The physician's experience of changing clinical practice: a struggle to unlearn.

BACKGROUND: Changing clinical practice is a difficult process, best illustrated by the time lag between evidence and use in practice and the extensive use of low-value care. Existing models mostly focus on the barriers to learning and implementing new knowledge. Changing clinical practice, however, includes not only the learning of new practices but also unlearning old and outmoded knowledge. There exists sparse literature regarding the unlearning that takes place at a physician level. Our research objective was to elucidate the experience of trying to abandon an outmoded clinical practice and its relation to learning a new one. METHODS: We used a grounded theory-based qualitative approach to conduct our study. We conducted 30-min in-person interviews with 15 primary care physicians at the Cleveland VA Medical Center and its clinics. We used a semi-structured interview guide to standardize the interviews. RESULTS: Our two findings include (1) practice change disturbs the status quo equilibrium. Establishing a new equilibrium that incorporates the change may be a struggle; and (2) part of the struggle to establish a new equilibrium incorporating a practice change involves both the "evidence" itself and tensions between evidence and context. CONCLUSIONS: Our findings provide evidence-based support for many of the empirical unlearning models that have been adapted to healthcare. Our findings differ from these empirical models in that they refute the static and unidirectional nature of change that previous models imply. Rather, our findings suggest that clinical practice is in a constant flux of change; each instance of unlearning and learning is merely a punctuation mark in this spectrum of change. We suggest that physician unlearning models be modified to reflect the constantly changing nature of clinical practice and demonstrate that change is a multi-directional process.

Limit cycles, complex Floquet multipliers, and intrinsic noise.

We study the effects of intrinsic noise on chemical reaction systems, which in the deterministic limit approach a limit cycle in an oscillatory manner. Previous studies of systems with an oscillatory approach to a fixed point have shown that the noise can transform the oscillatory decay into sustained coherent oscillations with a large amplitude. We show that a similar effect occurs when the stable attractors are limit cycles. We compute the correlation functions and spectral properties of the fluctuations in suitably comoving Frenet frames for several model systems including driven and coupled Brusselators, and the Willamowski-Rössler system. Analytical results are confirmed convincingly in numerical simulations. The effect is quite general, and occurs whenever the Floquet multipliers governing the stability of the limit cycle are complex, with the amplitude of the oscillations increasing as the instability boundary is approached.

The effects of stochastic population dynamics on food web structure.

We develop a stochastic, individual-based model for food web simulation which in the large-population limit reduces to the well-studied Webworld model, which has been used to successfully construct model food webs with several realistic features. We demonstrate that an almost exact match is found between the population dynamics in fixed food webs, and that the demographic fluctuations have systematic effects when the new model is used to construct food webs due to the presence of species with small populations.

Can it get any worse?

THE TWO FEATURE articles presented in this issue of Frontiers of Health Services Management speak to the challenges of Hurricane Katrina. The Tulane experience lists a multitude of problems, solutions, and successes, whereas the article by Drs. Rodriguez and Aguirre speaks to the impact on the infrastructure following the hurricane. In the federal report, "The Federal Response to Hurricane Katrina," the White House (2006) has labeled Katrina as "the most destructive natural disaster in U.S. history." Dr. E. L. Quarantelli (2006) might call Katrina a catastrophe. Regardless of what one calls the event, Hurricane Katrina has shown that the challenges leading up to and following a disaster/catastrophe will overwhelm everyone. People must understand that they cannot wait for a government, any government, to help them. We must be prepared to help ourselves.

Effects of peroxisome proliferator-activated receptor delta on placentation, adiposity, and colorectal cancer.

Targeting of the nuclear prostaglandin receptor peroxisome proliferator-activated receptor delta (PPARdelta) by homologous recombination results in placental defects and frequent (>90%) midgestation lethality. Surviving PPARdelta(-/-) mice exhibit a striking reduction in adiposity relative to wild-type levels. This effect is not reproduced in mice harboring an adipose tissue-specific deletion of PPARdelta, and thus likely reflects peripheral PPARdelta functions in systemic lipid metabolism. Finally, we observe that PPARdelta is dispensable for polyp formation in the intestine and colon of APC(min) mice, inconsistent with its recently proposed role in the establishment of colorectal tumors. Together, these observations reveal specific roles for PPARdelta in embryo development and adipocyte physiology, but not cancer.