Survey of source code metrics for evaluating testability of object oriented systems

Software testing is costly in terms of time and funds. Testability is a software characteristic that aims at producing systems easy to test. Several metrics have been proposed to identify the testability weaknesses. But it is sometimes difficult to be convinced that those metrics are really related with testability. This article is a critical survey of the source-code based metrics proposed in the literature for object-oriented software testability. It underlines the necessity to provide testability metrics that are proved to be intuitive and adequate for the testing cost prediction

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

Validation de métriques de testabilité logicielle pour les programmes objets

The most used validation method for software is testing. Testing process consists of executing the program by selecting a set of data and observing the outputs of the program. The testing process is a costly in terms of time and money. Estimating the effort of testing is important in order to be able to plan the testing phase. Therefore, some reliable indicators are required to predict the cost of testing, according to the selected testing strategy. Software testability is a concept that characterizes the effort of testing. A variety of software metrics were proposed in the literature as indicators of software testability. All of them focus on measuring some software attributes that intend to make test difficult. A few studies have been carried out in order to validate these metrics. Some of these studies have controversial results about same metrics. Our work in this thesis focuses on validating some testability metrics, and examining whether they could be really used as indicators of testability. Our approach in metrics validation considers both testability metrics and testing strategies, i.e. our methodology checks a specific metric against a specific testing criterion with respect to predefined hypotheses, and evaluates how much they are correlated. Additionally, we have defined new metrics which are a result of an adapting of some classical object-oriented metrics. The second part of our work concentrates on the testability antipatterns. The purpose of this part is checking some testability antipatterns and detecting at which point they are introduced during the software development phases.Pour les systèmes logiciels, la méthode de validation la plus utilisée est le test. Tester consiste en l'exécution du logiciel en sélectionnant des données et en observant/jugeant les sorties. C'est un processus souvent coûteux. Il dépend de la complexité du logiciel, des objectifs en termes de validation, des outils et du processus de développement. La testabilité logicielle s'intéresse à caractériser et prédire l'effort de test. Cela est nécessaire pour estimer le travail de test, prévoir les coûts, planifier et organiser le travail. De nombreuses mesures ont été proposées dans la littérature comme indicateurs du coût du test. Ces mesures sont focalisées sur l'évaluation de certains attributs qui peuvent rendre le test difficile. D'autres approches proposent de repérer des constructions difficiles à tester à l'aide de patrons (testability antipatterns) par exemple. D'une façon générale, peu d'études ont été réalisées pour valider ces métriques ou patrons. Certaines de ces études donnent des résultats contradictoires. Or il est essentiel de fournir des informations non biaisées. Notre travail de thèse porte en premier lieu sur la validation de certaines métriques de testabilité proposées pour la prédiction du coût du test de programmes objet. Notre approche s'appuie sur une mise en relation des métriques et des stratégies de test et vise à l'établissement de corrélation entre coût prédictive et coût effective. Ceci nous a conduit à raffiner certaines métriques étudiées. Dans un second temps, nous nous sommes intéressés à des patrons (testability antipatterns) visant à détecter des faiblesses dans le code vis à vis du test. Le but de cette étude est de comprendre à quels moments ces constructions sont introduites dans le code, afin de les repérer le plus efficacement possible

Is Depth of Inheritance Tree a Good Cost Prediction For Branch Coverage Testing?

International audienceDepth of Inheritance Tree (DIT) is supposed to be a factor influencing the cost of testing: test would be more expensive if DIT is large. A question is thus to know whether DIT can be used as a predictive metric to estimate the cost of testing. In this paper, we consider the cost of testing as the number of test cases required to achieve the branch coverage, which is a classical criterion for structural testing, and which is given by McCabe's Cyclomatic Complexity metric. We analyzed 25 applications to identify if the DIT is good test cost indicator. This paper shows that DITA is too abstract to be really relevant to predict the cost of testing

Analysis of the introduction of testability antipatterns during the development process

International audienceTestability is a software characteristic that aims at producing systems easy to test. A testability antipattern is a factor that could affect negatively the testability of software. In this paper we compare the antipatterns at source code level and at different abstraction levels, in order to understand at which point they are introduced during the development

Validation de métriques de testabilité logicielle pour les programmes objets

Pour les systèmes logiciels, la méthode de validation la plus utilisée est le test. Tester consiste en l'exécution du logiciel en sélectionnant des données. en observant/jugeant les sorties, C'est un processus souvent coûteux. L'effort de test est difficile à caractériser précisément. Il dépend de la complexité du logiciel, des objectifs en termes de validation, des outils et du processus développement. La testabilité logicielle s'intéresse à caractériser et prédire l'effort de test. Cela est nécessaire pour estimer le travail de test, prévoir les coûts, planifier et organiser le travail. De nombreuses mesures ont été proposées dans la littérature comme indicateurs du coût du test. Ces mesures sont focalisées sur l'évaluation de certains attributs qui peuvent rendre le test difficile. D'autre approches proposent de repèrer des constructions difficiles à tester à l'aide de patrons (testability antipatterns) par exemple, D'une, fa, çon générale, peu d'études ont été réalisées pour valider ces métriques ou patrons. Certaines de ces études donnent des résultats contradictoires. Or i est essentiel de fournir des informations non biaisées. Notre travail de thèse porte en premier lieu sur la validation de certaines métriques de testabilité proposées pour la prédiction du coût du test de programmes objet. Notre approche s'appuie sur une mise en relation des métriques et des stratégies de test et vise à l'établissement de corrélation entre coût prédictive et coût effective. Ceci nous a conduit à raffiner certaines des métriques étudiées. Dans un second temps, nous nous sommes intéressés à des patrons (testability antipattems) visant à détecter des faiblesses dans le code vis à vis du test. Le but de cette étude est de comprendre à quels moments ces constructions sont introduites dans le code, afin de les repérer le plus efficacement possible.The most used validation method for software is testing. Testing process consists of executing the program by selecting a set of data and observing the outputs of the program. The testing process is a costly in terms of time and money. Estimating the effort of testing is important in order to be able to plan the testing phase. Therefore, sorne reliable indicators are required to predict the cost oftesting, according to the selected testing strategy. Software testability is a concept that characterizes the effort of testing. A variety of software metrics were proposed in the literature as indicators of software testability. AIl of them focus on measuring sorne software attributes that intend to make test difficult. A few studies have been carried out in order to validate these metrics. Sorne of these studies have controversial results about same metrics. Our work in this thesis focuses on validating sorne testability metrics, and examining whether they could be really used as indicators of testability. Our approach in metrics validation considers both testability metrics and testing strategies, i.e. our methodology checks a specifie metric against a specifie testing criterion with respect to predefined hypotheses, and evaluates how much they are correlated. Additionally, we have defined new metrics which are a result of an adapting of sorne c1assical object-oriented metrics. The second part of our work concentrates on the testability antipattems. The purpose ofthis part is checking sorne testability antipatterns and detecting at which point they are introduced during the software development phases.GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

Background: 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods: This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494. Findings: Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation: Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding: National Institute for Health Research Global Health Research Unit

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

© 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licenseBackground: 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods: This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494. Findings: Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation: Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding: National Institute for Health Research Global Health Research Unit

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

© 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide. Methods: A multimethods analysis was performed as part of the GlobalSurg 3 study—a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital. Findings: Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3·85 [95% CI 2·58–5·75]; p<0·0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63·0% vs 82·7%; OR 0·35 [0·23–0·53]; p<0·0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer. Interpretation: Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised. Funding: National Institute for Health and Care Research