independent prognostic information in terms of mortality and heart disease independently of other strong and well-established risk markers including cholesterol, inflammatory cytokines, PWV and IMT.Trial registration: ClinicalTrials.gov NCT01049737.

PMID:33871700 | DOI:10.1007/s00380-021-01857-4

Neurosurg Rev. 2021 Apr 19. doi: 10.1007/s10143-021-01550-0. Online ahead of print.

ABSTRACT

Cerebral palsy (CP) is a chronic congenital disorder as the result of abnormal brain development. Children suffering from CP often battle debilitating chronic spasticity, which has been the focus of recent academic literature. In this systematic review, the authors aim to update the current neuromodulation procedures for the treatment of spasticity associated with CP in all age groups. A systematic review following was conducted using PubMed from inception to 2020. After initial title and abstract screening, 489 articles were identified, and 48 studies met the inclusion criteria for this review. In total, a majority of the published articles of treatments for CP were reporting the use of selective dorsal rhizotomy (SDR) (54%), and the remainder were of intrathecal baclofen (ITB) pumps (29%) and extracorporeal shockwave therapy (ESWT) (17%). Each method was found to have improvement of spasticity at a rate that achieved statistical significance. ITB pump therapy is an all-encompassing method of treating spasticity in children from CP, as it allows for a less invasive treatment that can be titrated to individual patient needs; however, its disadvantages include its long-term maintenance requirements. SDR appears to be an effective method for permanent spasticity relief in young patients. ESWT is a more recent and innovative technique for offering relief of spasticity while being minimally invasiveness. Further studies are needed to establish optimal frequencies and sites of application for ESWT.

PMID:33871733 | DOI:10.1007/s10143-021-01550-0