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David J Vanness

Publications and source records attributed to David J Vanness.

12 recordsLinked to original sources
PubMed2005

Effects of a hospitalist model on elderly patients with hip fracture.

BACKGROUND: Hospitalists' increased role in perioperative medicine allows for examination of their effects on surgical patients. This study examined the effects of a hospitalist service created to medically manage elderly patients with hip fracture. METHODS: During a 2-year historical cohort study of 466 patients 65 years or older admitted for surgical repair of hip fracture, we examined outcomes 1 year prior to and subsequent to the change from the standard to the hospitalist model. RESULTS: The mean (SD) time to surgery (38 [47] vs 25 [53] hours; P<.001), time from surgery to dismissal (9 [8] vs 7 [5] days; P = .04), and length of stay (10.6 [9] vs 8.4 [6] days; P<.001) were shorter in the hospitalist group. Predictors of shorter time to surgery were care by the hospitalist group (P = .002), older age (P = .01), and fall as the mechanism of fracture (P<.001), while American Society of Anesthesia scores of 3 and 4 were associated with increased time to surgery (P<.001). Receiving care by the hospitalist group (P<.001) and diagnosis of delirium (P<.001) were associated with increased chance of earlier dismissal, while admission to the intensive care unit decreased this chance (P<.001). Diagnosis of delirium was more frequent in the hospitalist group (74 [32.2%] of 230 vs 42 [17.8%] of 236; P<.001). There were no differences in inpatient deaths or 30-day readmission rates. CONCLUSION: In elderly patients with hip fracture, a hospitalist model decreased time to surgery, time from surgery to dismissal, and length of stay without adversely affecting inpatient deaths or 30-day readmission rates.

Aged↗
PubMed2005

The need for microsimulation to evaluate osteoporosis interventions.

Simulations play an increasingly important role in the evaluation of osteoporosis interventions. Existing evaluations have been based on "reduced-form" cohort simulations that do not reflect the complexity and heterogeneity of osteoporosis and its outcomes. Such simplified models offer parsimony and ease of use, but they also are limited in their ability to explain and extrapolate outcomes in a way that is most useful for both clinical and health policy decision makers. Alternatively, evaluations could be based on "structural" microsimulations, which explicitly model the underlying biology of osteoporosis at the individual level. The structural approach presents technical challenges, including the need to obtain more-detailed data and the requirement that underlying biological models be validated. However, evaluations based on structural microsimulation may ultimately provide substantially more useful information, resulting in improved decision making.

Computer Simulation↗
PubMed2003

A structural econometric model of family valuation and choice of employer-sponsored health insurance in the United States.

This paper estimates a fully structural unitary household model of employment and health insurance decisions for dual wage-earner families with children in the United States, using data from the 1987 National Medical Expenditure Survey. Families choose hours of work and the breakdown of compensation between cash wages and health insurance benefits for each wage earner in order to maximize expected utility under uncertain need for medical care. Heterogeneous demand for the employer-sponsored health insurance is thus generated directly from variations in health status and earning potential. The paper concludes by discussing the benefits of using structural models for simulating welfare effects of insurance reform relative to the costly assumptions that must be imposed for identification.

Adolescent↗
PubMed2003

Extracolonic findings at CT colonography: evaluation of prevalence and cost in a screening population.

BACKGROUND & AIMS: To assess the prevalence and spectrum of extracolonic findings in a screening population undergoing computed tomography colonography (CTC), and to evaluate the short-term direct medical costs incurred from subsequent radiologic follow-up evaluation. METHODS: Six hundred and eighty-one asymptomatic patients undergoing colonoscopy screening consented to a CTC examination. Extracolonic CT findings were classified into high, medium, and low importance. Clinical and radiologic follow-up, missed lesions, and outcomes were assessed by chart review (time interval, 410-1513 days; median, 913 days). Short-term direct medical costs of radiologic follow-up were determined based on Medicare 2002 reimbursement rates. RESULTS: Extracolonic findings were found commonly. These were categorized as high clinical importance in 71 (10%) individuals, as medium importance in 183 individuals (27%), and as low importance in 341 individuals (50%). Subsequent medical or surgical interventions resulted from these findings in 9 of the 681 patients (1.3%). Costs of subsequent radiologic follow-up studies were calculated as $23,380.59 (average added costs per CTC examination $34.33). CONCLUSIONS: CTC commonly detects extracolonic findings that can be considered clinically important when applied to an asymptomatic screening population. Although such incidental findings add benefit to the screening intervention, moderate incremental costs are incurred based on additional radiologic procedures generated during short-term follow-up.

Adult↗
PubMed2003

Factors influencing clinical decisions to initiate thyroxine therapy for patients with mildly increased serum thyrotropin (5.1-10.0 mIU/L).

OBJECTIVE: To determine factors that influence clinicians' decisions to treat subclinical hypothyroidism. PATIENTS AND METHODS: We studied patients living within 120 miles of our institution in Rochester, Minn, whose serum thyrotropin value was between 5.1 and 10.0 mIU/L from January 1, 1995, through December 31,1996. Exclusion criteria were history of thyroid disease or prior abnormal thyrotropin level and fewer than 5 follow-up visits or fewer than 2 follow-up thyrotropin measurements. Of the 2655 patients in this cohort, only 55% (1466) had measurement of thyroid microsomal antibodies (TMAb). From this group, records of 539 patients were selected randomly according to antibody status (238 with positive, 199 with negative, and 102 with no TMAb measurement). After exclusion of patients receiving thyroxine replacement and other medications affecting thyroid function, patients with postpartum thyroiditis, and patients in the intensive care unit, data from 450 patients were analyzed. RESULTS: Thyroxine therapy was prescribed for 39% of the patients with thyrotropin levels between 5.1 and 10.0 mIU/L. In multivariate analysis, TMAb status (P < .001), index thyrotropin (P < .002), and free thyroxine (FT4) (P = .03) were the strongest predictors for the decision to treat. Fifty-nine percent of the patients with positive TMAb were treated compared with 24% of those with negative TMAb and 30% of those who did not have a TMAb test. The mean thyrotropin level in the treated group was 7.1 mIU/L compared with 63 mIU/L in the untreated group. The mean FT4 level was 1.08 ng/dL in the treated group who had this measured compared with 1.16 ng/dL in the untreated group. Treated patients were younger than untreated patients (56.5 years vs 60.6 years), and the proportion of female patients was higher in the treated group compared with the untreated group (75.8% vs 65.2%); however, neither of these differences was significant after correction for the multiple comparisons. In multivariate analysis neither age nor sex was a significant predictor of treatment, but in the subgroup comparison, patients aged 31 to 50 years were twice as likely to be treated compared with those aged 61 to 80 years. CONCLUSION: Among patients with serum thyrotropin levels of 5.1 to 10.0 mIU/L, those with positive TMAb values, those with higher thyrotropin values, and those with lower FT4 values were more likely to receive thyroxine therapy. Younger patients were more likely to be treated than older patients.

Adult↗
PubMed2002

Preemptive use of oral ganciclovir to prevent cytomegalovirus infection in liver transplant patients: a randomized, placebo-controlled trial.

The use of postdetection antiviral treatment of cytomegalovirus (CMV) as a strategy to prevent infection and disease in solid-organ transplant patients has not been evaluated by placebo-controlled trials. We carried out such a study in 69 patients who had received liver transplants and had positive results of CMV polymerase chain reaction within 8 weeks after transplantation but did not have concomitant CMV infection or disease. These patients were randomly assigned to receive placebo or oral ganciclovir for 8 weeks. CMV infection developed in 21% and disease developed in 12% of placebo recipients (P =.022), compared with 3% and 0%, respectively, among ganciclovir recipients (P =.003). Similarly, in the placebo arm, 55% and 36% of CMV-negative patients who received organs from CMV-positive donors developed CMV infection or disease, respectively (P =.02), compared with 11% and 0% of such patients in the ganciclovir arm (P <.01). Oral ganciclovir administered on CMV detection by PCR prevents CMV infection or disease after liver transplantation.

Administration, Oral↗
PubMed2002

Bayesian estimation, simulation and uncertainty analysis: the cost-effectiveness of ganciclovir prophylaxis in liver transplantation.

This paper demonstrates the usefulness of combining simulation with Bayesian estimation methods in analysis of cost-effectiveness data collected alongside a clinical trial. Specifically, we use Markov Chain Monte Carlo (MCMC) to estimate a system of generalized linear models relating costs and outcomes to a disease process affected by treatment under alternative therapies. The MCMC draws are used as parameters in simulations which yield inference about the relative cost-effectiveness of the novel therapy under a variety of scenarios. Total parametric uncertainty is assessed directly by examining the joint distribution of simulated average incremental cost and effectiveness. The approach allows flexibility in assessing treatment in various counterfactual premises and quantifies the global effect of parametric uncertainty on a decision-maker's confidence in adopting one therapy over the other.

Antiviral Agents↗
PubMed2002

Government mandates and employer-sponsored health insurance: who is still not covered?

We characterize employer-sponsored health insurance offering strategies in light of benefit non-discrimination and minimum wage regulation when workers have heterogeneous earnings and partially unobservable demand for (and cost of) insurance. We then empirically examine how earnings and expected medical expenses are associated with low wage workers' ability to obtain insurance before and after enactment of federal benefit non-discrimination rules. We find no evidence that the non-discrimination rules helped low wage workers (especially those with high own or children's expected medical expenses) to obtain insurance.

Adolescent↗
PubMedDate not supplied

The cost-effectiveness of acetaminophen, NSAIDs, and selective COX-2 inhibitors in the treatment of symptomatic knee osteoarthritis.

OBJECTIVE: The objective of this study was to conduct an economic evaluation of rofecoxib and celecoxib compared with high-dose acetaminophen or ibuprofen with and without misoprostol for patients with symptomatic knee osteoarthritis (OA). METHODS: A decision analysis model was designed over 6 months using two measures of effectiveness: 1) number of upper gastrointestinal (GI) adverse events averted; and 2) number of patients who achieved perceptible pain relief. Separate analyses were conducted for all patients and for those who did not respond to acetaminophen. Outcome probabilities were obtained from a comprehensive review of randomized controlled trials and observational studies. Costs were derived from actual resource utilization of OA patients. RESULTS: In terms of averting GI events, acetaminophen dominates the other options for an average risk patient population. For patients who did not respond to acetaminophen, rofecoxib had the lowest incremental cost-effectiveness ratio (ICER) per GI event avoided (32,000 US dollars) relative to ibuprofen. In terms of pain control, ibuprofen had an ICER of 610.77 US dollars per additional patient achieving minimal perceptible clinical improvement (MPCI) relative to acetaminophen, while rofecoxib had an ICER of 12,000 US dollars relative to ibuprofen. For patients who did not respond to acetaminophen and who are at high risk of developing an adverse GI event, rofecoxib dominates ibuprofen as the preferred alternative for both measures of effectiveness. One-way, two-way, and probabilistic sensitivity analyses established that these results were generally robust. CONCLUSIONS: Our results suggest that for average-risk knee OA patients, acetaminophen dominates the other therapies in terms of cost per GI event averted. In terms of pain relief, cost-effectiveness acceptability curves indicate that if one values pain relief below 275 US dollars per patient achieving MPCI, acetaminophen is the therapy most likely to be optimal; between 275 US dollars and 14,150 US dollars, ibuprofen is most likely to be optimal; and above 14,150 US dollars, rofecoxib is most likely to be optimal.

Acetaminophen↗
PubMedDate not supplied

Predicting persistently high primary care use.

PURPOSE: We wanted to identify risk factors for persistently high use of primary care. METHODS: We analyzed outpatient office visits to practitioners in family medicine, general internal medicine, general pediatrics, and obstetrics for 1997-1999 among patients in a small Midwestern city covered by a fee-for-service insurance plan with no co-payments for physician visits and no requirement for referral to specialty care. Logistic regression was used to predict which patients with 10 or more primary care visits in 1997 would repeat high use in 1998 based on demographic and diagnostic categories (adjusted clinical groups [ACGs]). A confirmatory data set (high primary care use in 1998 persistent into 1999) was used to evaluate the model. RESULTS: Two percent of the 54,074 patients had 10 or more primary care visits in 1997, and of these, almost 19% had 10 or more visits in the next year. Among adults, 4 ambulatory diagnosis groups (ADGs) were simultaneously positive predictors of repeated high primary care visits: unstable chronic medical conditions, see and reassure conditions, minor time-limited psychosocial conditions, and minor signs and symptoms. Meanwhile, pregnancy was negatively associated. The area under the receiver operating characteristic (ROC) curve was 0.794 for adults in the developmental data set and 0.752 in the confirmatory data set, indicating a moderately accurate assessment. A satisfactory model was not developed for pediatric patients. CONCLUSIONS: Many persistently high primary care users appear to be overserviced but underserved, with underlying problems not addressed by a medical approach. Some may benefit from psychosocial support, whereas others may be good candidates for disease management interventions.

Adult↗