Biomedical subjects

Walton Sumner

Publications and source records attributed to Walton Sumner.

7 recordsLinked to original sources

PubMed2003

Utility assessment among patients with dry eye disease.

PURPOSE: To determine utilities (patient preferences) for dry eye disease. DESIGN: Survey study. PARTICIPANTS: Fifty-six patients with mild, moderate, or severe dry eye treated by ophthalmologists in the Eye Care Services department of Henry Ford Health Care System. TESTING: Patients completed interactive software utility assessment questionnaires by the time trade-off (TTO) method. Utility scores were scaled such that a score of 1.0 = perfect health and 0 = death. Dry eye severity was independently classified using clinical parameters and physician/patient assessments. Global health status, visual functioning, and ocular symptoms were assessed by the Short Form-36 Health Survey, 25-Item National Eye Institute Visual Function Questionnaire (NEI VFQ-25), and Ocular Surface Disease Index survey instruments. MAIN OUTCOME MEASURES: Utility scores for a range of dry eye severity states. These utilities were compared with utilities reported for other disease states. Correlations with the general and vision-related health status measures were conducted. RESULTS: Fifty-six patients completed the utility assessments with acceptable reliability. Mean utilities for moderate (0.78) and severe dry eye (0.72) by TTO were similar to historical reports for moderate (0.75) and more severe (class III/IV) angina (0.71), respectively. Utility scores correlated with the NEI VFQ-25 composite score (rho = 0.32; P = 0.037) and with components of other health measures. CONCLUSIONS: Utilities for the more severe forms of dry eye are in the range of conditions like class III/IV angina (0.71) that are widely recognized as lowering health utilities. Our results underscore how significantly dry eye impacts patients compared with other medical conditions.

Adult↗

PubMed2002

Patient preferences for outcomes associated with surgical management of prostate cancer.

PURPOSE: We used utility assessment to evaluate patient preferences for current urinary and sexual function after radical prostatectomy. MATERIALS AND METHODS: We measured preferences in 209 community volunteers enrolled in a prostate cancer screening study who underwent radical prostatectomy between 1994 and 1998. We compared preferences in 3 outcome groups, namely men bothered by current urinary and sexual functioning, only bothered by current sexual functioning and not bothered by current sexual or urinary functioning. Preferences were assessed via a computer based interview using time trade-off and standard gamble methods. Current functioning was assessed via a standardized questionnaire. RESULTS: Median time trade-off and standard gamble utilities were high at 0.9 across outcome groups, indicating that men were not willing to give up many remaining life years (10% of remaining life expectancy) with current functioning to achieve ideal functioning. However, mean time trade-off and standard gamble scores significantly decreased as the burden increased in men bothered by current sexual and urinary function (0.77 and 0.82), bothered by current sexual function only (0.87 and 0.89) and not bothered by sexual or urinary function (0.92 and 0.96, respectively). CONCLUSIONS: Health related quality of life was generally good in this observational study of patients treated for prostate cancer with radical prostatectomy. In addition, those bothered by urinary and/or sexual function would not be willing to trade much of the remaining life span to achieve perfect functioning. However, the perception of side effects was bothersome enough in some men to warrant appropriate patient counseling regarding the potential risks and benefits.

Aged↗

PubMed2002

Evidence for the rapid construction of preference during utility assessments.

Subjects often construct preferences during the elicitation process. This could have implications for the processes automated utility assessments use to find indifference points. In particular, if subjects frequently shift preferences during elicitation processes, then reversible and irreversible procedures might reach different results. We analyzed series of choices made by two groups of subjects during computerized standard gambles for monocular and binocular blindness, comparing the utility assessed in a reversible search process with the utility that would have resulted from an irreversible search process. A minority of subjects reversed their choices during the assessments. The mean differences between these utilities and the predicted results of an irreversible search were quite small. Consequently, automated standard gamble surveys can terminate quickly, using irreversible searches, with little likelihood of skewing population results. Clinical decision support systems can use simple mechanisms to accommodate infrequent preference reversals, such as restarting a search.

Adult↗

PubMed2002

Validation of electronic student encounter logs in an emergency medicine clerkship.

Handheld electronic patient encounter logs offer opportunities to understand and enhance medical students' clinical experiences. Before using the data, the reliability of log entries needs to be verified. We assessed the sensitivity and specificity of handheld patient encounter logs by comparing documented entries with reliable external data sources. During an Emergency Medicine clerkship, medical students voluntarily recorded their patients' diagnoses in an Electronic Student Encounter Log (E-SEL) on handheld computers. We used patient demographics to match anonymous log entries with medical charts. Most students recorded 60% or more of their patient encounters and on average 60% of their patients' medical problems in the log. The false positive rate was 26% for patient encounters and 19% for patient problems. In general, students recorded more diagnoses in more detail than was available in the patient's ED chart. Improvements in the log's interface and documentation incentives should enhance the log's accuracy and utility.

Clinical Clerkship↗

PubMed2002

Modeling fatigue.

The American Board of Family Practice is developing a patient simulation program to evaluate diagnostic and management skills. The simulator must give temporally and physiologically reasonable answers to symptom questions such as "Have you been tired?" A three-step process generates symptom histories. In the first step, the simulator determines points in time where it should calculate instantaneous symptom status. In the second step, a Bayesian network implementing a roughly physiologic model of the symptom generates a value on a severity scale at each sampling time. Positive, zero, and negative values represent increased, normal, and decreased status, as applicable. The simulator plots these values over time. In the third step, another Bayesian network inspects this plot and reports how the symptom changed over time. This mechanism handles major trends, multiple and concurrent symptom causes, and gradually effective treatments. Other temporal insights, such as observations about short-term symptom relief, require complimentary mechanisms.

Artificial Intelligence↗

PubMedDate not supplied

Automated current health time-trade-off assessments in women's health.

OBJECTIVE: To motivate the role for preference assessment in women's health and to report pilot data addressing the performance of automated time-trade-off (TTO) valuations of current health, which were developed to estimate quality-adjusted life years (QALYs) in the women's health setting. METHODS: Values for current health relative to perfect health and death were assessed using an annual time trade-off (1-year horizon and sleep as the trading metaphor), a lifetime time trade-off, and a visual analog scale (VAS). All instruments were administered twice within a 12- to 14-day window among a convenience sample of 27 women. RESULTS: Valuation of health was similar for both time trade-offs (mean of 0.95 for both), but was significantly lower for the VAS (mean of 0.84, Wilcoxon signed-rank p-value < 0.001). Reliability using the intraclass correlation coefficient was 0.67 +/- 0.09 and 0.75 +/- 0.07 for the annual and lifetime time trade-offs, respectively, and 0.89 +/- 0.03 for the VAS. Construct validity was supported by consistent trends in time-trade-off utilities across tertiles of the Short Form 36 (SF-36) general health subscale (trend test p-value < 0.001). CONCLUSION: Automated time trade-offs for current health provide a promising approach for use in women's health studies where impact on QALYs must be measured. Natural areas of application include the economic evaluation of preventive interventions in postmenopausal women.

Adult↗

PubMedDate not supplied

Computer-based testing in family practice certification and recertification.

BACKGROUND: The member boards of the American Board of Medical Specialties have agreed to expand the scope of certification to include assessment of medical knowledge, practice-based learning and improvement, patient care, interpersonal and communication skills, systems-based practice, and professionalism. Multiple-choice examinations provide limited ability to assess these dimensions. METHODS: The American Board of Family Practice (ABFP) has developed a computer simulation system to facilitate more comprehensive candidate evaluation. The system consists of a knowledge base, a simulation program to create patient scenarios, an interface for presenting simulations to users, and an administrative database to track candidate performance and interactions with the system. The system uses population distributions for disease states to produce cases and evolves patients in response to candidate interventions, such as pharmacological and nonpharmacological therapies. We use Bayesian belief networks to model patient characteristics and comorbid condition interactions. RESULTS: Simulations have been created for 7 disease states; ultimately simulations will be available for 25 to 30 disease states. Initial testing will take place in regional examination centers but will ultimately use the Internet for convenient access for certification and recertification candidates. CONCLUSION: The ABFP will begin field-testing the system in early 2003 and will include simulations in the certification and recertification examination process in 2004.

Bayes Theorem↗