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Biomedical subjects

Chris Sistrom

Publications and source records attributed to Chris Sistrom.

8 recordsLinked to original sources
PubMed2006

Inference and uncertainty in radiology.

This paper seeks to enhance understanding of the philosophical underpinnings of our discipline and the resulting practical implications. Radiology reports exist in order to convey new knowledge about a patient's condition based on empiric observations from anatomic or functional images of the body. The route to explanation and prediction from empiric evidence is mostly through inference based on inductive (and sometimes abductive) arguments. The conclusions of inductive arguments are, by definition, contingent and provisional. Therefore, it is necessary to deal in some way with the uncertainty of inferential conclusions (i.e. interpretations) made in radiology reports. Two paradigms for managing uncertainty in natural sciences exist in dialectic tension with each other. These are the frequentist and Bayesian theories of probability. Tension between them is mirrored during routine interactions among radiologists and clinicians. I will describe these core issues and argue that they are quite relevant to routine image interpretation and reporting.

Bayes Theorem↗
PubMed2005

The socioeconomic aspects of information technology for health care with emphasis on radiology.

RATIONALE AND OBJECTIVES: Information technology is the key to cost effective and error free medical care in the United States and the only problem is that there is not enough of it yet. During the past 15 years, billions of dollars have been spent on information technology for health care with very little benefit but significant adverse effects on patients, physicians, and nurses. The truth about health care information technology (HIT) probably lies somewhere between these extreme statements, representing technophile and skeptical views, respectively. MATERIALS AND METHODS: There is no doubt that computer and communication hardware has reached a state of sophistication and availability in which any and all necessary information can be generated, stored, and distributed to health care workers in support of their patient care tasks. The barriers to rapid and widespread development and diffusion of cost effective and practically useful HIT are exclusively related to human factors. RESULTS: This article explores some of the organizational, cultural, cognitive, and economic forces that interact to influence success of HIT initiatives in health care organizations. A key point to be recognized is that the intrinsically handcrafted nature of health care work combined with high degrees of complexity and contingency make it impossible to "computerize" with the same ease and completeness of other industries. The major thrust of the argument is that designers of information systems and health care informatics managers must meet needs of patients and care providers. The software they create and implement should promote, support, and enhance the existing processes of health care rather than seeking to dictate how direct care providers should do their work. CONCLUSIONS: Instead of looking for "buy in" from physicians and nurses, the informatics community must return the authority over functional specification of patient care information systems to them--where it belonged in the first place. This same lesson about computer technology and organizational politics is also being learned in the business community, where executives are reclaiming responsibility for mission critical informatics decisions.

Decision Support Techniques↗
PubMed2005

Assessment of the understanding of the risks and benefits of hormone replacement therapy (HRT) in primary care physicians.

OBJECTIVE: This study was designed to assess the understanding of primary care physicians who practice in the state of Florida of the risks and benefits of hormone replacement therapy as described in the Women's Health Initiative clinical trial. STUDY DESIGN: All primary care physicians in the state of Florida, including family practice, internal medicine, and Ob/Gyn were identified and mailed an anonymous survey asking about their understanding of the risks and benefits of hormone replacement therapy (HRT), including heart disease, breast cancer, osteoporotic fractures, colon cancer, stroke, and death. Univariate statistics stratified by specialty were performed with Kruskal-Wallis one-way analysis of variance. RESULTS: Six thousand one hundred twenty-five surveys were mailed, with the return of 600 completed surveys, including 203 Ob/Gyn, 145 internal medicine, 219 family practice, and 33 other. Overall, Ob/Gyns had a more positive view of HRT, and internal medicine had a relatively negative view of HRT. In general, respondents overestimated the risk attributable to hormone replacement therapy. Ob/Gyns were significantly more likely to provide accurate assessments of these risks and benefits compared with the other specialties. Respondents correctly identified the magnitude of risks and benefits 28% of the time, 67% of the time overestimated risks and benefits, and 5% of the time misunderstood the direction of risk vs benefit of HRT. CONCLUSION: This study suggests that the findings of the Women's Health Initiative are misunderstood by the majority of primary care specialists, although Ob/Gyns have a better understanding of the risks and benefits compared to other specialties. We hypothesize that respondents that overestimate the increase or decrease in risk were making the error of confusing relative risk with absolute risk difference. There is a great need for physician education about the attributable risks and benefits of HRT.

Family Practice↗
PubMed2004

A randomized, multicenter study comparing the efficacy of recombinant FSH vs recombinant FSH with Ganirelix during superovulation/IUI therapy.

OBJECTIVE: The purpose of this study was to determine if use of a Gonadotropin releasing hormone (GnRH) antagonist, Ganirelix (Antagon), can improve pregnancy rates during superovulation with recombinant follicle-stimulating hormone (rFSH) followed by intrauterine insemination (IUI). STUDY DESIGN: This was a multicenter, prospective, randomized, open-label, assessor-blind, controlled trial of females (n = 54), ages 18 to 39 undergoing superovulation/IUI with up to 4 cycles of superovulation/IUI without Ganirelix (n = 66), or up to 4 cycles of superovulation/IUI with the addition of Ganirelix (n = 52). RESULTS: No statistically significant difference in clinical pregnancy rates per cycle initiated was found for patients in the treatment or control group (12% vs 7%, P =.29). Other variables assessed, including endometrial thickness, size of follicles, peak serum estradiol levels, mid-lutea progesterone levels, and total vials of rFSH used also showed no statistically significant difference. CONCLUSION: Superovulation/IUI cycles using Ganirelix produce similar pregnancy rates when compared with cycles not using a GnRH antagonist, although there is a trend towards better pregnancy rates in cycles with Ganirelix.

Adult↗
PubMed2004

Reporting instruction for radiology residents.

RATIONALE AND OBJECTIVES: To determine the amount of formal instruction and evaluation about reporting given to radiology residents in the U.S.A., to document report generation methods and to quantify the performance of physician coding. MATERIALS AND METHODS: E-mail requests with links to a web-based, anonymous survey were sent to program directors of all accredited radiology residencies in the USA. Demographic questions included university or private affiliation, number of residents, geographic location, and number of hospitals covered. Subject-specific items covered the amount of didactic instruction, formal evaluation of reports, and use of structured reports. A didactic activity index (DAI) was calculated as the sum of answers to domain-specific questions and tested for relation to demographic variables. We also asked about dictation methods and International Classification of Diseases (ICD) or Common Procedural Terminology (CPT) coding of examinations by radiologists. RESULTS: Of the 191 active radiology residencies, 151 (79%) completed the survey. Responses for hours of didactic instruction in reporting given more than a 4-year residency were distributed as follows: 0-1 = 40%, 2-4 = 46%, >4 = 14%. The percentage of resident reports formally graded was distributed as follows: 0-1 = 82%, 2-4 = 8%, >4 = 10%. The extent to which faculty-designed, structured reports were used by residents was distributed as follows: none = 16%, minimal = 25%, few = 17%, some = 33%, most = 9%. The DAI was normally distributed with a mean of 14.8 and a standard deviation of 2.4. Military programs had higher DAIs than university residencies (P = .03). There was no significant relation between any other program demographic variables and the DAI (P > .05). A substantial number of programs reported that physicians performed coding for some or most studies: ICD-9 = 30%, CPT = 26%. The dominant method for report generation was human transcription in 79% followed by speech recognition at 19%. Speech recognition penetration (departments reporting use of the technology for at least some dictation) was estimated to be 38%. CONCLUSION: In 86% of sampled radiology residencies, trainees receive no more than one hour of didactic instruction in radiology reporting per year. An aggregate measure of didactic activity about interpretative reporting was identical across all program demographic variables except that military residencies seemed to do slightly more than those located at universities.

Data Collection↗
PubMed2004

A simple method for importing multiple image files into PowerPoint.

OBJECTIVE: We developed a method for automatically inserting a large number of images into a PowerPoint presentation document. CONCLUSION: We designed, tested, and now routinely use a simple macro program for importing all images contained in a single directory into a PowerPoint presentation. The complete text of the macro code is included in this article, and readers are encouraged to experiment with it.

Radiology Information Systems↗
PubMedDate not supplied

Optic neuropathy secondary to cat scratch disease: distinguishing MR imaging features from other types of optic neuropathies.

BACKGROUND AND PURPOSE: MR imaging characteristics of optic neuropathy caused by cat scratch disease have not yet been described; this lack of information may result in incorrect diagnosis and may contribute to initiation of inappropriate therapy. Our study was based on the hypothesis that cat scratch disease-related optic neuropathy has distinct MR imaging features compared with those of other types of optic neuropathies. METHODS: Eighty-two patients with various causes of optic neuropathy and available MR imaging examinations were included in this study. Two readers blinded to the diagnosis reviewed the MR images independently in regard to presence, location, and extent of optic nerve enhancement. The MR imaging findings were correlated with the final diagnosis. RESULTS: Eleven percent (9/82) of the patients received a final diagnosis of cat scratch disease. Optic nerve enhancement in patients with cat scratch disease (5/37) was localized to a 3- to 4-mm segment at the optic nerve-globe junction. All other patients with optic neuropathy (31/37) with one exception showed enhancement away from the optic nerve-globe junction or a long-segment enhancement when the optic nerve-globe junction was also involved. Four patients with cat scratch disease did not show any optic nerve MR abnormalities. CONCLUSION: Unilateral, short-segment enhancement localized to the optic nerve-globe junction is highly specific for cat scratch disease as the underlying cause of optic neuropathy and may help in establishing the diagnosis of this condition.

Adolescent↗