Table Of Instruments Research Articles

Effect of a portable ultra-clean exponential airflow unit on the particle distribution in an operating room

The effects of a mobile laminar airflow unit on the concentration, deposition and distribution of bacteria-carrying particles in an operating room are investigated. The exploration is carried out using numerical calculation schemes (computational fluid dynamics approach). The model validation was performed through result comparisons with published measurement data from literature. Two types of mobile screen units were evaluated as an extension of turbulent-mixing operating-room ventilation. Airborne particle concentration/sedimentation was recorded with and without a screen unit on the operating table and two instrument tables. Both active and passive air sampling were examined and the results are compared. It was found that the additional mobile ultra-clean laminar airflow unit reduces the counts of airborne bacteria and surface contamination to a level acceptable for infection-prone surgeries.

Does a mobile laminar airflow screen reduce bacterial contamination in the operating room? A numerical study using computational fluid dynamics technique.

BackgroundAir-borne bacteria in the operating room (OR) may contaminate the surgical wound, either by direct sedimentation from the air or indirectly, by contaminated sterile instruments. Reduced air contamination can be achieved with an efficient ventilation system. The current study assesses the additive effect of a mobile laminar airflow (MLAF) unit on the microbiological air quality in an OR supplied with turbulent-mixing air ventilation.MethodsA recently designed OR in NKS (Nya Karolinska Sjukhuset, Stockholm, Sweden) was the physical model for this study. Simulation was made with MLAF units adjacent to the operating table and the instrument tables, in addition to conventional turbulent-mixing ventilation. The evaluation used numerical calculation by computational fluid dynamics (CFD). Sedimentation rates (CFU/m2/h) were calculated above the operating table and two instrument tables, and in the periphery of the OR. Bacterial air contamination (CFU/m3) was simulated above the surgical and instrument tables with and without the MLAF unit.ResultsThe counts of airborne and sedimenting, bacteria-carrying particles downstream of the surgical team were reduced to an acceptable level for orthopedic/implant surgery when the MLAF units were added to conventional OR ventilation. No significant differences in mean sedimentation rates were found in the periphery of the OR.ConclusionsThe MLAF screen unit can be a suitable option when the main OR ventilation system is unable to reduce the level of microbial contamination to an acceptable level for orthopedic implant surgery. However, MLAF effect is limited to an area within 1 m from the screen. Increasing air velocity from the MLAF above 0.4 m/s does not increase the impact area.

Inertial Measures of Motion for Clinical Biomechanics: Comparative Assessment of Accuracy under Controlled Conditions - Effect of Velocity

BackgroundInertial measurement of motion with Attitude and Heading Reference Systems (AHRS) is emerging as an alternative to 3D motion capture systems in biomechanics. The objectives of this study are: 1) to describe the absolute and relative accuracy of multiple units of commercially available AHRS under various types of motion; and 2) to evaluate the effect of motion velocity on the accuracy of these measurements.MethodsThe criterion validity of accuracy was established under controlled conditions using an instrumented Gimbal table. AHRS modules were carefully attached to the center plate of the Gimbal table and put through experimental static and dynamic conditions. Static and absolute accuracy was assessed by comparing the AHRS orientation measurement to those obtained using an optical gold standard. Relative accuracy was assessed by measuring the variation in relative orientation between modules during trials.FindingsEvaluated AHRS systems demonstrated good absolute static accuracy (mean error < 0.5o) and clinically acceptable absolute accuracy under condition of slow motions (mean error between 0.5o and 3.1o). In slow motions, relative accuracy varied from 2o to 7o depending on the type of AHRS and the type of rotation. Absolute and relative accuracy were significantly affected (p<0.05) by velocity during sustained motions. The extent of that effect varied across AHRS.InterpretationAbsolute and relative accuracy of AHRS are affected by environmental magnetic perturbations and conditions of motions. Relative accuracy of AHRS is mostly affected by the ability of all modules to locate the same global reference coordinate system at all time.ConclusionsExisting AHRS systems can be considered for use in clinical biomechanics under constrained conditions of use. While their individual capacity to track absolute motion is relatively consistent, the use of multiple AHRS modules to compute relative motion between rigid bodies needs to be optimized according to the conditions of operation.

Kinematic Soil-Structure Interaction Effect in Layered Liquefiable Soils on Foundation Input Motion

The principal objective of this study is to make use of medium and strong motion data from instrumented shaking table tests to evaluate the effects of kinematic soil-structure interaction on foundation input motion (FIM). The shaking table tests consisted of a 2×2 pile group in two-and three-layered liquefiable soils (models 1 and 2). Each test model was subjected to three realistic earthquake motions with peak accelerations ranging from 0.13g to 0.50g, and time step ranging from 0.006 to 0.02 sec. The three input earthquake motion represented the realistic earthquake motion with high frequency, low frequency and high amplitude. The foundation/free-field ground motion variations were quantified in terms of acceleration time histories and Fourier amplitude spectrum. Preliminary analysis of the data suggests that (1) regarding the input motion with high frequency, the higher peak acceleration of the foundation indicates the structure feedback and kinematic interaction between the soil and foundation during shaking; soil layering has little effect on foundation input motion, (2) regarding the input motion with low frequency, the kinematic soil-structure interaction increases the foundation response for model 2 while reduces it for model 1. The soil profile has significant effect on the predominant frequency, (3) regarding the input motion with high amplitude, the higher response of foundation in model 1 indicates the stronger kinematic SSI effect. The small deviation between the free field and foundation in model 2 indicates the coherent motion of the foundation with soil and no obvious kinematic SSI effect, (4) soil liquefaction has significant effect on the values of peak acceleration and peak Fourier amplitude.

Cómo minimizar errores al realizar la adaptación transcultural y la validación de los cuestionarios sobre calidad de vida: aspectos prácticos

The development and validation of questionnaires for evaluating quality of life (QoL) has become an important area of research. However, there is a proliferation of non-validated measuring instruments in the health setting that do not contribute to advances in scientific knowledge. To present, through the analysis of available validated questionnaires, a checklist of the practical aspects of how to carry out the cross-cultural adaptation of QoL questionnaires (generic, or disease-specific) so that no step is overlooked in the evaluation process, and thus help prevent the elaboration of insufficient or incomplete validations. We have consulted basic textbooks and Pubmed databases using the following keywords quality of life, questionnaires, and gastroenterology, confined to «validation studies» in English, Spanish, and Portuguese, and with no time limit, for the purpose of analyzing the translation and validation of the questionnaires available through the Mapi Institute and PROQOLID websites. A checklist is presented to aid in the planning and carrying out of the cross-cultural adaptation of QoL questionnaires, in conjunction with a glossary of key terms in the area of knowledge. The acronym DSTAC was used, which refers to each of the 5 stages involved in the recommended procedure. In addition, we provide a table of the QoL instruments that have been validated into Spanish. This article provides information on how to adapt QoL questionnaires from a cross-cultural perspective, as well as to minimize common errors.

The importance of protecting surgical instrument tables from intraoperative contamination in clean surgeries

to compare the degree of bacterial contamination of surgical instrument tables used in clean surgical procedures, either protected with plastic fields, sterilized with ethylene oxide, or disinfected with 70% alcohol and 1% iodine solutions. This is a randomized clinical trial in which samples were collected from the surfaces of surgical instrument tables before and after each procedure. Microbiological analysis was performed to identify microorganisms and their respective antimicrobial resistance. Bacterial growth in the surgeries using sterilized plastic was 5.71% before and 28.6% after surgery and, 2.9% and 45.7% respectively in surgeries using disinfection with 70% alcohol and 1% iodine solutions; no statistical difference was found between the methods. both methods present similar protection, however, 70% alcohol and 1% iodine do not generate solid waste.

Estimating Friction Parameters in Reaction Wheels for Attitude Control

The ever-increasing use of artificial satellites in both the study of terrestrial and space phenomena demands a search for increasingly accurate and reliable pointing systems. It is common nowadays to employ reaction wheels for attitude control that provide wide range of torque magnitude, high reliability, and little power consumption. However, the bearing friction causes the response of wheel to be nonlinear, which may compromise the stability and precision of the control system as a whole. This work presents a characterization of a typical reaction wheel of 0.65 Nms maximum angular momentum storage, in order to estimate their friction parameters. It used a friction model that takes into account the Coulomb friction, viscous friction, and static friction, according to the Stribeck formulation. The parameters were estimated by means of a nonlinear batch least squares procedure, from data raised experimentally. The results have shown wide agreement with the experimental data and were also close to a deterministic model, previously obtained for this wheel. This model was then employed in a Dynamic Model Compensator (DMC) control, which successfully reduced the attitude steady state error of an instrumented one-axis air-bearing table.

Total hip replacement

ABSTRACT:A total hip replacement (THR) is a salvage operation that is undertaken when medical management fails. The coxofemoral joint is replaced to maintain function of the limb and to provide a better quality of life for that patient. As this is a complex and painful procedure, thought must be given to providing adequate analgesia both peri- and postoperatively. The VN who runs the instrument table for each THR needs an extensive knowledge of the equipment required and the order in which it is used. Postoperative nursing care is paramount with every THR.

Mobile laminar air flow screen for additional operating room ventilation: reduction of intraoperative bacterial contamination during total knee arthroplasty

BackgroundSurgical site infections are important complications in orthopedic surgery. A mobile laminar air flow (LAF) screen could represent a useful addition to an operating room (OR) with conventional turbulent air ventilation (12.5 air changes/h), as it could decrease the bacterial count near the operating field. The purpose of this study was to evaluate LAF efficacy at reducing bacterial contamination in the surgical area during 34 total knee arthroplasties (TKAs).Materials and methodsThe additional unit was used in 17 operations; the LAF was positioned beside the operating table between two of the surgeons, with the air flow directed towards the surgical area (wound). The whole team wore conventional OR clothing and the correct hygiene procedures and rituals were used. Bacterial air contamination (CFU/m3) was evaluated in the wound area in 17 operations with the LAF unit and 17 without the LAF unit.ResultsThe LAF unit reduced the mean bacterial count in the wound area from 23.5 CFU/m3 without the LAF to 3.5 CFU/m3 with the LAF (P < 0.0001), which is below the suggested limit for an OR with ultraclean laminar ventilation. There were no significant differences in the mean bacterial count in the instrument table area: 28.6 CFU/m3 were recorded with the LAF (N = 6) unit and 30.8 CFU/m3 (N = 6) without the LAF unit (P = 0.631). During six operations with LAF and six without LAF, particle counts were performed and the number of 0.5 μm particles was analyzed. The particle counts decreased significantly when the LAF unit was used (P = 0.003).ConclusionWhen a mobile LAF unit was added to the standard OR ventilation, bacterial contamination of the wound area significantly decreased to below the accepted level for an ultraclean OR, preventing SSI infections.

Testing the effectiveness of operating room ventilation with regard to removal of airborne bacteria

In this research the ability of the ventilation system in an operating room to keep the operating table and the instrument tables free from airborne bacteria has been evaluated in an experimental mock-up for different ventilation systems under various static circumstances. To accomplish this, the VDI 2167 particle test has been used as a basis. In this test particles are released on the floor and smoke concentrations are measured on the operating table. The VDI 2167 method was able to distinguish the different systems, but did not provide for a complete evaluation. The thermal balance in the room plays a major role in whether a laminar downflow system works and the VDI method does not incorporate this into the tests in an adequate manner. Moreover, the influence of surgical lighting is not included in the test method in an effective way.

Objective concurrent feedback on force parameters improves performance of lumbar mobilisation, but skill retention declines rapidly

Objective To determine the optimum practice for students to apply lumbar mobilisations with force parameters consistent with an experienced therapist. Design Thirty physiotherapy students attended three practice sessions over two weeks where they performed lumbar mobilisations on a fellow student. Students viewed feedback on their applied forces (measured using an instrumented treatment table) in real-time on a computer screen. Performance was tested before and after feedback at each practice session and at follow up sessions one week and three months later. Outcome measures A greater accuracy in manual force application was defined as a smaller difference between each student-applied force parameter (mean peak force (N), force amplitude (N), and oscillation frequency (Hz)), and that previously applied by an expert. Test data from each session was analysed using Friedman's and Wilcoxon signed rank tests to determine student learning and retention. Results Students were more accurate after feedback at Session 1 (median difference between student and expert force parameters 7.7 N, IQR 3.2–15.3) than before feedback (median 17.5, IQR 7.3–33.6, P < 0.001). Increased practice improved performance, with the greatest accuracy after feedback at Session 3 (median 7.0, IQR 3.5–11.9, P < 0.01). Retention however was poor, with performance at follow-up sessions no different to baseline. Conclusions Students apply more consistent and accurate mean peak force, force amplitude and oscillation frequency after practising with objective, concurrent feedback. Additional practice sessions further improve performance, however retention is poor.

Impact of different-sized laminar air flow versus no laminar air flow on bacterial counts in the operating room during orthopedic surgery

This study investigated the influence of the size of unidirectional ceiling distribution systems on counts of viable microorganisms recovered at defined sites in operating room (ORs) and on instrument tables during orthopedic surgery. We compared bacterial sedimentation during 80 orthopedic surgeries. A total of 19 surgeries were performed in ORs with a large (518 cm × 380 cm) unidirectional ceiling distribution (colloquially known as laminar air flow [LAF]) ventilation system, 21 procedures in ORs with a small (380 cm × 120 cm) LAF system, and 40 procedures in ORs with no LAF system. Bacterial sedimentation was evaluated using both settle plates and nitrocellulose membranes. Multivariate linear regression analysis revealed that the colony-forming unit count on nitrocellulose membranes positioned on the instrument table was significantly associated only with the size of the unidirectional LAF distribution system (P < .001), not with the duration of the surgical intervention (P = .753) or with the number of persons present during the surgical intervention (P = .291). Our findings indicate that simply having an LAF ventilation system in place will not provide bacteria-free conditions at the surgical site and on the instrument table. In view of the limited number of procedures studied, our findings require confirmation and further investigations on the ideal, but affordable, size of LAF ventilation systems.

Individualized multi-modal management of osteitis pubis in an Australian Rules footballer

Objective The purpose of this case report is to describe and discuss the successful management of osteitis pubis in a semi-elite Australian Rules football player through the utilization of an individualized multi-modal treatment approach provided by a chiropractor. Clinical Features A 20-year-old male semi-elite Australian Rules football player presented to a chiropractic clinic with groin pain of eight months duration. A clinical diagnosis of osteitis pubis was made through synthesis of the patient history and physical examination. Intervention and Outcome Treatment consisted of high velocity low amplitude spinal manipulative therapy, mechanically assisted adjusting techniques utilizing a hand-held mechanical thrusting instrument and drop piece table, myofascial release and active release soft tissue techniques, proprioceptive neuromuscular facilitation stretching, and an individually designed rehabilitation program. Resolution of signs and symptoms occurred over four weeks. No recurrence of injury was reported over a six-month period. Conclusions This case suggests that the implementation of an individualized multi-modal management approach directed specifically toward an athlete's deficiencies and requirements, may lead to a more rapid recovery from osteitis pubis.

Table of Data Protection and Privacy Law Instruments Regulating Transborder Data Flows

An increasing number of laws, regulations, treaties, and private sector instruments from around the world regulate the transborder flow of personal data. This document categorizes and describes them, as of March 1, 2011; it is an annex to a study that will be attached to the forthcoming OECD report on the 30th anniversary of the OECD Privacy Guidelines.

An Evaluation of Potential for Alternate Return Site Burns Due to Capacitive Coupling Between Active Electrode and Ground While Using Electrosurgery Units

In Brief Before the 1970s, the circuits used in electrosurgery units (ESUs) were referenced to ground. As a result, patients who came in contact with alternate paths to ground sometimes received burns. Examples of such alternate paths include current flow through metallic operating table frames, metallic frames under the instrument tables, intravenous poles, electrocardiogram probes, and towel clips. After isolation transformers were introduced in the 1970s, the ESU circuits became floating, with no direct path to ground. This significantly reduced the incidence of burns due to electrosurgery. This article evaluates the potential for alternate return site burns when using modern ESUs. A computer simulation and a laboratory test with a real ESU were performed. It is concluded that under specific circumstances a patient can be burned after 20 seconds of continuous ESU activation. These circumstances include (1) activation of the ESU without contact between the active electrode and the patient, (2) a small alternate return site contact area of 1 cm2, and (3) the use of a high-power, 200-W cut mode. Before the 1970s, the circuits used in electrosurgery units were referenced to ground. As a result, patients who came in contact with alternate paths to ground sometimes received burns. Examples of such alternate paths include current flow through metallic operating table frames, metallic frames under the instrument tables, intravenous poles, electrocardiogram probes, and towel clips. After isolation transformers were introduced in the 1970s, the electrosurgery unit circuits became floating, with no direct path to ground. This significantly reduced the incidence of burns due to electrosurgery. This paper evaluates the potential for alternate return site burns when using modern ESU's. A computer simulation and a laboratory test with a real ESU were performed. It is concluded that under specific circumstances a patient can be burned after 20 seconds of continuous ESU activation. These circumstances include i) activation of the ESU without contact between the active electrode and the patient, ii) a small alternate return site contract area of 1cm2, and iii) the use of a high power 200 W cut mode.

Assessment of horizontal laminar air flow instrument table for additional ultraclean space during surgery

The area in a vertical ultraclean laminar air flow (LAF) theatre is usually too small to accommodate all the equipment needed for major surgery. We investigated the addition of an instrument table supplied with fixed ultraclean LAF and placed alongside the existing main LAF unit, to determine its physical and bacteriological effect on the main unit. In phase 1, with two investigators but without a patient, smoke tests showed no intrusion of air from the table into the main unit and particle counts did not show any adverse effect on the main LAF unit. In phase 2, during patients undergoing two total knee replacements, the LAF table and a table without LAF were placed alongside the main LAF unit. The tables were subjected to the activity of an extra operating room (OR) nurse working from inside the main LAF vigorously simulating handling of instruments. During this activity, the >5μm particle counts were 275/m(3) at the instrument table with LAF and 8550/m(3) at the table without LAF (P<0.0001). Also, without the OR nurse activity, the particle counts, just inside the main unit and adjacent to the LAF table, were significantly reduced (P<0.03-0.003). Sedimentation plates on the LAF table and in the main unit registered 22 and 25cfu/m(2)/h respectively compared with 45cfu/m(2)/h at the instrument table without LAF. In conclusion, the results from the smoke tests, particle counts and bacteriological evaluation showed that the additional instrument table supplied with LAF is efficient and can be safely used as an extension additional to a main OR LAF unit.

A Comparison of Cervical Spine Mobilization Forces Applied by Experienced and Novice Physiotherapists

Clinical measurement, cross-sectional. To compare cervical mobilization forces applied by physiotherapists and students, and the factors associated with forces for each group. Cervical spine joint mobilization is a common manual technique for treating patients with mechanical neck pain. But little is known about the forces applied during this technique. Potential variability between therapists may result from clinical experience or may be due to factors present in individuals prior to clinical practice exposure. One hundred sixteen practicing physiotherapists and 120 physiotherapy students without clinical experience applied grades I through IV posteroanterior mobilization to the premarked C2 and C7 spinous and articular processes of 1 of 67 asymptomatic subjects. An instrumented table recorded applied forces (N), force amplitudes (N), and oscillation frequencies (Hz), and a custom device measured subjects' spinal stiffness (N/mm). Independent t tests were used to compare the forces applied by therapists and students, intraclass correlation coefficients were used to determine variability, and linear regression was used to establish factors associated with applied forces. Students' forces were generally lower (mean difference, 15.7 N for grades III and IV; P<.001) and applied with slower oscillation frequencies (0.12 Hz; P<.001) than therapists' forces. Similar factors were associated with applied forces for both groups: male gender and greater subject body weight were associated with higher applied forces, and greater C2 stiffness with lower forces. Having thumb pain was associated with lower applied forces for therapists but higher ones for students. Students apply lower forces than therapists. Similar factors appear to affect applied forces regardless of clinical experience.

Influence of Tempering Temperature in Wear of AISI T15 HSS Tools Produced by HIP and Liquid Phase Vacuum Sintering

AbstractThis work aims to investigate the influence of tempering temperature in the wear resistance of AISI T15 HSS tools produced by two different sintering processes – hot isostatic pressing (HIP) and liquid phase vacuum sintering. All materials are submitted to annealing at 870°C, quenching at 1210°C and triple tempering at 540, 550 and 560 °C. Density measurements, hardness and bend strength (transversal rupture strength – TRS) tests are accomplished. To identify the present phases and to evaluate the obtained microstructures, analysis in optical microscopy, SEM and EDX are done. Interchangeable inserts are manufactured by electrical discharge machining process. Frontal machining without coolant of normalized AISI 1045 steel plates is employed. The cutting forces are monitored via a transducer basically constituted of an instrumented table with four load cells mounted with “Strain Gages” sensors capable to measure the cutting efforts. The tools wear is analyzed and used to estimate the performance of two different HSS tools. For both investigated materials, the tools tempered at 540 °C show the lowest wearing.

Cervical spine mobilisation forces applied by physiotherapy students

Objectives Postero-anterior (PA) mobilisation is commonly used in cervical spine treatment and included in physiotherapy curricula. The manual forces that students apply while learning cervical mobilisation are not known. Quantifying these forces informs the development of strategies for learning to apply cervical mobilisation effectively and safely. This study describes the mechanical properties of cervical PA mobilisation techniques applied by students, and investigates factors associated with force application. Participants Physiotherapy students ( n = 120) mobilised one of 32 asymptomatic subjects. Methods Students applied Grades I to IV central and unilateral PA mobilisation to C2 and C7 of one asymptomatic subject. Manual forces were measured in three directions using an instrumented treatment table. Spinal stiffness of mobilised subjects was measured at C2 and C7 using a device that applied a standard oscillating force while measuring this force and its concurrent displacement. Analysis of variance was used to determine differences between techniques and grades, intraclass correlation coefficients (ICC) were used to calculate the inter- and intrastudent repeatability of forces, and linear regression was used to determine the associations between applied forces and characteristics of students and mobilised subjects. Results Mobilisation forces increased from Grades I to IV (highest mean peak force, Grade IV C7 central PA technique: 63.7 N). Interstudent reliability was poor [ICC(2,1) = 0.23, 95% confidence interval (CI) 0.14 to 0.43], but intrastudent repeatability of forces was somewhat better (0.83, 95% CI 0.81 to 0.86). Higher applied force was associated with greater C7 stiffness, increased frequency of thumb pain, male gender of the student or mobilised subject, and a student being earlier in their learning process. Lower forces were associated with greater C2 stiffness. Conclusion This study describes the cervical mobilisation forces applied by students, and the characteristics of the student and mobilised subject associated with these forces. These results form a basis for the development of strategies to provide objective feedback to students learning to apply cervical mobilisation.

Assessments tools for risk prediction of cardiovascular diseases.

Scientific backgroundCardiovascular diseases have an enormous epidemiological and economic importance. For the selection of persons with increased total cardiovascular risk for individual-targeted (e. g. drug-based) prevention interventions different risk prognosis instruments (equations, point scores and table charts) were derived from studies or databases. The transferability of these prognostic instruments on the populations not examined in these data sources as well as their comparability are not clear. Research questionsThe evaluation addresses the questions on the existence of instruments for risk prediction of cardiovascular diseases, their transferability and comparability. MethodsA systematic literature search was performed in the medical electronic databases in April 2008 beginning from 2004 and was completed with a hand search. Publications on the prognostic instruments for cardiovascular diseases as well as publications addressing external validity and/or comparing prognostic instruments were included in the evaluation. Results The systematic lierature search yielded 734 hits. Three systematic reviews, 38 publications with descriptions of prognostic instruments and 29 publications with data on the validity of the prognosis instruments were identified. Most risk prognosis instruments are based on the Framingham cohort of the USA. Only the PROCAM study is completely based on the German reference population. Almost all prognostic instruments use the variables sex, age, smoking, different parameters of the lipid status and of the blood pressure. Different cardiovascular events are considered to be an end parameter in the prognosis instruments. The time span for predicted events in the studies mostly comprises ten years. Data on calibration of the prognosis instruments (a quotient of the predicted by the observed risk) are presented in nearly half of the studies on the validation, however in no study from Germany. Only single studies find the levels of calibration between 0.9 and 1.1. Many studies on the transferability of the prognosis instruments show a value of the discrimination (correct differentiation of persons with different risk levels, best value 1.0) between 0.7 and 0.8, few studies between 0.8 and 0.9 and no study over 0.9. The studies addressing the discrimination of the prognostic instruments on the German population almost always find values between 0.7 and 0.8. The comparison of the validity of different risk prognosis instruments shows a trend for a better calibration and a better discrimination for the prognosis instruments examined on the derivation and/or validation cohorts of one of the compared prognostic instruments. Comparing the prognostic instruments on other cohorts, the newly derived Framingham prognostic instruments show a better discrimination in comparison with previously derived instruments. No studies exists comparing different prognostic instruments on the German population. DiscussionThe geographic variance of the cardiovascular morbidity and mortality supposed to be the most important factor limiting the transferability of the prognostic instruments. An appropriate recalibration is considered to be an approach for the improvement of the transferability. ConclusionsThe identified instruments for the risk prediction of cardiovascular diseases are insufficiently validated on the German population. Their use can lead to false risk estimation for a single person. Therefore, the existing prognostic instruments should be used for the informed decision-making and for the therapy selection in Germany only with critical caution.