Analyzing software data bindings in large-scale systems

One central feature of the structure of a software system is the coupling among its components (e.g., subsystems. modules) and the cohesion within them. The purpose of this study is to quantify ratios of coupling and cohesion and use them in the generation of hierarchical system descriptions. The ability of the hierarchical descriptions to localize errors by identifying error-prone system structure is evaluated using actual error data. Measures of data interaction, called data bindings, are used as the basis for calculating software coupling and cohesion. A 135,000 source line system from a production environment has been selected for empirical analysis. Software error data was collected from high-level system design through system test and from some field operation of the system. A set of five tools is applied to calculate the data bindings automatically, and cluster analysis is used to determine a hierarchical description of each of the system's 77 subsystems. An analysis of variance model is used to characterize subsystems and individual routines that had either many/few errors or high/low error correction effort

Calculation and use of an environment's characteristic software metric set

Since both cost/quality and production environments differ, this study presents an approach for customizing a characteristic set of software metrics to an environment. The approach is applied in the Software Engineering Laboratory (SEL), a NASA Goddard production environment, to 49 candidate process and product metrics of 652 modules from six (51,000 to 112,000 lines) projects. For this particular environment, the method yielded the characteristic metric set (source lines, fault correction effort per executable statement, design effort, code effort, number of I/O parameters, number of versions). The uses examined for a characteristic metric set include forecasting the effort for development, modification, and fault correction of modules based on historical data

Next generation software environments : principles, problems, and research directions

The past decade has seen a burgeoning of research and development in software environments. Conferences have been devoted to the topic of practical environments, journal papers produced, and commercial systems sold. Given all the activity, one might expect a great deal of consensus on issues, approaches, and techniques. This is not the case, however. Indeed, the term "environment" is still used in a variety of conflicting ways. Nevertheless substantial progress has been made and we are at least nearing consensus on many critical issues.The purpose of this paper is to characterize environments, describe several important principles that have emerged in the last decade or so, note current open problems, and describe some approaches to these problems, with particular emphasis on the activities of one large-scale research program, the Arcadia project. Consideration is also given to two related topics: empirical evaluation and technology transition. That is, how can environments and their constituents be evaluated, and how can new developments be moved effectively into the production sector

Concentrated Perchlorate at the Mars Phoenix Landing Site: Evidence for Thin Film Liquid Water on Mars

NASA\u27s Phoenix mission, which landed on the northern plains of Mars in 2008, returned evidence of the perchlorate anion distributed evenly throughout the soil column at the landing site. Here, we use spectral data from Phoenix\u27s Surface Stereo Imager to map the distribution of perchlorate salts at the Phoenix landing site, and find that perchlorate salt has been locally concentrated into subsurface patches, similar to salt patches that result from aqueous dissolution and redistribution on Earth. We propose that thin films of liquid water are responsible for translocating perchlorate from the surface to the subsurface, and for concentrating it in patches. The thin films are interpreted to result from melting of minor ice covers related to seasonal and long-term obliquity cycles

Acute kidney injury associated with COVID-19: A retrospective cohort study

BackgroundInitial reports indicate a high incidence of acute kidney injury (AKI) in Coronavirus Disease 2019 (COVID-19), but more data are required to clarify if COVID-19 is an independent risk factor for AKI and how COVID-19–associated AKI may differ from AKI due to other causes. We therefore sought to study the relationship between COVID-19, AKI, and outcomes in a retrospective cohort of patients admitted to 2 acute hospitals in Derby, United Kingdom.Methods and findingsWe extracted electronic data from 4,759 hospitalised patients who were tested for COVID-19 between 5 March 2020 and 12 May 2020. The data were linked to electronic patient records and laboratory information management systems. The primary outcome was AKI, and secondary outcomes included in-hospital mortality, need for ventilatory support, intensive care unit (ICU) admission, and length of stay. As compared to the COVID-19–negative group (n = 3,374), COVID-19 patients (n = 1,161) were older (72.1 ± 16.1 versus 65.3 ± 20.4 years, p [less than] 0.001), had a greater proportion of men (56.6% versus 44.9%, p [less than] 0.001), greater proportion of Asian ethnicity (8.3% versus 4.0%, p [less than] 0.001), and lower proportion of white ethnicity (75.5% versus 82.5%, p < 0.001). AKI developed in 304 (26.2%) COVID-19–positive patients (COVID-19 AKI) and 420 (12.4%) COVID-19–negative patients (AKI controls). COVID-19 patients aged 65 to 84 years (odds ratio [OR] 1.67, 95% confidence interval [CI] 1.11 to 2.50), needing mechanical ventilation (OR 8.74, 95% CI 5.27 to 14.77), having congestive cardiac failure (OR 1.72, 95% CI 1.18 to 2.50), chronic liver disease (OR 3.43, 95% CI 1.17 to 10.00), and chronic kidney disease (CKD) (OR 2.81, 95% CI 1.97 to 4.01) had higher odds for developing AKI. Mortality was higher in COVID-19 AKI versus COVID-19 patients without AKI (60.5% versus 27.4%, p [less than] 0.001), and AKI was an independent predictor of mortality (OR 3.27, 95% CI 2.39 to 4.48). Compared with AKI controls, COVID-19 AKI was observed in a higher proportion of men (58.9% versus 51%, p = 0.04) and lower proportion with white ethnicity (74.7% versus 86.9%, p = 0.003); was more frequently associated with cerebrovascular disease (11.8% versus 6.0%, p = 0.006), chronic lung disease (28.0% versus 19.3%, p = 0.007), diabetes (24.7% versus 17.9%, p = 0.03), and CKD (34.2% versus 20.0%, p [less than] 0.001); and was more likely to be hospital acquired (61.2% versus 46.4%, p < 0.001). Mortality was higher in the COVID-19 AKI as compared to the control AKI group (60.5% versus 27.6%, p [less than] 0.001). In multivariable analysis, AKI patients aged 65 to 84 years, (OR 3.08, 95% CI 1.77 to 5.35) and ≥85 years of age (OR 3.54, 95% CI 1.87 to 6.70), peak AKI stage 2 (OR 1.74, 95% CI 1.05 to 2.90), AKI stage 3 (OR 2.01, 95% CI 1.13 to 3.57), and COVID-19 (OR 3.80, 95% CI 2.62 to 5.51) had higher odds of death. Limitations of the study include retrospective design, lack of urinalysis data, and low ethnic diversity of the region.ConclusionsWe observed a high incidence of AKI in patients with COVID-19 that was associated with a 3-fold higher odds of death than COVID-19 without AKI and a 4-fold higher odds of death than AKI due to other causes. These data indicate that patients with COVID-19 should be monitored for the development of AKI and measures taken to prevent this

A simple care bundle for use in acute kidney injury: a propensity score-matched cohort study

Background Consensus guidelines for acute kidney injury (AKI) have recommended prompt treatment including attention to fluid balance, drug dosing and avoidance of nephrotoxins. These simple measures can be incorporated in a care bundle to facilitate early implementation. The objective of this study was to assess the effect of compliance with the AKI care bundle (AKI-CB) on in-hospital case–fatality and AKI progression. Methods In this larger, propensity score-matched cohort of multifactorial AKI, we examined the impact of compliance with an AKI-CB in 3717 consecutive episodes of AKI in 3518 patients between 1 August 2013 and 31 January 2015. Propensity score matching was performed to match 939 AKI events where the AKI-CB was completed with 1823 AKI events where AKI-CB was not completed. Results The AKI-CB was completed in 25.6% of patients within 24 h. The unadjusted case–fatality was higher when the AKI-CB was not completed versus when the AKI-CB was completed (24.4 versus 20.4%, P = 0.017). In multivariable analysis, AKI-CB completion within 24 h was associated with lower odds for in-hospital death [odds ratio (OR): 0.76; 95% confidence interval (95% CI): 0.62–0.92]. Increasing age (OR: 1.04; 95% CI: 1.03–1.05), hospital-acquired AKI (OR: 1.28; 95% CI: 1.04–1.58), AKI stage 2 (OR: 1.91; 95% CI: 1.53–2.39) and increasing Charlson's comorbidity index (CCI) [OR: 3.31 (95% CI: 2.37–4.64) for CCI of more than 5 compared with zero] had higher odds for death, whereas AKI during elective admission was associated with lower odds for death (OR: 0.29; 95% CI: 0.16–0.52). Progression to higher AKI stages was lower when the AKI-CB was completed (4.2 versus 6.7%, P = 0.02). Conclusions Compliance with an AKI-CB was associated with lower mortality and reduced progression of AKI to higher stages. The AKI-CB is simple and inexpensive, and could therefore be applied in all healthcare settings to improve outcomes

International criteria for acute kidney injury: advantages and remaining challenges

• Acute Kidney Injury (AKI) is defined using widely accepted international criteria that are based on changes in serum creatinine concentration and degree of oliguria. • AKI, when defined in this way, has a strong association with poor patient outcomes, including high mortality rates and longer hospital admissions with increased resource utilisation and subsequent chronic kidney disease. • The detection of AKI using current criteria can assist with AKI diagnosis and stratification of individual patient risk. • The diagnosis of AKI requires clinical judgement to integrate the definition of AKI with the clinical situation, to determine underlying cause of AKI, and to take account of factors that may affect performance of current definitions

Decision regret in men living with and beyond nonmetastatic prostate cancer in the United Kingdom: A population‐based patient‐reported outcome study

Objective: Clinical options for managing nonmetastatic prostate cancer (PCa) vary. Each option has side effects associated with it, leading to difficulty in decision‐making. This study aimed to assess the relationship between patient involvement in treatment decision‐making and subsequent decision regret (DR), and quantify the impact of health‐related quality of life (HRQL) outcomes on DR. Methods: Men living in the United Kingdom, 18 to 42 months after diagnosis of PCa, were identified from cancer registration data and sent a questionnaire. Measures included the Decision Regret Scale (DRS), Expanded Prostate cancer Index Composite short form (EPIC‐26), EQ‐5D‐5L, and an item on involvement in treatment decision‐making. Multivariable ordinal regression was utilized, with DR categorized as none, mild, or moderate/severe regret. Results: A total of 17 193 men with stage I‐III PCa completed the DRS: 36.6% reported no regret, 43.3% mild regret, and 20.0% moderate/severe regret. The odds of reporting DR were greater if men indicated their views were not taken into account odds ratio ([OR] = 6.42, 95% CI: 5.39‐7.64) or were involved “to some extent” in decision‐making (OR = 4.63, 95% CI: 4.27‐5.02), compared with men who were “definitely” involved. After adjustment, including for involvement, men reporting moderate/big problems with urinary, bowel, or sexual function were more likely to experience regret compared with men with no/small problems. Better HRQL scores were associated with lower levels of DR. Conclusions: This large‐scale study demonstrates the benefit of patient involvement in treatment decision‐making for nonmetastatic PCa. However, men experiencing side effects and poorer HRQL report greater DR. Promoting engagement in clinical decision‐making represents good practice and may reduce the risk of subsequent regret

Regional variations in quality of survival among men with prostate cancer across the United Kingdom

Purpose: Prostate cancer incidence, treatment and survival rates vary throughout the United Kingdom (UK) but little is known about regional differences in quality of survival. Objective: To investigate variations in patient-reported outcomes between UK countries and English Cancer Alliances. Design, setting and participants: A cross-sectional postal survey of prostate cancer survivors diagnosed 18-42 months previously. Outcome measurements and statistical analysis: Urinary, bowel, sexual problems and vitality were patient reported using the EPIC-26 questionnaire. General health was also self-assessed. Regional variations were identified using multivariable log-linear regression. Results and limitations: 35,823 men responded; 60.8% of those invited. Self-assessed health was significantly lower than the UK average in Wales and Scotland. Respondents reported more urinary incontinence in Scotland, more urinary irritation/obstruction in Scotland and Northern Ireland (NI), poorer bowel function in Scotland and NI, worse sexual function in Scotland, and reduced vitality/hormonal function in Scotland, Wales and NI. Self-assessed health was poorer than the English average in South Yorkshire and North-East & Cumbria, with more urinary incontinence in North-East & Cumbria and Peninsula, greater sexual problems in West Midlands and poorer vitality in North-East & Cumbria and West Midlands. Limitations include difficulty identifying clinically significant differences and limited information on pre-treatment conditions. Conclusions: Despite adjustment for treatment, clinical and socio-demographic factors, quality of survival among prostate cancer survivors varied by area of residence. Adoption of best practice from areas performing well could support enhanced survival quality in poorer performing areas, particularly with regards bowel problems and vitality, where clinically relevant differences were reported. Patient summary: We conducted a UK-wide survey of patient’s quality of life after treatment for prostate cancer. Outcomes were found to vary depending upon where patients live. Different service providers need to ensure that all prostate cancer patients receive the same follow up care