Category: Statistics

BMJ Open. 2022 Sep 5;12(9):e060026. doi: 10.1136/bmjopen-2021-060026.

ABSTRACT

OBJECTIVES: To develop a disease stratification model for COVID-19 that updates according to changes in a patient’s condition while in hospital to facilitate patient management and resource allocation.

DESIGN: In this retrospective cohort study, we adopted a landmarking approach to dynamic prediction of all-cause in-hospital mortality over the next 48 hours. We accounted for informative predictor missingness and selected predictors using penalised regression.

SETTING: All data used in this study were obtained from a single UK teaching hospital.

PARTICIPANTS: We developed the model using 473 consecutive patients with COVID-19 presenting to a UK hospital between 1 March 2020 and 12 September 2020; and temporally validated using data on 1119 patients presenting between 13 September 2020 and 17 March 2021.

PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome is all-cause in-hospital mortality within 48 hours of the prediction time. We accounted for the competing risks of discharge from hospital alive and transfer to a tertiary intensive care unit for extracorporeal membrane oxygenation.

RESULTS: Our final model includes age, Clinical Frailty Scale score, heart rate, respiratory rate, oxygen saturation/fractional inspired oxygen ratio, white cell count, presence of acidosis (pH <7.35) and interleukin-6. Internal validation achieved an area under the receiver operating characteristic (AUROC) of 0.90 (95% CI 0.87 to 0.93) and temporal validation gave an AUROC of 0.86 (95% CI 0.83 to 0.88).

CONCLUSIONS: Our model incorporates both static risk factors (eg, age) and evolving clinical and laboratory data, to provide a dynamic risk prediction model that adapts to both sudden and gradual changes in an individual patient’s clinical condition. On successful external validation, the model has the potential to be a powerful clinical risk assessment tool.

TRIAL REGISTRATION: The study is registered as ‘researchregistry5464’ on the Research Registry (www.researchregistry.com).

PMID:36691139 | DOI:10.1136/bmjopen-2021-060026

BMJ Open. 2022 Sep 6;12(9):e058467. doi: 10.1136/bmjopen-2021-058467.

ABSTRACT

INTRODUCTION: Poor medication adherence is associated with worsening patient health outcomes and increasing healthcare costs. A holistic tool to assess both medication adherence and drivers of adherence behaviour has yet to be developed. This study aimed to examine SPUR, a multifactorial patient-reported outcome measure of medication adherence in patients living with type 2 diabetes, with a view to develop a suitable model for psychometric analysis.Furthermore, the study aimed to explore the relationship between the SPUR model and socio-clinical factors of medication adherence.

RESEARCH DESIGN AND METHODS: The study recruited 378 adult patients living with type 2 diabetes from a mix of community and secondary-care settings to participate in this non-interventional cross-sectional study. The original SPUR-45 tool was completed by participants with other patient-reported outcome measures for comparison, in addition to the collection of two objective adherence measures; HbA_1c and the medication possession ratio (MPR).

RESULTS: Factor and reliability analysis conducted on SPUR-45 produced a revised and more concise version (27-items) of the tool, SPUR-27, which was psychometrically assessed. SPUR-27 observed strong internal consistency with significant correlations to the other psychometric measures (Beliefs about Medication Questionnaire, Diabetes Treatment Satisfaction Questionnaire, Medicine Adherence Rating Scale) completed by participants. Higher SPUR-27 scores were associated with lower HbA_1c values and a higher MPR, as well as other predicted socio-clinical factors such as higher income, increased age and lower body mass index.

CONCLUSIONS: SPUR-27 demonstrated strong psychometric properties. Further work should look to examine the test-retest reliability of the model as well as examine transferability to other chronic conditions and broader population samples. Overall, the initial findings suggest that SPUR-27 is a reliable model for the multifactorial assessment of medication adherence among patients living with type 2 diabetes.

PMID:36691135 | DOI:10.1136/bmjopen-2021-058467

Nanotechnology. 2023 Jan 23. doi: 10.1088/1361-6528/acb558. Online ahead of print.

ABSTRACT

The search for new strategies to curb the spread of the SARS-CoV-2 coronavirus, which causes COVID-19, has become a global priority. Various nanomaterials have been proposed as ideal candidates to inactivate the virus; however, because of the high level of biosecurity required for their use, alternative models should be determined. This study aimed to compare the effects of two types of nanomaterials-gold (AuNPs) and silver nanoparticles (AgNPs), recognized for their antiviral activity and affinity with the coronavirus spike protein-using PhiX174 and enveloped Phi6 bacteriophages as models. To reduce the nanoparticles’ toxicity, a species known for its intermediate antiviral activity, Solanum mammosum L. (Sm), was used. NPs prepared with sodium borohydride (NaBH4) functioned as the control. Antiviral activity against PhiX174 and Phi6 was analyzed using its seed, fruit, leaves, and essential oil; the leaves were the most effective on Phi6. Using the aqueous extract of the leaves, AuNPs-Sm of 5.34 ± 2.25 nm and AgNPs-Sm of 15.92 ± 8.03 nm, measured by transmission electron microscopy (TEM), were obtained. When comparing NPs with precursors, both gold(III) acetate and silver nitrate were more toxic than their respective NPs (99.99% at 1 mg/mL). The AuNPs-Sm were less toxic, reaching 99.30% viral inactivation at 1 mg/mL, unlike the AgNPs-Sm, which reached 99.94% at 0.01 mg/mL. Gallic acid was the main component identified in the leaf extract using high performance liquid chromatography with diode array detection (HPLC-DAD). The FT-IR spectra showed the presence of a large proportion of polyphenolic compounds, and the antioxidant analysis confirmed the antiradical activity. The control NPs showed less antiviral activity than the AuNPs-Sm and AgNPs-Sm, which was statistically significant; this demonstrates that both the S. mammosum extract and its corresponding NPs have a greater antiviral effect on the surrogate Phi bacteriophage, which is an appropriate model for studying SARS-CoV-2.

PMID:36689773 | DOI:10.1088/1361-6528/acb558

Math Med Biol. 2023 Jan 23:dqad001. doi: 10.1093/imammb/dqad001. Online ahead of print.

ABSTRACT

Current understanding of arrhythmia mechanisms and design of anti-arrhythmic drug therapies hinges on the assumption that myocytes from the same region of a single heart have similar, if not identical, action potential waveforms and drug responses. On the contrary, recent experiments reveal significant heterogeneity in uncoupled healthy myocytes both from different hearts as well as from identical regions within a single heart. In this work, a methodology is developed for quantifying the individual electrophysiological properties of large numbers of uncoupled cardiomyocytes under ion channel block in terms of the parameters values of a conceptual fast-slow model of electrical excitability. The approach is applied to a population of nearly 500 rabbit ventricular myocytes for which action potential duration (APD) before and after the application of the drug nifedipine was experimentally measured (Lachaud et al., 2022, Cardiovasc. Res.). To this end, drug action is represented by a multiplicative factor to an effective ion conductance, a closed form asymptotic expression for APD is derived and inverted to determine model parameters as functions of APD and ΔAPD (drug-induced change in APD) for each myocyte. Two free protocol-related quantities are calibrated to experiment using an adaptive-domain procedure based on an original assumption of optimal excitability. The explicit APD expression and the resulting set of model parameter values allow (a) direct evaluation of conditions necessary to maintain fixed APD or ΔAPD, (b) predictions of the proportion of cells remaining excitable after drug application, (c) predictions of stimulus period dependency and (d) predictions of dose-response curves, the latter being in agreement with additional experimental data.

PMID:36689769 | DOI:10.1093/imammb/dqad001

Probl Endokrinol (Mosk). 2022 Nov 3;68(6):110-120. doi: 10.14341/probl13166.

ABSTRACT

BACKGROUND: Adrenocortical adenomas are often followed with steroid hormones hyperproduction, and therefore determination of their concentration plays an important role in the differential diagnosis of adrenal diseases. Steroid profiling by tandem mass spectrometry is one of the main diagnostic methods in steroidogenesis characterization. Currently plasma and urinary steroid profiling is of particular interest in differential diagnosis and subtyping patients with adrenocortical adenomas.

AIM: Steroid profiling of pediatric patients with adrenal diseases (incidentalomas, ACTH-secreting pituitary adenoma, ACTH-independent Cushing syndrome, premature adrenarche).

MATERIALS AND METHODS: We conducted a retrospective analysis of steroid profile of 41 pediatric patients with adrenal diseases who were observed between 2005 and 2020 at the Endocrinology Research Centre.

RESULTS: All patients were divided into groups due to diagnosis: with ACTH-secreting pituitary adenoma [n=7], ACTH-independent Cushing syndrome (autonomous cortisol secretion by an adrenal adenoma) [n=4], with incidentaloma [n=7] and premature adrenarche [n=23]. In group of patients with ACTH-independent Cushing syndrome identified statistically significant higher levels of 11-deoxycortisol (р=0, 0035) and significant lower levels of 17-hydroxypregnenolone (р=0, 0026) and DHEA (р=0, 0047) compared to other groups. Statistically significant differences in steroid profiles between other groups were not identified.

CONCLUSION: Results of our study steroid profiling can be used as additional differential diagnosis method in patients with adrenocortical adenomas with or without hormonal hyperproduction (ACTH-independent Cushing syndrome and incidentaloma). Further studies are needed to identify steroid markers for subtyping pediatric adrenal diseases.

PMID:36689716 | DOI:10.14341/probl13166

Probl Endokrinol (Mosk). 2023 Jan 24;68(6):89-109. doi: 10.14341/probl13165.

ABSTRACT

BACKGROUND: There is enough evidence of the negative impact of excess weight on the formation and progression of res piratory pathology. Given the continuing SARS-CoV-2 pandemic, it is relevant to determine the relationship between body mass index (BMI) and the clinical features of the novel coronavirus infection (NCI).

AIM: To study the effect of BMI on the course of the acute SARS-COV-2 infection and the post-covid period.

MATERIALS AND METHODS: AKTIV and AKTIV 2 are multicenter non-interventional real-world registers. The АКТИВ registry (n=6396) includes non-overlapping outpatient and inpatient arms with 6 visits in each. The АКТИВ 2 registry (n=2968) collected the data of hospitalized patients and included 3 visits. All subjects were divided into 3 groups: not overweight (n=2139), overweight (n=2931) and obese (n=2666).

RESULTS: A higher BMI was significantly associated with a more severe course of the infection in the form of acute kidney injury (p=0.018), cytokine storm (p&lt;0.001), serum C-reactive protein over 100 mg/l (p&lt;0.001), and the need for targeted therapy (p&lt;0.001) in the hospitalized patients. Obesity increased the odds of myocarditis by 1,84 times (95% confidence interval [CI]: 1,13-3,00) and the need for anticytokine therapy by 1,7 times (95% CI: 1,30-2,30).The patients with the 1st and 2nd degree obesity, undergoing the inpatient treatment, tended to have a higher probability of a mortality rate. While in case of morbid obesity patients this tendency is the most significant (odds ratio – 1,78; 95% CI: 1,13-2,70). At the same time, the patients whose chronical diseases first appeared after the convalescence period, and those who had certain complaints missing before SARS-CoV-2 infection, more often had BMI of more than 30 kg/m2 (p&lt;0,001).Additionally, the odds of death increased by 2,23 times (95% CI: 1,05-4,72) within 3 months after recovery in obese people over the age of 60 yearsCONCLUSION. Overweight and/or obesity is a significant risk factor for severe course of the new coronavirus infection and the associated cardiovascular and kidney damage Overweight people and patients with the 1st and 2nd degree obesity tend to have a high risk of death of SARS-CoV-2 infection in both acute and post-covid periods. On top of that, in case of morbid obesity patients this tendency is statistically significant. Normalization of body weight is a strategic objective of modern medicine and can contribute to prevention of respiratory conditions, severe course and complications of the new coronavirus infection.

PMID:36689715 | DOI:10.14341/probl13165

Probl Endokrinol (Mosk). 2023 Jan 8;68(6):76-88. doi: 10.14341/probl13172.

ABSTRACT

BACKGROUND: Adrenocortical cancer (ACC) is an orphan malignant tumor of the adrenal cortex with a predominantly poor prognosis and an aggressive clinical course. Nowadays, mitotane is a non-alternative drug in the treatment of ACC. The search for prognostic parameters that determine the sensitivity of ACC to ongoing treatment is currently an urgent task. Expression levels of the large subunit of ribonucleotide reductase M1 (RRM1), cytochrome P450 2W1 (CYP2W1), and sterol- O-acyltransferase-1 (SOAT1) are considered as potential predictors of response to mitotane therapy.

AIM: To assess the immunohistochemical expression of RRM1, CYP2W1 and SOAT1 in ACC as markers of clinical outcomes and response to the therapy with mitotane.

MATERIALS AND METHODS: The study included 62 patients older than 17 years of age with a diagnosis of ACC confirmed histologically and immunohistochemically. Mitotane therapy was initiated in 29 patients in the postoperative period, 33 patients were under dynamic observation without concomitant drug treatment. Antibodies to RRM1, CYP2W1, SOAT1 were used diluted in accordance with recommendations of firms-manufacturers for immunohistochemical detection.

RESULTS: In the group of patients with low and moderate RRM1, CYP2W1 and SOAT1 immunoreactivity in the tumor and no antitumor therapy, a better DFS was noted (p=0.037, p=0.020 and p=0.001, respectively) compared to the group of patients receiving mitotane therapy at this level of marker expression. With high immunoreactivity of the markers, no statistically significant differences in DFS were found.

CONCLUSION: Consistent with the findings in our study, low expression of RRM1, CYP2W1 and SOAT1 was associated with worse DFS with antitumor therapy. The results of the work indicate the need to assess the levels of immunoreactivity of these markers in patients with ACC before starting treatment with mitotane in order to predict the efficiency of therapy.

PMID:36689714 | DOI:10.14341/probl13172

Probl Endokrinol (Mosk). 2022 Oct 12;68(6):43-48. doi: 10.14341/probl13151.

ABSTRACT

BACKGROUND: Pregnancy is a condition with important structural and physiological changes in the thyroid gland. In this regard, experts of thyroid associations have recommended developing specific reference intervals taking into account the natural and socio-geographical characteristics of the region under study.

AIM: To conduct an epidemiological analysis and evaluate TSH reference intervals in pregnant women living in the central regions of the Russian Federation with mild iodine deficiency.

MATERIALS AND METHODS: We have conducted the observational multicenter cross-sectional study included 2008 healthy pregnant women at different trimesters of pregnancy, from three regions of the Russian Federation (Moscow, Ivanovo and Smolensk). We assessed the level of thyroid-stimulating hormone, antibodies to thyroid peroxidase, antibodies to serum thyroglobulin, the level of iodine concentration in the morning portion of urine (cerium arsenic method) and we have conducted a questionnaire (date birth and gestational age). Women with elevated titers of anti-TPO and/or anti-TG antibodies were excluded from the study (245 women). As a result, we assessed high and medium levels of TSH and its overestimation with iodine sufficiency in pregnant women. The results are presented using the calculation of 2.5 and 97.5 percentiles.

RESULTS: We confirmed the presence of iodine deficiency in the study areas. The median concentration of iodine in the urine was: in Moscow 106 μg/l, in Ivanovo 119 μg/l, in Smolensk 134 μg/l. Pregnant women were divided into 2 groups according to iodine adequacy. In the group with optimal iodine supply, the level of TSH was 0,006-3,36 in the 1st trimester, 0,20-3,74 in the 2nd trimester, and 0,33-3,68 mIU/L in the 3rd trimester. In the group with mild iodine deficiency – in the 1st trimester it was 0,11-3,00, in the 2nd trimester 0,22-3,78, in the 3rd trimester 0,07-3,04 mIU/l. Statistical analysis of the data revealed that when comparing the level of TSH by trimester, depending on the place of residence, no statistical difference was found (p = 0,239).

CONCLUSION: We obtained that the level of TSH in healthy pregnant women living in the central regions of the Russian Federation does not exceed 3.8 mIU/l in all trimesters.

PMID:36689710 | DOI:10.14341/probl13151

Probl Endokrinol (Mosk). 2022 Aug 15;68(6):30-42. doi: 10.14341/probl13144.

ABSTRACT

AIM: To determine significant factors affecting the survival of patients with ectopic ACTH syndrome (EAS).

MATERIALS AND METHODS: A multi-center, observational study with a retrospective analysis of patients with EAS. The end point of the study was the fatal outcome of patients from various causes. In order to identify predictors of survival or mortality, univariate and multifactorial Cox regression analyses were carried out. ROC-analysis was used to determine the prognostic threshold values of individual predictors. The survival analysis was carried out using the Kaplan-Mayer method. Statistical data processing was carried out by using IBM SPSS Statistics 23.

RESULTS: The age of patients at the time of diagnosis ranged from 12 to 76 years (Me 40 years [28;54]). The age of the studied population was 55 years [38; 64] for women and 42 years [32; 54] for men. The median period of observation was 50 months [13;91], with a maximum follow-up of 382 months. 92 patients (60,9%) had bronchopulmonary NET, 17 (11,3%) – thymic carcinoid, 8 – pancreatic NET, 5 -pheochromocytoma, 1- cecum NET, 1- appendix carcinoid tumor, 1 – medullary thyroid cancer and 26 (17,2%) patients had an occult NET. The primary tumor was removed in 101 patients (66,9%). Bilateral adrenalectomy was performed in 42 (27,8%) cases. Metastases were revealed in 23,2% (n=35) of patients. Relapse of the disease was observed in 24,4%, long-term remission was preserved in 64 patients (74,4%). Death occurred in 42 patients (28%). The average age of survivors was 47,0±15,2 versus 53,5±15,6 years for the deceased (p=0,022). The average survival time from diagnosis for the deceased was 32 months, Me 16,5 months [7;54]. Multivariate analysis revealed that the following factors have a direct impact on survival: age of diagnosis ≥51 years (OR 4,493; 95% CI 2,056-9,818, p&lt;0,001), bronchopulmonary neuroendocrine tumor (NET) (OR 0,281; 95% CI 0,119-0,665, p=0,004), the presence of distant metastases (OR 2,489; 95% CI 1,141-5,427, p=0,022), late-night salivary cortisol (LNSC) ≥122,2 nmol/L (OR 2,493; 95% CI 1,014-6,128, p=0,047).

CONCLUSION: The prognosis of patients with EAS is influenced by the age of diagnosis, NET localization, distant metastases and level of LNSC. The most common cause of ectopic ACTH syndrome was bronchopulmonary NET which was associated with the best survival rate.

PMID:36689709 | DOI:10.14341/probl13144

Probl Endokrinol (Mosk). 2022 Jul 31;68(6):12-21. doi: 10.14341/probl12892.

ABSTRACT

BACKGROUND: The issues of monitoring the effectiveness of iodine deficiency prevention programs are an important component in the process of iodine elimination. Neonatal thyrotropin (TSH) has been used as a criterion for the severity of iodine deficiency since 1994, however, the question of the “cut-off point” of the neonatal TSH level has been widely discussed in the recent literature.

AIM: Evaluate the criterion for neonatal hyperthyroidism above 5 mIU/l from the perspective of monitoring iodine deficiency and establish a «cut-off point» on the model of healthy pregnant women with adequate iodine status.

MATERIALS AND METHODS: A prospective study was conducted in a population of pregnant women in the city of Tyumen, with the formation of observation groups according to the level of iodine excretion in the urine – the main group (with adequate iodine status throughout the entire gestation period) and the comparison group (women with iodine levels less than 150 μg/l). The results of neonatal screening for congenital hypothyroidism in children of women participating in the study were evaluated. The frequency of neonatal TSH above 5mIU/l was assessed in the observation groups. ROC-analysis was performed and a «cut-off point» of the level of neonatal TSH was established as an indicator of iodine deficiency.

RESULTS: The median urinary iodine concentration in the population of pregnant women in Tyumen was 159.05 μg/l, the incidence of goiter was 0.38%, the incidence of neonatal hyperthyroidism above 5 mIU/l was 2.88%, which characterizes adequate iodine intake in the pregnant population women. The frequency of neonatal TSH above 5 mIU/l in newborns from women from the main group was 1.47%, and in the comparison group – 9.3% (p = 0.076). ROC analysis revealed a threshold value of neonatal TSH of 2.77 mIU/l at the cut-off point, which corresponded to the highest value of the Youden index. Urinary iodine concentrations greater than 150 μg/l were predicted for nTSH values below this value.

CONCLUSION: Analysis of databases of neonatal screening for congenital hypothyroidism makes it possible to effectively, quickly and at minimal cost annually assess the iodine status in the population. The established «cut-off point» of neonatal TSH in the model of healthy pregnant women with adequate iodine intake in our work is 2.77 mIU/l, the absence of statistically significant differences in the incidence of neonatal hyperthyroidism above 5 mIU/l from women with different iodine status during pregnancy indicate the need to revise the existing threshold of 5 mIU/l and may be an incentive to conduct large-scale studies in regions with different iodine supply.

PMID:36689707 | DOI:10.14341/probl12892