The aim of this study was to evaluate a case-mix system to classify inpatients with mental disorders in Germany by means of self-report and expert-rated instruments. The use of case-mix systems enhances the transparency of performance and cost structure and can thus improve the quality of mental health care. We analysed a consecutive sample of 1677 inpatients with mental disorders from 11 hospitals using regression tree analysis. The model assigns patients to 17 groups, accounting for 17% of the variance for duration of stay. Patients with eating disorders had a longer duration of stay than patients with anxiety disorder, duration of mental illness of less than 3–5 years, lower levels of interpersonal problems and higher occupational position. The results showed that besides diagnosis, variables such as duration of illness and interpersonal problems are important for classifying inpatients with mental disorders. The results of the study should be critically reviewed regarding the empirical results of other studies and the appropriateness of case group concepts for inpatients with mental disorders.

While we know that upcoding of diagnosis-related groups (DRGs) regularly occurs, we have little knowledge of the role of the technical features of coding systems in inducing coding behaviour. This paper presents methods for investigating the financial structure of the Dutch DRG system, and more in particular the grouper software, to gain such insight. The paper describes a system for investigating the robustness of the reward structure, by simulating the response of the DRG system to small changes in individual coding. The results from these analyses are used to visualise some data on coding behaviour, and to investigate how this behaviour is affected by incentives in the technical features of the DRG system. A number of technical weaknesses in the system are also identified.

Dorsal root ganglia (DRG) respond to peripheral nerve injury by up-regulating nitric oxide (NO) production by neurons and glia in addition to local fibroblasts, endothelium and macrophages. We hypothesise that NO produced from these cells has specific roles. We have shown that when neuronal NO synthase (nNOS) is blocked in axotomised DRG, neurons undergo degenerative changes (Thippeswamy et al., 2001, 2007a). Further, we demonstrated that increased neuronal NO production, in response to axotomy/growth factor-deprivation in vitro, signals glial cells to produce trophic factors to support neuronal survival (Thippeswamy et al., 2005a). Recently, we found that treating satellite glia–neuron co-cultures with nNOS inhibitor, 7-nitroindazole (7NI), decreases the number of nestin+ cells that show neuron-like morphology. Cultured/axotomised DRG also upregulate inducible NOS (iNOS) in non-neuronal cells. Therefore, it is plausible that degenerative changes following nNOS inhibition are also due to iNOS-mediated excessive NO production by non-neuronal cells, which indeed is cytotoxic. NG-nitro-l-arginine methylester (L-NAME), the pan NOS inhibitor did not significantly change nNOS+ neuron number in axotomised DRG compared to 7NI suggesting that iNOS-mediated NO contributes to the degenerative process. In this paper, these findings from our and others' past work on NO-mediated neuron–glia signalling in axotomised DRG are discussed.

The extension and directionality of neurite outgrowth are key to achieving successful target connections during both CNS development and during the re-establishment of connections lost after neural trauma. The degree of axonal elongation depends, in large part, on the spatial arrangement of astrocytic processes rich in growth-promoting proteins. Because astrocytes in culture align their processes on exposure to an electrical field of physiological strength, we sought to determine the extent to which aligned astrocytes affect neurite outgrowth. To this end, dorsal root ganglia cells were seeded onto cultured rat astrocytes that were pre-aligned by exposure to an electric field of physiological strength (500 mV mm−1). Using confocal microscopy and digital image analysis, we found that neurite outgrowth at 24 hours and at 48 hours is enhanced significantly and directed consistently along the aligned astrocyte processes. Moreover, this directed neurite outgrowth is maintained when grown on fixed, aligned astrocytes. Collectively, these results indicate that endogenous electric fields present within the developing CNS might act to align astrocyte processes, which can promote and direct neurite growth. Furthermore, these results demonstrate a simple method to produce an aligned cellular substrate, which might be used to direct regenerating neurites.

Objectives: Calculations of healthcare costs rarely disclose the specific approach used to allocate the cost of hospitalizations by diagnosis. However, the type of approach used can have a major impact on the findings in the case of significant comorbidities. The present analyses compared three approaches for attributing Medicare DRG reimbursements (which were used as surrogates for average costs) for hospitalization by diagnosis.

Methods: Medical resource utilization data from the National Hospital Discharge Survey were analyzed using each of three allocation approaches: a) attributing 100% of the cost of hospitalization to the disease when it was the first-listed diagnosis; b) attributing a portion of the cost of hospitalization to the disease, depending on its position in the list of diagnoses and the relevance of any comorbidities; and c) an incremental analysis of cost based upon the hospitalization experiences of an age and gender matched cohort. These three approaches were applied to the cost of hospitalization for chronic obstructive pulmonary disease (COPD).

Results: The first approach projected 206,098 hospitalizations at $3,449 per hospitalization for a projected U.S. annual total of $711 million. The second approach projected 681,547 hospitalizations at $3,205 per hospitalization for a projected U.S. annual total of $2.2 billion. The third approach also projected 681,547 hospitalizations, but at $2,361 per hospitalization, for a projected U.S. annual total of $1.6 billion.

Conclusions: Expanding from the example on COPD, the limitations of each approach are described and their applications to other conditions are presented.