A methodology to estimate the potential to move inpatient to one day surgery

BACKGROUND: The proportion of surgery performed as a day case varies greatly between countries. Low rates suggest a large growth potential in many countries. Measuring the potential development of one day surgery should be grounded on a comprehensive list of eligible procedures, based on a priori criteria, independent of local practices. We propose an algorithmic method, using only routinely available hospital data to identify surgical hospitalizations that could have been performed as one day treatment. METHODS: Moving inpatient surgery to one day surgery was considered feasible if at least one surgical intervention was eligible for one day surgery and if none of the following criteria were present: intervention or affection requiring an inpatient stay, patient transferred or died, and length of stay greater than four days. The eligibility of a procedure to be treated as a day case was mainly established on three a priori criteria: surgical access (endoscopic or not), the invasiveness of the procedure and the size of the operated organ. Few overrides of these criteria occurred when procedures were associated with risk of immediate complications, slow physiological recovery or pain treatment requiring hospital infrastructure. The algorithm was applied to a random sample of one million inpatient US stays and more than 600 thousand Swiss inpatient stays, in the year 2002. RESULTS: The validity of our method was demonstrated by the few discrepancies between the a priori criteria based list of eligible procedures, and a state list used for reimbursement purposes, the low proportion of hospitalizations eligible for one day care found in the US sample (4.9 versus 19.4% in the Swiss sample), and the distribution of the elective procedures found eligible in Swiss hospitals, well supported by the literature. There were large variations of the proportion of candidates for one day surgery among elective surgical hospitalizations between Swiss hospitals (3 to 45.3%). CONCLUSION: The proposed approach allows the monitoring of the proportion of inpatient stay candidates for one day surgery. It could be used for infrastructure planning, resources negotiation and the surveillance of appropriate resource utilization

Cooperative courtship display in Long-tailed Manakins Chiroxiphia linearis: predictors of courtship success revealed through full characterization of display

The Pipridae comprise 52 species of manakins with a wide variety of courtship behaviours, ranging from solitary display, to traditional leks, to cooperative display. Long-tailed Manakins (Chiroxiphia linearis) exhibit an exploded lek-breeding system wherein two unrelated males cooperate to perform complex courtship displays for females. Our objectives in this study were to fully characterize the courtship display of Long-tailed Manakins, to evaluate the sequence and stereotypy of the display, and to investigate specific predictors of copulation success. Whereas the display of Long-tailed Manakins has traditionally been divided into two major parts, the hopping display and the butterfly display, we identified and characterized 16 individual display elements within these larger components of the display. We also determined that some aspects of the display are highly structured and stereotypical in performance, such that certain elements of the display are highly likely to be preceded or followed by particular elements. Nevertheless, other aspects of the display were much more flexible in terms of element sequence. We also found that the length and rate of performance of individual display elements were highly variable across displays. We therefore evaluated whether individual elements of the display could predict courtship success. Our results show that a number of highly correlated elements, namely upright postures, bounces, angel flights, and bows, can predict whether a display ends in copulation with a female. This research enhances our understanding of male display behaviour and female choice in Long-tailed Manakins, and may shed some light on the evolution of complex courtship displays in birds

Hybridization promotes evolvability in African cichlids: connections between transgressive segregation and phenotypic integration

Hybridization is a potential source of novel variation through (1) transgressive segregation, and (2) changes in the patterns and strength of phenotypic integration. We investigated the capacity of hybridization to generate novel phenotypic variation in African cichlids by examining a large F2 population generated by hybridizing two Lake Malawi cichlid species with differently shaped heads. Our morphometric analysis focused on the lateral and ventral views of the head. While the lateral view exhibited marked transgressive segregation, the ventral view showed a limited ability for transgression, indicating a difference in the genetic architecture and selective history between alternate views of the head. Moreover, hybrids showed a marked reduction in integration, with a lower degree of integration observed in transgressive individuals. In all, these data offer novel insights into how hybridization can promote evolvability, and provide a possible explanation for how broad phenotypic diversity may be achieved in rapidly evolving groups