Disease-Specific Assessment of Quality of Life after Decompression Surgery for Graves' Ophthalmopathy

Purpose

Graves' ophthalmopathy (GO) is an organ-specific autoimmune disease. Hydrophily of accumulated acidic mucopolysaccharides into bulbar adipose tissue leads to swelling of the eye muscles. Orbital surgical decompression is performed in severe cases of compressive optic neuropathy and severe corneal exposure or failure of steroid therapy. The study was designed to evaluate decompression surgery with respect to the clinical benefit and the patient's satisfaction by means of a disease-specific questionnaire.

METHODS

The 90-item study questionnaire was distributed to 105 patients with GO who underwent orbital decompression surgery at the authors' institution.

Results

A total of 88% of patients stated that decompression had helped them, 80% of the interviewees would undergo decompression again, 78% were content with their eye symptoms, and 71% were satisfied with the cosmetic result of decompression. Furthermore, analysis showed a clinically relevant increase in quality of life after surgery. The correlation between the clinical endpoint proptosis at last examination and the quality of life score proved to be significant (p=0.05).

CONCLUSIONS

The large majority of interviewees were satisfied with the result of the orbital decompression. These results confirmed that disfiguring proptosis is an important indication for decompression surgery.

Clinical Outcome and Subjective Quality of Life after Photodynamic Therapy in Patients with Age-Related Macular Degeneration

PURPOSE

Whereas the efficacy of photodynamic therapy (PDT) in preventing the progression of age-related macular degeneration (ARMD) is established, its effect on quality of life is under discussion.

METHODS

All patients who underwent PDT during 2000 and 2001 at the University Eye Hospital of Mainz were interviewed using a standardized 82-item questionnaire on quality of life and patient satisfaction in ophthalmologic patients. Information was assessed in terms of 82 questions; global scores ranging from 1.0 (optimum self-estimated quality of life) to 4.0 (worst) were derived. Cataract patients' scores were used to characterize the ARMD patients' subjective outcome; the latter were then related to clinical outcome parameters via logistic regressions.

RESULTS

A total of 84 patients (50% female, median age 77 years) were interviewed, who underwent a median of three PDT interventions. During the period of PDT treatment, their median decrease in visual acuity was 3 lines from 0.125 to 0.063. Patients who reported a subjective increase in visual function during this period showed a median private flexibility score of 1.86; patients with the subjective impression of visual function decrease, a median score of 2.71; the median scores for mobility were 2.00 versus 3.00, for flexibility in reading 1.91 versus 3.64, for psychological stress 1.56 versus 2.25, and for communicational flexibility 1.72 versus 2.25. The difference in reading flexibility was statistically significant (p=0.001) after correction for clinical cofactors.

CONCLUSIONS

The established clinical benefit of PDT treatment concerning its efficacy in ARMD progression prevention coincides with an at least slight subjective benefit in quality of life and patient satisfaction. However, the latter is associated with the patients' subjective impression of visual acuity progression rather than with clinically validated outcome after PDT treatment.

[Evaluation of methodological quality in published RCTs on cataract surgery : Pilot study on the degree of adherence to CONSORT statement requirements and their qualitative validity]

BACKGROUND

The CONSORT statement can be considered as a guideline to ensure transparency in the reporting of randomized clinical trials (RCT), in addition to specific author instructions and requirements of journals. It provides a total of 25 criteria and 12 additional subcriteria on methodological and regulatorical determinants of clinical trials. The availability of the CONSORT recommendations, however, does not necessarily imply adherence to their obligations and correct realisation of the latter from a methodological perspective, so that even in ophthalmology a lack of transparency in trial reporting cannot be excluded.

OBJECTIVE

The question was whether a consistent consideration of the CONSORT checklist criteria by authors actually implied transparent reporting of underlying study results.

MATERIALS AND METHODS

This pilot study was based on a random sample of six published RCTs on cataract surgery extracted from an existing trial publication register. Compliance with each of the 25 CONSORT criteria and its 12 subcriteria and the content accuracy of the latter were independently assessed by two parallel raters for the six trial publications.

RESULTS

The median compliance with the 37 CONSORT criteria and subcriteria was 62% [min-max 48-81%]; the median fraction of their correct implementation was 47% [min-max 34-69%].

CONCLUSIONS

Promotion of transparent reporting by means of the CONSORT statement appears to be problematic in implementation. There is a discrepancy between information as required by CONSORT and the content accuracy of its actual presentation. Thus, in particular, reviewers of clinical trial publications should not only check for the presence of data to be provided according to CONSORT, but also verify the meaningfulness in the respective context, at least on a random basis.

[Conception and Content Validation of a Questionnaire Relating to the Potential Need for Information of Visually Impaired Persons with Regard to Services and Contact Persons]

A questionnaire was drafted to identify the needs of visually impaired persons and to optimize their access to non-medical support and services. Subjects had to rate a list of 15 everyday activities that are typically affected by visual impairment (for example, being able to orient themselves in the home environment), by indicating the degree to which they perceive each activity to be affected, using a four-stage scale. They had to evaluate these aspects by means of a relevance assessment. The needs profile derived from this is then correlated with individualized information for assistance and support. The questionnaire shall be made available for use by subjects through advisers in some ophthalmic practices and via the internet. The validity of the content of the proposed tool was evaluated on the basis of a survey of 59 experts in the fields of medical, optical and psychological care and of persons involved in training initiatives. The experts were asked to rate the activities by relevance and clarity of the wording and to propose methods to further develop and optimize the content. The validity of the content was quantified according to a process adopted in the literature, based on the parameters Interrater Agreement (IRA) and Content Validity Index (CVI). The results of all responses (n = 19) and the sub-group analysis suggest that the questionnaire adequately reflects the potential needs profile of visually impaired persons. Overall, there was at least 80% agreement among the 19 experts for 93% of the proposed parameterisation of the activities relating to the relevance and clarity of the wording. Individual proposals for optimization of the design of the questionnaire were adopted.

Clinical outcome and cost effectiveness of inpatient rehabilitation after total hip and knee arthroplasty. A multi-centre cohort benchmarking study between nine rehabilitation departments in Rhineland-Palatinate (Western Germany)

BACKGROUND

Rehabilitation after hip and knee replacement surgery is effective, but cost intensive. To ensure consistent cost-effectiveness across different providers prospective cohort studies on its clinical and economic outcome are recommended. Comparisons alongside suitable outcome quality indicators enable to contrast different providers and--in case of clinically or economically relevant differences--reveal constructive approaches to quality improvement.

AIM

Therefore an external benchmarking for posthospital curative treatment after hip and knee arthroplasty between nine inpatient rehabilitation departments in the German Federal Land Rhineland-Palatinate was implemented based on data acquired between 01/2007 and 12/2009.

DESIGN

Multi-centre retrospective cohort benchmarking study.

SETTING

Inpatient rehabilitation in nine rehabilitation departments

POPULATION

A total of 8672 patients after unilateral hip arthroplasty (THA) and 8180 patients after unilateral knee replacement (TKA) surgery were investigated. The median age of the patients after hip arthroplasty varied between 71 and 75 years, after knee arthroplasty between 72 and 75 years. The department-wise proportions of female patients ranged from 62% to 77% (THA) and from 70% to 81% (TKA).

METHODS

Data on clinical outcome of inpatient rehabilitation after THA and TKA were documented using the EVAReha® software. As primary indicator of clinical outcome quality the intra-individual pre-post change in the total Staffelstein Index was determined [%], as primary economic indicator the cost-normalized effect estimate (CNEE) was estimated [%/€] relating the individual Staffelstein Index change to a patient's respective direct costs [€] paid by the statutory health insurance.

RESULTS

In the nine departments the median Staffelstein index increase after THA ranged between 18% to 31% corresponding to median CNEEs ranging from 9% to 15% Staffelstein increase per €1000 investment of the statutory health (Kruskal/Wallis P<0.001). After TKA the median Staffelstein index increase ranged between 19% to 34% corresponding to median CNEEs ranging from 9% to 16% Staffelstein increase per 1,000 € investment of the statutory health (Kruskal / Wallis P<0.001).

CONCLUSION

Inpatient follow-up treatment after hip and after knee replacement surgery demonstrated a statistically significant and both clinically and economically relevant heterogeneity between the departments. Additional exploratory analyses by means of adjustment with further predictors could not resolve these heterogeneities.

CLINICAL REHABILITATION IMPACT

Benchmark information on cost effectiveness would enable departments to learn from the "best" and to implement corresponding peer cooperation, to then identify own shortcomings and potentials, and thereby to analyze and optimize local processes.

[Prospective Reliability Trial to Assess Inter and Intra Observer Reliability of Rebound Tonometry in the Eyes of Healthy Probands]

PURPOSE

A prospective reliability trial was implemented to estimate the inter- and intraobserver reproducibility of iCare® rebound tonometry in healthy proband eyes.

MATERIAL AND METHODS

Three independent observers performed three replicate measurements, respectively, by means of the iCare®PRO rebound tonometry device in 20 eyes of 20 healthy probands. Two of these observers were medical doctors with an at least two years experience in ophthalmological patient care, the third observer was a study nurse with several years practice in applying ophthalmological diagnostic procedures. Each observer's replicate measurements were averaged and then compared by means of a global Friedman test for interobserver bias in the parallel rebound tonometry measurements at the 5 % significance level. In addition, variance component analysis was performed on the overall repeated measurement design to estimate the iCare® reliability coefficient [%] (100 % indicating total reproducibility in absence of any inter or intra observer bias).

RESULTS

The respective observers' median average measurements were 15.9 mmHg (interquartile range 15.1 to 17.5 mmHg) and 15.1 mmHg (14.3 to 15.6 mmHg) for the medical doctors, furthermore 16.8 mmHg (14.2 to 18.9 mmHg) for the study nurse; the averaged measurement series showed a significant interobserver bias (Friedman p = 0.006). Variance component analysis revealed an overall iCare® reliability of 35 % (95 % confidence interval 26 to 44 %).

CONCLUSION

In this repeated measurement design iCare® rebound tonometry measurements showed significant interobserver bias and thereby notably reduced overall reliability. In particular, the intraindividual measurement profiles showed a gradient towards smaller values during the 9 replicates' series; furthermore the study nurses' measurements showed notably increased variability. As a consequence the routine use of iCare® rebound tonometry must be critically discussed at least when being delegated to less experienced staff.

[Case numbers and revenues of main and affiliated ophthalmological departments: Developments since 2005]

BACKGROUND

Currently, very little data exist on the development of healthcare-related and financial parameters of both types of inpatient treatment: clinical units run by affiliated physicians and those run by hospital physicians.

AIM

This study used a methodology based on published secondary data to estimate the annual number of cases and revenues for in inpatient ophthalmological treatment differentiated into clinical units run by affiliated physicians and those run by hospital physicians.

MATERIAL AND METHODS

The case-based flat-rate catalogs and accompanying research data published annually by the Institute for the Hospital Remuneration System (Institut für Entgeltsysteme im Krankenhaus, InEK) served as a data source. The numbers of annual cases according to major diagnostic categories (MDC) and diagnosis-related groups (DRG), stratified by the unit type are reported for the period 2005-2012. The cumulative total revenues were calculated based on the number of ophthalmological cases, the effective DRG cost weighting, the length of stay and the national basic case values.

RESULTS

Between 2005 and 2012 the units run by affiliated physicians showed a contrasting trend to those run by hospital physicians: the number of cases in units run by hospital physicians increased by  14 %, while those in units run by affiliated physicians decreased by  6 %. Up to 2012 the effective cost weighting for cases in units run by hospital physicians decreased to 0.60 (- 3 %) and increased to 0.43 (+ 5 %) for units run by affiliated physicians. In 2012 the corresponding effective case revenue accounted for 1767 euros and 1271 euros, respectively. Total revenue estimates for all inpatient ophthalmological treatment increased from 549 million euros in 2005 to 630 million euros in 2012, while the share of units run by affiliated physicians amounted to 10.6 % and 9.7 %, respectively.

CONCLUSION

According to the indicators "number of cases" and "total revenue", the affiliated ophthalmologists lost ground compared with inpatient units run by hospital physicians over the period from 2005-2012.

[German Total Ankle Replacement Register of the German Foot and Ankle Society (D. A. F.) - presentation of design and reliability of the data as well as first results]

INTRODUCTION

Even though arthroplasty of the ankle joint is considered to be an established procedure, only about 1,300 endoprostheses are implanted in Germany annually. Arthrodeses of the ankle joint are performed almost three times more often. This may be due to the availability of the procedure - more than twice as many providers perform arthrodesis - as well as the postulated high frequency of revision procedures of arthroplasties in the literature. In those publications, however, there is often no clear differentiation between revision surgery with exchange of components, subsequent interventions due to complications and subsequent surgery not associated with complications. The German Orthopaedic Foot and Ankle Association's (D. A. F.) registry for total ankle replacement collects data pertaining to perioperative complications as well as cause, nature and extent of the subsequent interventions, and postoperative patient satisfaction.

MATERIAL AND METHODS

The D. A. F.'s total ankle replacement register is a nation-wide, voluntary registry. After giving written informed consent, the patients can be added to the database by participating providers. Data are collected during hospital stay for surgical treatment, during routine follow-up inspections and in the context of revision surgery. The information can be submitted in paper-based or online formats. The survey instruments are available as minimum data sets or scientific questionnaires which include patient-reported outcome measures (PROMs). The pseudonymous clinical data are collected and evaluated at the Institute for Evaluative Research in Medicine, University of Bern/Switzerland (IEFM). The patient-related data remain on the register's module server in North Rhine-Westphalia, Germany. The registry's methodology as well as the results of the revisions and patient satisfaction for 115 patients with a two year follow-up period are presented. Statistical analyses are performed with SAS™ (Version 9.4, SAS Institute, Inc., Cary, NC, USA).

RESULTS

About 2½ years after the register was launched there are 621 datasets on primary implantations, 1,427 on follow-ups and 121 records on re-operation available. 49 % of the patients received their implants due to post-traumatic osteoarthritis, 27 % because of a primary osteoarthritis and 15 % of patients suffered from a rheumatic disease. More than 90 % of the primary interventions proceeded without complications. Subsequent interventions were recorded for 84 patients, which corresponds to a rate of 13.5 % with respect to the primary implantations. It should be noted that these secondary procedures also include two-stage procedures not due to a complication. "True revisions" are interventions with exchange of components due to mechanical complications and/or infection and were present in 7.6 % of patients. 415 of the patients commented on their satisfaction with the operative result during the last follow-up: 89.9 % of patients evaluate their outcome as excellent or good, 9.4 % as moderate and only 0.7 % (3 patients) as poor. In these three cases a component loosening or symptomatic USG osteoarthritis was present. Two-year follow-up data using the American Orthopedic Foot and Ankle Society Ankle and Hindfoot Scale (AOFAS-AHS) are already available for 115 patients. The median AOFAS-AHS score increased from 33 points preoperatively to more than 80 points three to six months postoperatively. This increase remained nearly constant over the entire two-year follow-up period.

CONCLUSION

Covering less than 10 % of the approximately 240 providers in Germany and approximately 12 % of the annually implanted total ankle-replacements, the D. A. F.-register is still far from being seen as a national registry. Nevertheless, geographical coverage and inclusion of "high-" (more than 100 total ankle replacements a year) and "low-volume surgeons" (less than 5 total ankle replacements a year) make the register representative for Germany. The registry data show that the number of subsequent interventions and in particular the "true revision" procedures are markedly lower than the 20 % often postulated in the literature. In addition, a high level of patient satisfaction over the short and medium term is recorded. From the perspective of the authors, these results indicate that total ankle arthroplasty - given a correct indication and appropriate selection of patients - is not inferior to an ankle arthrodesis concerning patients' satisfaction and function. First valid survival rates can be expected about 10 years after the register's start.

[Case control trial on putative factors antagonising the successful project course of MD thesis projects]

INTRODUCTION

Award of the degree MD has special relevance in Germany since the underlying research project can be started during the qualification for admission to doctoral training. This leads to a large number of thesis projects with a not always sufficiently pronounced enthusiasm and thus poor chances of success. Accordingly a case control study was undertaken in the Department of Human Medicine, Witten/Herdecke University to investigate reported drop-outs of thesis projects.

MATERIAL AND METHOD

In autumn 2012 all students in the clinical phases of human medicine education were surveyed using a self-conceived questionnaire on previously initiated or terminated thesis projects, "terminated" is defined as the unsuccessful ending of a project after working for at least 3 months. Individually reported thesis terminations were evaluated using defined items in a 4-stage Likert scale regarding thesis plan and project, subsequently, graduate students who successfully completed a project received the same questionnaire. The items possibly corresponding to process determinants were averaged to a total of 7 dimensions prior to the analysis; the resulting scores were normalised in value ranges 0.0 to 1.0 (1.0 = optimal project situation) whereby individual items could be included in several scores. By means of 5 items a primary endpoint from the faculty's perspective on "compliance with formal procedures" was aggregated; by means of a two-sided Wilcoxon test at the 5 % level students with unsuccessful and successful courses were compared along the corresponding scores.

RESULTS

181 of 276 students from 7 study semesters participated in the screening; details of 17 terminations and 23 currently successful courses could be evaluated in the case control study. For significant differences (p < 0.001) between unsuccessful and successful courses in the primary endpoint, median scores of 0.17 (0.07-0.50) versus 0.73 (0.53-0.83) were estimated.

CONCLUSION

There were differences between unsuccessful and (as yet) successful courses, especially with regard to the aspects "compliance with formal procedures". Thus a recommendation can be derived in the sense of a stricter and, if necessary, sanctioning demand for formal procedures such as early reporting of thesis projects to the responsible committees. A weakness is the low number of evaluable self-reported drop-outs as well as the overall moderate response rate.

[Randomised pilot study for quantification of benefit from the patient's point of view of deep oscillation treatment in primary wound healing]

BACKGROUND AND AIM OF THE INVESTIGATION: Deep oscillation refers to an electromechanical therapy method in which electrostatic attraction and friction, produced by the use of a hand-held applicator, create resonance vibrations in treated tissue. In a pilot clinical trial the impact of deep oscillation has been examined in relation to the physiological parameters of wound healing on postoperative wounds.

MATERIAL AND METHODS

Following osteosynthesis operations (extremities and spinal column), 40 patients were stratified by operation localisation and randomised into two samples (intervention [n = 20], control [n = 20]). Aside from primary care of the operation wound, finding-oriented deep oscillation was applied for at least one week following the operation in the intervention sample. The intra-individual reduction in postoperative pain occurrence between day 2 and day 7 of the postsurgical period was quantified by means of a visual analogue scale (VAS) serving as primary clinical end point from the patient's point of view. Confirmatory analysis of this primary endpoint was based on a two-sample Wilcoxon test at the 5 % level of significance.

RESULTS

According to VAS pain occurrence declined in the intervention group from day 2 to day 7 in the postoperative period by a median of 3 points (P) (quartile range -4-0.25 P) and a mean of -2.3 P, the control group remained (almost) unaltered with a median difference of 0 P (-2-0 P) and a mean difference of -0.85 P; the treatment groups differed significantly in the postoperative profile of VAS-based pain sensation (Wilcoxon p = 0.006). None of the secondary endpoints showed any locally significant sample differences.

DISCUSSION

These results demonstrate a significant pain-alleviating effect of deep oscillation. However, the exact physiological effects underpinning the impact of deep oscillation are still not completely understood.

[Metaanalysis to estimate the expected drop out-rates reported in clinical trials on cataract surgery]

BACKGROUND

A realistic sample size calculation is crucial to achieve significant results in clinical trials. As an expected drop out-rate has to be included in the sample size calculation, current practice consists in the presumption of drop out-rates published in previous similar investigations. This approach may, however, result in severely over- or under-estimated sample sizes. Therefore this meta-analysis sought to aggregate the drop out-rates from published clinical trial reports on cataract surgery to derive a quantitative suggestion for the planning of future clinical trials.

METHODS

The data collection was a complete review of all prospective and retrospective studies in five journals of the years 2002-2012; trial-wise recall rates of subjects at follow-up 3, 6, 12, and 24 months after recruitment were documented. The primary endpoint of the meta-analysis was the reported drop out-rates after 6 months. 95 % confidence intervals were calculated for each trial, respectively; a median drop out-rate was estimated including its 95 % confidence interval. The drop-out-rate estimates were furthermore stratified by design characteristics of the reported studies.

RESULTS

For randomised clinical trials on cataract surgery, the median drop out-rate increased during the follow-up period of 24 months from 4 % at three months to 17 % at 24 months after recruitment; for the six-month drop out-rate a median drop-out rate of 3 % (95 % CI 0 %; 14 %) was estimated.

CONCLUSION

Drop out-rates in sample size calculations for clinical trials on cataract surgery were found to be over-estimated in general, ending up in the calculation of overly large patient numbers and thereby in both ethical and economic consequences. For randomised clinical trials on cataract surgery the median drop out-rate can be expected to be 5 % during a six-month follow-up and may rise up to 15 % during a 12-month trial period.

[How is ophthalmic undersupply demonstrated in socially disadvantaged people? Cross-sectional pilot investigation on the parametrisation of endpoints for patient-centred care research]

BACKGROUND

Many people depend on additional help to maintain their daily needs. In these circumstances preventive medical check-ups are frequently not attended, so that disease development may remain undetected until advanced stages or correctable disorders may not be treated. A fully anonymised cross-sectional study was set up to assess feasibility of parametrisation and to quantify sensitive indicators for screening for possible ophthalmic undersupply in socially disadvantaged people.

METHODS

In 2011 a free, voluntary and anonymous ophthalmic examination was offered to attendees of the "Oberhausener Tafel" social project. The visual acuity was checked with adjustment of the objective refractional error via autorefractor, without or with glasses (if available). In addition, an examination of the anterior and posterior segments of the eye was done in miosis. As primary endpoint a corrected visual acuity of > 0.5 combined with a presenting visual acuity ≤ 0.5 on the same eye in at least one eye was considered. A key secondary endpoint was defined as the absolute deviation of at least 1 D in at least one eye between the spherical equivalent measurement of the corrective values of the glasses and the autorefractor readings. The primary intention of this pilot investigation was to assess the feasibility of this endpoint parametrisation and to quantify the corresponding endpoint prevalences.

RESULTS

Data of 37 participants could be evaluated, 28 of whom brought their glasses. The best available visual acuity ranged from 0.12 to 1.3 with a median per eye of 0.63. In comparison, the corrected visual acuity per eye was 0.8 (range 0.32-1.0). In 54 % the presenting visual acuity was one- or both-eyed ≤ 0.5, but could be reduced to 30 % (one- or both-eyed) after correction of the objective refractional error. In summary, presenting visual acuity in comparison to corrected visual acuity showed potential for an at least one-eyed improvement for at least two lines in 46 % of the participants. Furthermore, 19 participants showed disorders concerning the anterior or posterior eye segment.

CONCLUSION

In the examined population the visual acuity could be improved by two lines in merely 50 % of the participants by adjusting refractive errors. The results indicate the need for discussion on how to lower the threshold for attending preventive ophthalmic examinations.

Clinical benefit and cost effectiveness of total knee arthroplasty in the older patient

Purpose

Total knee arthroplasty (TKA) is an effective, but also cost-intensive health care procedure for the elderly. Furthermore, bearing demographic changes in Western Europe in mind, TKA-associated financial investment for health care insurers will increase notably and thereby catalyze discussions on ressource allocation to Orthopedic surgery. To derive a quantitative rationale for such discussions within Western Europe's health care systems, a prospective assessment of both the benefit of TKA from a patient's perspective as well as its cost effectiveness from a health care insurer's perspective was implemented.

Methods

A prospective cost effectiveness trial recruited a total of 65 patients (60% females), who underwent TKA in 2006; median age of patients was 66 years (interquartile range 61 - 74 years). Before and three months after surgery patients were interviewed by means of the EuroQol-5D and the WOMAC questionnaires to assess their individual benefit due to TKA and the subsequent inpatient rehabilitation. Both questionnaires' benefit estimates were transformed into the number of gained quality adjusted life years [QALYs]. Total direct cost estimates for the overall care were based on German DRG and rehabilitation cost rates [€]. The primary clinical endpoint of the investigation was the individual number of QALYs gained by TKA based on the WOMAC interview; the primary health economic endpoint was the marginal cost effectiveness ratio (MCER) relating the costs to the associated gain in quality of life [€/QALY].

Results

Total direct costs for the overall procedure were estimed 9549 € in median. The WOMAC based interview revealed an overall gain of 4.59 QALYs (interquartile range 2.39 - 6.21 QALYs), resulting in marginal costs of 1795 €/QALY (1488 - 3288 €/QALY). The corresponding EuroQol based estimates were 2.93 QALYs (1.75 - 5.59 QALYs) and 3063 €/QALY (1613 - 5291 €/QALY). Logistic regression modelling identified the patients' age as the primary determinant of cost effectiveness (Likelihood Ratio p = 0.006): patients younger than 60 years showed a median gain of 6.45 QALYs and median marginal costs of 1463 €/QALY, patients between 60 - 70 years 5.47 QALYs and 1744 €/QALY, patients older than 70 years 2.76 QALYs and 3186 €/QALY.

Conclusion

TKA was proven to be cost effective from a health care insurer's perspective, although its marginal costs notably increased with increasing age. Note, however, that this age-related gradient in marginal cost effectiveness is of comparable order as the changes in cost effectiveness due to variation of the underlying assessment instrument.

[Evaluation of possible prognostic factors for the course of visual acuity after intravitreal ttriamconolone acetonide]

BACKGROUND

Intrvitreal injections are increasingly applied in the treatment of macular oedema of different origins. So far no clear preoperative prognostic factors are known. This investigation was implemented to quantify the predictive value of preoperative retinal sensitivity assessments by means of microperimetry with regard to the short-term course of visual acuity.

METHODS

42 patients with macular oedema due different ocular diseases (such as diabetic maculopathy, retinal vein occlusion, Irvine Gass syndrome) were examined pre- and postoperatively by means of microperimetry, fixation, optical coherence tomography and fluorescein angiography. Their medical history, treatment to date, visual acuity, central retinal thickness and retinal sensitivity were recorded before and six weeks after intravitreal injection of triamcinolone acetonide.

RESULTS

The data from 38 injections could be evaluated; 21 eyes showed an improvement in visual acuity of more than one line. However, statistically significant prognostic factors could not be identified: patients with a visual acuity increase of at least one line showed a median total retinal sensitivity of 8.5 dB (5.0-11.0 dB) versus 8.3 dB (3.6-12.8 dB) in patients with unchanged or decreasing visual acuity (Wilcoxon p = 0.706). The same tendency was observed in retinal thickness with medians of 618 µm (483-689 µm) versus 558 µm (447-621 µm; Wilcoxon p = 0.220). However, a moderate association of the visual outcome with the 6 weeks change in total retinal sensitivity was observed. Patients with visual improvement of at least one line showed a significant sensitivity increase of 1.7 dB in median versus a median decrease of 0.8 dB in patients with stable or worsened visual acuity (sign test p = 0.003 and p = 0.629, respectively).

CONCLUSION

The presented data did not reveal statistically significant predictors of the short-term visual outcome after triamzinolone injection by means preoperative microperimetry assessment.

[Clinical risk management in german hospitals - does size really matter?]

PURPOSE

In the last years, German hospitals have implemented different measures to increase patient safety. Special importance has been attached to near miss reporting systems (critical incident reporting system, CIRS) as instruments for risk identification in health care, instruments that promise high potential for organisational learning. To gain insight into the current status of critical incident reporting systems and other instruments for clinical risk management, a survey among 341 hospitals was carried out in 2009. Questions covered a process of six steps: from risk strategy to methods for risk identification, to risk analysis and risk assessment, to risk controlling and risk monitoring.

MATERIAL AND METHODS

Structured telephone interviews were conducted with 341 German hospitals, featuring in their statutory quality reports certain predefined key terms that indicated the concluded or planned implementation of clinical risk management. The main objective of those interviews was to check the relation between status/organisation of self-reported risk management and both operator (private, public, NPO) and size of hospital.

RESULTS

The implementation of near miss reporting systems (CIRS) in German hospitals has been constantly rising since 2004: in 2009, 54 % of the interviewed hospitals reported an implemented CIRS; of these, 72 % reported the system to be hospital-wide. An association between CIRS and private, public or NPO-operator could not be detected (Fisher p = 1.000); however, the degree of CIRS implementation was significantly increasing with the size of the hospital, i.e., the number of beds (Fisher p = 0.008): only 38 % of the hospitals with less than 100 beds reported CIRS implementation against 52 % of those between 100 to 500 beds, and 67 % of those with more than 500 beds. While 62 % of the hospitals interviewed reported the maintenance of a risk management committee, only 14 % reported the implementation of risk analysing techniques. As to clinical risk management, 92 % of the hospitals see potential for internal improvement; 44 % have already communicated with external consultants.

CONCLUSION

While identification of clinical risks with near miss and other incident reporting systems meets increasing acceptance, the learning potential based on incident reporting is not yet appropriately being used. There is a deficit regarding systematic and comprehensive risk assessment and controlling; this will have to be met by improving the organisational framework for clinical risk management.

Social, educational, and occupational predictors of total hip replacement outcome

OBJECTIVE

There is limited evidence on social, educational, and occupational factors as predictors of response to total hip replacement (THR). We aimed to analyze these factors in a large population-based setting.

METHOD

Patients of the Dresden Hip Surgery Registry were recruited and the pre and post (6 months) operative functional status was assessed using the global Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) score (0-100 points). Non-response was defined a gain of <20 points in WOMAC score over a 6 months period and was analyzed with respect to six socioeconomic parameters. Multiple logistic regression modeling was applied to adjust for age, sex, BMI, co-morbidity, and preoperative functional status.

RESULTS

Data from 1007 patients (mean age 61 years, STD 13; 55% women) were included. The average preoperative WOMAC score was 45.8 which increased to 84.4 after surgery. 38.2%, 36.6%, and 25.3% of the patients attended school for 8, 9, and 12 years, respectively. 54.1% were retired, 26.9% worked full time, and 6.7% received a disability pension. A 14.8% of the patients did not achieve a gain of > or =20 points in WOMAC score and were classified as non-responders. After control for confounders, significantly increased risks of non-response were found for widowed patients compared to singles [odds ratio (OR) 4.30, 1.45-12.71], those who lived alone (OR 1.70, 1.02-2.85), and patients with a disability pension compared to those who worked full time (OR 5.81, 2.33-14.46). The risk of non-response decreased with increasing length of school education (12 vs 8 years: OR 0.49, 0.27-0.89). Compared to workers, employees (OR 0.55, 0.33-0.90) and self-employed patients (OR 0.41, 0.18-0.94) showed significantly decreased risks of non-response.

CONCLUSION

Socioeconomic parameters are independent predictors of response to THR. This can help to improve the health service by identifying subgroups which need special attention in order to increase the response rate.

[Training recommendations for exercise intensity with regard to maximal fat oxidation]

BACKGROUND AND OBJECTIVE

Training intensity at maximal fat oxidation differs among individuals. The aim of this study was to investigate whether a training recommendation according to a person's maximal fat oxidation rate [fat( (max)]) can be based on a lactate treadmill test and its resulting lactate concentration and heart rate profiles.

METHODS

Nine women and eleven men aged 31 - 49 years performed an ergospirometric and a standard lactate treadmill test. In the first test fat( (max)) was assessed by accustoming for 30 min at very low speed and then pace rising by three-minute stages. The standard lactate treadmill test was passed one to three weeks afterwards with stage increases every 5 min.

RESULTS

When fat( (max)) was reached the probands had a median heart rate of 138 bpm. There was a significant difference (p < 0,001) from the heart rate at a lactate concentration of 2 mmol/l in the second test (median 153 bpm), serving as a reference for training recommendation. However, the median heart rate at fat( (max)) did not differ significantly from the value at first lactate rise (median 134 bpm). The heart rate interval at fat oxidation of more than 90 % of fat( (max)) ranged from a median of 125 to 151 bpm.

CONCLUSION

A suitable approximation of a heart rate near fat( (max),) as a surrogate for the lactate test, seems to be the heart rate at first lactate rise or the heart rate corresponding to a lactate level of 2 mmol/l minus 15 bpm.

Short-term outcome after posterior versus lateral surgical approach for total hip arthroplasty - A randomized clinical trial

Purpose

Currently, total hip replacement (THR) is most commonly performed via a posterior or a direct lateral approach, but the impact of the latter on the invention's outcome has yet not been quantified.

Methods

We compared the short-term outcome of cementless THR using the both approaches in a prospective, randomized controlled trial. 60 patients with unilateral osteoarthritis were included. Outcome assessment was performed one day before surgery and one week, four weeks, six weeks and 12 weeks after surgery, respectively, using the Harris Hip score as primary objective.

Results

We found no significant difference in the intraindividual Harris Hip Score improvement at the pre-and three months post-operative assessments between both treatment groups (p = 0.115). However, Harris Hip scores and most functional and psychometric secondary endpoints showed a consistent tendency of a slightly better three months result in patients implanted via the posterior approach. In contrast a significant shorter operating time of the direct lateral approach was recorded (67 minutes versus 76 minutes, p < 0.001).

Conclusion

In our opinion this slightly better short-term functional outcome after posterior approach is not clinical relevant. However, to make definitive conclusions all clinical relevant factors (i.e. mid- to long-term function, satisfaction, complication rates and long-term survival) have to be taken into account. Level of evidence: I - therapeutic

Hyperpolarised 3He MRI versus HRCT in COPD and normal volunteers: PHIL trial

The aim of the present study was to apply hyperpolarised (HP) (3)He magnetic resonance imaging (MRI) to identify patients with chronic obstructive pulmonary disease (COPD) and alpha(1)-antitrypsin deficiency (alpha(1)-ATD) from healthy volunteers and compare HP (3)He MRI findings with high-resolution computed tomography (HRCT) in a multicentre study. Quantitative measurements of HP (3)He MRI (apparent diffusion coefficient (ADC)) and HRCT (mean lung density (MLD)) were correlated with pulmonary function tests. A prospective three centre study enrolled 122 subjects with COPD (either acquired or genetic) and age-matched never-smokers. All diagnostic studies were completed in 94 subjects (52 with COPD; 13 with alpha(1)-ATD; 29 healthy subjects; 63 males; and 31 females; median age 62 yrs). The consensus assessment of radiologists, blinded for other test results, estimated nonventilated lung volume (HP (3)He MRI) and percentage diseased lung (HRCT). Quantitative evaluation of all data for each centre consisted of ADC (HP (3)He MRI) and MLD measurements (HRCT), and correlation with forced expiratory volume in 1 s (FEV(1))/forced vital capacity (FVC) indicating airway obstruction, and the diffusing capacity of the lung for carbon monoxide (D(L,CO)) indicating alveolar destruction. Using lung function tests as a reference, regional analysis of HP (3)He MRI and HRCT correctly categorised normal volunteers in 100% and 97%, COPD in 42% and 69% and alpha(1)-ATD in 69% and 85% of cases, respectively. Direct comparison of HP (3)He MRI and CT revealed 23% of subjects with moderate/severe structural abnormalities had only mild ventilation defects. In comparison with lung function tests, ADC was more effective in separating COPD patients from healthy subjects than MLD (p<0.001 versus 0.038). ADC measurements showed better correlation with D(L,CO) than MLD (r = 0.59 versus 0.29). Hyperpolarised (3)He MRI correctly categorised patients with COPD and normal volunteers. It offers additional functional information, without the use of ionising radiation whereas HRCT gives better morphological information. We showed the feasibility of a multicentre study using different magnetic resonance systems.

Fuctional outcome after open and arthroscopic bankart repair for traumatic shoulder instability

Purpose

Both open and arthroscopic Bankart repair are established procedures in the treatment of anterior shoulder instability. While the open procedure is still considered as the "golden standard" functional outcome is supposed to be better in the arthroscopic procedure. The aim of this retrospective study was to compare the functional outcome between open and arthroscopic Bankart repair.

Materials and methods

In 199 patients a Bankart procedure with suture anchors was performed, either arthroscopically in presence of an detached, but not elongated capsulolabral complex (40) or open (159). After a median time of 31 months (12 to 67 months) 174 patients were contacted and agreed to follow-up, 135 after open and 39 after arthroscopic Bankart procedure.

Results

Re-dislocations occurred in 8% after open and 15% after arthroscopic Bankart procedure. After open surgery 4 of the 11 re-dislocations occurred after a new adequate trauma and 1 of the 6 re-dislocations after arthroscopic surgery. Re-dislocations after arthroscopic procedure occured earlier than after open Bankart repair. An external rotation lag of 20° or more was observed more often (16%) after open than after arthroscopic surgery (3%). The Rowe score demonstrated "good" or "excellent" functional results in 87% after open and in 80% patients after arthroscopic treatment.

Conclusion

In this retrospective investigation the open Bankart procedure demonstrated good functional results. The arthroscopic treatment without capsular shift resulted in a better range of motion, but showed a tendency towards more frequently and earlier recurrence of instability. Sensitive patient selection for arthroscopic Bankart repair is recommended especially in patients with more than five dislocations.

Computer-assisted and conventional total knee replacement: a comparative, prospective, randomised study with radiological and CT evaluation

After obtaining informed consent, 80 patients were randomised to undergo a navigated or conventional total knee replacement. All received a cemented, unconstrained, cruciate-retaining implant with a rotating platform. Full-length standing and lateral radiographs and CT scans of the hip, knee and ankle joint were carried out five to seven days after operation. No notable differences were found between computer-assisted navigation and conventional implantation techniques as regards the rotational alignment of the femoral or tibial components. Although the deviation from the transepicondylar axis was relatively low, there was a considerable range of deviation for the tibial rotational alignment. There was no statistically significant difference regarding the occurrence pattern of outliers in mechanical malalignment but the number of outliers was reduced in the navigated group.

Birmingham Hip Resurfacing arthroplasty: short-term clinical and radiographic outcome

BACKGROUND

Aim of our study was to evaluate the clinical and radiographic outcome of the first 300 consecutively implanted Birmingham Hip Resurfacing arthroplasties (BHR) in our department.

METHODS

300 BHR arthroplasties were performed in 263 patients until May 2003. Primary clinical endpoints of the investigation were the implant survival and the total Harris hip score, assessed at the last examination.

RESULTS

At a median follow-up time of 24 months the Kaplan/Meier survivor estimate was 98%. 6 implant revisions were performed due to infection (2), malposition (1), femoral neck fracture (1), primary unstable cup (1) and chronic pain (1), respectively. The median Harris hip score improved from 51 points to 96 points at last follow-up. No hip showed radiographic signs of aseptic implant loosening.

CONCLUSIONS

The preliminary experience with the BHR for the younger adult requiring hip arthroplasty is encouraging, but has to be reproduced in the long-term.

[Clinical pathways. A useful steering instrument or a limitation for medical treatment?]

Clinical pathways can be used to organize the optimal sequence for medical procedures. This process is patient centered and developed through the collaborative work of the participating medical specialties. The goals of clinical pathways are facilitation of outcomes, reduction of variance in patient care and cost containment. Clinical pathways can be used for patient information, internal and external transparency and in total quality management. The management of medical organisations can be supported by introducing the data from clinical pathways into prospective clinical and financial control.

Komplikationen nach Laser-in-Situ-Keratomileusis (LASIK): Ergebnisse einer Metaanalyse zu Inzidenzen und Folgekosten

PURPOSE

Laser in situ Keratomileusis (LASIK) is considered to be safe and effective for the treatment of moderate myopia. Nevertheless, the treatment can result in complications, associated with additional costs for treatment of the latter and an associated reduction of the primary treatment's overall cost efficiency.

METHODS

To both identify clinically relevant LASIK-associated complications and to estimate their expectable incidence and treatment cost-profile, a quantitative meta-analysis of trial publications between 1995 - 2004 was implemented. Inclusion criteria were a minimum sample size of 25 eyes, a reported preoperative patient refraction between - 1 und - 14 dioptres and the documentation of an at least 6 months recall period. For each reported complication its "meta incidence" (point estimate and 95 % confidence interval) was estimated. Furthermore, for each complication a clinical pathway for its treatment was modelled assuming a worst case scenario; the treatment costs for this pathway were simulated. The resulting costs for the treatment of one complication were then averaged by the expectable incidence of the respective complication; the maximum "expectable" costs for the respective complication's treatment were then summed up to correct the overall LASIK direct costs.

RESULTS

A total of 30 trial reports was included into the meta-analysis; in total, 21 clinically relevant complications were identified (31 % intraoperative complications, among which 19 % were microkeratome-associated, versus 69 % postoperative complications, among which 87 % were classified as long-term postoperative). The most frequent complication was "light sensations" with a meta incidence of 46 % (95 % confidence interval 42 - 50 %), the most cost intensive complications were those requiring clinical re-treatment (overall meta incidence 24 % and expectable cost increase of 449 euro per primary LASIK procedure). In summary the total direct costs of 2426 euro per eye for the initial LASIK procedure may be increased by a total of maximum 648.30 euro, according to a maximum "expectable" cost increase of 27 % per primary LASIK due to complications.

CONCLUSION

At least the worst case scenario introduced into this investigation demonstrated an economically relevant order for the expectable LASIK complications and the associated additional costs for complication treatment.

Turned, Machined Versus Double-Etched Dental Implants In Vivo

BACKGROUND

Positive effects on the clinical outcome of moderately rough implant surfaces are described. Intercomparison of clinical data, however, is rarely found.

PURPOSE

The aim of this study was to compare the clinical results of two macroscopically identical implants, the one with a turned, machined and the other with an etched surface.

MATERIALS AND METHODS

In a retrospective cohort study, the included implants followed the criteria: standard surgical protocol, >12 months in situ; minimally rough self-threading implants with a turned, machined surface (Mk II Nobel Biocare AB, Göteborg, Sweden], n=210); etched implants of the same macrodesign (3i Implant Innovations Inc., Palm Beach Gardens, FL, USA], n=151), length > or = 10 mm. Clinical data and implant success were rated. Resonance frequency analysis (RFA) and Periotest (Siemens AG, Bensheim, Germany) were measured and related to the corresponding implant survival rate in the respective group.

RESULTS

The total number of implants was 361, of which 264 (73%) were subject to clinical reexamination. RFA and Periotest could be recorded in 25% of the implants. Neither clinically relevant nor statistically significant differences between the surface designs were found in the RFA (64 +/- 8.6 vs 63 +/- 9.7), in Periotest (-2 +/- 3.3 vs -1 +/- 5.1), and in mean survival periods (49 months, 95% confidence interval CI]: 46-51 months, for the turned vs 46 months, 95% CI: 43-49 months, for the double-etched implant). After osteoplastic procedures, a significantly higher rate of implant losses in the turned, machined implant group was observed (17 vs 1) with a mean survival period of 43 (40-46) months for the turned and 46 (45-48) months for the double-etched implants.

CONCLUSION

No difference between implants with two different minimally rough surfaces was found. A positive effect of surface roughness is observed in poor quality bone, but the pivotal proof of this effect is still lacking.

[Incremental cost effectiveness of multifocal cataract surgery]

PURPOSE

Supplementation of cataract patients with multifocal intraocular lenses involves an additional financial investment when compared to the corresponding monofocal supplementation, which usually is not funded by German health care insurers. In the context of recent resource allocation discussions, however, the cost effectiveness of multifocal cataract surgery could become an important rationale. Therefore an evidence-based estimation of its cost effectiveness was carried out.

METHODS

Three independent meta-analyses were implemented to estimate the gain in uncorrected near visual acuity and best corrected visual acuity (vision lines) as well as the predictability (fraction of patients without need for reading aids) of multifocal supplementation. Study reports published between 1995 and 2004 (English or German language) were screened for appropriate key words. Meta effects in visual gain and predictability were estimated by means and standard deviations of the reported effect measures. Cost data were estimated by German DRG rates and individual lens costs; the cost effectiveness of multifocal cataract surgery was then computed in terms of its marginal cost effectiveness ratio (MCER) for each clinical benefit endpoint; the incremental costs of multifocal versus monofocal cataract surgery were further estimated by means of their respective incremental cost effectiveness ratio (ICER). An independent meta-analysis estimated the complication profiles to be expected after monofocal and multifocal cataract surgery in order to evaluate expectable complication-associated additional costs of both procedures; the marginal and incremental cost effectiveness estimates were adjusted accordingly. A sensitivity analysis comprised cost variations of +/- 10 % and utility variations alongside the meta effect estimate's 95 % confidence intervals.

RESULTS

Total direct costs from the health care insurer's perspective were estimated 3363 euro, associated with a visual meta benefit in best corrected visual acuity and near visual acuity of 5.1 lines (95 % confidence interval 3.8 - 6.4 lines) and 6.1 lines (4.7 - 7.5 lines), respectively, and a meta predictability estimate of 81 % (72 - 89 %). The mean MCER for best corrected visual acuity results became 659 euro per gained visual acuity line (sensitivity range 473 - 973 euro). For near visual acuity, a mean MCER of 555 euro (sensitivity range 404 - 787 euro) per gained visual line was found. In terms of incremental costs, multifocal cataract surgery implied an additional mean investment of 63 euro (sensitivity range 0 - 234 euro) per additionally gained near visual acuity line, and 5 euro (0 - 18 euro) per additionally gained percentage point in predictability, when compared to monofocal cataract surgery as the standard treatment. The meta-analysis on complication profiles revealed posterior capsule opacification (meta incidence 20 %) and vitreous loss (meta incidence 2 %) as the complications to be expected most frequently. The cost adjustment for expectable complication patterns after multifocal cataract surgery implied total direct costs of 3491 euro, resulting in marginal costs of 576 euro per line (sensitivity range 419 - 817 euro per line) gained in near visual acuity and 684 euro per line (491 - 1011 euro per line) gained in best corrected visual acuity.

CONCLUSION

Bearing incremental costs of 63 euro per additionally gained vision line (near visual acuity) in mind, multifocal cataract surgery comprises a cost effective alternative to the monofocal standard treatment.

Ausgleich des kornealen Astigmatismus mit torischer Intraokularlinse: Ergebnisse der Multicenterstudie

This clinical trial was conducted to evaluate visual acuity, refraction and rotation after implantation of the foldable toric intraocular lens (IOL) MicroSil Toric.

PATIENTS AND METHODS

68 eyes of 48 patients from four different surgical departments were examined over a follow-up of three months after cataract surgery.

RESULTS

An individually produced IOL with cylindrical correction between 2.0 and 12.0 D was implanted in all eyes. Postoperatively, 68 % of the eyes achieved an uncorrected visual acuity (VA) of 0.5 or better, 12 % achieved 1.0 or better. A corrected VA of 0.5 or better was achieved by 85 %, 31 % achieved a corrected VA of 1.0 or better. Corrected VA improved by 3 (+/- 2) lines. The uncorrected VA improved by 6.0 lines in the mean. The increases in uncorrected and corrected VA were statistically significant (p < 0.001). The efficacy index amounted to 1.1 in the median and 1.3 (+/- 1.5) in the mean. Residual refraction (spherical equivalent) was 0.89 D (+/- 0.7 D) in the mean and was reduced by 5.14 D (+/- 4.78 D) in the mean. The total astigmatic error was reduced both in a statistically as well as in a clinically significant manner from 4.6 D (+/- 2.3 D) to 1.12 D (+/- 0.9 D) in the mean. 75 % of eyes needed a postoperative cylindrical correction of less than 1.5 D, 95 % less than 2.25 D. Corneal astigmatism was not changed significantly (p = 0,435). The surgically induced astigmatism (Naeser) amounted to 0.7 D in the median. In 85 % of the cases IOL rotation was less than 5 degrees. 15 % of the IOLs rotated more than 5 degrees, one IOL more than 10 degrees (max. 28 degrees). Patients ranked their surgical outcome on a scale from 1 (very good) to 6 (poor) which resulted in a mean score of 1.9 (+/- 1.0; min. 1.0; max. 5.0). No clinically relevant correlations of clinical parameters and satisfaction were detected.

CONCLUSION

Implantation of the foldable, toric IOL with Z-haptics decreased the refractive error and improved postoperative visual outcome. This IOL was suitable for low as well as for high astigmatism. IOL rotation was low during the follow-up of three months resulting in sufficient correction of the pre-existing astigmatism.

The comparison of clinical imaging devices with respect to parallel readings in both devices

OBJECTIVE

Many proposals for the comparison of diagnostic devices refer to the computation of ROC curves or sensitivity / specificity-based parameters, thereby strictly assuming the presence of a reliably parameterized clinical reference method. When none of the devices under consideration can be regarded as a reference, Cohen's kappa coefficient for assessing the methods' relative agreement becomes increasingly popular. If, however, not only the agreement between two diagnostic devices, but also the devices' reliability must be taken into account (for example, if multiple parallel readings are obtained from one or both of the devices), no corresponding coefficients can be obtained from standard software. Bearing the recent modifications in the German Medicinal Devices Law (Medizinproduktegesetz) in mind, such methods will soon become necessary and strongly demanded for the sake of immediate re-evaluation of previously certified medicinal devices.

METHODS

Generalizations of Cohen's kappa (kappa) for complex multi reader designs can be found by estimating weighted averages of the observed and expected agreement among subsets of parallel readings. A flexible, although instructive, strategy for designing kappa coefficients in the context of method comparison trials is proposed, which measures the two methods' overall agreement while correcting for each method's underlying inter / intra observer reliability. Cluster algorithms will be outlined, which allow to identify (in)compatible clusters of readings. Their application will be illustrated by means of the intraindividual comparison of two different strategies in radiographical imaging, where none of the underlying imaging methods can be regarded as a reference.

RESULTS

The algorithms are illustrated by the comparison of two radiological imaging devices R and F, where none of these imaging methods could be considered as a valid reference, i.e. replicate readings by three independent radiologists were taken from each device, respectively. The setting allowed for intraindividual comparison of the imaging methods, since each of the three involved radiologists took one reading from both devices on each of 120 individuals. The algorithm identifies a subset of compatible reading patterns with an overall agreement of kappa = 0.83 (95% confidence interval 0.78 - 0.88) despite the fact, that the underlying readings arose from two different imaging devices. An obvious interpretation suggests, that the gradient in experience between the readers was more relevant to their reading patterns' outcome than any difference between the imaging devices.

CONCLUSIONS

The generalized kappa coefficients can be modified according to the study design at hand to instructively identify (in)compatible clusters of multiple parallel reading patterns; the relative agreement of imaging methods can be estimated as well as each imaging method's internal reliability as assessed by parallel readings from the respective methods.

First experiences with DIN ISO 14835-1 in the context of vibration-induced white finger disease

OBJECTIVES

In order to establish an international standard of cold provocation test in the assessment of vibration-induced white finger (VWF) disease, an ISO-working group tentatively created the DIN ISO 14835-1. Based on this new standard, previously existing testing conditions had to be modified. Since a comparison of current and previous evaluation procedures is necessary for both the individual assessment and the performance of metaanalyses, the revision and validation of criteria for the examination of the cold provocation tests are appropriate and necessary.

METHODS

Twenty-one individuals suffering from VWF disease whose disorder was accepted as an occupational disease underwent the cold provocation test on two successive days following a 2- and a 5-min-long exposure to the cold. As a benchmark for classification as 'normal' or 'pathological', the 15-min mark after a 2-min-long exposure was chosen. A skin temperature of 28 degrees C was selected for discrimination between 'non-pathological' (at least 28 degrees C) and 'pathological' test results.

RESULTS

It could be shown, that exposures to cold water (12 degrees C) over 2 and 5 min lead to similar rewarming profiles, who differ in median systematically by 1 degrees C. A modification of the former classification rule should be considered. After a 5 min exposure, the classification criterion can be based on the temperature assessments measured after 20 min; alternatively the cut point can be reduced from 28 to 27 degrees C while maintaining the previous assessment time of t = 15 min.

CONCLUSIONS

The shown results represent the first attempt of modifying the previous classification criteria of the cold provocation test within the scope of the VWF disease. In view of the described problems of the study design there is no doubt that continuing modifications and their validation on the base of larger collectives groups are necessary.

Rotationsstabilität monofokaler Intraokularlinsen mit C-Haptik versus Z-Haptik nach Kataraktchirurgie

The aim of the study was to compare the rotational stability of intraocular lenses (IOLs) with C-loop haptics and those with Z haptics. A total of 50 patients with cataracts were prospectively randomised in equal numbers using a design equivalent to IOL MS 612 S (C-loop haptic) and MS 6120 (Z haptic, both HumanOptics, Erlangen). Complete ophthalmological examinations were performed including assessment of the IOL rotation after 1 day, 1 month and 3 months postoperatively. The significances between the groups were evaluated using the Wilcoxon test. The Fisher exact test was used for the primary finding of the study (rotation of at least 10 degrees ). The IOL group with the C-loop haptics showed a median lens rotation of 0 degrees on the first day and 2 degrees clockwise after 1 month and 3 months. In the Z haptic group, there was no median rotation in the IOL group. Moreover, the range of IOL rotation of the C-loop haptics was broader (3 months postoperatively: maximum in the C-loop haptics: 21 degrees with 15.5 degrees in the Z haptics). There was no significant difference at any time. At 3 months postoperatively, 32% of the C-loop haptic IOL and 16% of the Z haptic IOL rotated at least 10 degrees (P=0.32). In 59% of the IOL with C-loop haptics, the direction of the rotation was clockwise. This was 40% for the IOL with Z haptics (P=0.33). At 3 months postoperatively, both IOLs demonstrated good rotational stability with a low mean deviation from the target axis. IOLs with Z haptics showed a tendency to greater rotational stability than C-loop haptics but without any significant difference. There was no significant difference in visual rehabilitation.

Survival rate of endodontically treated teeth in relation to conservative vs post insertion techniques -- a retrospective study

AIMS AND METHODS

The purpose of this retrospective, non-randomised cohort study was to evaluate the success rate of 775 endodontically treated teeth depending on the restoration type. A total of 508 patients with 775 endodontically treated teeth were examined during at least 12 months. The radiographic controls, time span between root canal filling and definitive restoration, restoration material type, inserted post system type and the occurrence of possible endodontically as well as restorative post-operative complications were recorded.

RESULTS

18.3% of the 775 investigated teeth were incisors and canines, 33.5% were premolars and 48.2% molars. Pre-fabricated and casted metal post systems were used only in 15.6% of the endodontically treated teeth (18.4% incisors and canines, 44.8% premolars, 36.8% molars). 6.6% of the teeth had endodontically related symptoms or severe complications, whereas in 13.2% of the teeth restored with metal posts showed complications, such as root or crown fractures. The Cox-Regression analysis showed that teeth restored with a post system had a statistically significant higher failure rate (p = 0.044) than those which had been restored without posts.

CONCLUSIONS

The results showed a high success rate for endodontically treated teeth when the final restoration was placed within a short period of time (two weeks). A higher tooth loss was observed when metal post systems were employed suggesting that precaution is recommended when these types of posts are inserted.

Anteil des frühen systolischen Flussanstiegs am antegrad fließenden Gesamtvolumen bei Phasenkontrast-Flussmessungen in Atemanhaltetechnik

PURPOSE

To evaluate the contribution of early systole for the assessment of antegrade aortic flow volume by breath-hold velocity-encoded magnetic resonance (MR) flow measurements.

MATERIALS AND METHODS

Expiratory breath-hold fast low-angle shot (FLASH) phase-contrast flow measurements (temporal resolution tRes 61 msec, shared phases) perpendicular to the proximal ascending aorta and short axis true fast imaging with steady-state precession (TrueFISP) cine MR ventriculometry (tRes 34.5 msec) were performed in ten healthy male volunteers on a 1.5 T MR system (Sonata, Siemens Medical Solutions). Antegrade aortic flow volume (AFV) and left ventricular stroke volume (LV-SV) were evaluated using Argus Ventricular Function and Argus Flow Software, version MR 2002B (Siemens Medical Solutions). A beta release of Argus Flow MR 2004A allowed interpolation of the flow up-slope during early systole to the preceding R-wave trigger. The respective intraindividual median differences between the AFV of each flow evaluation and LV-SV as well as between both AFV measurements were calculated and compared using the sign test for paired samples.

RESULTS

Non-interpolated AFV significantly deviated from LV-SV (p = 0.006), underestimating the latter by 13.1 mL (13 %). Interpolating aortic flow during early systole significantly increased AFV by 10.8 mL (13 %) compared to the flow evaluation which did not take early systole into account (p = 0.006). AFV with interpolation of early systolic flow agreed well with LV-SV (median difference - 3.0 mL or - 3 %, respectively), and no significant difference between these measurements was found (p = 1.0).

CONCLUSION

Flow during early systole contributes substantially to total forward flow volume in the ascending aorta. Interpolation of the early systolic up-slope is therefore recommended for the evaluation of breath-hold phase-contrast flow measurements.

Systematische Analyse der Geometrie eines definierten Kontrastmittelbolus - Implikationen für die kontrastmittelverstärkte 3D-MR-Angiographie thorakaler Gefäße

PURPOSE

Little is known about the dispersion of a defined contrast bolus during its passage through the heart and pulmonary vasculature. The purpose of this study was to analyze factors influencing a defined contrast bolus for ce-MRA of thoracic vessels.

MATERIALS AND METHODS

For analysis of bolus geometry, an ECG-gated saturation-recovery Turbo-Flash sequence with a TI of 20 msec was used. It was acquired axially at the level of the pulmonary trunc, so that with one data acquisition a curve analysis was possible in the ascending and descending aorta, and in the pulmonary trunc. Twenty-nine patients received 3 ml of Gd-DTPA diluted with saline to a total of 20 ml. Contrast injection was done using a MR compatible power injector with injection rates varying between 1, 2 and 4 ml/sec. Each injection was followed by a saline flush of 20 ml with the same injection rate and mode. Cardiac function was assessed by cine imaging, and phase contrast measurements. After normalization to baseline signal intensity (SI), bolus curves were fitted using a gamma-variate fit and peak signal intensity (peak SI), time-to-peak (TP), upslope, mean transit time (MTT) and dispersion of the contrast bolus were calculated. Furthermore, T (1) and [Gd] in the experimental setting were calculated as follows: T (1) = T (1 o)/ ln [SI/SI (0)], and [Gd] (exp) = [1/T (1) - 1/T (1 o)]/ R (1.) They were then extrapolated [Gd] to clinical conditions by [Gd] (clin) = [Gd] (exp) . 10/1.5, and minimal blood T (1) by T (1)(clin) = 1 / [1/T (1 o) + R (1) [Gd] (clin)].

RESULTS

With increasing injection rate, there was a significant decrease (p < 0.001) of MTT in all target vessels. However, this decrease was not linear: a 4-fold increase in injection rate lead to a 2-fold decrease in MTT e. g. in the ascending aorta. MTT was significantly shorter in the pulmonary trunc compared with that in the ascending and descending aorta (p < 0.001), regardless of injection rate (p < 0.001). Vice versa, dispersion of the contrast bolus was significantly lower in the pulmonary trunc, and increased with higher injection rates. There was no clinically relevant difference in minimal blood T (1) between the different target vessels, for clinical conditions extrapolated values ranged between 20 und 79 msec. Heart function parameters only had a minor influence of bolus curve parameters.

CONCLUSION

Analysis of bolus geometry enables determination of transit times of a defined contrast bolus through a defined target vessel in the thoracic cavity. Bolus geometry is mainly determined by injection parameters, cardiac function is of minor importance. Dispersion of contrast bolus and MTT increase from the pulmonary trunc to the ascending aorta. The knowledge of these facts may help optimizing of injection parameters and the total amount of contrast agent for contrast-enhanced MRA of thoracic vessels.

Transpalpebral tonometry: reliability and comparison with Goldmann applanation tonometry and palpation in healthy volunteers

BACKGROUND/AIM

TGDc-01 is a new, portable, transpalpebral tonometry device. The aim of this study was to evaluate the reproducibility of this method, including intraobserver and interobserver deviations, and to compare the results with those of Goldmann applanation tonometry and palpation of intraocular pressure (IOP).

METHODS

A total of 40 eyes of 20 healthy volunteers were included. Two independent parallel observers (1 and 2) performed three replicate measurements per eye, respectively, both using TGDc01 tonometry, one observer (3) performed three replicate measurements using Goldmann applanation tonometry, and one observer (4) measured the IOP via palpation. Intraindividual deviations within and between both observers using TGDc-01 tonometry and between all three methods were investigated about clinically relevance by comparison of medians and quartiles, statistically significance by pairwise sign tests. Comparisons between observers and methods were based on averaged IOP values of the three individual measurements for each observer and each patient. Intraobserver deviations were analysed by means of Friedman tests.

RESULTS

Observers 1 and 2 showed a statistically significant intraobserver deviation when using TGCc-01 (Friedman p = 0.007 for observer 1 and p = 0.002 for observer 2). There was no statistically significant interobserver deviation between observers 1 and 2 (sign test p = 0.200); however, in 45% of the eyes interobserver deviations were larger than plus or minus 3 mm Hg. The median intraindividual deviation between TGDc-01 and Goldmann (TGDc-01 minus Goldmann) was 0 mm Hg (interquartile range -1; 2 mm Hg; sign test p = 0.522); but deviations were larger than plus or minus 3 mm Hg for 38% of the 40 eyes. Median intraindividual deviation between TGDc-01 and palpation (TGDc-01 minus palpation) was -2 mm Hg (interquartile range -4; 1 mm Hg; sign test p = 0.018), but deviations were larger than plus or minus 3 mmHg for 43% of eyes. Median intraindividual deviation between Goldmann and palpation (palpation minus Goldmann) was 2 mm Hg (interquartile range -2; 4 mm Hg; p = 0.429), but deviations were larger than plus or minus 3 mm Hg in 48% of the eyes.

CONCLUSION

Interobserver deviations using TGDc-01 tonometry and intraindividual deviations between TGDc-01 tonometry, Goldmann applanation tonometry, and palpation of IOP were found to be clinically relevant. Thus, according to our results TGDc-01 could not be established as a substitute or diagnostic alternative method for Goldmann applanation tonometry. But as deviations between TGDc01 and Goldmann turned out smaller than between palpation of IOP and Goldmann, TGDc-01 seems to provide a better choice for tonometry in patients, in whom Goldmann applanation tonometry is not possible.

Epidemiological and health economical evaluation of intraoperative antibiosis as a protective agent against endophthalmitis after cataract surgery

OBJECTIVE

To evaluate risk factors for endophthalmitis after cataract surgery and to retest recent findings on the protective effect of intraoperative antibiosis and the promoting effect of the clear corneal as compared to sclerocorneal incision. In addition, the economics of intraocular intraoperative antibiosis as a prophylaxis in cataract surgery are asketched.

DESIGN

Survey study.

PARTICIPANTS

Five hundred thirty-eight ophthalmosurgical centres in Germany.

MAIN OUTCOME MEASURE

epidemiological evaluation: responder specific endophthalmitis incidence in year 2000; economical evaluation: direct cost analysis based on incidence data and local cost estimates (health service's perspective).

RESULTS

A total of 310 (58%) questionnaires were computed resulting in an overall count of 404,356 cataract surgeries and 291 self-reported endophthalmitis cases (crude rate 0.072%). The risk of postoperative endophthalmitis for sclerocorneal versus clear corneal incisions was not significantly reduced (relative risk 0.97, 99% confidence interval 0.69-1.38). The hypothesis of a protective effect of intraocular antibiosis could be confirmed by a significantly decreased risk ratio of 0.69 (99% confidence interval 0.48-0.99) indicating a significant benefit from intraoperative intraocular antibiosis. A similar tendency was observed for an intraoperative periocular antibiosis with a significantly reduced risk ratio of 0.68 (99% confidence interval 0.49-0.96). These risk estimates had been adjusted for the size of the surgical centre: a significantly reduced risk ratio of 0.70 (99% confidence interval 0.49-0.98) for postoperative endophthalmitis was observed for local centres. Cost evaluation for the prophylactic use of intraocular intraoperative antibiosis in cataract surgery revealed an economically relevant decrease in direct endophthalmitis associated costs.

CONCLUSIONS

Whereas this 2000 appraisal of a recent survey in 1996 could not reproduce the benefit of sclerocorneal incision, the protective effect of intraoperative intraocular antibiotic prophylaxis could be confirmed. However, the results of this survey have to be interpreted with care, since it is not based on individual case information, but rather on aggregate questionnaire data.

Osteosynthese von Oberarmkopffrakturen

BACKGROUND

Intramedullary nails and angle-fixed plates have recently been used in proximal humerus fractures. Rigid implants might be associated with an increased risk of failure in osteoporotic conditions.

METHODS

Unstable fractures of the surgical neck were created in 24 pairs of human humeri. The biomechanical properties of four implants were analysed. These were a nail with conventional interlocking (PHN-K), a nail with spiral blade interlocking (PHN-S), the T-plate, and an internal fixator with elastic screw properties (reference). The specimens were subjected to axial loading and torque. Stiffness, plastic deformity, and load to failure were assessed.

RESULTS

The PHN-S was stiffer than the internal fixator. The PHN-K and T-plate were stiffer only during torque. Less subsidence was observed for the PHN-S. This implant failed at higher loads than the other implants.

CONCLUSIONS

The PHN-S offers biomechanical advantages in unstable fractures of the surgical neck of the humerus. Elastic implant properties, however, are disadvantageous.

Cumulative incidence rates of the mucopolysaccharidoses in Germany

In order to estimate the cumulative incidence rates of the mucopolysaccharidoses (MPS) in Germany, a retrospective epidemiological survey covering the period between 1980 and 1995 was implemented. Multiple ascertainment sources were used to identify affected patients. A prevalence of approximately 0.69 cases per 100,000 births was obtained for MPS I (Hurler phenotype). Within the study period, 4 patients with Hurler/Scheie phenotype and 7 cases with Scheie disease were detected. The cumulative incidence for MPS II (Hunter syndrome) was estimated as 0.64 cases per 100,000 births (1.3 cases per 100,000 male live births); that for MPS III (Sanfilippo syndrome types A, B and C) as 1.57 cases in 100,000 births; that for MPS IV A (Morquio syndrome) as 0.38 cases in 100,000; and that for MPS VI (Maroteaux-Lamy syndrome) as 0.23 cases per 100,000 births. Two cases of MPS IVB (beta-galactosidase deficiency) have been identified, but no patients with MPS VII or MPS IX. A relatively high number of patients with MPS IIIB, MPS IVA and MPS VI were of Turkish origin. The crude rate for all types of mucopolysaccharidoses is approximately 3.53 cases in 100,000 live births. The cumulative incidence pattern of MPS in Germany was compared with the corresponding rates among other industrial nations obtained from recent literature: the crude cumulative rates for all types of mucopolysaccharidoses (3.4-4.5 in 100,000 live births) were similar among all published populations; however, different frequencies of the various forms of MPS were observed.