A privacy calculus model for contact tracing apps: Analyzing the use behavior of the German Corona-Warn-App with a longitudinal user study

The SARS-CoV-2 pandemic is a pressing societal issue today. The German government promotes a contract tracing app named Corona-Warn-App (CWA), aiming to change citizens' health behaviors during the pandemic by raising awareness about potential infections and enable infection chain tracking. Technical implementations, citizens' perceptions, and public debates around apps differ between countries, e. g., in Germany there has been a huge discussion on potential privacy issues of the app. Thus, we analyze effects of privacy concerns regarding the CWA, perceived CWA benefits, and trust in the German healthcare system to answer why citizens use the CWA. In our initial conference publication at ICT Systems Security and Privacy Protection - 37th IFIP TC 11 International Conference, SEC 2022, we used a sample with 1752 actual users and non-users of the CWA and and support for the privacy calculus theory, i. e., individuals weigh privacy concerns and benefits in their use decision. Thus, citizens privacy perceptions about health technologies (e. g., shaped by public debates) are crucial as they can hinder adoption and negatively affect future fights against pandemics. In this special issue, we adapt our previous work by conducting a second survey 10 months after our initial study with the same pool of participants (830 participants from the first study participated in the second survey). The goal of this longitudinal study is to assess changes in the perceptions of users and non-users over time and to evaluate the influence of the significantly lower hospitalization and death rates on the use behavior which we could observe during the second survey. Our results show that the privacy calculus is relatively stable over time. The only relationship which significantly changes over time is the effect of privacy concerns on the use behavior which significantly decreases over time, i. e., privacy concerns have a lower negative effect one the CWA use indicating that it did not play such an important role in the use decision at a later point in time in the pandemic. We contribute to the literature by introducing one of the rare longitudinal analyses in the literature focusing on the privacy calculus and changes over time in the relevant constructs as well as the relationships between the calculus constructs and target variables (in our case use behavior of a contact tracing app). We can see that the explanatory power of the privacy calculus model is relatively stable over time even if strong externalities might affect individual perceptions related to the model.

The Impact of Individuals' Social Environments on Contact Tracing App Use: Survey Study

BACKGROUND

The German Corona-Warn-App (CWA) is a contact tracing app to mitigate the spread of SARS-CoV-2. As of today, it has been downloaded approximately 45 million times.

OBJECTIVE

This study aims to investigate the influence of (non)users' social environments on the usage of the CWA during 2 periods with relatively lower death rates and higher death rates caused by SARS-CoV-2.

METHODS

We conducted a longitudinal survey study in Germany with 833 participants in 2 waves to investigate how participants perceive their peer groups' opinion about making use of the German CWA to mitigate the risk of SARS-CoV-2. In addition, we asked whether this perceived opinion, in turn, influences the participants with respect to their own decision to use the CWA. We analyzed these questions with generalized estimating equations. Further, 2 related sample tests were performed to test for differences between users of the CWA and nonusers and between the 2 points in time (wave 1 with the highest death rates observable during the pandemic in Germany versus wave 2 with significantly lower death rates).

RESULTS

Participants perceived that peer groups have a positive opinion toward using the CWA, with more positive opinions by the media, family doctors, politicians, and virologists/Robert Koch Institute and a lower, only slightly negative opinion originating from social media. Users of the CWA perceived their peer groups' opinions about using the app as more positive than nonusers do. Furthermore, the perceived positive opinion of the media (P=.001) and politicians (P<.001) was significantly lower in wave 2 compared with that in wave 1. The perceived opinion of friends and family (P<.001) as well as their perceived influence (P=.02) among nonusers toward using the CWA was significantly higher in the latter period compared with that in wave 1. The influence of virologists (in Germany primarily communicated via the Robert Koch Institute) had the highest positive effect on using the CWA (B=0.363, P<.001). We only found 1 decreasing effect of the influence of politicians (B=-0.098, P=.04).

CONCLUSIONS

Opinions of peer groups play an important role when it comes to the adoption of the CWA. Our results show that the influence of virologists/Robert Koch Institute and family/friends exerts the strongest effect on participants' decisions to use the CWA while politicians had a slightly negative influence. Our results also indicate that it is crucial to accompany the introduction of such a contact tracing app with explanations and a media campaign to support its adoption that is backed up by political decision makers and subject matter experts.

Techniques for the Investigation of Segmented Sensors Using the Two Photon Absorption-Transient Current Technique

The two photon absorption-transient current technique (TPA-TCT) was used to investigate a silicon strip detector with illumination from the top. Measurement and analysis techniques for the TPA-TCT of segmented devices are presented and discussed using a passive strip CMOS detector and a standard strip detector as an example. The influence of laser beam clipping and reflection is shown, and a method that allows to compensate these intensity-related effects for investigation of the electric field is introduced and successfully employed. Additionally, the mirror technique is introduced, which exploits reflection at a metallised back side to enable the measurement directly below a top metallisation while illuminating from the top.

Fiber laser system of 1550 nm femtosecond pulses with configurable properties for the two-photon excitation of transient currents in semiconductor detectors

A fiber laser system emitting ultrashort femtosecond pulses at 1550 nm with configurable properties has been developed as an excitation source for the two-photon absorption transient current technique (TPA-TCT). The modules of the system are designed to provide the optical specifications required at the output for localized characterization of semiconductor radiation detectors: variation of pulse energy between 10 nJ and 10p J, variation of the pulse repetition rate from 8.2 MHz to single shot, and variation of pulse duration between 300 and 600 fs. The validity of the system as an excitation source in the TPA-TCT is demonstrated by measuring spatially resolved excited charge carriers in a silicon detector.

How Privacy Concerns, Trust and Risk Beliefs, and Privacy Literacy Influence Users' Intentions to Use Privacy-Enhancing Technologies

Due to an increasing collection of personal data by internet companies and several data breaches, research related to privacy gained importance in the last years in the information systems domain. Privacy concerns can strongly influence users' decision to use a service. The Internet Users Information Privacy Concerns (IUIPC) construct is one operationalization to measure the impact of privacy concerns on the use of technologies. However, when applied to a privacy enhancing technology (PET) such as an anonymization service, the original rationales do not hold anymore. In particular, an inverted impact of trusting and risk beliefs on behavioral intentions can be expected. We show that the IUIPC model needs to be adapted for the case of PETs. In addition, we extend the original causal model by including trusting beliefs in the anonymization service itself as well as a measure for privacy literacy. A survey among 124 users of the anonymization service Tor shows that trust in Tor has a statistically significant effect on the actual use behavior of the PET. In addition, the results indicate that privacy literacy has a negative impact on trusting beliefs in general and a positive effect on trust in Tor.

Decreased tacrolimus plasma concentrations during HCV therapy: a drug-drug interaction or is there an alternative explanation?

Chronic hepatitis C virus (HCV) infection can cause severe liver cirrhosis, for which liver transplantation is the only therapy. To prevent organ rejection, transplanted patients are treated with immunosuppressive agents. We describe two transplanted patients treated with tacrolimus who were simultaneously treated with direct-acting antivirals (DAAs) for their chronic HCV infection. No pharmacokinetic drug-drug interactions (DDIs) were expected between tacrolimus and the selected DAAs. However, in both patients, tacrolimus plasma concentrations decreased during HCV treatment. We hypothesise that decreased plasma concentrations were not caused by a DDI but were an indirect result of the clearance of the HCV infection. During chronic HCV infection, pro-inflammatory cytokines may inhibit cytochrome P450 (CYP) enzymes, which are primarily responsible for tacrolimus metabolism. If this is true, then with clearance of the virus the activity of these enzymes will normalise and tacrolimus metabolism will increase. These changes were clinically relevant because the tacrolimus dosage needed to be adjusted. Therefore, physicians should be aware that CYP substrates with narrow therapeutic ranges might require dose adaption during HCV therapy with DAAs.

Iron burns: a problem in adults as well as children

Burns from domestic irons are potentially preventable injuries which can result in significant morbidity. Several studies have reported these injuries in children but there are no reports to date in adults. Epidemiology, management and outcome of these injuries is described, and possible preventative strategies are discussed. We present a retrospective case note review of 50 adult and paediatric patients with electric iron burns. Cases were identified from data collected for a national burns database. Information regarding demographics, burn characteristics, treatment and long term outcome was gathered from the medical records. 42 children and 8 adults sustained a burn from an iron during the 4-year study period. The majority of paediatric patients were under 4 years of age. Most burns were small (< 1% TBSA) but despite this 30 (60%) patients were admitted to hospital and 13 (26%) required at least one surgical procedure. In children, most burns occurred at home and were commonly due to pulling the flex or knocking the iron from its surface. In adults, 50% of injuries were associated with epilepsy. Burns from domestic irons are relatively common and cause significant morbidity despite their small size. A bimodal presentation is seen with injuries occurring either before the age of 4 years or during adulthood, when they are typically associated with an underlying medical condition. Education campaigns and design features such as a retractable cord may further reduce the incidence of this type of burn.

Screening for autoantibodies in chronic hepatitis C patients has no effect on treatment initiation or outcome

Autoantibodies in hepatitis C virus-infected patients may indicate autoimmune hepatitis or other immune-mediated diseases. This may impact safety and efficacy of interferon-based therapy of chronic hepatitis C. We investigated the association between a positive test result for a variety of autoantibodies and the initiation and efficacy of therapy for chronic hepatitis C. We analysed an observational cohort of 24 306 patients for an association between autoantibodies and treatment outcome. 8241 patients were tested simultaneously for antinuclear antibodies (ANA), liver kidney microsomal antibodies (LKM), smooth muscle antibodies (SMA) and antimitochondrial antibodies (AMA). Matched-pair analysis was performed matching one autoantibody-positive patient to three controls. Control patients had negative tests for all four antibodies. Analyses were performed for patients with a single positive autoantibody test and for patients with multiple positive autoantibody tests. A positive test result for ANA, LKM, SMA or AMA did not affect the physician's decision to initiate therapy with pegylated interferon and ribavirin. In addition, a positive test for one or multiple autoantibodies did not adversely affect sustained virologic response. There was no difference in fibrosis stage or alanine transaminase at baseline or during therapy irrespective of antibody status. Thyroid dysfunction was more frequent in patients with positive LKM antibodies (P = 0.004). Initiation of therapy for chronic hepatitis C and outcome were not affected by the presence of ANA, LKM, SMA or AMA. Routine testing of these autoantibodies seems not warranted. Determination of autoantibodies should be guided by individualized clinical decisions.

Exchanging the as-1-like element of the PR-1 promoter by the as-1 element of the CaMV 35S promoter abolishes salicylic acid responsiveness and regulation by NPR1 and SNI1

The plant defense hormone salicylic acid (SA) activates gene expression through a number of different mechanisms. In Arabidopsis thaliana, the SA-induced PATHOGENESIS RELATED (PR)-1 promoter is regulated through TGA transcription factors binding to the two TGACG motifs of the so called as-1 (activation sequence-1)-like element which is located between base pair positions -665 and -641. Activation is mediated by the transcriptional co-activator NPR1 (NON EXPRESSOR OF PR GENES1), which physically interacts with TGA factors. Moreover, the promoter is under the control of the negative regulator SNI1 (SUPPRESSOR OF NPR1, INDUCIBLE1). We have recently reported that SNI1-mediated repression of basal promoter activities and NPR1-dependent induction are maintained in a truncated PR-1 promoter that contains sequences between -816 and -573 upstream of the -68 promoter region. In this addendum, we report that the expression characteristics of this truncated PR-1 promoter is changed profoundly when its as-1-like element is replaced by the as-1 element of Cauliflower Mosaic Virus 35S promoter which also contains two TGACG motifs. The resulting chimeric promoter showed high constitutive activity that was independent from SA, NPR1 and SNI1. Thus, the configuration of two TGA binding sites within the PR-1 promoter determines whether NPR1 can induce and whether SNI1 can repress the promoter.

The Arabidopsis PR-1 promoter contains multiple integration sites for the coactivator NPR1 and the repressor SNI1

Systemic acquired resistance is a broad-spectrum plant immune response involving massive transcriptional reprogramming. The Arabidopsis (Arabidopsis thaliana) PATHOGENESIS-RELATED-1 (PR-1) gene has been used in numerous studies to elucidate transcriptional control mechanisms regulating systemic acquired resistance. WRKY transcription factors and basic leucine zipper proteins of the TGA family regulate the PR-1 promoter by binding to specific cis-elements. In addition, the promoter is under the control of two proteins that do not directly contact the DNA: the positive regulator NONEXPRESSOR OF PR GENES1 (NPR1), which physically interacts with TGA factors, and the repressor SUPPRESSOR OF NPR1, INDUCIBLE1 (SNI1). In this study, we analyzed the importance of the TGA-binding sites LS5 and LS7 and the WKRY box LS4 for regulation by NPR1 and SNI1. In the absence of LS5 and LS7, NPR1 activates the PR-1 promoter through a mechanism that requires LS4. Since transcriptional activation of WRKY genes is under the control of NPR1 and since LS4 is not sufficient for the activation of a truncated PR-1 promoter by the effector protein NPR1-VP16 in transient assays, it is concluded that the LS4-dependent activation of the PR-1 promoter is indirect. In the case of NPR1 acting directly through TGA factors at its target promoters, two TGA-binding sites are necessary but not sufficient for NPR1 function in transgenic plants and in the NPR-VP16-based trans-activation assay in protoplasts. SNI1 exerts its negative effect in the noninduced state by targeting unknown proteins associated with sequences between bp -816 and -573. Under induced conditions, SNI1 negatively regulates the function of WRKY transcription factors binding to WKRY boxes between bp -550 and -510.

[Anatomic and subjective success of structured surgical treatment strategy in the management of chronic epiphora - a postoperative analysis of contentment]

BACKGROUND

Epiphora is the result of hypersecretion or reduced tear outflow because of relative or absolute obstruction of the lacrimal system. For the treatment a specific surgical procedure is usually required. Herein we present the subjective and objective findings of 243 consecutive patients with non-irritative induced epiphora, who underwent an operation in a standardised therapy scheme, which is used at the eye departments of the Universities of Lübeck and Würzburg.

PATIENTS AND METHODS

In a retrospective cohort study 243 patients were included who underwent lateral tarsal strip (n = 72), external dacryocystorhinostomy (DCR) in the case of an absolute nasolacrimal duct obstruction (NLDO) (n = 116) and relative NLDO (n = 25), DCR with canalicular surgery (n = 18) and simple canalicular surgery (n = 12) with a follow-up of at least 6 month. Common patient and cosmetical satisfaction, intensity of symptoms and further symptoms of 168 patients were evaluated by sending a questionnaire with subsequent telephone survey. Objective findings were recorded from hospital charts.

RESULTS

59.5% of the patients were free of complaints, 19.6% had an absolute decrease of symptoms (epiphora outside and in windy weather) and 20.8 % persistent epiphora (symptoms both in- and outside persisted). 81% of patients with absolute NLDO and 57% with relative NLDO were graded as being free of symptoms, 7% (24%) as a relative decrease and 12% (19%) as a persistence of symptoms. There was a significant difference in success between these indications (p = 0.018). Patency of the lacrimal system assessed by irrigation was found in 95% (absolute NLDO). Commonly, 73.8% were satisfied, 7.7% indifferent and 18.4 % not satisfied. 4 patients were cosmetically not satisfied.

CONCLUSIONS

Use of a standardised therapy scheme reduces the symptoms in 79.1% of the patients. In patients with absolute NLDO external DCR achieves an anatomic success rate of 95% and a subjective improvement in 88% with excellent cosmetic results. In comparison with absolute NLDO the success rate of relative NLDO is lower, but still with a subjective improvement in 81%. Our results show that postoperative success depends on the preoperative cause of the epiphora.

[Epidemiology of chronic hepatitis C in Germany--an analysis of 10,326 patients in hepatitis centres and outpatient units]

Little is known about the epidemiology of chronic hepatitis C (CHC) in Germany and especially about the importance of transmission, duration of infection, genotypes, symptoms and quality of life of the patients. The current study prospectively evaluates epidemiological and clinical data of patients infected with the hepatitis C virus (HCV). Using online data entry, various characteristics of 10,326 untreated patients with CHC were documented from March 2003 until May 2006 in 352 centres all over Germany. Mean age of patients was 43.4 years. Patients infected by i.v. drug abuse were considerably younger (36.5 years) than the remaining patients (49.2 years). As indicated by their native language, 64.4% of the patients came from Germany and 19.2% from Russia. 61.7% were infected with genotype 1 and 34.9% with genotype 2 or 3. 45.5% of the patients had been infected by i.v. drug abuse. In at least 5.4% of the patients liver cirrhosis had been proved by biopsy. 63.5% of the patients felt an impairment of quality of life caused by CHC. In many patients infected with hepatitis C socio-economic issues are existent. This is reflected, i.e., in very high rates of unemployment in special subpopulations. Coinfections with hepatitis B and HIV occurred in 1.5% and 4.7%, respectively. Nearly 80% of patients were managed near their homes. The data of the 10 326 patients represent about 2% of all German patients with CHC. This database is up to now the largest of its kind and gives a representative insight into the epidemiological situation of CHC in Germany.

[Late needling with 5-fluorouracil when scarring of filtering bleb seems imminent]

BACKGROUND

Evaluation of needling and 5-fluorouracil (5-FU) injections more than 4 months after preceding filtration surgery.

PATIENTS AND METHOD

Retrospective analysis of 17 eyes in 14 patients who underwent needling of the filtering bleb and administration of 5-FU by injection at least 4 months after trabeculectomy (TE) with mitomycin C (MMC; same surgeon throughout). Complete success was defined as a reduction of intraocular pressure (IOP) by >30% from the baseline value without further medication and, in cases of primary open-angle glaucoma, IOP of 18 mmHg. The mean period of follow-up was 8.1 months (3-24 months).

RESULTS

One to four needlings (Ø 1.6) with one to five injections (Ø 3.1) of 5-FU were performed as required according to clinical need an average of 31.3 months (4-108 m) after TE. The mean baseline IOP was 25 mmHg (+/-SD 6.02; median 25 mmHg). After needling and 5-FU injection the mean IOD at the last hospital visit was 13.64 mmHg (+/-SD 5.2, median 13 mmHg; p<0,001). Complete success was achieved in 82.4% of these cases. The mean reduction in IOP was 11.2 mmHg (0-22 mmHg). In the cases with successful outcome (14 of 17 eyes) the mean IOP reduction from baseline was 55%. Three eyes required further treatment. Complications encountered were hyphaema (2 cases), subconjunctival bleeding (1 case) and corneal erosion (3 cases).

CONCLUSION

Late needling and injections of 5-FU can restore filtering bleb function even over 4 months after initial surgery. The high success rate and low incidence of complications together with the simple procedure justify regarding this approach as an alternative that can be used before passing on to more invasive interventions.

The New York High-Risk Project: comorbidity for axis I disorders is preceded by childhood behavioral disturbance

The relationship between childhood behavioral disturbance and comorbidity for adult psychiatric disorders has not been sufficiently investigated. Subjects of this report (N = 185) were offspring of parents with schizophrenia or affective disorder and of normal parents from the New York High-Risk Project. Data on childhood behavior at the mean age of 9.5 years were obtained in a parent interview at initial assessment in 1971-72. Adulthood outcomes were assessed through standardized interviews, and lifetime axis I diagnoses were based on Research Diagnostic Criteria. Subjects with comorbidity for axis I disorders exhibited significantly more behavioral problems as children, compared with those who developed either one or no psychiatric disorder in adulthood. This association was not biased by gender or parental diagnosis of psychiatric disorder. The findings emphasize that psychiatric comorbidity can be traced back to childhood and underline the importance of longitudinal observations in psychiatric research.

Relationship between childhood behavioral disturbance and later schizophrenia in the New York High-Risk Project

OBJECTIVE

An association between childhood behavioral disturbance and adulthood schizophrenia has been seen previously in retrospective or follow-back studies and in prospective studies. The authors examined the relationship between childhood behavioral problems and adulthood schizophrenia-related psychoses. Because a high rate of childhood behavioral problems is known to be associated with adult substance abuse, these analyses controlled for substance abuse.

METHOD

The subjects of this investigation (N = 185) were offspring of parents with schizophrenia or affective disorder and of normal parents from the New York High-Risk Project (sample A). Data on childhood behavioral problems were obtained in a parent interview at initial assessment in 1971-1972. Adulthood outcomes (schizophrenia-related psychoses, affective disorders, anxiety disorders, substance abuse) were based on lifetime axis I diagnoses according to the Research Diagnostic Criteria.

RESULTS

Substance abuse had a significant interaction with the clinical outcome groups. In subjects without substance abuse, those with schizophrenia-related psychoses had exhibited significantly more behavioral problems as children than had adult offspring with affective or anxiety disorder or with substance abuse only or no disorder.

CONCLUSIONS

These results support the view that schizophrenia-related psychoses can be followed back to early behavioral disturbances. The confounding effects of substance abuse should be statistically controlled in studies of longitudinal associations between childhood behavioral disturbance and axis I outcomes.

The New York High-Risk Project. Prevalence and comorbidity of axis I disorders in offspring of schizophrenic parents at 25-year follow-up

BACKGROUND

The New York High-Risk Project is a study of offspring of patients with schizophrenia (HRSz group) or affective illness (HRAff group) and psychiatrically normal parents (NC group) observed prospectively from childhood to adulthood. We herein present lifetime prevalence and comorbidity rates of Axis I disorders in subjects and their siblings from sample A of the project.

METHODS

Schedule for Affective Disorders and Schizophrenia-Lifetime Version interviews conducted with the offspring in adulthood were used to obtain diagnoses of Axis I disorders.

RESULTS

Schizophrenia and unspecified psychoses occurred only in the HRSz group. However, schizoaffective and psychotic affective disorders occurred equally in the HRSz and HRAff groups. Total rates of psychosis in these groups were significantly higher than in the NC group. All groups had similar rates of nonpsychotic affective and substance abuse disorders. The HRAff group, however, had significantly more total affective illness than the NC group and tended to have more anxiety disorders than the other groups. Comorbidity rates in the HRSz and HRAff groups were nearly twice those of the NC group.

CONCLUSIONS

The familial liabilities to schizophrenia and affective disorders show specificities and commonalities, differing markedly from each other in their expression of some disorders and sharing others. Patterns of comorbidity are generally, although not entirely, similar to these liabilities.

Initial experience of using GRAFTAC absorbable staples to attach split skin grafts

The GRAFTAC skin stapler with absorbable tacs has been used to attach split-skin grafts in 28 patients, under a variety of clinical situations, and the outcomes studied. This knowledge has been reviewed in the light of our existing experience with the more familiar metal staple. Details of the patients and their conditions are presented, with two illustrative case histories, including one where both Graftac and metal staples were used. The relative costs were analysed and an attempt made to compare the cost-effectiveness of tacs and staples. A rationale for use of the more expensive GRAFTAC stapler is presented.

[Chemotherapy protocol for metastasizing colorectal carcinoma. Methotrexate, 5-fluorouracil and cytarabine]

A new treatment protocol was developed for colorectal carcinomas consisting of sequential administration of methotrexate, 5-fluorouracil and cytarabine. The latter was included into the protocol in order to suppress the DNA salvage pathway of tumour cells. The sequential high-dosage combination was administered to 34 patients with metastatic colorectal carcinoma, 23 patients had been pretreated with cytostatics. Remission could be achieved in 14 out of the 34 patients. Two patients with carcinoma of the rectum have complete clinical remission lasting for 7 months. Eight of the 14 patients responding to treatment had had cytostatic pretreatment. The median time of survival of patients in remission is 15 months, median survival of non-responders 4,3 months. Combination treatment was well tolerated. Leuko- and thrombocytopenia according to grade 3 and 4 of the WHO classification were only rarely observed.