An elastic net penalized small area model combining unit- and area-level data for regional hypertension prevalence estimation.

Hypertension is a highly prevalent cardiovascular disease. It marks a considerable cost factor to many national health systems. Despite its prevalence, regional disease distributions are often unknown and must be estimated from survey data. However, health surveys frequently lack in regional observations due to limited resources. Obtained prevalence estimates suffer from unacceptably large sampling variances and are not reliable. Small area estimation solves this problem by linking auxiliary data from multiple regions in suitable regression models. Typically, either unit- or area-level observations are considered for this purpose. But with respect to hypertension, both levels should be used. Hypertension has characteristic comorbidities and is strongly related to lifestyle features, which are unit-level information. It is also correlated with socioeconomic indicators that are usually measured on the area-level. But the level combination is challenging as it requires multi-level model parameter estimation from small samples. We use a multi-level small area model with level-specific penalization to overcome this issue. Model parameter estimation is performed via stochastic coordinate gradient descent. A jackknife estimator of the mean squared error is presented. The methodology is applied to combine health survey data and administrative records to estimate regional hypertension prevalence in Germany.

[Routine diagnosis in patients with latent sinus node syndrome]. / Zur Routinediagnostik bei Patienten mit latentem Sinusknotensyndrom.

The establishment of latent disturbances of the sinus node function is with high security successful by the determination of the sinus node recovery time only after medicamentous provocation with propranolol/atropin and verapamil, since the sensitivity of the determination of the sinus node recovery time is to small in the up to now usual way and in normal findings it is not able to exclude a sinus node dysfunction. The course of the investigation could be optimized according to the fact that despite complete medicamentous provocation only one running through stimulation is necessary without an endangering of the patient being the results. By this means of 75 patients 32 patients (43%) could be identified as sinus node syndrome of different degree of severity. On the basis of the improved ability of statement the determination of the sinus node recovery time for the diagnostics in patients with unclear syncopes and inconspicuous findings of the ECG should be performed only after a combined medicamentous provocation.