[Structural differences between health insurance funds and their impact on health services research: results from the Bertelsmann Health-Care Monitor]

AIM

Claims data of health insurance companies are an important database for health services research. We investigated if there are differences in baseline characteristics and prevalence of chronic diseases between members of several health insurance funds in Germany, and if so, whether adjusting for age and sex could explain these differences.

METHODS

10 representative surveys (conducted between 2004 and 2008) of the 'Bertelsmann Health-Care Monitor' comprising 15 089 participants aged 18 to 79 years were analysed. Our main independent variable was membership in one of 8 health insurance funds. The prevalence of self-reported hypertension, diabetes, atopic diseases, coronary heart disease and heart failure was studied. We first estimated the crude prevalence of chronic diseases stratified by these funds. We further fitted logistic regression models and adjusted for age and sex as well as for further comorbidities and health related factors.

RESULTS

Most respondents were insured in the BKK (Betriebskrankenkassen; 20.1%), the AOK (Allgemeinen Ortskrankenkassen; 19.2%) and private health insurances (15.3%). Substantial differences were found according to age, sex, educational level and prevalences of chronic diseases. Stratified by health insurance funds, prevalences ranged between 17.1-29.6% for hypertension, between 3.9-11.4% for diabetes, between 4.3-6.7% for atopic diseases, between 3.4-6.7% for coronary heart disease and between 2.6-5.7% for heart failure. When adjusting for sex and age, estimates for all 5 diseases were significant higher in AOK members compared to privately insured persons (3 diseases within the BAMER and the DAK, accordingly). In total, this was the case for 17 out of 35 comparisons. Even after adjusting for further comorbidities and health related factors 6 out of 35 comparisons showed significant increased estimates compared to privately insured persons.

CONCLUSION

We found considerable differences in the prevalence of chronic diseases between German health insurance funds that remained after controlling for age and sex, and even after adjustment for further health-related variables. Further methodological studies are urgently needed to assess strengths and weaknesses of German claim data.

[Urology needs health services research: the case of small renal tumours]

The central tasks of health services research include the description and analysis of health care under everyday conditions as well as the development and evaluation of new concepts. As a first step, the reality of the health services' situation should be assessed using representative data. For that, registries, claims data of health insurance funds or observational studies are suitable. To investigate specific patterns or decisions, qualitative methods are of importance. To evaluate the effectiveness of health care concepts or structures, pragmatic randomized, controlled trials are considered to provide the best evidence. In this paper we discuss these questions on the basis of treatment for patients with small renal masses. Although recent guidelines recommend nephron-sparing surgery instead of radical nephrectomy for these patients, international studies suggest that there is a significant underuse of nephron-sparing procedures. However, national data describing the situation in Germany are necessary to analyse reasons and to develop new concepts which subsequently have to be tested in randomized trials. Therefore, the aim of health services research is to create a scientific basis for continuous improvements in health care. Urology needs health services research and we should find ways to overcome barriers to improve quality of care.

Immortal time bias and survival in patients who self-monitor blood glucose in the Retrolective Study: self-monitoring of Blood Glucose and Outcome in Patients with Type 2 Diabetes (ROSSO)

AIMS/HYPOTHESIS

In the February 2006 issue of Diabetologia, the observational Retrolective Study: Self-monitoring of Blood Glucose and Outcome in Patients with Type 2 Diabetes (ROSSO) reported a 51% reduction in the risk of all-cause mortality in patients with type 2 diabetes who performed self-monitoring of blood glucose (SMBG). However, these impressive benefits conflict with results from observational studies and randomised controlled trials. We aimed to show that these findings are caused by a flawed design that introduced immortal time bias.

METHODS

We illustrate the bias in the ROSSO study and demonstrate that it is large enough to completely explain the apparently protective effect of SMBG on all-cause mortality.

RESULTS

In the ROSSO study, patients were classified as exposed to SMBG for their whole follow-up time if they performed self-monitoring for at least 1 year during the study period. Thus, the time between cohort entry and the date after 1 year self-monitoring was performed is unavoidably 'immortal' for patients with SMBG. Patients had to survive at least 1 year to be classified as exposed to this intervention and were artificially 'protected' from death. Based on published information, the total amount of misclassified immortal person-time in the SMBG group is at least 5,082 of 9,248 person-years at risk (55%). After re-classification of immortal person-time as unexposed, the unadjusted relative risk changed from 0.59 to 1.95.

CONCLUSIONS/INTERPRETATION

The apparently protective effect of SMBG on all-cause mortality observed in the ROSSO study is completely explained by immortal time bias.

Successful long-term correction of autosomal recessive hyper-IgE syndrome due to DOCK8 deficiency by hematopoietic stem cell transplantation

Autosomal dominant hyper-IgE syndrome (AD-HIES), characterised by eczema, increased susceptibility to skin and lung infections, elevated IgE and skeletal abnormalities is associated with heterozygous STAT3 mutations. The autosomal recessive variant (AR-HIES) has similar immunological findings but mainly lacks extraimmune manifestations. Several AR-HIES patients have recently been shown to harbour mutations in the gene for dedicator of cytokinesis 8 (DOCK8). Here, we present the long-term outcome of a girl having received a hematopoietic stem cell graft for an at that time genetically undefined combined immunodeficiency associated with severe eczema, multiple food allergies, excessively elevated serum IgE levels and eosinophilia. She was recently found to carry a homozygous nonsense mutation in the DOCK8 gene. HSCT resulted in complete immunological correction, even though mixed donor chimerism occurred. Clinically, the outcome was characterised by disappearance of skin manifestations and severe infections, improvement of pulmonary function and constant decline of IgE levels. Outcome in untransplanted DOCK8 deficient patients is poor because of frequent life-threatening infections, CNS bleeding and infarction, and increased susceptibility to malignancy. This argues for early curative therapeutic approaches, supported by this report of successful long-term outcome after HSCT.

Home-based subcutaneous immunoglobulin G replacement therapy under real-life conditions in children and adults with antibody deficiency

Background

Subcutaneous immunoglobulin (SCIG) therapy is an alternative to intravenous immunoglobulin (IVIG) therapy.

Methods

We evaluated the efficacy and safety of the SCIG Vivaglobin^® (formerly known as Beriglobin^® SC) under real-life conditions in a post-marketing observational study in 82 patients with primary or secondary antibody deficiencies. Health-related quality of life (HRQoL) was evaluated in a subset of 30 patients previously treated with IVIG (including 11 children < 14 years) using the Short Form 36 (SF-36) for patients ≥ 14 years of age (adults) and the Child Health Questionnaire - Parental Form 50 (CHQ-PF50) for children < 14 years of age. Treatment preferences were assessed in adults.

Results

The mean serum immunoglobulin G (IgG) trough level during SCIG treatment (7.5 g/L) was higher than during previous IVIG treatment (6.6 g/L; p < 0.01). The investigators assessed the efficacy of SCIG therapy as "excellent" in 89% of patients. No systemic adverse drug reactions were observed. Improvements by ≥ 5 points were observed in 5 of 8 SF36 subscales and in 6 of 12 CHQ-PF50 subscales. Statistically significant improvements (p ≤ 0.05) were observed for the SF-36 subscales of bodily pain, general health perceptions, and vitality (adults), and for the CHQ-PF50 subscales of general health perceptions, parental impact - time, parental impact - emotional, and family activities (children). Patients preferred SCIG over IVIG therapy (92%) and home therapy over therapy at the clinic/physician (83%).

Conclusion

This study confirms that therapy with Vivaglobin^® at home is effective, safe, well tolerated, and improves quality of life in patients with antibody deficiency.

Fatigue, sleepiness, and physical activity in patients with multiple sclerosis

Fatigue is a frequent and disabling symptom in patients with multiple sclerosis (MS). The objective of the study was to compare fatigue and sleepiness in MS, and their relationship to physical activity. Eighty patients with MS rated the extent of experienced fatigue (Fatigue Severity Scale, FSS) and sleepiness (Epworth Sleepiness Scale, ESS). The relationship between the scales was analysed for the scales as a whole and for single items. The clinical status of the patients was measured with the Extended Disability Status Scale (EDSS). In addition, physical activity was recorded continuously for 1 week by wrist actigraphy. The mean scores of fatigue and sleepiness were significantly correlated (FSS vs. ESS r=0.42). Single item analysis suggests that fatigue and sleepiness converge for situations that demand self-paced activation, while they differ for situations in which external cues contribute to the level of activation. While fatigue correlated significantly with age (r=0.40), disease severity (EDSS, r=0.38), and disease duration (r=0.25), this was not the case for sleepiness. Single patient analysis showed a larger scatter of sleepiness scores in fatigued patients (FSS>4) than in non-fatigued patients. Probably, there is a subgroup of MS patients with sleep disturbances that rate high on ESS and FSS. The amount of physical activity, which was measured actigraphically, decreased with disease severity (EDSS) while it did not correlate with fatigue or sleepiness.

Dimethyl sulfoxide can initiate cell divisions of arrested callus protoplasts by promoting cortical microtubule assembly

A serious problem in the technology of plant cell culture is that isolated protoplasts from many species are reluctant to divide. We have succeeded in inducing consecutive divisions in a "naturally" arrested system-i.e., protoplasts from a hibiscus cell line, which do not divide under standard conditions-and in an artificially arrested system-i.e., colchicine-inhibited callus protoplasts of Nicotiana glutinosa, which do readily divide in the absence of colchicine. In both cases, the reinstallation of a net of cortical microtubules, which had been affected either by colchicine or by the protoplast isolation procedure, resulted in continuous divisions of the formerly arrested protoplasts. Several compounds known to support microtubule assembly in vitro were tested for their ability to promote microtubule assembly in vivo. Best results were obtained by addition of dimethyl sulfoxide to the culture medium. Unlimited amounts of callus could be produced with the dimethyl sulfoxide method from protoplasts which never developed a single callus in control experiments.

Unicondylar knee replacement with a new tensioner device: clinical results of a multicentre study on 168 cases

INTRODUCTION

Ligament balancing is an established surgical technique in total knee arthroplasty with good clinical results. A similar technique for unicondylar knee arthroplasty was developed. The aim of this study was to asses the outcomes of a unicondylar knee replacement implanted with a ligament tensor.

MATERIALS AND METHODS

A prospective multicentre study of 168 medial compartment unicondylar knee prosthesis with a minimum follow-up of 2 years. Clinically, the knee society score was recorded. For subjective assessment, the visual analogue scale (VAS) for pain and satisfaction was used. Radiographic analysis was performed to determine radiolucent lines. The surgical technique was based on a ligament-orientated procedure. With this technique, the femoral orientation, flexion/extension gaps and limb alignment is determined with a unique ligament tensor.

RESULTS

The total KSS increased from 110.9 +/- 27.5 points preoperative to 176.5 +/- 21.1 points after 24 months. VAS for pain decreased from 6.0 +/- 1.9 preoperative to 2.8 +/- 1.7 after 24 months. VAS for satisfaction increased in the same period from 4.3 +/- 1.9 to 8.9 +/- 1.7. Four tibia implants had thin continuous radiolucent lines. Nine adverse events are reported. One patient died of unrelated causes. Five polyethylene inlays dislocated, one of five dislocated due to a fall. Three unicondylar knee prostheses were revised to a total knee arthroplasty, one because of undiagnosed pain, one for infection and one for femoral component malalignment.

CONCLUSION

We have demonstrated the efficacy of a tension-controlled ligament-balanced surgical technique for unicompartmental knee prosthesis that gives satisfying and reproducible short-term results.

A novel technique for selective NF-kappaB inhibition in Kupffer cells: contrary effects in fulminant hepatitis and ischaemia-reperfusion

BACKGROUND AND AIMS

The transcription factor nuclear factor kappa B (NF-kappaB) has risen as a promising target for anti-inflammatory therapeutics. In the liver, however, NF-kappaB inhibition mediates both damaging and protective effects. The outcome is deemed to depend on the liver cell type addressed. Recent gene knock-out studies focused on the role of NF-kappaB in hepatocytes, whereas the role of NF-kappaB in Kupffer cells has not yet been investigated in vivo. Here we present a novel approach, which may be suitable for clinical application, to selectively target NF-kappaB in Kupffer cells and analyse the effects in experimental models of liver injury.

METHODS

NF-kappaB inhibiting decoy oligodeoxynucleotides were loaded upon gelatin nanoparticles (D-NPs) and their in vivo distribution was determined by confocal microscopy. Liver damage, NF-kappaB activity, cytokine levels and apoptotic protein expression were evaluated after lipopolysaccharide (LPS), d-galactosamine (GalN)/LPS, or concanavalin A (ConA) challenge and partial warm ischaemia and subsequent reperfusion, respectively.

RESULTS

D-NPs were selectively taken up by Kupffer cells and inhibited NF-kappaB activation. Inhibition of NF-kappaB in Kupffer cells improved survival and reduced liver injury after GalN/LPS as well as after ConA challenge. While anti-apoptotic protein expression in liver tissue was not reduced, pro-apoptotic players such as cJun N-terminal kinase (JNK) were inhibited. In contrast, selective inhibition of NF-kappaB augmented reperfusion injury.

CONCLUSIONS

NF-kappaB inhibiting decoy oligodeoxynucleotide-loaded gelatin nanoparticles is a novel tool to selectively inhibit NF-kappaB activation in Kupffer cells in vivo. Thus, liver injury can be reduced in experimental fulminant hepatitis, but increased at ischaemia-reperfusion.

[Use of zolpidem and zopiclone on private prescriptions between 1993 and 2007]

OBJECTIVE

Aim of this study was to analyse the amount of so-called private prescriptions of zolpidem and zopiclone (Z drugs) over a 15-year period in Germany. Any doctor can prescribe drugs privately. Private prescriptions are fully funded by the patients. At present the total number of doctors' prescriptions in Germany is undocumented because this information is not recorded in insurance claims data. This may be one reason why physicians prescribe drugs that are associated with abuse and dependence (such as Z drugs) more frequently on private prescriptions.

METHODS

We compared utilization data from statutory health insurance claims with the purchasing statistics from public pharmacies over the years 1993-2007.

RESULTS

Throughout the study period, purchases of zolpidem and zopiclone increased from 1.4 million to 3.7 million packages and 0.8 million to 3.9 million packages, respectively. A constantly rising proportion of private prescriptions for zolpidem resp. zopiclone were issued between 1993 (+6% resp. +6%), 1999 (+43% resp. +34%), and 2007 (+122% resp. +72%).

CONCLUSION

Since their approval in Germany, zopiclone and especially zolpidem have frequently been dispensed on private prescriptions.