The Randomized Shortened Dental Arch Study

The evidence concerning the management of shortened dental arch (SDA) cases is sparse. This multi-center study was aimed at generating data on outcomes and survival rates for two common treatments, removable dental prostheses (RDP) for molar replacement or no replacement (SDA). The hypothesis was that the treatments lead to different incidences of tooth loss. We included 215 patients with complete molar loss in one jaw. Molars were either replaced by RDP or not replaced, according to the SDA concept. First tooth loss after treatment was the primary outcome measure. This event occurred in 13 patients in the RDP group and nine patients in the SDA group. The respective Kaplan-Meier survival rates at 38 months were 0.83 (95% CI: 0.74-0.91) in the RDP group and 0.86 (95% CI: 0.78-0.95) in the SDA group, the difference being non-significant.

Facet tropism and facet joint orientation: risk factors for the development of early biochemical alterations of lumbar intervertebral discs

OBJECTIVE

To assess the glycosaminoglycan (GAG) content of lumbar intervertebral discs (IVD) in healthy volunteers with facet tropism (FT) and sagittal facet joint (FJ) orientation using glycosaminoglycan chemical exchange saturation transfer imaging (gagCEST).

METHOD

Seventy-five lumbar IVDs of twenty-five young, healthy volunteers without any history of lumbar spine pathologies (13 female; 12 male; mean age: 28.0 ± 4.4 years; range: 21-35 years) were examined with a 3T MRI scanner. Orientation of FT and FJ were assessed for L3/4, L4/5 and L5/S1 using standard T2 weighted images. Biochemical gagCEST imaging was used to determine the GAG content of each nucleus pulposus (NP) and annulus fibrosus (AF).

RESULTS

Significantly higher gagCEST values of NP were found in volunteers without FT and normal FJ orientation compared to volunteers with FT and sagittal FJ orientation >45° (P < 0.0001). GagCEST values were significantly higher in volunteers without FT compared to volunteers with moderate or severe FT (moderate FT: P < 0.0001; severe FT: P = 0.0033). Volunteers with normal FJ orientation showed significantly higher gagCEST values compared to those with sagittal FJ orientation >45° (P < 0.001). We found a significant, negative correlation between gagCEST values and higher angels in sagittal FJ orientation (rho = -0.459; P < 0.0001).

CONCLUSION

GagCEST analysis indicated lower GAG values of NP in young volunteers with FT and sagittal orientated FJ, indicating that FT and sagittal orientation of the FJ represent risk factors for the development of early biochemical alterations of lumbar IVDs.

Sex related differences in therapy and outcome of patients with intermittent claudication in a real-world cohort

BACKGROUND AND AIMS

The prevalence of lower extremity artery disease (LEAD) is increasing worldwide and sex-related differences are a current matter of debate.

METHODS

We analysed claims data on unselected patients with in-patient treatment for LEAD with intermittent claudication (IC; Rutherford grade 1-3) from 01.01.2014 to 31.12.2015. Data files included diagnostic and procedural information from two years before index, and a five-year follow-up.

RESULTS

Our analysis comprised 42,197 IC patients, thereof 28,520 (68%) male. Male patients were younger (median: 66.4 years vs. 72.6 years) but presented with higher frequency of cardiovascular risk factors such as diabetes (40% female vs. 46% male), atrial fibrillation (13% vs. 17%), chronic coronary syndrome (41% vs. 53%), chronic heart failure (23% vs. 27%), or chronic kidney disease (29% vs. 32%; all p < 0.001; age adjusted). Revascularisation applied in 80% of patients, thereof endovascular approach predominantly in female and surgery in male patients. Concomitant pharmacotherapy with statins (74% at 2 years) and platelet inhibitors (75% respectively) were long lasting below guideline recommendation, under-use being more pronounced in women. Two years after index, one-third of IC patients had subsequent revascularisation, one-quarter progressed to chronic limb threatening ischemia (CLTI), and 2% underwent amputation. Male sex was an independent risk factor for long-term mortality (female HR 0.75; 95%-CI 0.72-0.79; p < 0.001) and CLTI (female HR 0.89; 95%-CI 0.86-0.92; p < 0.001) during follow-up.

CONCLUSIONS

The majority of in-patient treated patients for IC are male, presenting with worse cardiovascular risk profiles. In view of a general under-supply with statins and platelet inhibitors, women received somewhat less often preventive medication. Despite low LEAD stages at index, serious prognosis was observed in the long term. Particularly male patients were at high risk for all-cause mortality and the combined endpoint CLTI and death.

[Modern study designs and analysis methods in clinical research]

BACKGROUND

Progress in the field of medical research requires further development of clinical trial methodology to overcome the challenges resulting from small patient populations and restricted resources.

METHODS

Classical single-stage designs with fixed sample sizes do not allow for interim analyses or design modifications. In contrast, adaptive designs adhere to established quality criteria while providing flexibility when conducting a clinical trial. In the face of new discoveries or information collected in the course of a trial, sample size adjustment, the selection of the target population and further design modifications can be performed. This enhances the chance of success of a clinical trial. Besides adaptive designs, classical approaches may be replaced or complemented by Bayesian methods. In a Bayesian approach prior knowledge can be efficiently included and hence the amount of information utilized in statistical analyses is increased. Furthermore, Bayes procedures allow the results of a statistical evaluation to be displayed very clearly.

CONCLUSION

Modern approaches, such as adaptive designs and Bayesian designs overcome the challenges in clinical research due to enhanced flexibility and efficiency. In addition, both approaches can be combined.