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H S Stern

Publications and source records attributed to H S Stern.

83 records · Page 5Linked to original sources
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Posterior predictive model checks for disease mapping models.

Disease incidence or disease mortality rates for small areas are often displayed on maps. Maps of raw rates, disease counts divided by the total population at risk, have been criticized as unreliable due to non-constant variance associated with heterogeneity in base population size. This has led to the use of model-based Bayes or empirical Bayes point estimates for map creation. Because the maps have important epidemiological and political consequences, for example, they are often used to identify small areas with unusually high or low unexplained risk, it is important that the assumptions of the underlying models be scrutinized. We review the use of posterior predictive model checks, which compare features of the observed data to the same features of replicate data generated under the model, for assessing model fitness. One crucial issue is whether extrema are potentially important epidemiological findings or merely evidence of poor model fit. We propose the use of the cross-validation posterior predictive distribution, obtained by reanalyzing the data without a suspect small area, as a method for assessing whether the observed count in the area is consistent with the model. Because it may not be feasible to actually reanalyze the data for each suspect small area in large data sets, two methods for approximating the cross-validation posterior predictive distribution are described.

Algorithms↗
PubMedDate not supplied

The length of the anal canal.

The authors measured the length of the surgical anal canal (anorectal ring to anal verge) in 108 men and 103 women; the age ranged from 18 to 90 years (average 59 years). The average length of the surgical anal canal was 4.2 cm (range 3.0-5.3 cm). In men the average length was 4.4 cm (range 3.2-5.3 cm) compared with the average length of 4.9 cm (range 3.0-5.0 cm) in women (P less than 0.001). The average length of the anatomic anal canal (dentate line to anal verge) was 2.1 cm (range 1.0-3.8 cm). In men, the average length was 2.2 cm (range 1.4-3.8 cm), whereas in women the average length was 2.0 cm (range 1.0-3.2 cm) (P less than .01). The length of the anatomic anal canal has no relationship to the length of the surgical anal canal or vice versa (P less than 0.1). There was no statistically significant difference in the length of the surgical anal canal or the anatomic anal canal in persons below 60 years old versus those above in either sex (P greater than 0.01).

Adolescent↗
PubMedDate not supplied

The versatile superficial inferior epigastric artery free flap.

A series of 27 successful Superficial Inferior Epigastric Artery free flaps were analysed for a number of clinical and surgical variables. The anatomy and surgical technique of the flap are detailed and its advantages and disadvantages relative to other free flaps used for soft tissue contour are considered. Analysis of the variety of recipient sites of this flap is presented, as are details of the vascular pedicle and our experience with its constancy. It has been found to be a safe flap in experienced hands, with an aesthetic donor site scar, no functional loss and it lends itself to subsequent recontouring with suction assisted lipectomy or open techniques.

Abdomen↗