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result(s) for
"Krisam, Johannes"
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Predicting survival from colorectal cancer histology slides using deep learning: A retrospective multicenter study
by
Hoffmeister, Michael
,
Weis, Cleo-Aron
,
Jansen, Lina
in
Aging
,
Artificial intelligence
,
Artificial neural networks
2019
For virtually every patient with colorectal cancer (CRC), hematoxylin-eosin (HE)-stained tissue slides are available. These images contain quantitative information, which is not routinely used to objectively extract prognostic biomarkers. In the present study, we investigated whether deep convolutional neural networks (CNNs) can extract prognosticators directly from these widely available images.
We hand-delineated single-tissue regions in 86 CRC tissue slides, yielding more than 100,000 HE image patches, and used these to train a CNN by transfer learning, reaching a nine-class accuracy of >94% in an independent data set of 7,180 images from 25 CRC patients. With this tool, we performed automated tissue decomposition of representative multitissue HE images from 862 HE slides in 500 stage I-IV CRC patients in the The Cancer Genome Atlas (TCGA) cohort, a large international multicenter collection of CRC tissue. Based on the output neuron activations in the CNN, we calculated a \"deep stroma score,\" which was an independent prognostic factor for overall survival (OS) in a multivariable Cox proportional hazard model (hazard ratio [HR] with 95% confidence interval [CI]: 1.99 [1.27-3.12], p = 0.0028), while in the same cohort, manual quantification of stromal areas and a gene expression signature of cancer-associated fibroblasts (CAFs) were only prognostic in specific tumor stages. We validated these findings in an independent cohort of 409 stage I-IV CRC patients from the \"Darmkrebs: Chancen der Verhütung durch Screening\" (DACHS) study who were recruited between 2003 and 2007 in multiple institutions in Germany. Again, the score was an independent prognostic factor for OS (HR 1.63 [1.14-2.33], p = 0.008), CRC-specific OS (HR 2.29 [1.5-3.48], p = 0.0004), and relapse-free survival (RFS; HR 1.92 [1.34-2.76], p = 0.0004). A prospective validation is required before this biomarker can be implemented in clinical workflows.
In our retrospective study, we show that a CNN can assess the human tumor microenvironment and predict prognosis directly from histopathological images.
Journal Article
University students’ economic situation during the COVID-19 pandemic: A cross-sectional study in Germany
by
Gewalt, Sandra Claudia
,
Krisam, Regina
,
Krisam, Johannes
in
Adult
,
College students
,
Colleges & universities
2022
The COVID-19 pandemic caused a major economic downturn that disproportionally affected university students. This empirical research investigated effects and risk factors of the pandemic on students’ economic situation with focus on financial distress and financial limitations. Data was collected using an online survey in May and June 2020 from students (n = 917) enrolled at universities in Germany. 80.6% were enrolled in bachelor programs (n = 738), the mean semester was 3.8 (standard deviation (SD = 2.0) and students’ mean age was 23.1 years (SD = 4.1). 51.8% (n = 472) were female and 47.4% (n = 432) male. 56.7% (n = 506) of students worked before the pandemic. More than one third reported a decrease in income (36.5%; n = 334) and an increase in financial constraints (38.7%; n = 354). A multivariate logistic regression analysis showed that students with regular income were less likely to experience financial distress compared to those without (odds ratio (OR) = 0.456; p = 0.014). Furthermore, working part-time as associated with a higher financial distress compared to those without part-time employment (OR = 1.811; p = 0.003). Students who worked part-time before the pandemic also had a higher probability of increased financial restriction (or constraint) compared to those who did not work part-time (OR = 2.094; p < 0.001). University students were disproportionally affected by the economic consequences of the COVID-19 pandemic, which increased students’ economic uncertainty. To offset such problems, financial aid schemes for students need to be made available to alleviate distress and to allow students to focus on their studies but should not compound problems by leading to financial hardship at a later point in time.
Journal Article
What do Germans really think about health-nudges?
2021
Background
In recent years, policymakers have increasingly used behaviourally informed policies, including ‘nudges’. They have been implemented to produce desirable social outcomes such as healthier eating and physical activity. In Germany, a small research team at the Federal Chancellery acts as the central unit to promote the introduction of nudges in the design of public life. Despite this, the nudging concept itself as well as the understanding around it has not spread widely among German citizens. When reporting about the concept, German media is often very critical of the concept.
Methods
Using a for age, sex and educational level nationally representative online survey with 1000 participants, we investigate whether German citizens know about the concept of nudging. We also explore if they approve of the theoretical concept as well as a list of seven specific interventions regarding healthy eating and physical activity. A particular focus is placed on whether the level of approval is dependent on the target group of the intervention, as well as different intervention-initiators.
Results
We find that nearly 80% of the respondents have never heard of nudging. However when being provided with a definition, we find that a strong majority (90%) supports the concept of nudging as well as all the specific interventions. Acceptance rates are higher if interventions are targeted at the general population compared to only children. All initiators – statutory health insurers, the government, private companies, and independent experts – are accepted as nudge initiators.
Conclusion
Amongst Germans nudges are an accepted method to promote health behaviours. Policy makers from various fields in Germany should take that into account to improve future health policy.
Journal Article
\University students' economic situation during the COVID-19 pandemic: A cross-sectional study in Germany\
2022
The COVID-19 pandemic caused a major economic downturn that disproportionally affected university students. This empirical research investigated effects and risk factors of the pandemic on students' economic situation with focus on financial distress and financial limitations. Data was collected using an online survey in May and June 2020 from students (n = 917) enrolled at universities in Germany. 80.6% were enrolled in bachelor programs (n = 738), the mean semester was 3.8 (standard deviation (SD = 2.0) and students' mean age was 23.1 years (SD = 4.1). 51.8% (n = 472) were female and 47.4% (n = 432) male. 56.7% (n = 506) of students worked before the pandemic. More than one third reported a decrease in income (36.5%; n = 334) and an increase in financial constraints (38.7%; n = 354). A multivariate logistic regression analysis showed that students with regular income were less likely to experience financial distress compared to those without (odds ratio (OR) = 0.456; p = 0.014). Furthermore, working part-time as associated with a higher financial distress compared to those without part-time employment (OR = 1.811; p = 0.003). Students who worked part-time before the pandemic also had a higher probability of increased financial restriction (or constraint) compared to those who did not work part-time (OR = 2.094; p < 0.001). University students were disproportionally affected by the economic consequences of the COVID-19 pandemic, which increased students' economic uncertainty. To offset such problems, financial aid schemes for students need to be made available to alleviate distress and to allow students to focus on their studies but should not compound problems by leading to financial hardship at a later point in time.
Journal Article
Correction: Forced randomization: the what, why, and how
by
Krisam, Johannes
,
Carter, Kerstine
,
Kuznetsova, Olga
in
Correction
,
Health Sciences
,
Medicine
2024
Journal Article
Effect of endodontic treatment on periodontal healing of grade 3 endo-periodontal lesions without root damage in periodontally compromised patients—a retrospective pilot study
2021
Objectives
There is little evidence about the effect of different treatment protocols for grade 3 endo-periodontal lesions without root damage in patients with periodontitis according to the new classification of periodontal disease. The aim of this study is to evaluate the impact of endodontic treatment on the achievement of periodontal healing.
Materials and methods
Teeth with the initial diagnosis endo-periodontal lesion without root damage grade 3, treated with a standardized endodontic treatment protocol, were included in this study. A retrospective analysis was performed to assess the impact on periodontal healing by evaluating probing pocket depth (PPD), clinical attachment gain (CAL), and periapical index score (PAI).
Results
Nineteen teeth and 13 patients were included. A mean reduction of 3.19 ± 3.41 mm in PPD was recorded. The mean CAL gain was 2.33± 3.75 mm. Five teeth (45.4%) showed an improvement of PAI and were classified as treatment success.
Conclusions
The results failed to show a highly predictable treatment outcome for endo-periodontal lesion grade 3 without root damage in patients with periodontitis. However, endodontic therapy alone resulted in treatment success for some of the teeth, which would otherwise have had a poor prognosis.
Clinical relevance
Endo-periodontal lesions can often be challenging for dentists in daily clinical practice. To date, there is not much evidence for practitioners to rely on. Therefore, this study aims to strengthen the evidence for the management and treatment of endo-periodontal lesions. Although the outcome is not highly predictable yet, teeth with the initial diagnosis endo-periodontal lesion without root damage grade 3 can benefit from an endodontic treatment.
Journal Article
Forced randomization: the what, why, and how
by
Krisam, Johannes
,
Carter, Kerstine
,
Kuznetsova, Olga
in
Clinical trials
,
Drug supply chain management
,
Evaluation
2024
Background
When running a randomized controlled trial (RCT), a clinical site may face a situation when an eligible trial participant is to be randomized to the treatment that is not available at the site. In this case, there are two options: not to enroll the participant, or, without disclosing to the site, allocate the participant to a treatment arm with drug available at the site using a built-in feature of the interactive response technology (IRT). In the latter case, one has employed a “forced randomization” (FR). There seems to be an industry-wide consensus that using FR can be acceptable in confirmatory trials provided there are “not too many” instances of forcing. A better understanding of statistical properties of FR is warranted.
Methods
We described four different IRT configurations with or without FR and illustrated them using a simple example. We discussed potential merits of FR and outlined some relevant theoretical risks and risk mitigation strategies. We performed a search using Cortellis Regulatory Intelligence database (IDRAC) (
www.cortellis.com
) to understand the prevalence of FR in clinical trial practice. We also proposed a structured template for development and evaluation of randomization designs featuring FR and showcased an application of this template for a hypothetical multi-center 1:1 RCT under three experimental settings (“base case”, “slower recruitment”, and “faster recruitment”) to explore the effect of four different IRT configurations in combination with three different drug supply/re-supply strategies on some important operating characteristics of the trial. We also supplied the Julia code that can be used to reproduce our simulation results and generate additional results under user-specified experimental scenarios.
Results
FR can eliminate refusals to randomize patients, which can cause frustration for patients and study site personnel, improve the study logistics, drug supply management, cost-efficiency, and recruitment time. Nevertheless, FR carries some potential risks that should be reviewed at the study planning stage and, ideally, prospectively addressed through risk mitigation planning. The Cortellis search identified only 9 submissions that have reported the use of FR; typically, the FR option was documented in IRT specifications. Our simulation evidence showed that under the considered realistic experimental settings, the percentage of FR is expected to be low. When FR with backfilling was used in combination with high re-supply strategy, the final treatment imbalance was negligibly small, the proportion of patients not randomized due to the lack of drug supply was close to zero, and the time to complete recruitment was shortened compared to the case when FR was not allowed. The drug overage was primarily determined by the intensity of the re-supply strategy and to a smaller extent by the presence or absence of the FR feature in IRT.
Conclusion
FR with a carefully chosen drug supply/re-supply strategy can result in quantifiable improvements in the patients’ and site personnel experience, trial logistics and efficiency while preventing an undesirable refusal to randomize a patient and a consequential unblinding at the site. FR is a useful design feature of multi-center RCTs provided it is properly planned for and carefully implemented.
Journal Article
Diphtheria outbreak in Yemen: the impact of conflict on a fragile health system
by
Kuunibe, Naasegnibe
,
Dureab, Fekri
,
Krisam, Johannes
in
Airway management
,
Analysis
,
Bivariate analysis
2019
Background
War in Yemen started three years ago, and continues unabated with a steadily rising number of direct and indirect victims thus leaving the majority of Yemen’s population in dire need of humanitarian assistance. The conflict adversely affects basic socioeconomic and health conditions across the country.
Methods
This study analyzed the recent ongoing diphtheria outbreak in Yemen and in particular, the health system’s failure to ensure immunization coverage and respond to this outbreak. Data from the weekly bulletins of the national electronic Disease Early Warning System’s (eDEWS) daily diphtheria reports and district immunization coverage were analyzed. The number of diphtheria cases and deaths, and immunization coverage (DPT) were reviewed by district including the degree to which a district was affected by conflict using a simple scoring system. A logistic regression and bivariate correlation were applied using the annual immunization coverage per district to determine if there was an association between diphtheria, immunization coverage and conflict.
Results
The study results confirm the association between the increasing cases of diphtheria, immunization coverage and ongoing conflict. A total of 1294 probable cases of diphtheria were reported from 177 districts with an overall case fatality rate of 5.6%. Approximately 65% of the patients were children under 15 years, and 46% of the cases had never been vaccinated against diphtheria. The risk of an outbreak increased by 11-fold if the district was experiencing ongoing conflict
p
< 0.05. In the presence of conflict (whether past or ongoing), the risk of an outbreak decreased by 0.98 if immunization coverage was high
p
> 0.05.
Conclusion
The conflict is continuously devastating the health system in Yemen with serious consequences on morbidity and mortality. Therefore, the humanitarian response should focus on strengthening health services including routine immunization procedures to avoid further outbreaks of life-threatening infectious diseases, such as diphtheria.
Journal Article
Thoracic radiotherapy plus Durvalumab in elderly and/or frail NSCLC stage III patients unfit for chemotherapy - employing optimized (hypofractionated) radiotherapy to foster durvalumab efficacy: study protocol of the TRADE-hypo trial
by
Christopoulos, Petros
,
Krisam, Johannes
,
Thomas, Michael
in
Adult
,
Anti-PD-L1 monoclonal antibody
,
Antibodies, Monoclonal - administration & dosage
2020
Background
Non-small cell lung cancer is the most common cause of cancer death worldwide, highlighting the need for novel therapeutic concepts. In particular, there is still a lack of treatment strategies for the group of elderly and frail patients, who are frequently not capable of receiving standard therapy regimens. Despite comprising the majority of lung cancer patients, this group is underrepresented in clinical trials. This applies also to elderly and frail patients suffering from unresectable stage III NSCLC, who are unfit for chemotherapy, and, therefore, cannot receive the standard therapy comprising of radiochemotherapy and the recently approved subsequent durvalumab consolidation therapy. These patients often receive radiotherapy only, which raises the concern of undertreatment. The TRADE-hypo trial aims at optimizing treatment of this patient group by combining radiotherapy with concomitant durvalumab administration, thereby employing the immune-promoting effects of radiotherapy, and determining safety, feasibility, and efficacy of this treatment.
Methods/ design
In this prospective phase II clinical trial, durvalumab therapy will be combined with either conventionally fractionated (CON-group) or hypofractionated (HYPO-group) thoracic radiotherapy. A safety stop-and-go lead-in phase will assess safety of hypofractionated radiotherapy with respect to severe pneumonitis in small patient cohorts before opening full enrollment. Tumor tissue, blood and stool samples will be collected before and during the study period to investigate the immunological mechanisms responsible for checkpoint inhibitor efficacy and immune-promoting effects of radiotherapy.
Discussion
Preclinical data suggests that irradiation-induced immunogenicity can be further increased if applied in a hypofractionated setting, potentially boosting the expected synergistic effect with immune checkpoint inhibition in restoring the immune anti-tumor response. If proven safe and efficient, a hypofractionated radiation schedule can provide a considerably more practicable option for the patient. Taking into consideration the intend to develop a combination treatment strategy that can be made available to patients soon after proving to be efficient and the potentially elevated toxicity of a hypofractionated radiotherapy approach, this trial was designed as a two-trials-in-one design. An accompanying translational research program is planned striving to gain insights into the tumor-host biology and to identify suitable biomarkers to predict therapy response.
Trial registration
Clinicaltrials.gov
,
NCT04351256
. Registered 17 April 2020,
Eudra-CT,
2019–002192-33
. Registered 24 October 2019,
Journal Article
HELP — Heidelberg decision aid for lung cancer patients: a randomized controlled clinical trial
by
Krisam, Johannes
,
Siegle, Anja
,
Villalobos, Matthias
in
Anxiety
,
Biomedicine
,
Care and treatment
2023
Background
Shared decision-making (SDM), which increases the patient’s well-being, adherence, and success of treatment, is becoming increasingly important in medicine and especially in oncology. To empower patients to participate more actively in consultations with their physicians decision aids have been developed. In non-curative settings, such as the treatment of advanced lung cancer, decisions differ substantially from the curative setting, as uncertain gains in terms of survival outcomes and quality of life have to be weighed against the severe side effects of treatment regimens. There is still a lack of tools developed and implemented for such specific settings in cancer therapy that support shared decision-making. The aim of our study is to evaluate the effectiveness of the HELP decision aid.
Methods
The HELP-study is designed as a randomized, controlled, open monocenter trial with two parallel groups. The intervention consists of the use of the HELP decision aid brochure, accompanied by a decision coaching session. The primary endpoint is clarity of personal attitude as operationalized by the Decisional Conflict Scale (DCS) after the decision coaching. Randomization will be performed as stratified block randomization according to the characteristic of preferred decision-making at baseline with a 1:1 allocation.
The participants in the control group get usual care, i.e., the doctor-patient conversation takes place without preliminary coaching and deliberation about their preferences and goals.
Discussion
Developing decision aids (DA) for (lung) cancer patients with limited prognosis should empower patients to address these aspects and include information about “Best Supportive Care” as a treatment option. Using and implementing the decision aid HELP can not only give patients the possibility to include their personal wishes and values in the decision-making process, but also raise the awareness of shared decision-making itself among these patients and their physicians.
Trial registration
German Clinical Trial Register DRKS00028023. Registered on 8 February 2022.
Journal Article