Electronic Signature for Medical Documents – Integration and Evaluation of a Public Key Infrastructure in Hospitals

Objectives: Our objectives were to determine the user-oriented and legal requirements for a Public Key Infrastructure (PKI) for electronic signatures for medical documents, and to translate these requirements into a general model for a signature system. A prototype of this model was then implemented and evaluated in clinical routine use.

Methods: Analyses of documents, processes, interviews, observations, and of the available literature supplied the foundations for the development of the signature system model. Eight participants of the Department of Dermatology of the Heidelberg University Medical Center evaluated the implemented prototype from December 2000 to January 2001, during the course of an intervention study. By means of questionnaires, interviews, observations and database analyses, the usefulness and user acceptance of the electronic signature and its integration into electronic discharge letters were established.

Results: Since the major part of medical documents generated in a hospital are signature-relevant, they will require electronic signatures in the future. A PKI must meet the multitude of responsibilities and security needs required in a hospital. Also, the signature functionality must be integrated directly into the workflow surrounding document creation. A developed signature model, fulfilling user-oriented and legal requirements, was implemented using hard and software components that conform to the German Signature Law. It was integrated into the existing hospital information system of the Heidelberg University Medical Center. At the end of the intervention study, the average acceptance scores achieved were x = 3,90; sD = 0,42 on a scale of 1 (very negative attitude) to 5 (very positive attitude) for the electronic signature procedure. Acceptance of the integration into computer-supported discharge letter writing reached x = 3,91; sD = 0,47. On average, the discharge letters were completed 7.18 days earlier.

Conclusion: The electronic signature is indispensable for the further development of electronic patient records. Application-independent hard and software components, in accordance with the signature law, must be integrated into electronic patient records, and provided to certification services using standardized interfaces. Signature-oriented workflow and document management components are essential for user acceptance in routine clinical use.

Computation of the asymptotic states of modulated open quantum systems with a numerically exact realization of the quantum trajectory method

Quantum systems out of equilibrium are presently a subject of active research, both in theoretical and experimental domains. In this work, we consider time-periodically modulated quantum systems that are in contact with a stationary environment. Within the framework of a quantum master equation, the asymptotic states of such systems are described by time-periodic density operators. Resolution of these operators constitutes a nontrivial computational task. Approaches based on spectral and iterative methods are restricted to systems with the dimension of the hosting Hilbert space dimH=N≲300, while the direct long-time numerical integration of the master equation becomes increasingly problematic for N≳400, especially when the coupling to the environment is weak. To go beyond this limit, we use the quantum trajectory method, which unravels the master equation for the density operator into a set of stochastic processes for wave functions. The asymptotic density matrix is calculated by performing a statistical sampling over the ensemble of quantum trajectories, preceded by a long transient propagation. We follow the ideology of event-driven programming and construct a new algorithmic realization of the method. The algorithm is computationally efficient, allowing for long "leaps" forward in time. It is also numerically exact, in the sense that, being given the list of uniformly distributed (on the unit interval) random numbers, {η_{1},η_{2},...,η_{n}}, one could propagate a quantum trajectory (with η_{i}'s as norm thresholds) in a numerically exact way. By using a scalable N-particle quantum model, we demonstrate that the algorithm allows us to resolve the asymptotic density operator of the model system with N=2000 states on a regular-size computer cluster, thus reaching the scale on which numerical studies of modulated Hamiltonian systems are currently performed.

High ligation of the saphenofemoral junction is necessary!

Neovascularisation can compromise the success of high ligation and resection of the greater saphenous vein. Studies using duplexultrasound to classify recurrent groin veins have described rates of neovascularisation as high as 60% and raised the question whether high ligation is actually able to prevent groin recurrences. In the present study, recurrent groin veins were excised and examined histologically in order to prove whether neovascularisation is the main cause for sapheno-femoral recurrences. Patients, methods: 419 patients accounting for 458 legs with clinically symptomatic groin recurrences were included in a country-wide multicenter study. The recurrent groin veins were excised in a standardized fashion and subsequently divided into the different types of recurrence based on histopathological criteria. Results: 427 specimen (93%) were available for histopathological examination. In 69 cases (16.2%) a neovascularisation was found to be the cause of recurrence. 311 specimen (72.8%) contained a long residual stump of the greater saphenous vein, out of which 32 (7.5%) showed additional neovascularisation at the site of the ligation. In 29 cases (6.8%) a venous side branch was found to be the recurrent groin vein. 11 specimen (2.6%) did not contain any evidence of venous material and in another 7 cases (1.6%) it was not possible to clearly identify the cause of recurrence during the histo pathological workup. Conclusion: The high rates of neovascularisation described in several duplex ultrasound studies could not be confirmed in our investigation. Recurrences seem to be mainly caused by a technically incorrect initial operation which leaves a long residual stump of the saphenous vein in place. Following a technically correct high ligation, clinically relevant recurrences appear to be rare. This finding underlines the necessity of a high ligation of the saphenous vein according to current guidelines.

Der lang belassene Saphenastumpf

Ziel: Nach endovenöser Hitzeablation der V. saphena magna verbleibt im Bereich der Krosse nahezu regelhaft bis zu 5 cm langer Venenstumpf unverschlossen. Aufgrund fehlender Langzeiterfahrungen ist unklar, ob sich aus dem zurückgelassenen Stumpf im Spätverlauf ein Leistenrezidiv entwickelt. Um Anhaltspunkte für den potenziellen Zeitpunkt der Rezidiventwicklung zu gewinnen, sollte bei Pat. mit histologisch gesichertem Saphenastumpfrezidiv geklärt werden, wie lange es dauerte, bis nach dem Ersteingriff Rezidiv klinisch apperent wird. Methoden: Im Rahmen einer an sieben Zentren durchgeführten Multizenterstudie wurden operativ exstirpierte Leistenrezidive histologisch klassifiziert. Die Pat. mit eindeutigem Saphenastumpfrezidiv wurden anhand eines standardisierten Fragebogens nach den ersten Rezidivzeichen befragt. Anhand der Angaben wurde das beschwerdefreie Intervall ermittelt, das Zeitraum zwischen dem Ersteingriff und dem ersten Auftreten von Rezidivzeichen kennzeichnet. Ergebnisse: Bei 251 Pat. wurde an 278 Extremitäten ein lang belassener Saphenastumpf als Ursache des Leistenrezidivs ermittelt. den meisten Pat. bestand nach dem Ersteingriff ein beschwerdefreies Intervall, das im Durchschnitt 7,4 ± 5,70 Jahre betrug. Rezidivvarizen kündigten nach durchschnittlich 6,3 ± 5,68 Jahre und Stauungsbeschwerden nach durchschnittlich 8,5 ± 5,71 Jahre das Rezidiv an. Schlussfolgerungen: Überträgt man die Erfahrungen aus operativen Therapie auf die unverschlossenen Krossestümpfe nach endovenöser Therapie, so ist frühestens nach 7–8 Jahren mit den klinischen Zeichen eines Leistenrezidivs zu rechnen. Die gegenwärtig vorhandenen Nachbeobachtungszeiten reichen nicht aus, um den Langzeitverlauf nach endovenöser Therapie beurteilen zu können.

Saphenofemoraler Neoreflux nach Lasertherapie, Crossektomie/ Stripping oder Crossektomie/ Lasertherapie

Einleitung: In der vorliegenden Arbeit gilt es, mittelfristige Refluxbefunde nach 2 und 6 Monaten sowie die klinischen und sonografischen Befunde im Bereich der Magnacrosse zu beschreiben, die für eine langfristige Entwicklung von Bedeutung sein könnten.

Material und Methode: Die offene multizentrisch prospektiv randomisierte kontrollierte 3-armige Vergleichsstudie zwischen der endoluminalen Lasertherapie und der invaginierend durchgeführten modifizierten offen operativen Therapie der Stammvarikosis der Vena saphena magna (VSM) hat den primären Endpunkt der Beobachtung der mittelund langfristigen Rezidiventwicklung mit einem Ausgangspunkt im Inguinalbereich. (Laserprozedur mit 980 nm Laser (Biolitec), Continous-Mode-Verfahren mit 30 Watt). Um die Bedeutung der Crossektomie in Bezug zur Entstehung eines Crosserezidivs herauszuarbeiten wurde eine dritte Gruppe gebildet, in der die Lasertherapie des Stammvenenabschnitts mit einer Crossektomie der Vena saphena magna kombiniert wurde.

Ergebnisse: 449 Patienten wurden perioperativ und nach 2 Monaten untersucht. 388 Patienten konnten nach 6 Monaten nachuntersucht werden. Nach 2 und 6 Monaten zeigten sich signifikant mehr inguinale Refluxe und Seitenäste in den Lasergruppen.

Ausblick: Die Befunde werden in einer derzeit laufenden Nachuntersuchung überprüft und auf ihre klinische Relevanz für das Langzeitergebnis getestet.

Increase in the incidence of severe hypoglycaemia in people with Type 2 diabetes in spite of new drugs: analysis based on health insurance data from Germany

AIM

To evaluate the use of new anti-hyperglycaemic agents that offer effective glycaemic control while reducing risk of hypoglycaemia, by analysing the incidence rates of severe hypoglycaemia in 2006 vs 2011 in relation to the medication.

METHODS

This cross-sectional, population-based study used German health insurance data. All adults diagnosed with Type 2 diabetes mellitus (extrapolated to the German population: 6.35 million in 2006 and 7.52 million in 2011) were screened for severe hypoglycaemia. Anti-hyperglycaemic agents were identified by their Anatomical Therapeutic Chemical code, and defined daily doses of each medication were calculated.

RESULTS

The severe hypoglycaemic event rate was 460 per 100,000 people/year in 2006 and 490 per 100,000 people/year in 2011. In 2006 and 2011, 10.9% and 7.3%, respectively, of all people with severe hypoglycaemia were on sulfonylureas, while 12.7% and 9.3%, respectively, were on a combination therapy of metformin and sulfonylureas. Among those with severe hypoglycaemia, there were no prescriptions of dipeptidyl peptidase-4 inhibitors or glucagon-like peptide-1 receptor agonists in 2006, but in 2011, 1.55% and 0.17%, of those with severe hypoglycaemia were receiving the respective treatments. In 2006 vs 2011, human insulin was prescribed for 11.3% vs 10.3% of people with severe hypoglycaemia, while insulin analogues were prescribed for 5.4% vs 8.1%, and mixed human insulins for 19.7% vs 14.0% of patients with severe hypoglycaemia. People receiving insulin analogue therapy had a higher risk of severe hypoglycaemia than those receiving metformin, after adjusting for age, gender, nephropathy diagnosis and year of survey (odds ratio 14.6; CI 13.3-15.9).

CONCLUSION

The incidence of severe hypoglycaemic events in Germany increased between 2006 and 2011, despite increased use of newer anti-hyperglycaemic agents and decreased use of insulins.

Reduced electrode arrays for the automated detection of rhythmic and periodic patterns in the intensive care unit: Frequently tried, frequently failed?

OBJECTIVE

To investigate the effect of systematic electrode reduction from a common 10-20 EEG system on pattern detection sensitivity (SEN).

METHODS

Two reviewers rated 17130 one-minute segments of 83 prospectively recorded cEEGs according to the ACNS standardized critical care EEG terminology (CCET), including burst suppression patterns (BS) and unequivocal electrographic seizures. Consensus annotations between reviewers were used as a gold standard to determine pattern detection SEN and specificity (SPE) of a computational algorithm (baseline, 19 electrodes). Electrodes were than reduced one by one in four different variations. SENs and SPEs were calculated to determine the most beneficial assembly with respect to the number and location of electrodes.

RESULTS

High automated baseline SENs (84.99-93.39%) and SPEs (90.05-95.6%) were achieved for all patterns. Best overall results in detecting BS and CCET patterns were found using the "hairline+vertex" montage. While the "forehead+behind ear" montage showed an advantage in detecting ictal patterns, reaching a 15% drop of SEN with 10 electrodes, all montages could detect BS sufficiently if at least nine electrodes were available.

CONCLUSION

For the first time an automated approach was used to systematically evaluate the effect of electrode reduction on pattern detection SEN in cEEG.

SIGNIFICANCE

Prediction of the expected detection SEN of specific EEG patterns with reduced EEG montages in ICU patients.

Applicability of NeuroTrend as a bedside monitor in the neuro ICU

OBJECTIVE

To assess whether ICU caregivers can correctly read and interpret continuous EEG (cEEG) data displayed with the computer algorithm NeuroTrend (NT) with the main attention on seizure detection and determination of sedation depth.

METHODS

120 screenshots of NT (480h of cEEG) were rated by 18 briefly trained nurses and biomedical analysts. Multirater agreements (MRA) as well as interrater agreements (IRA) compared to an expert opinion (EXO) were calculated for items such as pattern type, pattern location, interruption of recording, seizure suspicion, consistency of frequency, seizure tendency and level of sedation.

RESULTS

MRA as well as IRA were almost perfect (80-100%) for interruption of recording, spike-and-waves, rhythmic delta activity and burst suppression. A substantial agreement (60-80%) was found for electrographic seizure patterns, periodic discharges and seizure suspicion. Except for pattern localization (70.83-92.26%), items requiring a precondition and especially those who needed interpretation like consistency of frequency (47.47-79.15%) or level of sedation (41.10%) showed lower agreements.

CONCLUSIONS

The present study demonstrates that NT might be a useful bedside monitor in cases of subclinical seizures. Determination of correct sedation depth by ICU caregivers requires a more detailed training.

SIGNIFICANCE

Computer algorithms may reduce the workload of cEEG analysis in ICU patients.

Misreporting of Product Adherence in the MTN-003/VOICE Trial for HIV Prevention in Africa: Participants' Explanations for Dishonesty

Consistent over-reporting of product use limits researchers' ability to accurately measure adherence and estimate product efficacy in HIV prevention trials. While lying is a universal characteristic of the human condition, growing evidence of a stark discrepancy between self-reported product use and biologic or pharmacokinetic evidence demands examination of the reasons research participants frequently misrepresent product use in order to mitigate this challenge in future research. This study (VOICE-D) was an ancillary post-trial study of the vaginal and oral interventions to control the epidemic (VOICE) phase IIb trial (MTN 003). It was conducted in three African countries to elicit candid accounts from former VOICE trial participants about why actual product use was lower than reported. In total 171 participants were enrolled between December 2012 and March 2014 in South Africa (n = 47), Uganda (n = 59) and Zimbabwe (n = 65). Data suggested that participants understood the importance of daily product use and honest reporting, yet acknowledged that research participants typically lie. Participants cited multiple reasons for misreporting adherence, including human nature, self-presentation with study staff, fear of repercussions (study termination resulting in loss of benefits and experience of HIV-related stigma), a permissive environment in which it was easy to get away with misreporting, and avoiding inconvenient additional counseling. Some participants also reported mistrust of the staff and reciprocal dishonesty about the study products. Many suggested real-time blood-monitoring during trials would encourage greater fidelity to product use and honesty in reporting. Participants at all sites understood the importance of daily product use and honesty, while also acknowledging widespread misreporting of product use. Narratives of dishonesty may suggest a wider social context of hiding products from partners and distrust about research, influenced by rumors circulating in clinic waiting-rooms and surrounding communities. Prevailing power hierarchies between staff and participants may exacerbate misreporting. Participants recognized and suggested that objective, real-time feedback is needed to encourage honest reporting.

Mycophenolate mofetil and skin diseases

Mycophenolate mofetil (MMF) is an immunosuppressive drug the efficiency of which has been established in renal transplantation. Recent studies suggest that it may also be effective in the treatment of variant skin diseases especially if the skin lesions are triggered by lymphocytes. Studies have shown efficacy in autoimmune bullous dermatoses, atopic dermatitis and psoriasis. However, there are no placebo-controlled trials that support the use of MMF as first line therapy in these skin diseases.

Mycophenolate mofetil and skin diseases

Mycophenolate mofetil (MMF) is an immunosuppressive drug the efficiency of which has been established in renal transplantation. Recent studies suggest that it may also be effective in the treatment of variant skin diseases especially if the skin lesions are triggered by lymphocytes. Studies have shown efficacy in autoimmune bullous dermatoses, atopic dermatitis and psoriasis. However, there are no placebo-controlled trials that support the use of MMF as first line therapy in these skin diseases.

Determination of rate constants for trifluoromethyl radical addition to various alkenes via a practical method

A simple method for the determination of CF3-radical addition rate constants to various π-acceptors is introduced.

Anxiety and depression in long-term testicular germ cell tumor survivors

OBJECTIVE

Despite a good prognosis, the typically young age at diagnosis and physical sequelae may cause psychological distress in germ cell tumor survivors. We aimed to determine the frequency of anxiety and depression and analyze the impact of demographic and disease-related factors.

METHOD

We enrolled N=164 testicular germ cell tumor survivors receiving routine follow-up care at the University Cancer Center Hamburg and a specialized private practice (mean, 11.6 years after diagnosis). Patients completed the Generalized Anxiety Disorder Screener-7, the Patient Health Questionnaire-9 and the Memorial Symptom Assessment Scale-Short Form.

RESULTS

We found clinically significant anxiety present in 6.1% and depression present in 7.9% of survivors. A higher number of physical symptoms and having children were significantly associated with higher levels of both anxiety and depression in multivariate regression analyses controlling for age at diagnosis, cohabitation, socioeconomic status, time since diagnosis, metastatic disease and relapse. Younger age at diagnosis and shorter time since diagnosis were significantly associated with higher anxiety.

CONCLUSION

Although rates of clinically relevant anxiety and depression were comparably low, attention toward persisting physical symptoms and psychosocial needs related to a young age at diagnosis and having children will contribute to address potential long-term psychological distress in germ cell tumor survivors.

Group Singing as a Therapy during Diabetes Training--A Randomized Controlled Pilot Study

Comprehensive diabetes treatment has been shown to reduce quality of life in diabetic patients. However, there is evidence to suggest that group singing can have positive effects on quality of life in various clinical settings. In this randomized controlled pilot study, the effect of singing as a therapy to reduce stress and improve quality of life was investigated in insulin-dependent diabetic patients, undergoing a lifestyle intervention program. Patients from the singing group felt less discontented following treatment. This effect, however, was lost after 3 months. No effect on serum cortisol and plasma adrenocorticotropic hormone (ACTH) levels could be seen when comparing the singing group with the control group, although reduced levels of ACTH and cortisol 3 days after treatment could be found and were still present after 3 months within the group of patients who undertook singing as a therapy. Singing led to an increase in bodyweight, which interestingly had no effect on glucose control or methylglyoxal levels. Therefore, singing during a lifestyle intervention program for insulin-dependent diabetic patients had a short lasting and weak effect on patients' mood without affecting glucose control, but no significant effect on stress related hormones.