Mutual relationships between SARS-CoV-2 test numbers, fatality and morbidity rates

Background The number of SARS-CoV-2 tests conversely to other factors, such as age of population or comorbidities, influencing SARS-CoV-2 morbidity and fatality rates, can be increased or decreased by decision makers depending on the development of the pandemic, operational capacity, and financial restraints. The key objective of this study is to identify and describe, within the probabilistic approach, the relationships between SARS-CoV-2 test numbers and the mortality and morbidity rates. Methods The study is based on a statistical analysis of 1058 monthly observations relating to 107 countries, from six different continents, in an 11-month period from March 2020 to January 2021. The variable utilised can be defined as the number of tests performed in a given country in 1 month, to the number of cases reported in a prior month and morbidities and mortalities per 1 million population. The probabilities of different mortality and morbidity rates for different test numbers were determined by moving percentiles and fitted by the power law and by the three-segment piecewise-linear approximation based on Theil Sen trend lines. Results We have identified that for a given probability the dependence of mortality and morbidity rates on SARS-CoV-2 test rates follows a power law and it is well approximated by the three Theil Sen trend lines in the three test rate ranges. In all these ranges Spearman rho and Kendall tau-b rank correlation coefficients of test numbers and morbidity with fatality rates have values between − 0.5 and − 0.12 with p-values below 0.002. Conclusions According to the ABC classification: the most important, moderately important, and relatively unimportant ranges of test numbers for managing and control have been indicated based on the value of the Theil Sen trend line slope in the three SARS-CoV-2 test rate ranges identified. Recommendations for SARS-CoV-2 testing strategy are provided.

Analysis of inventory management of slow-moving spare parts by using ABC techniques and EOQ model-a case study

Computer spare parts (CSPs) inventory management (IM) is very important for many companies. Excess inventory leads to high storage costs. On the other hand, the lack of CSP has a strong impact on the quality of service. This study was conducted by Power-One Jordan Computer Hardware-Software company (POJCHSC), Amman, Jordan. The focus area was the IM department and the target sample was employees working in the management department. The results showed that factors influencing the management of slow moving CSPs include production costs, obsolescence and CSPs dependence availability and transportation costs. By forecasting during the study, the results showed that the demand for adapters and chargers would increase by 20%. This demand forecast was performed using the economical order quantity (EOQ) model. The percentage of profits made by this company is 48%, and this requires some intervention to prevent losses. The results of this study are useful to the company, as well as to other similar industries that deal with slow-moving items. These results will help to simplify IM of slow-moving items. When we focused on POJCHSC manufacturers, the disadvantages of using the traditional ABC classification model were identified. Therefore, there is a need to have an ABC classification that is improved and which takes into consideration the criticality of the slow-moving CSP.

SISTEMA DE GESTIÓN DE INVENTARIOS PARA COMPAÑÍAS DE HARDWARE - CASO DE ESTUDIO

Some hardware assembly and marketing companies do not apply proper inventory management, causing failures in the product records, which can lead to shortages if there is an unexpected high demand, affecting the costs of ledgers and generating the need for an inventory management system. For this purpose, a methodological process was carried out, starting with the diagnosis, identifying the main factors that need to be improved concerning the management of merchandise, such as lack of inventory policies or reorder level, found through tools such as the SWOT, Ishikawa Diagram and Vester Matrix. Subsequently, an ABC classification was made, in which 1664 products are ordered and 118 of them belong to category A and applying goodness-of-fit tests. Then, the system is characterized and the mathematical models that adjust to the proposed conditions are selected: CEP without shortages and discount by suppliers, which is validated with a simulation. As a result of this process, the policy is established and a 95% improvement in the information quality is observed as a result. Variables part of the models are proposed and developed in the simulation and improve the system by 20% because they impact several products which are the most essential for the company.

Evaluation of the Circles Measurement and the ABC Classification of Acromioclavicular Joint Injuries

Background: Acromioclavicular joint (ACJ) injuries are common. Despite this, it remains unclear how best to assess, classify, and manage these cases. A simple, reliable, valid, and accurate radiographic parameter to measure ACJ displacement would allow improved consistency of diagnosis and subsequent treatment pathways. Purpose: To evaluate “the circles measurement” and associated “ABC classification” as a tool for assessing ACJ displacement and injury classification. Study Design: Descriptive laboratory study. Methods: The circles measurement is taken from a lateral Alexander radiograph of the shoulder. The measurement is the center-to-center distance between 2 circles drawn to define the lateral extent of the clavicle and the anteromedial extent of the acromion; it is independent of the displacement plane, judging total ACJ displacement in any direction rather than trying to quantify vertical and/or horizontal displacement. When utilized clinically, the circles measurement is a single measurement calculated as the difference between values recorded for the injured and uninjured sides. Validation of the circles measurement was performed using lateral Alexander radiographs (including ±20° projection error in all planes) and computed tomography of standardized ACJ injury simulations. We assessed inter- and intrarater reliability, convergent validity, and discriminant validity of the circles measurement and subsequently generated a classification of ACJ injury based on displacement. Results: Reliability and validity of the circles measurement was excellent throughout. Interrater reliability (ICC [intraclass correlation coefficient] [2,1], 95% CI; n = 78; 4 observers) was 0.976 (0.964-0.985). Intrarater reliability (ICC [2,1]; 95% CI; n = 78; 2 measures) was 0.998 (0.996-0.998). Convergent validity (Pearson correlation coefficient, r) was 0.970 for ideal radiographs and 0.889 with ±20° projection error in all planes. Discriminant validity, with 1-way analysis of variance, showed a P value of <.0001 and effect size ( η2) of 0.960, with the ability to distinguish between the previously defined stable (Rockwood IIIA) and unstable (Rockwood IIIB) injuries. The results permitted objective, statistically sound parameters for the proposed ABC classification system. Conclusion: The circles measurement is a simple, reliable, valid, accurate, and resilient parameter for assessing ACJ displacement and can be used in conjunction with the proposed ABC classification to define ACJ injuries more accurately and objectively than previously described. Clinical Relevance: This novel parameter has the potential to standardize the initial assessment and possibly the subsequent clinical management of ACJ injuries, in addition to providing a standardized measure for future research.

A New Method of Storage Management Based on ABC Classification: A Case Study in Chinese Supermarkets’ Distribution Center

Most of the distribution centers of chain supermarkets in China adopt the excessively simple activity-based classification (ABC) as the management method of classifying warehousing work, which often leads to an increase in operation and storage costs of the enterprise, a decrease in efficiency of the commodity circulation operation, and, eventually, a loss in enterprise growth because the goods ordered by stores cannot be delivered immediately. In addition, many studies in recent years have aimed at solving the problems of ABC classification by using the concept, method, or model of multi-criteria; however, limitations can be found in these studies. The main purpose of this study is to propose a new method, based on ABC classification, to improve the shortcomings of traditional classification methods, especially for special industries such as chain supermarkets. First, the case was classified using the ABC classification method as designed according to the actual situation of the case, and then the modified Delphi method, factor analysis, and analytic network process (ANP) decision model constructed by focus group was applied. Finally, ANP is used to put forward a specific improvement scheme and countermeasures for the storage management classification plan of the case. Last but not least, to verify the applicability of the model, an actual case was used to test the model. The results show the reference value and practicability of the proposed model. Furthermore, it can be offered as a set of systematic and scientific decision-making reference standards for managers and decision-makers of chain supermarkets when making warehouse management plans and standards.

Inventory management and cost efficiency

This research aims to observe current inventory management applied by one of the medical equipment distributors specializing in eye health devices, and provide recommendations for an optimal inventory management system to achieve cost efficiency afterward. The method used in this research is quantitative, focusing on processing and analyzing numerical data obtained from the company to calculate safety stock and the number of orders. In addition, ABC classification is also used in data processing to group items based on their value. Items belonging to class A (having a value of 80% for the company) will be used in the data processing. The next step is to conduct forecasting simulations for demand forecasts. The results of the forecast will be used for calculating the safety stock and order quantity. The output from the results of data processing and analysis in this study shows 67 items included in class A, which will then be processed using Minitab software for forecasting. Based on comparing the four forecasting methods, the one with the lowest error value is Trend Analysis. If the company can apply the storage method according to the fixed-time period model calculation, there is a potential savings of US $ 717,133 or 63% of the total overstock

Survival of retinoblastoma patients: a cohort study by two Russian medical centers

Purpose. To evaluate the overall, disease-specific, event-free, relapse-free survival of retinoblastoma (RB) patients and cumulative probability of eye survival in such patients.Material and methods. The study included 223 children with RB (126 male, 97 female). Monolateral disease was diagnosed in 69.1 % of cases (n = 154), bilateral disease in 30.9 % (n = 69). The median follow-up was 40 months (interquartile range from 27 to 53 months). According to ABC classification, group A was diagnosed in 16 of 292 eyes (5.5 %), group B — in 53 (18.2 %), group C — in 41 (14.0 %), group D — 58 (19.9 %), and group E — in 124 (42.5 %). Group E was detected twice as often in patients with unilateral RB as in bilateral RB (56.5 % versus 26.8 %; p < 0.01). Stage T1 according to TNM classification was diagnosed in 69 cases (23.6 %), stage T2-T3 — in 213 cases (72.9 %). The extraocular form (stage T4) was detected in 3.4 % of cases (n = 10).Results. The overall five-year survival of patients treated for RB (n = 223) was 96.4 ± 1.4 %. The 5-year disease- specific survival (n = 222) was 96.8 ± 1.3 % in the general cohort, 96.5 ± 1.5 % in the group of children with monocular RB, 97.3 ± 2.7 % for binocular RB. Five-year event-free survival rate of children who received treatment (n = 223) was 66.7 ± 3.6 %, with monolateral lesion (n = 154) — 74.1 ± 4.2 %, with bilateral lesion — 50.6 ± 6.2 % (n = 69). Five-year relapse-free survival took place in 83.3 ± 3.1 %, with monolateral RB — 87.8 ± 3.3 %, with bilateral RB — 73.3 ± 6.4 %. Primary enucleation was performed in 121 of the 223 children treated for RB and included in the study. The frequency of primary enucleation with monocular RB was more than twice as high (55.2 %; 85 of 154 eyes) as with binocular RB (26.1 %; 36 of 138 eyes; p < 0.01). Organ-preserving treatment was carried out in 138 cases (171 eyes). It was effective in 123 (89.2 %) children (152 eyes; 88.9 %). 5-year ocular survival was 85.7 ± 3.7 %, with monolateral RB — 78.2 ± 6.6 %, with bilateral RB — 92.2 ± 2.8 %. Ocular survival counted separately for groups A, B, C, D, equaled 100 %, 100%, 76.6 ± 6.9 %, and 71.1 ± 11.9 %, respectively. The five-year disease-specific survival rate of children with monocular lesion given eye-preserving treatment was 100%, significantly higher than after primary enucleation — 93.4 ± 2.9 %.Conclusions. Modern combined retinoblastoma treatment is able to save the sick children’s lifes and and even their eyes and visual functions, which improves social adaptation and quality of life. It has been shown that, with a binocular form, it is possible to save more eyes than with a monocular form. Eye-preserving treatment administered to patients with intraocular RB under strictly observed criteria does not heighten the risk of metastasis. Yet timely enucleation in cases of absolute indications remains the method of choice in saving the life of a child.