Economic evaluation of chronic disease self-management for people with diabetes: a systematic review

AIMS

To systematically review the evidence on the costs and cost-effectiveness of self-management support interventions for people with diabetes.

BACKGROUND

Self-management support is the provision of education and supportive interventions to increase patients' skills and confidence in managing their health problems, potentially leading to improvements in HbA_1c levels in people with diabetes.

METHODS

Randomized controlled trials, observational studies or economic modelling studies were eligible for inclusion in the review. The target population was adults with diabetes. Interventions had to have a substantial component of self-management support and be compared with routine care. Study quality was evaluated using the Consensus on Health Economic Criteria and International Society of Pharmacoeconomic Outcomes Research questionnaires. A narrative review approach was used.

RESULTS

A total of 16 costing and 21 cost-effectiveness studies of a range of self-management support interventions were identified. There was reasonably consistent evidence across 22 studies evaluating education self-management support programmes suggesting these interventions are cost-effective or superior to usual care. Telemedicine-type interventions were more expensive than usual care and potentially not cost-effective. There was insufficient evidence regarding the other types of self-management interventions, including pharmacist-led and behavioural interventions. The identified studies were predominantly of poor quality, with outcomes based on short-term follow-up data and study designs at high risk of bias.

CONCLUSIONS

Self-management support education programmes may be cost-effective. There was limited evidence regarding other formats of self-management support interventions. The poor quality of many of the studies undermines the evidence base regarding the economic efficiency of self-management support interventions for people with diabetes.

The value of routine MR myelography at MRI of the lumbar spine

Purpose: To determine whether a commercially available automated MR myelogram sequence improves the interpretation and diagnostic yield at MRI of the lumbar spine.

Material and Methods: A total of 207 consecutive patients referred for MR examination of the lumbar spine for evaluation of low back pain or spinal radicular symptoms were included for study. All patients had initial imaging with sagittal T1-W and T2-W scans, followed by axial T2-W images. Subsequently an MR myelogram was acquired in each case in coronal, sagittal and oblique planes. MR myelogram images were evaluated initially and a diagnosis was established and recorded. Subsequently, a diagnosis was established by review of conventional images of the lumbar spine in sagittal and axial planes, in conjunction with the MR myelogram. The utility of the MR myelogram in establishing the diagnosis was graded on a 4-point scale, where grade 0 indicated that it contributed no additional information and grade 3 indicated that it was essential for diagnosis. Analysis of the additional value of myelography in patients with multilevel disease was made.

Results: Primary diagnoses were disc herniation in 69 cases (33%), degenerative disc disease in 51 cases (26%), spinal stenosis in 19 cases (9%), isolated lateral recess stenosis in 5 cases (2%), or other diagnoses, including facet degeneration in 48 cases (23%). Scans were normal in 15 cases (7%). MR myelography was graded as grade 0 in 151 cases (73%), grade 1 in 44 cases (21%) and grade 2 in 12 cases (6%). In no case was MR myelography essential for diagnosis (grade 3). In patients with multilevel disease (n = 27), in 17 cases MR myelography was graded as grade 1 (63%) and in 8 cases grade 2 (30%).

Conclusion: MR myelography when employed in routine practice was of limited value, assisting in establishing a diagnosis in a minority of cases (6%). The technique was of limited additional value in patients with multilevel pathology and to a lesser extent in patients with scoliosis, where it helped to establish the level most likely to account for pathology.

In vivo strain in the deep and superficial regions of the human patellar tendon

This study investigated strain differences within the patellar tendon (PT) mid-region using an ultrasound-based digital image correlation (DIC) method. Six healthy young participants performed six knee extensions to 60% of maximal voluntary isometric contraction on 2 days. Sagittal ultrasound videos recorded during each contraction were analyzed using the DIC method to determine the strain-torque relationships of the superficial, deep, and whole PT mid-regions. Significantly greater strain was observed in the deep vs superficial layer of the PT mid-region for all contraction intensities, with peak strains of 5.8% (SD 1.7) and 4.5% (SD 1.5), respectively. DIC-based measures of peak tendon strain were repeatable within [intraclass coefficients (ICC) >0.97] and between sessions (ICCs >0.83) and agreed well with the conventional point-to-point method. This study confirmed that significant differences exist between deep and superficial layers of PT mid-region during ramped isometric extensions. These findings support the use of DIC to examine regional strain patterns within the PT mid-region that may be important in the context of tendon injury and adaptation.

GABA and Glutamate in Children with Primary Complex Motor Stereotypies: An 1H-MRS Study at 7T

BACKGROUND AND PURPOSE

Complex motor stereotypies are rhythmic, repetitive, fixed, purposeful but purposeless movements that stop with distraction. They can occur in otherwise normal healthy children (primary stereotypies) as well in those with autism spectrum disorders (secondary stereotypies). The underlying neurobiologic basis for these movements is unknown but is thought to involve cortical-striatal-thalamo-cortical pathways. To further clarify potential neurochemical alterations, gamma-aminobutyric acid (GABA), glutamate, glutamine, N-acetylaspartate, and choline levels were measured in 4 frontostriatal regions by using (1)H MRS at 7T.

MATERIALS AND METHODS

A total of 18 children with primary complex motor stereotypies and 24 typically developing controls, ages 5-10 years, completed MR spectroscopy at 7T. Single voxel STEAM acquisitions from the anterior cingulate cortex, premotor cortex, dorsolateral prefrontal cortex, and striatum were obtained, and metabolites were quantified with respect to Cr by using LCModel.

RESULTS

The 7T scan was well tolerated by all the participants. Compared with the controls, children with complex motor stereotypies had lower levels of GABA in the anterior cingulate cortex (GABA/Cr, P = .049; GABA/Glu, P = .051) and striatum (GABA/Cr, P = .028; GABA/Glu, P = .0037) but not the dorsolateral prefrontal cortex or the premotor cortex. Glutamate, glutamine, NAA, and Cho levels did not differ between groups in any of the aforementioned regions. Within the complex motor stereotypies group, reduced GABA to Cr in the anterior cingulate cortex was significantly associated with greater severity of motor stereotypies (r = -0.59, P = .021).

CONCLUSIONS

These results indicate possible GABAergic dysfunction within corticostriatal pathways in children with primary complex motor stereotypies.

Inter-laboratory study of human in vitro toxicogenomics-based tests as alternative methods for evaluating chemical carcinogenicity: a bioinformatics perspective

The assessment of the carcinogenic potential of chemicals with alternative, human-based in vitro systems has become a major goal of toxicogenomics. The central read-out of these assays is the transcriptome, and while many studies exist that explored the gene expression responses of such systems, reports on robustness and reproducibility, when testing them independently in different laboratories, are still uncommon. Furthermore, there is limited knowledge about variability induced by the data analysis protocols. We have conducted an inter-laboratory study for testing chemical carcinogenicity evaluating two human in vitro assays: hepatoma-derived cells and hTERT-immortalized renal proximal tubule epithelial cells, representing liver and kidney as major target organs. Cellular systems were initially challenged with thirty compounds, genome-wide gene expression was measured with microarrays, and hazard classifiers were built from this training set. Subsequently, each system was independently established in three different laboratories, and gene expression measurements were conducted using anonymized compounds. Data analysis was performed independently by two separate groups applying different protocols for the assessment of inter-laboratory reproducibility and for the prediction of carcinogenic hazard. As a result, both workflows came to very similar conclusions with respect to (1) identification of experimental outliers, (2) overall assessment of robustness and inter-laboratory reproducibility and (3) re-classification of the unknown compounds to the respective toxicity classes. In summary, the developed bioinformatics workflows deliver accurate measures for inter-laboratory comparison studies, and the study can be used as guidance for validation of future carcinogenicity assays in order to implement testing of human in vitro alternatives to animal testing.