Using systems thinking to extend continuous quality improvement

Traditional CQI tools have proven effective in improving discrete processes, but the strengths of these tools often render them inappropriate to improve complex systems made up of multiple processes. After finding that CQI tools failed to reduce emergency department waiting times, a QI team applied systems thinking tools and learned that the cause of delays was rooted in interrelationships among processes, such as the impact on laboratory testing when emergent and routine patients arrived back to back. Computer modeling allowed the team to reject some quick fixes--such as adding ED beds--that simulations showed would be ineffective. By reorganizing patient flow and automating hospitalwide bed control, the team so far has reduced waiting times 19 percent and increased patient satisfaction despite an increase in census.     

Testosterone implantation reduces the motor effects of cocaine

The abuse of anabolic-androgenic steroids noted in recent years has been correlated with an increased likelihood of abuse of other drugs, including cocaine. This research was designed to investigate whether manipulation of androgen levels would alter the unconditioned behavioral effects of cocaine. The influence of testosterone on the locomotor activating effect of oral cocaine was evaluated. Subjects were male gonadally intact and castrated Wistar rats, implanted s.c. with either placebo or 100mg testosterone 30-day pellets. Beginning 7 days after pellet implantation, each animal in the four subgroups randomly received 0, 20, 40 and 80mg/kg cocaine (once, each dose). Cocaine 80mg/kg significantly enhanced locomotor activity in all groups except the intact testosterone-treated group. Of the four groups, this subgroup would have the highest plasma level of testosterone. These data suggest that chronic exogenous androgen administration may reduce the behavioral effects of cocaine.     

Cost-benefit analysis of transesophageal echocardiography in cardiac surgery

This article evaluates the costs and outcomes associated with TEE during and after cardiac surgery. The costs include the direct and indirect costs--the complications of TEE. The outcomes include the positive consequences or the benefits: money and lives saved. The article uses liberal (high) estimates of the direct and indirect costs of TEE and conservative (low) estimates of the benefits. The exact cost or benefit depends on the number of cases performed. The analysis shows that patients having surgery for congenital heart disease derive the greatest overall benefit: around $600 per case studied. Patients having valvular repair surgery derive the next greatest benefit: around $450 per case studied. In contrast patients having valve replacement have an overall cost of around $150 per case studied. Patients having surgery for coronary artery disease also derive an overall benefit: around $100-$300 per case studied, depending upon assumptions regarding TEE's role in prevention of intraoperative strokes. This analysis indicates that the financial benefits of TEE are substantial and frequently outweigh costs in patients requiring cardiac surgery.     

The necessity of a second prostate biopsy cannot be predicted by PSA or PSA derivatives (density or free:total ratio) in men with prior negative prostatic biopsies

Serum prostate specific antigen, prostate specific antigen density and free:total prostate specific antigen are known to be useful for determining the risk of prostate cancer in patients undergoing prostate cancer screening. The patient with a positive biopsy presents no future prostate specific antigen dilemma. Those with negative biopsies often go on to numerous repeat biopsies. Our goal was to establish criteria that could be used to identify patients who will require repeat prostate biopsies (possibly false negative initial biopsy), while not exposing the low risk population (probable true negative initial biopsy) to additional invasive procedures. Between March 1991 and March 1998, 148 patients who had a biopsy for an elevated prostate specific antigen value (4.1-10.0) or an altered digital rectal examination, had no cancer found in the specimen. From these, 51 (34.4%) had repeated biopsies, while the others persisted on close follow-up. We examined their serum prostate specific antigen, prostate specific antigen density and free:total prostate specific antigen value, as well as their age and histology results of the initial and repeat biopsy, to determine if any predictor of the need for a repeat biopsy could be identified. Eight (15.7%) from 51 men who had repeat biopsy had prostate cancer detected. Forty three (84.3%) patients persisted with a negative biopsy, despite filling the criteria for re-biopsy. Multivariate analysis failed to identify any significant predictors of prostate cancer in the repeat biopsy group. Despite initial success, the prostate specific antigen derivatives and free:total prostate specific antigen have not safely limited the number of biopsies performed for an abnormal prostate specific antigen (4.1-10.0). Neither prostate specific antigen density nor free:total prostate specific antigen predicted the need for repeat biopsy in this specific group. The results of this ongoing study demonstrate that to date, prostate specific antigen and prostate specific antigen derivatives can not be utilized to determine which patients will be at high risk for requiring repeat prostate biopsy. All patients must be closely monitored for evidence of a change in status from benign to malignant disease, and new markers for this purpose are urgently needed.